Journal of Oral Implantology Use of an Intraoral Laser Scanner During the Prosthetic Phase of Implant Dentistry: A Pilot Study --Manuscript Draft-Manuscript Number:
AAID-JOI-D-13-00132R1
Full Title:
Use of an Intraoral Laser Scanner During the Prosthetic Phase of Implant Dentistry: A Pilot Study
Short Title:
Use of an Intraoral Laser Scanner:A Pilot Study
Article Type:
Clinical Research
Keywords:
laser scanner; Accuracy; optical impressions; digital impressions; CAD/CAM abutments and crowns
Corresponding Author:
Cameron Y Lee, DMD, MD, PHD Temple University Kornberg School of Dentistry Aiea, Hawaii UNITED STATES
Corresponding Author Secondary Information: Corresponding Author's Institution:
Temple University Kornberg School of Dentistry
Corresponding Author's Secondary Institution: First Author:
Cameron Y Lee, DMD, MD, PHD
First Author Secondary Information: Order of Authors:
Cameron Y Lee, DMD, MD, PHD Natalie Wong, DDS Scott D Ganz, DMD Jonathan Mursic, RDT Jon B Suzuki, DDS, PHD, MBA
Order of Authors Secondary Information: Abstract:
The accuracy of a digital impression technique to fabricate the implant restoration and abutment for a dental implant using an intraoral scanner was evaluated in 36 patients missing a single posterior tooth in the mandible or maxilla restored with a single implant. Data from the scanning protocol was delivered via the Internet in the form of a standard triangulation language file to the manufacturing site for the production of a custom computer-aided design abutment and crown. All 36 restorations were evaluated for marginal integrity, interproximal contact points, and occlusion. Six of the 36 patients required contact adjustment, 7 required occlusal adjustment and 3 required a gingivectomy around the implant to completely seat the restoration. Chair time for adjustments did not exceed 15 minutes. Conclusion: An intraoroal laser scanner can be used with confidence to obtain consistent accurate digital impressions to fabricate custom restorations and abutments for dental implants.
Response to Reviewers:
Dear Manuscript Reviewer, All information has been added, including references in the manuscript. All corrections are in red ink. However, as for the suggestion of having a control group, we did not have a control group as this was a pilot study. A follow-up study using more complex cases will include a control group. Thanks, Cameron Lee, DMD MD PHD
Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation
Article File
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
1
1
Use of an Intraoral Laser Scanner During
2
the Prosthetic Phase of Implant Dentistry: A Pilot Study
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Cameron Y.S. Lee, DMD, MD, PHD 1 Natalie Wong, DDS 2 Scott D. Ganz, DMD 3 Jonathan Mursic, RDT 4 Jon B. Suzuki, DDS, PHD, MBA 5
1. Private Practice in Oral, Maxillofacial and Reconstructive Surgery. Aiea, HI. 98-1247 Kaahumanu Street. Suite 314. Aiea, Hawaii. Email: [email protected]. Address reprint requests to Dr. Lee. 2. Private Practice in Implant Dentistry and Prosthodontics. Toronto, Canada 3. Private Practice in Maxillofacial Prosthodontics. Fort Lee, NJ. 4. President, 5 Axis Dental Design, Toronto, Canada. 5. Professor and Director of Graduate Periodontology and Oral Implantology. Temple University. Kornberg School of Dentistry. Philadelphia, PA. Reprint requests and correspondence to: Cameron Y.S. Lee, DMD, MD, PHD, 98-1247 Kaahumanu Street. Suite 314. Aiea, Hawaii. Email: [email protected].
24 25 26
Disclosure
27
Dr Natalie Wong claims payment and lectures for BioHorizons. Dr. Scott Ganz lectures and claims
28
payment for Imaging Sciences, Inc. and Materialise Dental. All other co-authors report no
29
financial interest in the products or information listed in the article.
30 31 32
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
2
33 34 35 36
Use of an Intraoral Laser Scanner During
37
the Prosthetic Phase of Implant Dentistry: A Pilot Study
38 39 40 41 42 43 44 45 46
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
3
47
ABSTRACT
48
The accuracy of a digital impression technique to fabricate the implant restoration and abutment
49
for a dental implant using an intraoral laser scanner was evaluated in 36 patients missing a single
50
posterior tooth in the mandible or maxilla restored with a single implant. The spatial position of
51
each integrated implant including the surrounding anatomic hard and soft tissues of adjacent
52
structures was captured utilizing a special scanning abutment with an intraoral laser scanner. Data
53
from the scanning protocol was then delivered via the Internet in the form of an STL file to the
54
manufacturing site for the production of a custom CAD abutment and crown.
55
Results: All 36 restorations and abutments were delivered to the patient and evaluated for marginal
56
integrity, interproximal contact points and occlusion. Six of 36 patients required contact
57
adjustments, 7 patients required occlusal adjustments and 3 patients required a gingivectomy
58
around the implant to completely seat the restoration. Chair time for adjustments did not exceed 15
59
minutes. Conclusions: An intraoral laser scanner can be used with confidence to obtain consistent
60
accurate digital impressions to fabricate custom restorations and abutments for dental implants.
61 62
Key Words: Accuracy. Laser scanner. Optical impressions. Digital impressions. CAD/CAM
63
abutments and crowns.
64 65 66
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
4
67
Dental implants have become an accepted and routine treatment alternative for patients who are
68
missing teeth. Proper diagnosis of the potential implant receptor site has been greatly enhanced by
69
the evolution and acceptance of three dimensional imaging technology, such as CT (computed
70
tomography) and lower radiation CBCT (cone beam computed tomography) which provides
71
clinicians with an accurate assessment of each patient’s osseous anatomy. The precision of implant
72
placement provided by the integration of CBCT imaging and three dimensional (3D) interactive
73
treatment planning software and various applications of guided or surgery increases or encourages
74
the probability that the implant restorative dentist will fabricate an ideal restoration.
75
The restorative process traditionally has required the use of fixture level or abutment level
76
transfer posts to transfer the intraoral position of the dental implant to a working stone or epoxy
77
cast for the dental laboratory technician to fabricate the definitive restoration. Transfer components
78
were designed to be utilized with conventional dental impression materials and intraoral trays.
79
With this method, discrepancies may result due to distortion of the impression materials, improper
80
seating or rotation of the components. Such discrepancies can result in a misfit of the abutment or
81
the final restoration, or both. Therefore, the excellence and marginal fit of the definitive restoration
82
is dependent upon the accuracy of the dental impression and inter-occlusal records. In addition,
83
traditional laboratory procedures to fabricate the custom abutments and restorations for dental
84
implants has until recently been limited to the lost-wax casting technology.
85
During the prosthetic phase of implant dentistry, the goal is to fabricate an accurate, high
86
quality restoration and abutment with a proper emergence profile, anatomic contour, occlusion and
87
aesthetic appeal. Therefore, the impression material must capture the details of the abutment
88
margin, including the gingival anatomy, adjacent and opposing dentition. 1, 2 Other properties that
89
are of importance to the clinician are sufficient working time and setting time, hydrophilicity,
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
5
1-3
90
wettability, tear strength, and elastic recovery.
91
and dental impression materials may not be as accurate when used with metal or ceramic abutment
92
materials. 4, 5
However, the traditional impression technique
93
With traditional laboratory procedures, the dental laboratory must pour a stone or epoxy
94
working model to fabricate the implant restoration and abutment. The lost wax technique
95
developed in 1907 is still currently used in many dental laboratories.
96
technique can include the following: instability of the stone material, wax, casting investment, and
97
alloy material. The result of such inaccuracy is a poor fitting restoration and abutment.
98
overcome these problems, digital impression scanning devices and
99
design/computer aided manufacturing (CAD/CAM) technology have been introduced to the dental
100
community that offers alternatives to the traditional intraoral impression and laboratory
101
techniques. 7, 8, 11, 12
6
Inaccuracies with this
5-10
To
computer aided
102
In restorative dentistry, the use of intraoral scanning acquisition devices have been used for the
103
past 25 years since Duret and others originally pioneered dental CAD/CAM systems in the early
104
1970’s.
105
producing in-office ceramic restorations using CAD/CAM technology.
106
CAD/CAM technology and intraoral scanning devices have enabled clinicians to obtain accurate
107
digital records of the teeth and surrounding hard and soft tissue structures of the oral cavity.
108
Currently, there are several commercially available intraoral scanners that the dentist may use to
109
obtain digital impressions and include the following: CADENT iTero (Align Technology Inc., San
110
Jose, CA), CEREC (Sirona, Salzburg, Austria), E4D (D4D Technologies, Richardson, TX),
111
TRIOS (3 Shape, New Providence, NJ), LAVA Chairside Oral Scanner (3M ESPE, St Paul, MN);
112
and IOS FastScan (IOS Technologies, San Diego, CA). With their in-office milling units, CEREC
13, 14
This was followed by the development of the CEREC system which succeeded in 15, 16
The introduction of
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
6
113
and E4D have the ability to fabricate the definitive restoration in one office visit without the use of
114
traditional dental elastomeric impression materials.
115 116
Triangulation of Light Technology
117
The first dental intraoral digital scanning system (CEREC, Salzburg, Austria) with its in-office
118
ceramic block milling unit was based on the concept of triangulation of light, where the
119
intersection of light of three linear beams is used to locate a defined point in three dimensional
120
space.
121
surfaces that are not continuous will affect the accuracy of the triangulation scan with this
122
technology. 18 Therefore, the use of a reflective coating or opaque powder to create a uniform light
123
dispersion has been advocated for use during the scanning process. 19
12-18
Surfaces that do not disperse light evenly, such as enamel and amalgam, or curved
124 125
Parallel Confocal Imaging Technology
126
CADENT (Align Technology, Inc., San Jose, CA) developed a free-standing digital scanning
127
system that provides clinicians with an accurate alternative to conventional dental impression
128
techniques without the requirement of an in-office restoration milling unit. The refined digital
129
system that was first introduced in orthodontics to scan conventionally poured stone models for
130
orthodontic applications was then applied to conventional prosthodontics. 20, 21 Using the concept
131
of parallel confocal imaging technology used in microscopy, CADENT’s iTero scanning device
132
projects 100,000 points of red parallel laser light that converts the reflected light into digital
133
data.
134
through a small filtering device. The beams of the red laser light act as optical probes when
135
contacting the surfaces of an object and are able to record the anatomic surface details by detecting
22, 23
Only objects at a focal depth of 50 micrometers or less are capable of reflecting light
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
7
136
the confocal points. The advantage of this leading edge technology is that it is able to capture
137
details of different surface anatomy to within 15 micrometers without using a reflective surface
138
powder in the oral cavity. This property allows the clinician to place the disposable wand sheath
139
directly on the object (tooth or abutment scanning device) which increases stability and decreases
140
the need to rescan the patient. Various dental materials such as enamel, gold, amalgam, resins are
141
detected and recorded with equal accuracy.
142
Use of such advanced technology produces an accurate 3D image of the object being scanned in
143
virtual real time. The clinician is able to view the 3D replica once the scanning procedure is
144
complete. The goal of this clinical pilot study was to evaluate the practical use, workflow and
145
technique of intraoral laser scanning to capture the position of single tooth dental implants and the
146
adjacent anatomic structures to fabricate custom restorations and abutments utilizing CAD/CAM
147
technology. To complete this study, the CADENT iTero (Align Technology, San Jose, CA)
148
intraoral laser scanner was utilized to capture the digital data of 36 dental implants in the mandible
149
and maxilla.
150
Integrated Digital Imaging and Office Workflow
151
The iTero intraoral laser scanner consists of a mobile cart on wheels that can be moved to different
152
operatories.
153
the scanning procedure to prevent fogging of the lens that is attached to a proprietary data cable.
154
The data cable is attached to a computer with a liquid crystal display (LCD) monitor that processes
155
the electronic information. The entire digital scanning process is controlled by a wireless keyboard,
156
mouse, foot pedal and analytical instruments that are proprietary to the manufacturer.
24
The handheld laser scanner (wand) releases a light stream of compressed air during
157
Prior to initiating the prosthetic phase of treatment, the bone level around each of the implants
158
was evaluated with a periapical radiograph. During the second stage of surgery, the dental implant
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
8
159
was exposed and a transmucosal healing collar was placed on the implant to allow for soft tissue
160
healing for a period of 2-3 weeks. With completion of the soft tissue healing period, the traditional
161
fixture-level impression coping was substituted with an specialized implant scanning abutment
162
(ISA, 5 Axis, Toronto, Canada) that is specific to the implant manufacturer. The ISA transfers the
163
intraoral 3D position of the implant to the virtual digital cast through a registration process of the
164
specific shape geometry and anatomic surface facets. The ISA allows for an accurate digital
165
impression and provides information to the dental laboratory regarding implant platform diameter,
166
position of the implant, and the desired emergence profile. This digital impression technique also
167
eliminates the use of the prosthetic laboratory analog that is used in combination with the
168
traditional dental impression and resultant master cast.
169
The clinical workflow starts with scanning the ISA and adjacent teeth to obtain the required
170
surface anatomy (Fig. 1). To ensure proper vertical dimension and occlusal relations, the opposing
171
dentition is also scanned with the patient placed in maximal intercusspation. This eliminates the
172
need to obtain the traditional bite registration for fixed prosthetic cases, reducing chair time and
173
cost of materials. Once the arches are digitally scanned, the ISA is removed as the scanning
174
abutment might be too high and interfere with obtaining the bite registration of the maxillary and
175
mandibular teeth in complete intercuspation. When obtaining the bite registration, it is extremely
176
important that the patient is instructed to clench their teeth in the maximum intercuspation position
177
(MIP). This will allow the natural teeth to be slightly depressed into the periodontal ligament in the
178
alveolus of the jaw. This technique will allow fabrication of the restoration that is in “infra-
179
occlusion” or slightly out of occlusion to avoid a restoration that is supraocclusal that might result
180
in undesirable premature occlusal contacts with the opposing dentition. 25
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
9
181
During the scanning procedure of the ISA, the surrounding soft tissues, adjacent teeth and
182
opposing dentition can be viewed with real time images on the incorporated LED screen. With the
183
aid of visual and audible prompts, the operator can make the necessary adjustments to obtain an
184
accurate intraoral digital impression in virtual real time. The computer software automatically
185
“stitches” together the multiple, overlapping pictures in a transparent process known as real-time
186
modeling (RTM) to obtain the opposing arches in the MIP.
187
With each scan, the software captures 100,000 points of laser optical reference points to 21-23
188
construct the three dimensional object being scanned.
189
is obtained, the STL file is electronically sent to a Align Technology, Inc. partner laboratory over
190
the Internet using the proprietary computer software. The restorative driven software focuses on
191
material (Fig. 2).
Once the satisfactory digital impression
192 193
MATERIALS AND METHODS
194
Inclusion criteria to participate in this study included the need to replace a single posterior
195
maxillary or mandibular restoration; having adjacent teeth present to allow for contact
196
development and an opposing dentition. Digital impressions of the implant were obtained using the
197
ISA and the iTero intraoral scanner with the Align Technology, Inc. software. Informed consent
198
was obtained from all patients who agreed to participate in this clinical study.
199
An electronic laboratory prescription was completed by the dentist, which included patient
200
information and the type of restoration to be fabricated. The electronic data from the digital
201
impression was produced in the form of an open architecture STL file of the implant scanning
202
abutment, including the surrounding anatomic hard and soft tissues. This file was then sent
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
10
203
electronically via the Internet to the participating dental laboratory. The laboratory completed the
204
virtual CAD model and uploaded the design of the restoration and abutment for processing
205
(Fig. 3). The stereolithographic model and removable dies were then fabricated for completion of
206
the restoration and abutment. Software parameters to fabricate the custom restoration and abutment
207
include contours of the crown, emergence profile, interproximal and occlusal contacts and material
208
thickness to ensure strength of the restoration to resist occlusal forces.
209
The implant abutment can be milled using CAD/CAM technology as titanium, zirconium or a
210
hybrid (metal connection/ zirconium post). The definitive restoration can be custom milled as all-
211
ceramic restoration, or a porcelain fused to metal using traditional laboratory procedures. Milled
212
CAD/CAM custom polyurethane resin models are also available to the restorative dentist for the
213
purpose of checking the final fit of the restoration before delivering it to the patient. Such milled
214
CAD/CAM resin models are more durable and resistant to deformation, shrinkage, expansion,
215
chipping and fracture compared to stone models (4, 5). The result is a more accurate fitting
216
restoration with little to no chairside adjustment (5). The final custom abutment shape is milled in
217
the polyurethane model, eliminating the need to work directly on the final abutment in the
218
laboratory. This advanced technology may help avoid the inaccuracies associated with using
219
traditional hand processed laboratory techniques, such as investing, casting, divesting, sandblasting
220
and polishing. Two examiners (CYSL and NW) separately evaluated 36 implant restorations and
221
their abutments of maxillary and mandibular posterior restorations for marginal integrity,
222
interproximal contacts and occlusal accuracy.
223 224 225
RESULTS
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
11
226
Clinical parameters were evaluated for each completed abutment and restoration prior to
227
delivery to the patient. Upon delivery to the patient, each adjustment of the restoration was
228
monitored and time recorded. Overall esthetics of the case was also observed and recorded. Using
229
the following parameters (Table 1) all restorations and their corresponding abutments were
230
evaluated: marginal integrity with the abutment margin; interproximal contact points evaluated
231
with dental floss and occlusion evaluated with articulation paper.
232 233
_____Marginal Integrity: _____Restoration is or is not at level of abutment margin.
234
_____Interproximal Contact: _____Present or absent.
235
_____Occlusion: _____Clinically satisfactory or unsatisfactorily.
236
No restorations or abutments were returned to the dental laboratory for adjustment or remake.
237
All 36 restorations and their corresponding abutments were delivered to the patient in a single
238
office appointment. Of the patient cohort, 13 required adjustment of the restoration. Average chair
239
time for adjustment was 5 to 15 minutes. Six patient restorations required adjustment of the
240
interproximal contacts, while 7 patient restorations required occlusal adjustment. Of the seven
241
patients needing occlusal adjustment, three required gingivectomy procedures due to tissue
242
blanching and pain that prevented a complete seating of the custom abutment to the recommended
243
30 Ncm screw tightening,
244 245 246 247 248
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
12
249
DISCUSSION
250
Traditional elastomeric impressions have been utilized to fabricate the implant restoration and
251
abutment since Branemark and colleagues described their surgical and prosthetic protocol over 40
252
years ago.
253
conventional indirect method on stone and epoxy dies created from impressions of titanium
254
abutments, and the accuracy of coping fabrication via a direct method on the metal itself.
255
use of digital intraoral scanning eliminates the traditional analog of intraoral dental impressions in
256
conventional crown and bridge dies. The results of digital acquisition through optical scanning
257
have been consistent and accurate.
26
Ganz et al showed the inaccuracies of copings that were fabricated via the
4, 5
The
258
To evaluate the practical use and accuracy of the intraoral laser scanner with CAD/CAM
259
technology, an in-vivo study with the clinical parameters was selected because it reflects the daily
260
challenges that dentists encounter in private practice. An in-vitro study using typodonts such that
261
are utilized to teach students in dental school would have provided similar mechanics, but would
262
not have offered realistic conditions of the oral environment such as the constant flow of saliva,
263
soft tissue replication, adjacent hard tissues (enamel of the teeth), and opposing dentition of each
264
patient in this protocol. In-vivo studies allow for accurate assessment of technique because it
265
reflects the true clinical working conditions of the oral environment that definitely impacts the
266
quality of dental restorations.
267
However, in-vitro studies are important to obtain a physical reference, a master model and the
268
ability to record both the reference and replicas with the same digitization method in a real life
269
clinician presentation.
270
the validity and reproducibility of measurements on stereolithographic models and 3D digital
271
dental models using an intraoral laser scanner. The authors concluded that use of
27, 28
In one study using ten dry skulls, the authors attempted to determine
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
13
272
stereolithographic and digital models made with an intraoral laser scanner is valid and can
273
reproduce accurate measurements for measuring distances between the dentition. 29
274
With every restoration, the goal is to produce a quality restoration (Fig. 4) with good internal fit 30, 31
275
and controlled thickness of the cement space.
276
discrepancy of 150 microns or less is considered clinically acceptable, although there is no clinical
277
definition of an acceptable “restoration fit”. 32-35 Using a replica technique, Tsitrou and colleagues
278
using CEREC technology recorded crown gaps in the range of 91-105 microns.32 Restorations with
279
Procera AllCeram crowns on posterior teeth recorded marginal gaps between 90 to 145 microns.33
280
For the purposes of this study, marginal integrity of the restoration was evaluated with the
281
abutment without measuring marginal gap at extreme magnification. Although recurrent caries is
282
not observed at the implant restoration/abutment interface, the authors evaluated marginal integrity
283
based on the observation if the margin of the restoration reached the abutment margin.
284
It is generally accepted that a marginal gap
CAD/CAM technology is now able to decrease marginal accuracy to within 50 microns.
34
The
285
authors hypothesize that the marginal gap using digital impressions could be smaller when
286
compared to traditional elastomeric impressions, as reported by Syrek et al.35 With digital
287
impressions, an STL (standard triangulation language) data file is created, therefore no working
288
stone model and its associated shortcomings such as waxing, investing and casting during the
289
fabrication of the restoration are eliminated. Instead, a CAD/CAM generated stereolithographic
290
model with dies is created that eliminates the working stone model in the laboratory process and
291
results in an extremely accurate and aesthetically pleasing restoration (Figure 5). Seelbach et al
292
utilizing the LAVA COS System concluded that digital impression techniques can be regarded as a
293
clinical alternative to conventional impressions for fixed dental restorations.
294
be noted that these studies were even more demanding than the present study, as they were
36
However, it must
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
14
295
capturing tooth margins for crowns, and not scanning implant abutments which have a pre-defined
296
margin and specific geometric shape.
297
In the present study, similar results were experienced. All crowns were found to have
298
acceptable margin integrity. There was minimal adjustment of interproximal contacts and
299
occlusion. If adjustment was needed, it was because the contact points were too tight. There were
300
no open contacts. As of the date of submission of this paper, there have been no failures or
301
remakes of the restorations reported in this study utilizing the laser scanner to obtain digital
302
impressions.
303
Adjustment related to the size of the abutment and crown restoration was required in three of
304
the 36 patients (CYSL). When utilizing a custom CAD abutment with a morphological emergence
305
profile, tightening of the abutment screw to fully seat the abutment would significantly blanch the
306
gingiva and cause pain. The size discrepancy for proper emergence profile could prevent complete
307
seating of the abutment and restoration. In all three cases, gingivectomy procedures under local
308
anesthesia infiltration relieved the tissue allowing for complete seating of the abutment on to the
309
implant. This issue was encountered with the first three patients enrolled in this study and was
310
determined to be due to clinician inexperience using this leading edge technology in not properly
311
instructing the patients to clench their teeth into the maximum intercuspation position (MIP). Once
312
patients were instructed on the desired MIP, this problem was resolved and did not recur. Each
313
digitally scanned implant restoration averaged 0-15 minutes to adjust the restoration to clinical
314
function. The three patients that required the gingivectomy procedure to permit seating of the
315
abutment took the longest adjustment (15 minutes).
316
There are disadvantages to this technology. There is a definite learning curve with the digital
317
impression system, and will vary with each of the many manufacturers that may have differing
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
15
318
protocols. During the initial learning phase, there is a longer time to acquire each scan. However,
319
through repetition, the doctor and office staff gains clinical experience and becomes comfortable
320
using this advanced technology and scan time decreases with continued use.
321
A major disadvantage for each office is the initial cost of purchasing the laser scanning device.
322
In addition, dental laboratories that are not digitally equipped for each specific laser scanner will
323
be unable to receive the electronic data from the dentist office to fabricate the restoration and
324
abutment. Finally, there is the cost to produce a CAD/CAM generated custom implant restoration
325
and abutment. However, as of this writing, we are now in clinical trials using the implant
326
manufacturer’s pre-fabricated abutment. The pre-fabricated abutment is attached to the implant
327
and digitally scanned instead of the specific ISA. With this modification of the protocol that now
328
incorporates the use of a pre-fabricated stock abutment, we are able to decrease the dental
329
laboratory cost for the restoring dentist. It is anticipated that cost will likely decrease in the
330
immediate future as the clinical and laboratory workflow become standard procedures for both
331
conventional and implant dentistry. The cost will be offset by the savings in impression material
332
and decreased clinician chair time and less remakes of restorations. 37
333 334
CONCLUSION
335
This clinical pilot study demonstrated that an intraoral laser scanner can be used with
336
confidence to obtain consistent accurate digital impressions to fabricate custom restorations and
337
abutments for single tooth dental implants. The advantage of using this leading edge technology is
338
the elimination of potential errors during the acquisition phase’s real time view for the clinician
339
refining the impression procedure. With this technology, elimination of impression materials,
340
having to obtain a bite registration and a decrease in dentist chairside working time has been
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
16
341
demonstrated in this study. Due to the impressive results of this advanced technology, the present
342
clinical study has been expanded to include multiple single units, fixed partial dentures and
343
anterior restorations. The new data will be separately evaluated as part of a larger study in
344
progress.
345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
17
361
REFERENCES
362
1. Christensen GJ. The state of fixed prosthodontic impressions: room for improvement. J Am
363
Dent Assoc. 2005;136:343-346.
364
2. Christensen GJ. The challenge of conventional impressions. J Am Dent Assoc. 2008;139:347-
365
349.
366
3. Hack GD. In vitro evaluation of the iTero digital impression system. ADA Prof Prod Review.
367
2011;6:6-10.
368
4. Ganz SD, Desai N, Weiner S. Marginal integrity of direct and indirect castings for implant
369
abutments. J Oral Maxillofac Implants. 2006;21;593-598.
370
5. Priest G. Virtual-designed and computer milled implant abutments. J Oral Maxillofac Surg.
371
2005;63:22-32.
372
6. Christensen GJ. Impressions are changing: deciding on conventional, digital or digital plus in-
373
office milling. J Am Dent Assoc. 2009;140:1301-1304.
374
7. Farah JW, Brown L. Comparison of the fit of crowns based on digital impressions with 3M
375
ESPE Lava Chairside Oral Scanner C.O.S. vs. traditional impressions. The Dental Advisor
376
Research Report. No. 22. June 2009.
377
8. Kerstein RB, Castellucci F, Osorio J. Ideal gingival form with computer-generated permanent
378
healing abutments. Compend Contin Educ Dent. 2000;21:793-801.
379
9. Kerstein RB. Osorio J. Utilizing computer-generated duplicate titanium abutments to facilitate
380
intraoral and laboratory implant prosthesis fabrication. Pract Peridont Aesthet Dent. 2003;15:311-
381
314.
382
10. Lowe RA. CAD/CAM dentistry and chairside digital impression making. Dental Economics
383
supplement. September 2009.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
18
384
11. Miyazaki T, Hotta Y, Kunii J, et al. A review of dental CAD/CAM: current status and future
385
perspectives from 20 years experience. Dent Mater J. 2009; 28(1):44-56.
386
12. Duret F, Blouin JL, Duret B. CAD/CAM in dentistry. J Am Dent Assoc. 1988; 117:715-720.
387
13. Duret F, Preston JD. CAD/CAM imaging in dentistry. Curr Opin Dent. 1991; 1:150-154.
388
14. Mormann WH, Brandestini M, Lutz F, et al. Chairside computer-aided direct ceramic inlays.
389
Quintessence Int. 1989; 20:329-339.
390
15. Mormann WH. The evolution of the CEREC system. J Am Dent Assoc. 2006;137:7s-13s.
391
16. Cerec 3. Operating instructions for the acquisition unit. Sirona The Dental Company. 2004.
392
17. Allen KL, Schenkel AB, Estafan D. An overview of the CEREC 3D CAD/CAM system. Gen
393
Dent. 2004;52:234-235.
394
18. Kutulakos K. Steger E. A theory of specular and refractive shape by light-path triangulation.
395
Microsoft Research Technology. MSR-TR; 2005
396
19. Wilton T, Masters BR. Confocal microscopy: introduction to the feature issue. Appl Opt.
397
1994;33:565-566.
398
20. Marcel TJ. Three-dimensional on-screen virtual models. Am J Orthod Dentofacial Orthop.
399
2001; 119:666-668.
400
21. Peluso MJ, Josell SD, Levine SW, et al. Digital models: an introduction. Semin Orthod. 2004;
401
10:226-239.
402
22. Kennedy J. Confocal imaging. Andor Technology. www.andor.com. Accessed August 10,
403
2011.
404
23. Wilson T, Masters BR. Confocal microscopy: introduction to the feature issue. Appl Opt.
405
1994; 33:565-566.
406
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
19
407
24. Cadent. www.cadentitero.com. Accessed August 10, 2011.
408
25. Misch CE, Suzuki JB, Misch-Dietsh FM, et al. A positive correlation between occlusal trauma
409
and peri-imlant bone loss: literature support. Implant Dent. 2005; 14(2):108-116.
410
26. Branemark PI, Hansson BO, Adell R, et al. Osseointegrated implants in the treatment of
411
edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg Suppl. 1977;16:1-
412
132.
413
27. Fransson B, Oilo G, Gjeitanger R. The fit of metal-ceramic crowns, a clinical study. Dent
414
Mater. 1985;1:197-199.
415
28. Belser UC, MacEntee MI, Richter WA. Fit of three porcelain-fused-to-metal marginal designs
416
in vivo: a scanning electron microscope study. J Prosth Dent. 1985;53:24-29.
417
29. Cuperus AM, Harms MC, Rangel FA, et al. Dental models made with an intraoral scanner: a
418
validation study. Am J Orthod Dentofacial Orthop. 2012; 142(3):308-313.
419
30. Karlsson S. The fit of Procera titanium crowns. An in vitro and clinical study. Acta Odontol
420
Scand. 1993;51:129-134.
421
31. Sulainman F, Chai J, Jameson LM, et al. A comparison of the marginal fit in In-ceram, IPS
422
Empress, and Procera Crowns. Int J Prosthodontics. 1997;10:478-484.
423
32. Tsitrou EA, Northeast SE, van Noort R. Evaluation of the marginal fit of three margin designs
424
of resin composite crowns using CAD/CAM. J Dent. 2007;35:68-73.
425
33. Tinschert J, Natt G, Mautsch W, et al. Marginal fit of alumina and zirconia based fixed partial
426
dentures produced by a CAD/CAM system. Operative Dent. 2001;26:367-374.
427
34. McLaren E. Special Report. CAD/CAM dental technology. Compendium. May 2011.
428 429
the
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
20
430
35. Syrek A, Reich G, Ranftl D, et al. Clinical evaluation of all-ceramic crowns fabricated from
431
intraoral digital impressions based on the principle of active wavefront sampling. J Dent. 2010;
432
38(7):553-559.
433
36. Seelbach P, Brueckel C, Wostmann B. Accuracy of digital and conventional impression
434
techniques and workflow. Clin Oral Investig. 2012 Oct 21. (Epub ahead of print).
435
37. Ganz SD. Finally, a “win-win” solution: increasing accuracy while saving time, money with
436
computer-milled abutments. Dental Economics. May 2005; 80-86.
437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
21
453
LEGENDS
454 455
Fig. 1. Digital impression obtained using 5 Axis implant scanning abutment attached to dental
456
implant and scanned using intraoral laser scanner.
457
Top Left: BioHorizons Laser Lok dental implant without scanning abutment.
458
Top Right: BioHorizons Laser Lok specific scanning abutment attached to dental implant.
459
Bottom Left: Use of iTero intraoral optical laser scanner to scan implant scanning
460
abutment.
461
Bottom Right: 5 Axis dental implant scanning abutment.
462 463 464 465
Fig. 2. Digital images obtained from intraoral laser scanner. CAD/CAM technology will be used to fabricate abutment and restoration. Fig. 3. Stereolithographic models and dies fabricated from CAD/CAM technology to produce allceramic restoration.
466
Figure 4. CAD/CAM fabricated custom ceramic abutment and restoration.
467
Fig. 5. All-ceramic restoration in #29 area (Issaquah Dental Laboratory, Issaquah, WA). Excellent
468 469 470 471 472 473 474 475
aesthetic result.
1 2 3 4 5 6 476 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
22
Table 1. Clinical Parameters Used To Evaluate CAD/CAM Restoration (n=36)
Patient 1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Parameter
Time (minutes)
Interproximal Contact Occlusion
5
Interproximal Contact Occlusion Interproximal Contact
5
Occlusion Occlusion
Remarks
8
8 5, 5
7
Interproximal Contact
5
Occlusion
15
Gingivectomy
Occlusion
11
Gingivectomy
Occlusion Interproximal Contract
15 12
Gingivectomy
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
23
32 32 34 35
Interproximal Contact
6
36 477
Marginal Integrity: If margin of restoration is or is not at margin of abutment.
478
Interproximal Contact: If proximal contact is present or absent with adjacent tooth.
479
Occlusion: If occlusion was satisfactory or unsatisfactory with opposing tooth.
480
Time: Time measured in minutes to adjust restoration to clinical acceptability
481
482
483
484
Figure Click here to download Figure: iTero_PilotStudy_Photos_Lee_etal_PDF.pdf
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Cover Letter Click here to download Cover Letter: JamesRutkowskiLetter.doc
Rebuttal Letter (for revisions) Click here to download Rebuttal Letter (for revisions): JOI_RebuttalLetter.doc
*Copyright Form Click here to download Copyright Form: JOI_TransferOfCopyright.pdf
Copyright Form Click here to download Copyright Form: JOI_DrJonSuzuki_AuthorCopyright.pdf
Copyright Form Click here to download Copyright Form: JOI_DrScottGanz_AuthorCopyright.pdf
Copyright Form Click here to download Copyright Form: JOI_DrNatalieWong_CopyrightAuthor.pdf
Copyright Form Click here to download Copyright Form: JOI_JonathanMursic_AuthorCopyright.JPG
Copyright Form Click here to download Copyright Form: JOI_DrCameronLee_CopyrightAuthor.pdf
AAID-JOI-D-13-00132R1
Full Title:
Use of an Intraoral Laser Scanner During the Prosthetic Phase of Implant Dentistry: A Pilot Study
Short Title:
Use of an Intraoral Laser Scanner:A Pilot Study
Article Type:
Clinical Research
Keywords:
laser scanner; Accuracy; optical impressions; digital impressions; CAD/CAM abutments and crowns
Corresponding Author:
Cameron Y Lee, DMD, MD, PHD Temple University Kornberg School of Dentistry Aiea, Hawaii UNITED STATES
Corresponding Author Secondary Information: Corresponding Author's Institution:
Temple University Kornberg School of Dentistry
Corresponding Author's Secondary Institution: First Author:
Cameron Y Lee, DMD, MD, PHD
First Author Secondary Information: Order of Authors:
Cameron Y Lee, DMD, MD, PHD Natalie Wong, DDS Scott D Ganz, DMD Jonathan Mursic, RDT Jon B Suzuki, DDS, PHD, MBA
Order of Authors Secondary Information: Abstract:
The accuracy of a digital impression technique to fabricate the implant restoration and abutment for a dental implant using an intraoral scanner was evaluated in 36 patients missing a single posterior tooth in the mandible or maxilla restored with a single implant. Data from the scanning protocol was delivered via the Internet in the form of a standard triangulation language file to the manufacturing site for the production of a custom computer-aided design abutment and crown. All 36 restorations were evaluated for marginal integrity, interproximal contact points, and occlusion. Six of the 36 patients required contact adjustment, 7 required occlusal adjustment and 3 required a gingivectomy around the implant to completely seat the restoration. Chair time for adjustments did not exceed 15 minutes. Conclusion: An intraoroal laser scanner can be used with confidence to obtain consistent accurate digital impressions to fabricate custom restorations and abutments for dental implants.
Response to Reviewers:
Dear Manuscript Reviewer, All information has been added, including references in the manuscript. All corrections are in red ink. However, as for the suggestion of having a control group, we did not have a control group as this was a pilot study. A follow-up study using more complex cases will include a control group. Thanks, Cameron Lee, DMD MD PHD
Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation
Article File
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
1
1
Use of an Intraoral Laser Scanner During
2
the Prosthetic Phase of Implant Dentistry: A Pilot Study
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Cameron Y.S. Lee, DMD, MD, PHD 1 Natalie Wong, DDS 2 Scott D. Ganz, DMD 3 Jonathan Mursic, RDT 4 Jon B. Suzuki, DDS, PHD, MBA 5
1. Private Practice in Oral, Maxillofacial and Reconstructive Surgery. Aiea, HI. 98-1247 Kaahumanu Street. Suite 314. Aiea, Hawaii. Email: [email protected]. Address reprint requests to Dr. Lee. 2. Private Practice in Implant Dentistry and Prosthodontics. Toronto, Canada 3. Private Practice in Maxillofacial Prosthodontics. Fort Lee, NJ. 4. President, 5 Axis Dental Design, Toronto, Canada. 5. Professor and Director of Graduate Periodontology and Oral Implantology. Temple University. Kornberg School of Dentistry. Philadelphia, PA. Reprint requests and correspondence to: Cameron Y.S. Lee, DMD, MD, PHD, 98-1247 Kaahumanu Street. Suite 314. Aiea, Hawaii. Email: [email protected].
24 25 26
Disclosure
27
Dr Natalie Wong claims payment and lectures for BioHorizons. Dr. Scott Ganz lectures and claims
28
payment for Imaging Sciences, Inc. and Materialise Dental. All other co-authors report no
29
financial interest in the products or information listed in the article.
30 31 32
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
2
33 34 35 36
Use of an Intraoral Laser Scanner During
37
the Prosthetic Phase of Implant Dentistry: A Pilot Study
38 39 40 41 42 43 44 45 46
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
3
47
ABSTRACT
48
The accuracy of a digital impression technique to fabricate the implant restoration and abutment
49
for a dental implant using an intraoral laser scanner was evaluated in 36 patients missing a single
50
posterior tooth in the mandible or maxilla restored with a single implant. The spatial position of
51
each integrated implant including the surrounding anatomic hard and soft tissues of adjacent
52
structures was captured utilizing a special scanning abutment with an intraoral laser scanner. Data
53
from the scanning protocol was then delivered via the Internet in the form of an STL file to the
54
manufacturing site for the production of a custom CAD abutment and crown.
55
Results: All 36 restorations and abutments were delivered to the patient and evaluated for marginal
56
integrity, interproximal contact points and occlusion. Six of 36 patients required contact
57
adjustments, 7 patients required occlusal adjustments and 3 patients required a gingivectomy
58
around the implant to completely seat the restoration. Chair time for adjustments did not exceed 15
59
minutes. Conclusions: An intraoral laser scanner can be used with confidence to obtain consistent
60
accurate digital impressions to fabricate custom restorations and abutments for dental implants.
61 62
Key Words: Accuracy. Laser scanner. Optical impressions. Digital impressions. CAD/CAM
63
abutments and crowns.
64 65 66
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
4
67
Dental implants have become an accepted and routine treatment alternative for patients who are
68
missing teeth. Proper diagnosis of the potential implant receptor site has been greatly enhanced by
69
the evolution and acceptance of three dimensional imaging technology, such as CT (computed
70
tomography) and lower radiation CBCT (cone beam computed tomography) which provides
71
clinicians with an accurate assessment of each patient’s osseous anatomy. The precision of implant
72
placement provided by the integration of CBCT imaging and three dimensional (3D) interactive
73
treatment planning software and various applications of guided or surgery increases or encourages
74
the probability that the implant restorative dentist will fabricate an ideal restoration.
75
The restorative process traditionally has required the use of fixture level or abutment level
76
transfer posts to transfer the intraoral position of the dental implant to a working stone or epoxy
77
cast for the dental laboratory technician to fabricate the definitive restoration. Transfer components
78
were designed to be utilized with conventional dental impression materials and intraoral trays.
79
With this method, discrepancies may result due to distortion of the impression materials, improper
80
seating or rotation of the components. Such discrepancies can result in a misfit of the abutment or
81
the final restoration, or both. Therefore, the excellence and marginal fit of the definitive restoration
82
is dependent upon the accuracy of the dental impression and inter-occlusal records. In addition,
83
traditional laboratory procedures to fabricate the custom abutments and restorations for dental
84
implants has until recently been limited to the lost-wax casting technology.
85
During the prosthetic phase of implant dentistry, the goal is to fabricate an accurate, high
86
quality restoration and abutment with a proper emergence profile, anatomic contour, occlusion and
87
aesthetic appeal. Therefore, the impression material must capture the details of the abutment
88
margin, including the gingival anatomy, adjacent and opposing dentition. 1, 2 Other properties that
89
are of importance to the clinician are sufficient working time and setting time, hydrophilicity,
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
5
1-3
90
wettability, tear strength, and elastic recovery.
91
and dental impression materials may not be as accurate when used with metal or ceramic abutment
92
materials. 4, 5
However, the traditional impression technique
93
With traditional laboratory procedures, the dental laboratory must pour a stone or epoxy
94
working model to fabricate the implant restoration and abutment. The lost wax technique
95
developed in 1907 is still currently used in many dental laboratories.
96
technique can include the following: instability of the stone material, wax, casting investment, and
97
alloy material. The result of such inaccuracy is a poor fitting restoration and abutment.
98
overcome these problems, digital impression scanning devices and
99
design/computer aided manufacturing (CAD/CAM) technology have been introduced to the dental
100
community that offers alternatives to the traditional intraoral impression and laboratory
101
techniques. 7, 8, 11, 12
6
Inaccuracies with this
5-10
To
computer aided
102
In restorative dentistry, the use of intraoral scanning acquisition devices have been used for the
103
past 25 years since Duret and others originally pioneered dental CAD/CAM systems in the early
104
1970’s.
105
producing in-office ceramic restorations using CAD/CAM technology.
106
CAD/CAM technology and intraoral scanning devices have enabled clinicians to obtain accurate
107
digital records of the teeth and surrounding hard and soft tissue structures of the oral cavity.
108
Currently, there are several commercially available intraoral scanners that the dentist may use to
109
obtain digital impressions and include the following: CADENT iTero (Align Technology Inc., San
110
Jose, CA), CEREC (Sirona, Salzburg, Austria), E4D (D4D Technologies, Richardson, TX),
111
TRIOS (3 Shape, New Providence, NJ), LAVA Chairside Oral Scanner (3M ESPE, St Paul, MN);
112
and IOS FastScan (IOS Technologies, San Diego, CA). With their in-office milling units, CEREC
13, 14
This was followed by the development of the CEREC system which succeeded in 15, 16
The introduction of
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
6
113
and E4D have the ability to fabricate the definitive restoration in one office visit without the use of
114
traditional dental elastomeric impression materials.
115 116
Triangulation of Light Technology
117
The first dental intraoral digital scanning system (CEREC, Salzburg, Austria) with its in-office
118
ceramic block milling unit was based on the concept of triangulation of light, where the
119
intersection of light of three linear beams is used to locate a defined point in three dimensional
120
space.
121
surfaces that are not continuous will affect the accuracy of the triangulation scan with this
122
technology. 18 Therefore, the use of a reflective coating or opaque powder to create a uniform light
123
dispersion has been advocated for use during the scanning process. 19
12-18
Surfaces that do not disperse light evenly, such as enamel and amalgam, or curved
124 125
Parallel Confocal Imaging Technology
126
CADENT (Align Technology, Inc., San Jose, CA) developed a free-standing digital scanning
127
system that provides clinicians with an accurate alternative to conventional dental impression
128
techniques without the requirement of an in-office restoration milling unit. The refined digital
129
system that was first introduced in orthodontics to scan conventionally poured stone models for
130
orthodontic applications was then applied to conventional prosthodontics. 20, 21 Using the concept
131
of parallel confocal imaging technology used in microscopy, CADENT’s iTero scanning device
132
projects 100,000 points of red parallel laser light that converts the reflected light into digital
133
data.
134
through a small filtering device. The beams of the red laser light act as optical probes when
135
contacting the surfaces of an object and are able to record the anatomic surface details by detecting
22, 23
Only objects at a focal depth of 50 micrometers or less are capable of reflecting light
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
7
136
the confocal points. The advantage of this leading edge technology is that it is able to capture
137
details of different surface anatomy to within 15 micrometers without using a reflective surface
138
powder in the oral cavity. This property allows the clinician to place the disposable wand sheath
139
directly on the object (tooth or abutment scanning device) which increases stability and decreases
140
the need to rescan the patient. Various dental materials such as enamel, gold, amalgam, resins are
141
detected and recorded with equal accuracy.
142
Use of such advanced technology produces an accurate 3D image of the object being scanned in
143
virtual real time. The clinician is able to view the 3D replica once the scanning procedure is
144
complete. The goal of this clinical pilot study was to evaluate the practical use, workflow and
145
technique of intraoral laser scanning to capture the position of single tooth dental implants and the
146
adjacent anatomic structures to fabricate custom restorations and abutments utilizing CAD/CAM
147
technology. To complete this study, the CADENT iTero (Align Technology, San Jose, CA)
148
intraoral laser scanner was utilized to capture the digital data of 36 dental implants in the mandible
149
and maxilla.
150
Integrated Digital Imaging and Office Workflow
151
The iTero intraoral laser scanner consists of a mobile cart on wheels that can be moved to different
152
operatories.
153
the scanning procedure to prevent fogging of the lens that is attached to a proprietary data cable.
154
The data cable is attached to a computer with a liquid crystal display (LCD) monitor that processes
155
the electronic information. The entire digital scanning process is controlled by a wireless keyboard,
156
mouse, foot pedal and analytical instruments that are proprietary to the manufacturer.
24
The handheld laser scanner (wand) releases a light stream of compressed air during
157
Prior to initiating the prosthetic phase of treatment, the bone level around each of the implants
158
was evaluated with a periapical radiograph. During the second stage of surgery, the dental implant
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
8
159
was exposed and a transmucosal healing collar was placed on the implant to allow for soft tissue
160
healing for a period of 2-3 weeks. With completion of the soft tissue healing period, the traditional
161
fixture-level impression coping was substituted with an specialized implant scanning abutment
162
(ISA, 5 Axis, Toronto, Canada) that is specific to the implant manufacturer. The ISA transfers the
163
intraoral 3D position of the implant to the virtual digital cast through a registration process of the
164
specific shape geometry and anatomic surface facets. The ISA allows for an accurate digital
165
impression and provides information to the dental laboratory regarding implant platform diameter,
166
position of the implant, and the desired emergence profile. This digital impression technique also
167
eliminates the use of the prosthetic laboratory analog that is used in combination with the
168
traditional dental impression and resultant master cast.
169
The clinical workflow starts with scanning the ISA and adjacent teeth to obtain the required
170
surface anatomy (Fig. 1). To ensure proper vertical dimension and occlusal relations, the opposing
171
dentition is also scanned with the patient placed in maximal intercusspation. This eliminates the
172
need to obtain the traditional bite registration for fixed prosthetic cases, reducing chair time and
173
cost of materials. Once the arches are digitally scanned, the ISA is removed as the scanning
174
abutment might be too high and interfere with obtaining the bite registration of the maxillary and
175
mandibular teeth in complete intercuspation. When obtaining the bite registration, it is extremely
176
important that the patient is instructed to clench their teeth in the maximum intercuspation position
177
(MIP). This will allow the natural teeth to be slightly depressed into the periodontal ligament in the
178
alveolus of the jaw. This technique will allow fabrication of the restoration that is in “infra-
179
occlusion” or slightly out of occlusion to avoid a restoration that is supraocclusal that might result
180
in undesirable premature occlusal contacts with the opposing dentition. 25
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
9
181
During the scanning procedure of the ISA, the surrounding soft tissues, adjacent teeth and
182
opposing dentition can be viewed with real time images on the incorporated LED screen. With the
183
aid of visual and audible prompts, the operator can make the necessary adjustments to obtain an
184
accurate intraoral digital impression in virtual real time. The computer software automatically
185
“stitches” together the multiple, overlapping pictures in a transparent process known as real-time
186
modeling (RTM) to obtain the opposing arches in the MIP.
187
With each scan, the software captures 100,000 points of laser optical reference points to 21-23
188
construct the three dimensional object being scanned.
189
is obtained, the STL file is electronically sent to a Align Technology, Inc. partner laboratory over
190
the Internet using the proprietary computer software. The restorative driven software focuses on
191
material (Fig. 2).
Once the satisfactory digital impression
192 193
MATERIALS AND METHODS
194
Inclusion criteria to participate in this study included the need to replace a single posterior
195
maxillary or mandibular restoration; having adjacent teeth present to allow for contact
196
development and an opposing dentition. Digital impressions of the implant were obtained using the
197
ISA and the iTero intraoral scanner with the Align Technology, Inc. software. Informed consent
198
was obtained from all patients who agreed to participate in this clinical study.
199
An electronic laboratory prescription was completed by the dentist, which included patient
200
information and the type of restoration to be fabricated. The electronic data from the digital
201
impression was produced in the form of an open architecture STL file of the implant scanning
202
abutment, including the surrounding anatomic hard and soft tissues. This file was then sent
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
10
203
electronically via the Internet to the participating dental laboratory. The laboratory completed the
204
virtual CAD model and uploaded the design of the restoration and abutment for processing
205
(Fig. 3). The stereolithographic model and removable dies were then fabricated for completion of
206
the restoration and abutment. Software parameters to fabricate the custom restoration and abutment
207
include contours of the crown, emergence profile, interproximal and occlusal contacts and material
208
thickness to ensure strength of the restoration to resist occlusal forces.
209
The implant abutment can be milled using CAD/CAM technology as titanium, zirconium or a
210
hybrid (metal connection/ zirconium post). The definitive restoration can be custom milled as all-
211
ceramic restoration, or a porcelain fused to metal using traditional laboratory procedures. Milled
212
CAD/CAM custom polyurethane resin models are also available to the restorative dentist for the
213
purpose of checking the final fit of the restoration before delivering it to the patient. Such milled
214
CAD/CAM resin models are more durable and resistant to deformation, shrinkage, expansion,
215
chipping and fracture compared to stone models (4, 5). The result is a more accurate fitting
216
restoration with little to no chairside adjustment (5). The final custom abutment shape is milled in
217
the polyurethane model, eliminating the need to work directly on the final abutment in the
218
laboratory. This advanced technology may help avoid the inaccuracies associated with using
219
traditional hand processed laboratory techniques, such as investing, casting, divesting, sandblasting
220
and polishing. Two examiners (CYSL and NW) separately evaluated 36 implant restorations and
221
their abutments of maxillary and mandibular posterior restorations for marginal integrity,
222
interproximal contacts and occlusal accuracy.
223 224 225
RESULTS
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
11
226
Clinical parameters were evaluated for each completed abutment and restoration prior to
227
delivery to the patient. Upon delivery to the patient, each adjustment of the restoration was
228
monitored and time recorded. Overall esthetics of the case was also observed and recorded. Using
229
the following parameters (Table 1) all restorations and their corresponding abutments were
230
evaluated: marginal integrity with the abutment margin; interproximal contact points evaluated
231
with dental floss and occlusion evaluated with articulation paper.
232 233
_____Marginal Integrity: _____Restoration is or is not at level of abutment margin.
234
_____Interproximal Contact: _____Present or absent.
235
_____Occlusion: _____Clinically satisfactory or unsatisfactorily.
236
No restorations or abutments were returned to the dental laboratory for adjustment or remake.
237
All 36 restorations and their corresponding abutments were delivered to the patient in a single
238
office appointment. Of the patient cohort, 13 required adjustment of the restoration. Average chair
239
time for adjustment was 5 to 15 minutes. Six patient restorations required adjustment of the
240
interproximal contacts, while 7 patient restorations required occlusal adjustment. Of the seven
241
patients needing occlusal adjustment, three required gingivectomy procedures due to tissue
242
blanching and pain that prevented a complete seating of the custom abutment to the recommended
243
30 Ncm screw tightening,
244 245 246 247 248
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
12
249
DISCUSSION
250
Traditional elastomeric impressions have been utilized to fabricate the implant restoration and
251
abutment since Branemark and colleagues described their surgical and prosthetic protocol over 40
252
years ago.
253
conventional indirect method on stone and epoxy dies created from impressions of titanium
254
abutments, and the accuracy of coping fabrication via a direct method on the metal itself.
255
use of digital intraoral scanning eliminates the traditional analog of intraoral dental impressions in
256
conventional crown and bridge dies. The results of digital acquisition through optical scanning
257
have been consistent and accurate.
26
Ganz et al showed the inaccuracies of copings that were fabricated via the
4, 5
The
258
To evaluate the practical use and accuracy of the intraoral laser scanner with CAD/CAM
259
technology, an in-vivo study with the clinical parameters was selected because it reflects the daily
260
challenges that dentists encounter in private practice. An in-vitro study using typodonts such that
261
are utilized to teach students in dental school would have provided similar mechanics, but would
262
not have offered realistic conditions of the oral environment such as the constant flow of saliva,
263
soft tissue replication, adjacent hard tissues (enamel of the teeth), and opposing dentition of each
264
patient in this protocol. In-vivo studies allow for accurate assessment of technique because it
265
reflects the true clinical working conditions of the oral environment that definitely impacts the
266
quality of dental restorations.
267
However, in-vitro studies are important to obtain a physical reference, a master model and the
268
ability to record both the reference and replicas with the same digitization method in a real life
269
clinician presentation.
270
the validity and reproducibility of measurements on stereolithographic models and 3D digital
271
dental models using an intraoral laser scanner. The authors concluded that use of
27, 28
In one study using ten dry skulls, the authors attempted to determine
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
13
272
stereolithographic and digital models made with an intraoral laser scanner is valid and can
273
reproduce accurate measurements for measuring distances between the dentition. 29
274
With every restoration, the goal is to produce a quality restoration (Fig. 4) with good internal fit 30, 31
275
and controlled thickness of the cement space.
276
discrepancy of 150 microns or less is considered clinically acceptable, although there is no clinical
277
definition of an acceptable “restoration fit”. 32-35 Using a replica technique, Tsitrou and colleagues
278
using CEREC technology recorded crown gaps in the range of 91-105 microns.32 Restorations with
279
Procera AllCeram crowns on posterior teeth recorded marginal gaps between 90 to 145 microns.33
280
For the purposes of this study, marginal integrity of the restoration was evaluated with the
281
abutment without measuring marginal gap at extreme magnification. Although recurrent caries is
282
not observed at the implant restoration/abutment interface, the authors evaluated marginal integrity
283
based on the observation if the margin of the restoration reached the abutment margin.
284
It is generally accepted that a marginal gap
CAD/CAM technology is now able to decrease marginal accuracy to within 50 microns.
34
The
285
authors hypothesize that the marginal gap using digital impressions could be smaller when
286
compared to traditional elastomeric impressions, as reported by Syrek et al.35 With digital
287
impressions, an STL (standard triangulation language) data file is created, therefore no working
288
stone model and its associated shortcomings such as waxing, investing and casting during the
289
fabrication of the restoration are eliminated. Instead, a CAD/CAM generated stereolithographic
290
model with dies is created that eliminates the working stone model in the laboratory process and
291
results in an extremely accurate and aesthetically pleasing restoration (Figure 5). Seelbach et al
292
utilizing the LAVA COS System concluded that digital impression techniques can be regarded as a
293
clinical alternative to conventional impressions for fixed dental restorations.
294
be noted that these studies were even more demanding than the present study, as they were
36
However, it must
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
14
295
capturing tooth margins for crowns, and not scanning implant abutments which have a pre-defined
296
margin and specific geometric shape.
297
In the present study, similar results were experienced. All crowns were found to have
298
acceptable margin integrity. There was minimal adjustment of interproximal contacts and
299
occlusion. If adjustment was needed, it was because the contact points were too tight. There were
300
no open contacts. As of the date of submission of this paper, there have been no failures or
301
remakes of the restorations reported in this study utilizing the laser scanner to obtain digital
302
impressions.
303
Adjustment related to the size of the abutment and crown restoration was required in three of
304
the 36 patients (CYSL). When utilizing a custom CAD abutment with a morphological emergence
305
profile, tightening of the abutment screw to fully seat the abutment would significantly blanch the
306
gingiva and cause pain. The size discrepancy for proper emergence profile could prevent complete
307
seating of the abutment and restoration. In all three cases, gingivectomy procedures under local
308
anesthesia infiltration relieved the tissue allowing for complete seating of the abutment on to the
309
implant. This issue was encountered with the first three patients enrolled in this study and was
310
determined to be due to clinician inexperience using this leading edge technology in not properly
311
instructing the patients to clench their teeth into the maximum intercuspation position (MIP). Once
312
patients were instructed on the desired MIP, this problem was resolved and did not recur. Each
313
digitally scanned implant restoration averaged 0-15 minutes to adjust the restoration to clinical
314
function. The three patients that required the gingivectomy procedure to permit seating of the
315
abutment took the longest adjustment (15 minutes).
316
There are disadvantages to this technology. There is a definite learning curve with the digital
317
impression system, and will vary with each of the many manufacturers that may have differing
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
15
318
protocols. During the initial learning phase, there is a longer time to acquire each scan. However,
319
through repetition, the doctor and office staff gains clinical experience and becomes comfortable
320
using this advanced technology and scan time decreases with continued use.
321
A major disadvantage for each office is the initial cost of purchasing the laser scanning device.
322
In addition, dental laboratories that are not digitally equipped for each specific laser scanner will
323
be unable to receive the electronic data from the dentist office to fabricate the restoration and
324
abutment. Finally, there is the cost to produce a CAD/CAM generated custom implant restoration
325
and abutment. However, as of this writing, we are now in clinical trials using the implant
326
manufacturer’s pre-fabricated abutment. The pre-fabricated abutment is attached to the implant
327
and digitally scanned instead of the specific ISA. With this modification of the protocol that now
328
incorporates the use of a pre-fabricated stock abutment, we are able to decrease the dental
329
laboratory cost for the restoring dentist. It is anticipated that cost will likely decrease in the
330
immediate future as the clinical and laboratory workflow become standard procedures for both
331
conventional and implant dentistry. The cost will be offset by the savings in impression material
332
and decreased clinician chair time and less remakes of restorations. 37
333 334
CONCLUSION
335
This clinical pilot study demonstrated that an intraoral laser scanner can be used with
336
confidence to obtain consistent accurate digital impressions to fabricate custom restorations and
337
abutments for single tooth dental implants. The advantage of using this leading edge technology is
338
the elimination of potential errors during the acquisition phase’s real time view for the clinician
339
refining the impression procedure. With this technology, elimination of impression materials,
340
having to obtain a bite registration and a decrease in dentist chairside working time has been
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
16
341
demonstrated in this study. Due to the impressive results of this advanced technology, the present
342
clinical study has been expanded to include multiple single units, fixed partial dentures and
343
anterior restorations. The new data will be separately evaluated as part of a larger study in
344
progress.
345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
17
361
REFERENCES
362
1. Christensen GJ. The state of fixed prosthodontic impressions: room for improvement. J Am
363
Dent Assoc. 2005;136:343-346.
364
2. Christensen GJ. The challenge of conventional impressions. J Am Dent Assoc. 2008;139:347-
365
349.
366
3. Hack GD. In vitro evaluation of the iTero digital impression system. ADA Prof Prod Review.
367
2011;6:6-10.
368
4. Ganz SD, Desai N, Weiner S. Marginal integrity of direct and indirect castings for implant
369
abutments. J Oral Maxillofac Implants. 2006;21;593-598.
370
5. Priest G. Virtual-designed and computer milled implant abutments. J Oral Maxillofac Surg.
371
2005;63:22-32.
372
6. Christensen GJ. Impressions are changing: deciding on conventional, digital or digital plus in-
373
office milling. J Am Dent Assoc. 2009;140:1301-1304.
374
7. Farah JW, Brown L. Comparison of the fit of crowns based on digital impressions with 3M
375
ESPE Lava Chairside Oral Scanner C.O.S. vs. traditional impressions. The Dental Advisor
376
Research Report. No. 22. June 2009.
377
8. Kerstein RB, Castellucci F, Osorio J. Ideal gingival form with computer-generated permanent
378
healing abutments. Compend Contin Educ Dent. 2000;21:793-801.
379
9. Kerstein RB. Osorio J. Utilizing computer-generated duplicate titanium abutments to facilitate
380
intraoral and laboratory implant prosthesis fabrication. Pract Peridont Aesthet Dent. 2003;15:311-
381
314.
382
10. Lowe RA. CAD/CAM dentistry and chairside digital impression making. Dental Economics
383
supplement. September 2009.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
18
384
11. Miyazaki T, Hotta Y, Kunii J, et al. A review of dental CAD/CAM: current status and future
385
perspectives from 20 years experience. Dent Mater J. 2009; 28(1):44-56.
386
12. Duret F, Blouin JL, Duret B. CAD/CAM in dentistry. J Am Dent Assoc. 1988; 117:715-720.
387
13. Duret F, Preston JD. CAD/CAM imaging in dentistry. Curr Opin Dent. 1991; 1:150-154.
388
14. Mormann WH, Brandestini M, Lutz F, et al. Chairside computer-aided direct ceramic inlays.
389
Quintessence Int. 1989; 20:329-339.
390
15. Mormann WH. The evolution of the CEREC system. J Am Dent Assoc. 2006;137:7s-13s.
391
16. Cerec 3. Operating instructions for the acquisition unit. Sirona The Dental Company. 2004.
392
17. Allen KL, Schenkel AB, Estafan D. An overview of the CEREC 3D CAD/CAM system. Gen
393
Dent. 2004;52:234-235.
394
18. Kutulakos K. Steger E. A theory of specular and refractive shape by light-path triangulation.
395
Microsoft Research Technology. MSR-TR; 2005
396
19. Wilton T, Masters BR. Confocal microscopy: introduction to the feature issue. Appl Opt.
397
1994;33:565-566.
398
20. Marcel TJ. Three-dimensional on-screen virtual models. Am J Orthod Dentofacial Orthop.
399
2001; 119:666-668.
400
21. Peluso MJ, Josell SD, Levine SW, et al. Digital models: an introduction. Semin Orthod. 2004;
401
10:226-239.
402
22. Kennedy J. Confocal imaging. Andor Technology. www.andor.com. Accessed August 10,
403
2011.
404
23. Wilson T, Masters BR. Confocal microscopy: introduction to the feature issue. Appl Opt.
405
1994; 33:565-566.
406
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
19
407
24. Cadent. www.cadentitero.com. Accessed August 10, 2011.
408
25. Misch CE, Suzuki JB, Misch-Dietsh FM, et al. A positive correlation between occlusal trauma
409
and peri-imlant bone loss: literature support. Implant Dent. 2005; 14(2):108-116.
410
26. Branemark PI, Hansson BO, Adell R, et al. Osseointegrated implants in the treatment of
411
edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg Suppl. 1977;16:1-
412
132.
413
27. Fransson B, Oilo G, Gjeitanger R. The fit of metal-ceramic crowns, a clinical study. Dent
414
Mater. 1985;1:197-199.
415
28. Belser UC, MacEntee MI, Richter WA. Fit of three porcelain-fused-to-metal marginal designs
416
in vivo: a scanning electron microscope study. J Prosth Dent. 1985;53:24-29.
417
29. Cuperus AM, Harms MC, Rangel FA, et al. Dental models made with an intraoral scanner: a
418
validation study. Am J Orthod Dentofacial Orthop. 2012; 142(3):308-313.
419
30. Karlsson S. The fit of Procera titanium crowns. An in vitro and clinical study. Acta Odontol
420
Scand. 1993;51:129-134.
421
31. Sulainman F, Chai J, Jameson LM, et al. A comparison of the marginal fit in In-ceram, IPS
422
Empress, and Procera Crowns. Int J Prosthodontics. 1997;10:478-484.
423
32. Tsitrou EA, Northeast SE, van Noort R. Evaluation of the marginal fit of three margin designs
424
of resin composite crowns using CAD/CAM. J Dent. 2007;35:68-73.
425
33. Tinschert J, Natt G, Mautsch W, et al. Marginal fit of alumina and zirconia based fixed partial
426
dentures produced by a CAD/CAM system. Operative Dent. 2001;26:367-374.
427
34. McLaren E. Special Report. CAD/CAM dental technology. Compendium. May 2011.
428 429
the
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
20
430
35. Syrek A, Reich G, Ranftl D, et al. Clinical evaluation of all-ceramic crowns fabricated from
431
intraoral digital impressions based on the principle of active wavefront sampling. J Dent. 2010;
432
38(7):553-559.
433
36. Seelbach P, Brueckel C, Wostmann B. Accuracy of digital and conventional impression
434
techniques and workflow. Clin Oral Investig. 2012 Oct 21. (Epub ahead of print).
435
37. Ganz SD. Finally, a “win-win” solution: increasing accuracy while saving time, money with
436
computer-milled abutments. Dental Economics. May 2005; 80-86.
437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
21
453
LEGENDS
454 455
Fig. 1. Digital impression obtained using 5 Axis implant scanning abutment attached to dental
456
implant and scanned using intraoral laser scanner.
457
Top Left: BioHorizons Laser Lok dental implant without scanning abutment.
458
Top Right: BioHorizons Laser Lok specific scanning abutment attached to dental implant.
459
Bottom Left: Use of iTero intraoral optical laser scanner to scan implant scanning
460
abutment.
461
Bottom Right: 5 Axis dental implant scanning abutment.
462 463 464 465
Fig. 2. Digital images obtained from intraoral laser scanner. CAD/CAM technology will be used to fabricate abutment and restoration. Fig. 3. Stereolithographic models and dies fabricated from CAD/CAM technology to produce allceramic restoration.
466
Figure 4. CAD/CAM fabricated custom ceramic abutment and restoration.
467
Fig. 5. All-ceramic restoration in #29 area (Issaquah Dental Laboratory, Issaquah, WA). Excellent
468 469 470 471 472 473 474 475
aesthetic result.
1 2 3 4 5 6 476 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
22
Table 1. Clinical Parameters Used To Evaluate CAD/CAM Restoration (n=36)
Patient 1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Parameter
Time (minutes)
Interproximal Contact Occlusion
5
Interproximal Contact Occlusion Interproximal Contact
5
Occlusion Occlusion
Remarks
8
8 5, 5
7
Interproximal Contact
5
Occlusion
15
Gingivectomy
Occlusion
11
Gingivectomy
Occlusion Interproximal Contract
15 12
Gingivectomy
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
23
32 32 34 35
Interproximal Contact
6
36 477
Marginal Integrity: If margin of restoration is or is not at margin of abutment.
478
Interproximal Contact: If proximal contact is present or absent with adjacent tooth.
479
Occlusion: If occlusion was satisfactory or unsatisfactory with opposing tooth.
480
Time: Time measured in minutes to adjust restoration to clinical acceptability
481
482
483
484
Figure Click here to download Figure: iTero_PilotStudy_Photos_Lee_etal_PDF.pdf
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Cover Letter Click here to download Cover Letter: JamesRutkowskiLetter.doc
Rebuttal Letter (for revisions) Click here to download Rebuttal Letter (for revisions): JOI_RebuttalLetter.doc
*Copyright Form Click here to download Copyright Form: JOI_TransferOfCopyright.pdf
Copyright Form Click here to download Copyright Form: JOI_DrJonSuzuki_AuthorCopyright.pdf
Copyright Form Click here to download Copyright Form: JOI_DrScottGanz_AuthorCopyright.pdf
Copyright Form Click here to download Copyright Form: JOI_DrNatalieWong_CopyrightAuthor.pdf
Copyright Form Click here to download Copyright Form: JOI_JonathanMursic_AuthorCopyright.JPG
Copyright Form Click here to download Copyright Form: JOI_DrCameronLee_CopyrightAuthor.pdf
