J Periodontol • September 2014
Tissue Stability of Implants Placed in Fresh Extraction Sockets: A 5-Year Prospective Single-Cohort Study Ugo Covani,*† Luigi Canullo,† Paolo Toti,*† Fortunato Alfonsi,† and Antonio Barone*†
Background: Several materials have been used for ridge preservation after tooth extraction. This 5-year prospective single-cohort study is aimed at evaluating the success rate, marginal bone level (MBL), soft tissue stability, and subjective patient evaluation of implants placed in fresh extraction sockets with the use of a flapless technique and a xenograft to treat the peri-implant bone defect. Methods: Patients requiring a single implant in fresh extraction sockets were selected. After flapless extraction and implant insertion, the peri-implant bone defect was grafted with porcine bone. Collagen membrane was used to stabilize the graft. Four months later, a second surgery and prosthetic procedures were performed. Clinical parameters (width of keratinized gingiva [WKG], facial soft tissue level [FST], papilla index, plaque index, and bleeding on probing) were measured, and periapical radiographs were taken at the time of implant placement (baseline) and then at 1, 3, and 5 years thereafter. Image analysis software was applied to measure changes in the marginal bone level (DMBL). Additionally, patient satisfaction regarding the implant treatment was evaluated. All analyses were collected and measured by an independent, trained observer. Together with descriptive statistics, for each of the outcome variables, pairwise comparisons were performed using the Wilcoxon signed-rank test for matched samples. The level of statistical significance was set at 0.01 for all analyses. Results: Forty-seven consecutive patients were treated, with an implant survival rate at 5 years of 95.7%. DMBL showed statistically significant differences: mean values were -0.68 – 0.39, -0.94 – 0.44, and -1.08 – 0.43 mm at the 1, 3, and 5-year follow-up, respectively. Changes in WKG (DWKG) and FST (DFST) decreased from the 1-year point of the survey (0.80 – 0.79 and 0.71 – 0.73 mm for DWKG and DFST, respectively) to the last follow-up check at 5 years (0.67 – 0.74 and 0.56 – 0.69 mm for DWKG and DFST, respectively), with no significant differences. The papilla indexes showed significant differences among the baseline and all the other time points. Concerning patient satisfaction, at the last survey time point, 74% – 11.8% of patients were satisfied regarding the overall implant treatment, 73.0% – 11.1% gave a favorable opinion regarding the appearance of the peri-implant soft tissues, and 80.5% – 11.3% judged positively the finished appearance of the implant crown. No significant differences were obtained among the three follow-up times. Conclusions: The data of the present study suggest that the placement of a dental implant by means of a flapless technique in a fresh extraction socket filled with slowly resorbable graft biomaterial and with a delayed prosthetic restoration shows positive final esthetic outcomes. At the 5-year point of the survey, the changes in the bone level were minimal. Moreover, both midfacial tissue and the papillae maintained the early increase recorded before the first year of the follow-up. J Periodontol 2014;85:e323-e332. KEY WORDS Alveolar bone grafting; alveolar bone loss; dental implants, single-tooth; gingival recession; materials, biocompatible; tooth extraction. * Department of Surgical, Medical, Molecular, and Critical Area Pathology; University of Pisa; Pisa, Italy. † Tuscan Stomatologic Institute, Versilia General Hospital, Lido di Camaiore, Italy.
doi: 10.1902/jop.2014.140175
e323
Soft Tissue Stability for Immediate Implants
T
he current postextraction implant placement technique was first published in the early 1990s.1 In that study, the author described tooth extraction with the simultaneous placement of a titanium dental implant and an injection of particulate synthetic bone around the neck of the implant and into the peri-implant bone defect. Thenceforth, and especially in the past decade, there has been an increasing amount of articles concerning implant placement immediately after tooth extraction in the scientific literature.2 This is a consequence of the fact that this approach may clinically reduce treatment time and the number of surgeries, diminishing the clinical impact on the patient. An additional advantage of this approach is that the fresh extraction socket site in the immediate postextraction phase possesses a unique, characteristic wound-healing cascade. Therefore, three surgical strategies have been proposed to improve healing around implants inserted at the time of tooth extraction: 1) minimally invasive tooth extraction; 2) flapless surgery; and 3) a xenograft to augment the peri-implant bone defect. Although the scientific community agrees on minimizing trauma during extraction (avoiding any stress on the vestibular plate) and placing the implant so that it leans against the palatal wall to avoid fenestrations of the buccal wall and to improve the emergence profile,3-5 different opinions have been expressed regarding the surgical approach. In fact, some authors preferred open access to have visual control during surgery, considering the minimal amount of buccal bone resorption attributable to the flap elevation to be clinically irrelevant.6,7 Conversely, to minimize bone changes and prevent unesthetic scars or alterations in the mucogingival level, a flapless approach has been suggested.8,9 The presence of a gap between the fixture and the buccal bone wall was mentioned in the literature as one of the most common situations during placement of a postextraction implant, and there has been an ongoing debate regarding whether and how to fill this gap. Some authors suggested that in cases of horizontal bone defects that do not exceed 2 mm, implants placed in fresh extraction sockets could heal with good predictability without using any augmentation procedures.10 In contrast, other authors supported the hypothesis of using blood clot and autogenous bone for the peri-implant bone defects,8,11,12 whereas still others suggested the use of slow-resorption xenografts for peri-implant bone grafting.13,14 The use of such graft material seemed to preserve the soft and hard tissue architecture, which, when left to heal naturally, showed horizontal and vertical changes.15 The fresh extraction socket treatments
e324
Volume 85 • Number 9
were shown to reduce postextraction alveolar ridge dimensional changes, although some reviews in the literature highlighted that the graft materials were unable to completely prevent resorption of the buccal bone plate.16 The consequence of such a reduction was supposed to negatively affect the esthetic outcome.15 A few longitudinal studies were published in recent years on immediate implants using a flapless approach and a xenograft to augment the peri-implant bone defects.17,18 Conversely, no studies are available showing how changes in soft and hard tissue after implant insertion in fresh extraction socket might affect patient perception of the final esthetic outcome. For this reason, the aim of this 5-year prospective single-cohort study is to evaluate the success rate, marginal bone level (MBL), soft tissue stability, and the patients’ esthetic evaluation of implants placed in fresh extraction sockets with the use of a flapless technique associated with a xenograft to treat the peri-implant bone defect. MATERIALS AND METHODS Demographic data from the sample of patients are summarized in Table 1. The patients included 19 males and 26 females (aged 23 to 68 years; mean age: 42.8 – 13.2 years). Twelve of the 45 patients were smokers. This study is designed as a prospective cohort study and included consecutively treated patients. The trial was conducted at Versilia General Hospital, University of Pisa, Lido di Camaiore, Italy, from March 2007 to December 2008. Approval for the conduct of the trial was obtained from the ethical committee of Versilia General Hospital (Ethical Approval Form 214/2011). All the procedures were performed by two experienced operators (UC and AB) who received training during a 1-week session before beginning the study. The training included Table 1.
Patient Demographic and Clinical Data Parameter
Data
Sample size
45
Age (years), mean – SD Age range (years) Males/females
42.8 – 13.2 23 to 68 19/26
Incisor/canine/premolar
10/5/30
Smoking habit (yes/no)
12/33
BT (mm), mean – SD
0.76 – 0.24
BT = buccal plate thickness.
Covani, Canullo, Toti, Alfonsi, Barone
J Periodontol • September 2014
calibration for surgical and follow-up procedures as well as the handling of any complications. Patient eligibility criteria for inclusion in the study were as follows: 1) aged ‡18 years; 2) able to sign an informed consent form; 3) patients who presented a failing canine or premolar in the maxillary/ mandibular area requiring a tooth extraction and immediate dental implant placement; and 4) patients whose follow-up could be followed for ‡5 years (the present analysis represents a 5-year report following dental implant insertion as part of an ongoing study). Patients were excluded from the study if any of the following criteria were present: 1) history of systemic diseases that would contraindicate surgical treatment; 2) long-term steroidal and/or aminobisphosphonate therapy; 3) diabetes mellitus; 4) pregnancy or lactation; 5) uncontrolled periodontal disease; 6) patients declaring to smoke ‡10 cigarettes per day (patients smoking fewer than 10 cigarettes per day were requested to stop smoking before and after surgery, although their compliance could not be monitored); 7) absence of adjacent teeth; 8) extraction sites with a partial or complete deficiency of buccal bone plate; 9) failing tooth with acute infection; and 10) unwillingness to return for the follow-up examination. The study was conducted according to the principles outlined in the Declaration of Helsinki on clinical research involving humans, as revised in 2000. All patients received thorough explanations and had to complete a written informed consent form before being enrolled in the study. Patients who were included in the study were carefully evaluated by examining the clinical aspects and periapical/ panoramic radiographs; moreover, data were collected for each patient, such as age, sex, smoking habits, and indications for tooth extraction, which were based on both clinical and radiographic examination and tooth location. Surgery After the consent form was signed, all patients underwent at least one session of oral hygiene before the extraction procedure to provide a more favorable oral environment for wound healing. All patients underwent tooth extraction and clinical measurements at baseline; the dimensions of available alveolar bone and the presence of an intact buccal bone wall were evaluated. In a clinical situation in which an immediate implant could not be inserted, a ridge preservation procedure was performed; these patients were excluded from the study and received an implant 4 to 5 months later. The implants used for this study are all of the same brand‡ and are restored 4 months after implant placement.
All patients received prophylactic antibiotic therapy (2 g amoxicillin or 600 mg clindamycin if allergic to penicillin) 1 hour before the extraction procedure and continued to take the antibiotic postoperatively (1 g amoxicillin or 300 mg clindamycin) three times a day for 4 days. All patients rinsed for 1 minute with 0.2% chlorhexidine mouthwash before the surgery (and twice a day for the following 3 weeks) and were treated under local anesthesia using lidocaine with adrenaline 1:50,000. A flapless approach was chosen, and tooth extractions were performed with or without elevators to minimize the trauma; great care was taken to maintain the integrity of the buccal bone wall. Ultrasound bone surgery with specific tips was used at the mesial, distal, and lingual/palatal sites to allow easier tooth extraction if considered necessary. After extraction, the socket was carefully curetted, and, subsequently, the implant bed was prepared according to the standard procedure (with standard drills following the palatal bony wall as a guide, making maximum use of the bone apical to the removed tooth). A periodontal probe was used to verify the integrity of the bone walls and to measure the peri-implant bone defect after implant osteotomy preparation. Implants were placed with the implant platform at the marginal level of the palatal/lingual bone wall (Figs. 1 and 2). The peri-implant gap— between the implant surface and bone wall—was augmented with cortical porcine bone particles.§ Subsequently, a resorbable membranei was used to stabilize the graft, and a cross-mattress suture was used to stabilize the blood clot. The site was left for secondary soft tissue healing with a collagen membrane exposed to the oral cavity. Patients were instructed to continue with prophylactic antibiotic therapy, and 600-mg ibuprofen tablets were prescribed as an anti-inflammatory to be taken three times a day for as long as required. Sutures were removed after 10 days, and oral hygiene instructions were given. The second stage of implant surgery was performed 4 months after implant placement with a midcrestal incision to allow uncovering of the submerged implants and soft tissue healing. The final impressions were made with individual trays using polyvinyl siloxane material¶ to prepare the metal– ceramic crowns, which were cemented on personally tailored titanium abutments. Subsequently, all patients were enrolled in an oral hygiene maintenance schedule, with a recall visit every 3 months.
‡ § i ¶
Khono implants, Sweden & Martina, Due Carrare, Italy. Osteobiol Apatos, Tecnoss, Coazze, Italy. Osteobiol Evolution, Tecnoss. Flexitime, Heraeus Kulzer, Hanau, Germany.
e325
Soft Tissue Stability for Immediate Implants
Volume 85 • Number 9
Input Variables All measurements were acquired immediately after implant placement (baseline, or time T0), at 1 year after placement (T1), and at 3 and 5 years after dental implant insertion (T2 and T3, respectively). All the measurements were taken by a single examiner (PT), who was not involved in performing the surgical treatment, and are outlined here: 1) The diameter and length of the placed dental implants were measured. 2) Peri-implant MBL, evaluated on intraoral radiographs at the mesial (m) and distal (d) sites (mMBLX and dMBLX, in which X = 0, 1, 2, and 3 for times T0, T1, T2, and T3, respectively), was set as the distance between the reference point and the most apical point of the MBL. The reference point was the fixture– abutment interface. Digital intraoral periapical radiographs were taken (70 kVp, 7 mA) using a parallel cone technique with a digital sensor.# A paralleling device and individualized bite blocks made of polyvinyl siloxane impression material were used for the standardization of the x-ray geometry. Calibration was performed using the known thread-pitch distance of the implants (pitch of 1.0 mm). Previous known values, such as fixture diameter and length, were used for calibration when the threads were not clearly visible on the radiographs. Measurements were taken to the nearest millimeter using computer software.** 3) Width of keratinized gingiva (WKG) was measured midfacially from the gingival margin to the mucogingival junction of the intended extracted tooth (baseline) or the implant-supported restoration. 4) Facial soft tissue levels (FSTs) were evaluated by measuring the distance between the level of soft tissues at the midfacial gingival level and a reference line, which connected the FST of the adjacent teeth. 5) Buccal plate thickness (BT) was evaluated at baseline using a surgical caliper at both the midfacial level of the buccal bone plate and the most coronal point of the marginal crest. 6) Implant failure, which was considered to be any mobility of the implant and/or any infection that required removal or implant fracture, was evaluated. Implant stability was assessed manually at each time point of the study. 7) Plaque index (PI) and bleeding on probing (BOP) Figure 1.
Immediate dental implant placement, surgery, and follow-up. A) Buccal view of the extraction socket. B) Occlusal view of implant positioned before socket preservation. C) Corticocancellous porcine bone in bone defects filled and condensed around the placed implant (occlusal view). D) Occlusal view of tissue healing at 15 days. E) Buccal view of healed soft tissue at 12 months after prosthesis removal. Buccal view of restored implant after 3 years (F) and 5 years (G).
# Schick Technologies, Long Island City, NY. ** ImageTool v.3.00, University of Texas Health Science Center at San Antonio, San Antonio, TX.
e326
J Periodontol • September 2014
Covani, Canullo, Toti, Alfonsi, Barone
Figure 2.
Periapical radiographs before tooth extraction (A), immediately after dental implant placement (B), after 1 year (C), after 3 years (D), and after 5 years (E).
were acquired at the dental implant site for all four time points following an in-time, well-consolidated procedure.19,20 8) Last, a subjective evaluation of the total implant treatment was conducted: the patients expressed their degree of satisfaction regarding the total implant treatment (question A), the appearance of the peri-implant soft tissues (question B), and the appearance of the implant crown (question C) at the follow-up visits, using a systematic questionnaire after thorough information and instruction. The questionnaire and the information related are presented in Table 4. Each question was scored on a 100-mm visual analog scale (VAS), with 0 indicating extreme dissatisfaction and 100 indicating complete satisfaction. The VAS scores were measured to the nearest millimeter by a ruler. Outcome Variables The numerical outcome variables, which were obtained by an operation of subtraction, were marked with D and could be either negative or positive, with a reduction being represented by a negative value. 1) mDMBL and dDMBL were evaluated for each dental implant site by subtracting the T1, T2, and T3 values of the MBL from the respective baseline value (nDMBLX = nMBL0 - nMBLX, with n as mesial or distal, and X = 1, 2, and 3 for times T1, T2, and T3, respectively). 2) DFST was calculated by subtracting the baseline value from the respective values at times T1, T2, or T3, according to the formula DFSTX = FSTX - FST0 (with X = 1, 2, and 3 for times T1, T2, and T3, respectively). 3) DWKG was calculated by subtracting the baseline value from the respective values at times T1, T2, or T3, according to the formula DWKGX = WKGX - WKG0 (with X = 1, 2, and 3 for times T1, T2, and T3, respectively). 4) The interdental papilla (IP) was recorded at the dental implant site based on the papilla index proposed by Jemt:21 0 = no papilla; 1 = less than one-half papilla is present; 2 = greater
than half of the papilla height is present but not to the full extent of the contact point; 3 = papilla fills the entire proximal space and is in good harmony; and 4= papilla is hyperplastic. 5) Cumulative success rates for implants were calculated according to the criteria suggested by Buser,22 with a recorded radiologic periimplant bone resorption of not greater than 1.5 mm during the first year of loading and of 0.2 mm/year during the following years.23 6) For all the time points considered, PI and BOP were computed and expressed in percentages. Statistical Analyses The overall dataset was entered into a database, and descriptive analyses were performed automatically.†† Measurements in the text and tables are shown as mean – SD for numerical variables, whereas ranked variables are shown as median (interquartile ranges [IQRs], i.e., the difference between the 75th and 25th percentiles). A Lilliefors test was used to confirm normal distribution of the data related to each numerical variable for all the survey times. For each of the outcome variables, pairwise comparisons were performed using the Wilcoxon signed-rank test for matched samples to compare the time effects. The level of statistical significance was set at 0.01 for all analyses. Statistical software was used.‡‡ RESULTS In the present 5-year prospective single-cohort study, 47 patients were treated by single-tooth extraction and immediate flapless dental implant placement, with the peri-implant gap filled with a xenograft covered by a resorbable membrane. Of the 47 implants included in the study, two failed during the overall follow-up period, and therefore 45 dental †† Database Toolbox, MATLAB v.7.0.1, MathWorks, Natick, MA. ‡‡ Statistics Toolbox, MATLAB v.7.0.1, MathWorks.
e327
e328
Cumulative survival of dental implants (%)
97.9 (93.8 to 100)
95.7 (90.0 to 100)
95.7 (90.0 to 100)
Tissue Stability of Implants Placed in Fresh Extraction Sockets: A 5-Year Prospective Single-Cohort Study Ugo Covani,*† Luigi Canullo,† Paolo Toti,*† Fortunato Alfonsi,† and Antonio Barone*†
Background: Several materials have been used for ridge preservation after tooth extraction. This 5-year prospective single-cohort study is aimed at evaluating the success rate, marginal bone level (MBL), soft tissue stability, and subjective patient evaluation of implants placed in fresh extraction sockets with the use of a flapless technique and a xenograft to treat the peri-implant bone defect. Methods: Patients requiring a single implant in fresh extraction sockets were selected. After flapless extraction and implant insertion, the peri-implant bone defect was grafted with porcine bone. Collagen membrane was used to stabilize the graft. Four months later, a second surgery and prosthetic procedures were performed. Clinical parameters (width of keratinized gingiva [WKG], facial soft tissue level [FST], papilla index, plaque index, and bleeding on probing) were measured, and periapical radiographs were taken at the time of implant placement (baseline) and then at 1, 3, and 5 years thereafter. Image analysis software was applied to measure changes in the marginal bone level (DMBL). Additionally, patient satisfaction regarding the implant treatment was evaluated. All analyses were collected and measured by an independent, trained observer. Together with descriptive statistics, for each of the outcome variables, pairwise comparisons were performed using the Wilcoxon signed-rank test for matched samples. The level of statistical significance was set at 0.01 for all analyses. Results: Forty-seven consecutive patients were treated, with an implant survival rate at 5 years of 95.7%. DMBL showed statistically significant differences: mean values were -0.68 – 0.39, -0.94 – 0.44, and -1.08 – 0.43 mm at the 1, 3, and 5-year follow-up, respectively. Changes in WKG (DWKG) and FST (DFST) decreased from the 1-year point of the survey (0.80 – 0.79 and 0.71 – 0.73 mm for DWKG and DFST, respectively) to the last follow-up check at 5 years (0.67 – 0.74 and 0.56 – 0.69 mm for DWKG and DFST, respectively), with no significant differences. The papilla indexes showed significant differences among the baseline and all the other time points. Concerning patient satisfaction, at the last survey time point, 74% – 11.8% of patients were satisfied regarding the overall implant treatment, 73.0% – 11.1% gave a favorable opinion regarding the appearance of the peri-implant soft tissues, and 80.5% – 11.3% judged positively the finished appearance of the implant crown. No significant differences were obtained among the three follow-up times. Conclusions: The data of the present study suggest that the placement of a dental implant by means of a flapless technique in a fresh extraction socket filled with slowly resorbable graft biomaterial and with a delayed prosthetic restoration shows positive final esthetic outcomes. At the 5-year point of the survey, the changes in the bone level were minimal. Moreover, both midfacial tissue and the papillae maintained the early increase recorded before the first year of the follow-up. J Periodontol 2014;85:e323-e332. KEY WORDS Alveolar bone grafting; alveolar bone loss; dental implants, single-tooth; gingival recession; materials, biocompatible; tooth extraction. * Department of Surgical, Medical, Molecular, and Critical Area Pathology; University of Pisa; Pisa, Italy. † Tuscan Stomatologic Institute, Versilia General Hospital, Lido di Camaiore, Italy.
doi: 10.1902/jop.2014.140175
e323
Soft Tissue Stability for Immediate Implants
T
he current postextraction implant placement technique was first published in the early 1990s.1 In that study, the author described tooth extraction with the simultaneous placement of a titanium dental implant and an injection of particulate synthetic bone around the neck of the implant and into the peri-implant bone defect. Thenceforth, and especially in the past decade, there has been an increasing amount of articles concerning implant placement immediately after tooth extraction in the scientific literature.2 This is a consequence of the fact that this approach may clinically reduce treatment time and the number of surgeries, diminishing the clinical impact on the patient. An additional advantage of this approach is that the fresh extraction socket site in the immediate postextraction phase possesses a unique, characteristic wound-healing cascade. Therefore, three surgical strategies have been proposed to improve healing around implants inserted at the time of tooth extraction: 1) minimally invasive tooth extraction; 2) flapless surgery; and 3) a xenograft to augment the peri-implant bone defect. Although the scientific community agrees on minimizing trauma during extraction (avoiding any stress on the vestibular plate) and placing the implant so that it leans against the palatal wall to avoid fenestrations of the buccal wall and to improve the emergence profile,3-5 different opinions have been expressed regarding the surgical approach. In fact, some authors preferred open access to have visual control during surgery, considering the minimal amount of buccal bone resorption attributable to the flap elevation to be clinically irrelevant.6,7 Conversely, to minimize bone changes and prevent unesthetic scars or alterations in the mucogingival level, a flapless approach has been suggested.8,9 The presence of a gap between the fixture and the buccal bone wall was mentioned in the literature as one of the most common situations during placement of a postextraction implant, and there has been an ongoing debate regarding whether and how to fill this gap. Some authors suggested that in cases of horizontal bone defects that do not exceed 2 mm, implants placed in fresh extraction sockets could heal with good predictability without using any augmentation procedures.10 In contrast, other authors supported the hypothesis of using blood clot and autogenous bone for the peri-implant bone defects,8,11,12 whereas still others suggested the use of slow-resorption xenografts for peri-implant bone grafting.13,14 The use of such graft material seemed to preserve the soft and hard tissue architecture, which, when left to heal naturally, showed horizontal and vertical changes.15 The fresh extraction socket treatments
e324
Volume 85 • Number 9
were shown to reduce postextraction alveolar ridge dimensional changes, although some reviews in the literature highlighted that the graft materials were unable to completely prevent resorption of the buccal bone plate.16 The consequence of such a reduction was supposed to negatively affect the esthetic outcome.15 A few longitudinal studies were published in recent years on immediate implants using a flapless approach and a xenograft to augment the peri-implant bone defects.17,18 Conversely, no studies are available showing how changes in soft and hard tissue after implant insertion in fresh extraction socket might affect patient perception of the final esthetic outcome. For this reason, the aim of this 5-year prospective single-cohort study is to evaluate the success rate, marginal bone level (MBL), soft tissue stability, and the patients’ esthetic evaluation of implants placed in fresh extraction sockets with the use of a flapless technique associated with a xenograft to treat the peri-implant bone defect. MATERIALS AND METHODS Demographic data from the sample of patients are summarized in Table 1. The patients included 19 males and 26 females (aged 23 to 68 years; mean age: 42.8 – 13.2 years). Twelve of the 45 patients were smokers. This study is designed as a prospective cohort study and included consecutively treated patients. The trial was conducted at Versilia General Hospital, University of Pisa, Lido di Camaiore, Italy, from March 2007 to December 2008. Approval for the conduct of the trial was obtained from the ethical committee of Versilia General Hospital (Ethical Approval Form 214/2011). All the procedures were performed by two experienced operators (UC and AB) who received training during a 1-week session before beginning the study. The training included Table 1.
Patient Demographic and Clinical Data Parameter
Data
Sample size
45
Age (years), mean – SD Age range (years) Males/females
42.8 – 13.2 23 to 68 19/26
Incisor/canine/premolar
10/5/30
Smoking habit (yes/no)
12/33
BT (mm), mean – SD
0.76 – 0.24
BT = buccal plate thickness.
Covani, Canullo, Toti, Alfonsi, Barone
J Periodontol • September 2014
calibration for surgical and follow-up procedures as well as the handling of any complications. Patient eligibility criteria for inclusion in the study were as follows: 1) aged ‡18 years; 2) able to sign an informed consent form; 3) patients who presented a failing canine or premolar in the maxillary/ mandibular area requiring a tooth extraction and immediate dental implant placement; and 4) patients whose follow-up could be followed for ‡5 years (the present analysis represents a 5-year report following dental implant insertion as part of an ongoing study). Patients were excluded from the study if any of the following criteria were present: 1) history of systemic diseases that would contraindicate surgical treatment; 2) long-term steroidal and/or aminobisphosphonate therapy; 3) diabetes mellitus; 4) pregnancy or lactation; 5) uncontrolled periodontal disease; 6) patients declaring to smoke ‡10 cigarettes per day (patients smoking fewer than 10 cigarettes per day were requested to stop smoking before and after surgery, although their compliance could not be monitored); 7) absence of adjacent teeth; 8) extraction sites with a partial or complete deficiency of buccal bone plate; 9) failing tooth with acute infection; and 10) unwillingness to return for the follow-up examination. The study was conducted according to the principles outlined in the Declaration of Helsinki on clinical research involving humans, as revised in 2000. All patients received thorough explanations and had to complete a written informed consent form before being enrolled in the study. Patients who were included in the study were carefully evaluated by examining the clinical aspects and periapical/ panoramic radiographs; moreover, data were collected for each patient, such as age, sex, smoking habits, and indications for tooth extraction, which were based on both clinical and radiographic examination and tooth location. Surgery After the consent form was signed, all patients underwent at least one session of oral hygiene before the extraction procedure to provide a more favorable oral environment for wound healing. All patients underwent tooth extraction and clinical measurements at baseline; the dimensions of available alveolar bone and the presence of an intact buccal bone wall were evaluated. In a clinical situation in which an immediate implant could not be inserted, a ridge preservation procedure was performed; these patients were excluded from the study and received an implant 4 to 5 months later. The implants used for this study are all of the same brand‡ and are restored 4 months after implant placement.
All patients received prophylactic antibiotic therapy (2 g amoxicillin or 600 mg clindamycin if allergic to penicillin) 1 hour before the extraction procedure and continued to take the antibiotic postoperatively (1 g amoxicillin or 300 mg clindamycin) three times a day for 4 days. All patients rinsed for 1 minute with 0.2% chlorhexidine mouthwash before the surgery (and twice a day for the following 3 weeks) and were treated under local anesthesia using lidocaine with adrenaline 1:50,000. A flapless approach was chosen, and tooth extractions were performed with or without elevators to minimize the trauma; great care was taken to maintain the integrity of the buccal bone wall. Ultrasound bone surgery with specific tips was used at the mesial, distal, and lingual/palatal sites to allow easier tooth extraction if considered necessary. After extraction, the socket was carefully curetted, and, subsequently, the implant bed was prepared according to the standard procedure (with standard drills following the palatal bony wall as a guide, making maximum use of the bone apical to the removed tooth). A periodontal probe was used to verify the integrity of the bone walls and to measure the peri-implant bone defect after implant osteotomy preparation. Implants were placed with the implant platform at the marginal level of the palatal/lingual bone wall (Figs. 1 and 2). The peri-implant gap— between the implant surface and bone wall—was augmented with cortical porcine bone particles.§ Subsequently, a resorbable membranei was used to stabilize the graft, and a cross-mattress suture was used to stabilize the blood clot. The site was left for secondary soft tissue healing with a collagen membrane exposed to the oral cavity. Patients were instructed to continue with prophylactic antibiotic therapy, and 600-mg ibuprofen tablets were prescribed as an anti-inflammatory to be taken three times a day for as long as required. Sutures were removed after 10 days, and oral hygiene instructions were given. The second stage of implant surgery was performed 4 months after implant placement with a midcrestal incision to allow uncovering of the submerged implants and soft tissue healing. The final impressions were made with individual trays using polyvinyl siloxane material¶ to prepare the metal– ceramic crowns, which were cemented on personally tailored titanium abutments. Subsequently, all patients were enrolled in an oral hygiene maintenance schedule, with a recall visit every 3 months.
‡ § i ¶
Khono implants, Sweden & Martina, Due Carrare, Italy. Osteobiol Apatos, Tecnoss, Coazze, Italy. Osteobiol Evolution, Tecnoss. Flexitime, Heraeus Kulzer, Hanau, Germany.
e325
Soft Tissue Stability for Immediate Implants
Volume 85 • Number 9
Input Variables All measurements were acquired immediately after implant placement (baseline, or time T0), at 1 year after placement (T1), and at 3 and 5 years after dental implant insertion (T2 and T3, respectively). All the measurements were taken by a single examiner (PT), who was not involved in performing the surgical treatment, and are outlined here: 1) The diameter and length of the placed dental implants were measured. 2) Peri-implant MBL, evaluated on intraoral radiographs at the mesial (m) and distal (d) sites (mMBLX and dMBLX, in which X = 0, 1, 2, and 3 for times T0, T1, T2, and T3, respectively), was set as the distance between the reference point and the most apical point of the MBL. The reference point was the fixture– abutment interface. Digital intraoral periapical radiographs were taken (70 kVp, 7 mA) using a parallel cone technique with a digital sensor.# A paralleling device and individualized bite blocks made of polyvinyl siloxane impression material were used for the standardization of the x-ray geometry. Calibration was performed using the known thread-pitch distance of the implants (pitch of 1.0 mm). Previous known values, such as fixture diameter and length, were used for calibration when the threads were not clearly visible on the radiographs. Measurements were taken to the nearest millimeter using computer software.** 3) Width of keratinized gingiva (WKG) was measured midfacially from the gingival margin to the mucogingival junction of the intended extracted tooth (baseline) or the implant-supported restoration. 4) Facial soft tissue levels (FSTs) were evaluated by measuring the distance between the level of soft tissues at the midfacial gingival level and a reference line, which connected the FST of the adjacent teeth. 5) Buccal plate thickness (BT) was evaluated at baseline using a surgical caliper at both the midfacial level of the buccal bone plate and the most coronal point of the marginal crest. 6) Implant failure, which was considered to be any mobility of the implant and/or any infection that required removal or implant fracture, was evaluated. Implant stability was assessed manually at each time point of the study. 7) Plaque index (PI) and bleeding on probing (BOP) Figure 1.
Immediate dental implant placement, surgery, and follow-up. A) Buccal view of the extraction socket. B) Occlusal view of implant positioned before socket preservation. C) Corticocancellous porcine bone in bone defects filled and condensed around the placed implant (occlusal view). D) Occlusal view of tissue healing at 15 days. E) Buccal view of healed soft tissue at 12 months after prosthesis removal. Buccal view of restored implant after 3 years (F) and 5 years (G).
# Schick Technologies, Long Island City, NY. ** ImageTool v.3.00, University of Texas Health Science Center at San Antonio, San Antonio, TX.
e326
J Periodontol • September 2014
Covani, Canullo, Toti, Alfonsi, Barone
Figure 2.
Periapical radiographs before tooth extraction (A), immediately after dental implant placement (B), after 1 year (C), after 3 years (D), and after 5 years (E).
were acquired at the dental implant site for all four time points following an in-time, well-consolidated procedure.19,20 8) Last, a subjective evaluation of the total implant treatment was conducted: the patients expressed their degree of satisfaction regarding the total implant treatment (question A), the appearance of the peri-implant soft tissues (question B), and the appearance of the implant crown (question C) at the follow-up visits, using a systematic questionnaire after thorough information and instruction. The questionnaire and the information related are presented in Table 4. Each question was scored on a 100-mm visual analog scale (VAS), with 0 indicating extreme dissatisfaction and 100 indicating complete satisfaction. The VAS scores were measured to the nearest millimeter by a ruler. Outcome Variables The numerical outcome variables, which were obtained by an operation of subtraction, were marked with D and could be either negative or positive, with a reduction being represented by a negative value. 1) mDMBL and dDMBL were evaluated for each dental implant site by subtracting the T1, T2, and T3 values of the MBL from the respective baseline value (nDMBLX = nMBL0 - nMBLX, with n as mesial or distal, and X = 1, 2, and 3 for times T1, T2, and T3, respectively). 2) DFST was calculated by subtracting the baseline value from the respective values at times T1, T2, or T3, according to the formula DFSTX = FSTX - FST0 (with X = 1, 2, and 3 for times T1, T2, and T3, respectively). 3) DWKG was calculated by subtracting the baseline value from the respective values at times T1, T2, or T3, according to the formula DWKGX = WKGX - WKG0 (with X = 1, 2, and 3 for times T1, T2, and T3, respectively). 4) The interdental papilla (IP) was recorded at the dental implant site based on the papilla index proposed by Jemt:21 0 = no papilla; 1 = less than one-half papilla is present; 2 = greater
than half of the papilla height is present but not to the full extent of the contact point; 3 = papilla fills the entire proximal space and is in good harmony; and 4= papilla is hyperplastic. 5) Cumulative success rates for implants were calculated according to the criteria suggested by Buser,22 with a recorded radiologic periimplant bone resorption of not greater than 1.5 mm during the first year of loading and of 0.2 mm/year during the following years.23 6) For all the time points considered, PI and BOP were computed and expressed in percentages. Statistical Analyses The overall dataset was entered into a database, and descriptive analyses were performed automatically.†† Measurements in the text and tables are shown as mean – SD for numerical variables, whereas ranked variables are shown as median (interquartile ranges [IQRs], i.e., the difference between the 75th and 25th percentiles). A Lilliefors test was used to confirm normal distribution of the data related to each numerical variable for all the survey times. For each of the outcome variables, pairwise comparisons were performed using the Wilcoxon signed-rank test for matched samples to compare the time effects. The level of statistical significance was set at 0.01 for all analyses. Statistical software was used.‡‡ RESULTS In the present 5-year prospective single-cohort study, 47 patients were treated by single-tooth extraction and immediate flapless dental implant placement, with the peri-implant gap filled with a xenograft covered by a resorbable membrane. Of the 47 implants included in the study, two failed during the overall follow-up period, and therefore 45 dental †† Database Toolbox, MATLAB v.7.0.1, MathWorks, Natick, MA. ‡‡ Statistics Toolbox, MATLAB v.7.0.1, MathWorks.
e327
e328
Cumulative survival of dental implants (%)
97.9 (93.8 to 100)
95.7 (90.0 to 100)
95.7 (90.0 to 100)
