399

Comparative Clinical Study of Porous Hydroxyapatite and Decalcified FreezeDried Bone in Human Periodontal Defects Silvia Oreamuno, *

Henry

.

Vojislav Lekovic, f E.

Barrie

Jakéi, and Boris Prokicf *

Kenney, * Fermín A. Carranza, Jr., *

bony defects were treated with either porous hydroxyapatite (PHA) decalcified freeze-dried bone allograft (DFDB) implants at two different clinical centers. Twelve paired defects in 12 patients were treated at each center. Six months postsurgically the defects were measured to assess changes from the presurgical status. No statistically significant differences were found between the groups in changes in gingival fluid, bleeding index, plaque index, or tooth mobility. The porous hydroxyapatite implant produced greater reduction in pocket depth (P 0.03) and more gain in clinical attachment level (P 0.001) and defect fill (P 0.001) when compared with DFDB grafted sites. This study indicates that more clinical resolution of interproximal periodontal defects in humans can be obtained with the use of PHA than with the use of DFDB. J Periodontol 1990;61:399^04.

Interproximal

or

=

=

=

Key Words: Hydroxyapatite; bone transplantation; periodontal diseases/surgery.

defects associated with periodontal destruction have been treated surgically using both porous and decalcified freeze-dried bone allohydroxyapatite1-4 graft. 5-7 Previous studies have used either one or the other of these bone implant materials, but no comparative study is available where both of these bone substitutes were compared in the same patient. Porous hydroxyapatite (PHA) is made by hydrothermal chemical conversion of calcium carbonate (skeletal structure of a marine coral) to calcium phosphate in the crystalline form of hydroxyapatite. Its internal structure is composed of interconnecting pores of 190 to 230 µ in diameter. This material is available in granular or block form. Significant reduction in pocket depth and significant gain in attachment level have been reported with granular2 and block2-4 forms of PHA. A mean osseous defect fill of 3.53 mm has been reported after using PHA in a block form.3 No statistically significant differences were found when granular and block forms of PHA were compared.2 Decalcified freeze-dried bone allograft (DFDB) is processed from human cortical or cancellous bone to a particle size of 250 to 710 µ and is treated with 100% ethyl alcohol to reduce the lipid content. Décalcification is done with dilute hydrochloric acid extraction to calcium levels

Interproximal bony

UCLA School of Dentistry, Los Angeles, CA. tUniversity of Belgrade School of Dentistry, Belgrade, Yugoslavia. "

less than 0.07% by weight. The material is washed and buffered to a pH of 6.8 to 7.0 and lyophilized. Each 0.5 gram vial is stoppered under vacuum. Both implant materials are obtained in presterilized glass bottles, and stored until used at room temperature. A significant reduction in pocket depth and significant gain in probeable attachment level and defect fill have also been reported with the use of DFDB.5-7 A mean osseous defect fill of 2.57 mm was reported with this material.5 In spite of these separate trials, no direct comparative studies between PHA and DFDB were available. The purpose of the present investigation was to compare the effectiveness of PHA and DFDB as implant materials in human periodontal osseous defects. The study was carried out in two separate clinical trials at two clinical centers. The research protocol was similar for both centers and the results were collected independently with each research team having no knowledge of the results at the other center.

MATERIALS AND METHODS Twelve patients (mean age 41.41 years ± 11.47) with 12 matched pairs of similar interproximal angular osseous defects were selected at the University of California Los Angeles, School of Dentistry (Center A). Another 12 patients (mean age 36.21 ± 12.32) with a total of 12 paired defects were selected at the University of Belgrade (Center B). The inclusion criteria were the presence of two similar inter-

J Periodontol 400

July 1990'

TREATMENT OF PERIODONTAL DEFECTS

Figure 1. Presurgical photograph of the study areas of lower first molar).

areas

(mesial

and distal

proximal defects with pocket depth greater than 6 mm after initial therapy and the presence of an interproximal contact

Figure 2. Osseous defects (mesial and distal areas offirst molar) time of initial surgery. The furcations are not involved.

at

the

between the teeth involved. The exclusion criteria were systemic complications or allergies, teeth with furcation involvement, endodontically treated teeth, or the presence of any dental pathology. Each patient was treated with an initial phase of therapy including oral hygiene instruction, scaling and root planing under local anesthesia, and occlusal adjustment if trauma from occlusion was present. Following initial therapy (Fig. 1), the defects were randomly selected for implantation with either granular PHA (Interpore 200)* or cortical DFDB.§ Matched pairs were treated at the same time and using identical surgical

techniques.

following data were collected in Plaque Index,8 gingival fluid measurements from the interproximal areas utilizing the Periotron (Center A) and measurement of Ninhydrin stained strips (Center B). The Sulcular Bleeding Index9 was also recorded and the mobility of each tooth was assessed on a Prior to the surgery, the

a

sequential

manner:

scale 0 to 3.10 Pocket depths and clinical attachment level were measured with customized acrylic occlusal Stents using grooves to ensure a reproducible placement of the periodontal probe. Gingival recession of the interdental papilla was measured from the base of the stent to the gingival margin. Presurgical standardized periapical radiographs were taken using the extension cone paralleling technique with a personalized bite registration. Radiographs were repeated at 2 or 3 weeks postoperative and at 6 months. The surgical procedure consisted of an internal bevel incision at Center A and sulcular incision at Center B. Both techniques aimed at preserving as much interproximal tissue as possible. A full thickness flap was then elevated. Complete debridement of the osseous defects and thorough scal-

tlnterpore International, Irvine, CA. §Virginia Tissue Bank, Virginia Beach,

VA.

3. Measurements of the osseous defects at the time of initial surthe groove (arrow) where the probe is going to be placed to Note gery. take the measurements.

Figure

ing and root planing were done using curettes and ultrasonic sealers (Fig. 2). Measurements of the angular defects were taken from the base of the stent to the deepest portion of the osseous defect, and from the base of the stent to the alveolar crest (Fig. 3). Each defect was then filled with either PHA or DFDB up to the most coronal level of the adjacent alveolar process (Fig. 4). Flaps were sutured at their original level using horizontal or vertical cross mattechnique (Fig. 5) and a periodontal dressing was placed the surgical area. The patients were prescribed oral analgesic tablets as needed and oral penicillin for 7 days (250 mg 4 times a day). Chlorhexidine gluconate was also prescribed as a rinse for 2 to 4 weeks after surgery. Dressing tress

over

Volume 61 Number 7

OREAMTJNO, LEKOVIC, KENNEY, CARRANZA, TAKEI, PROKIC

Figure 4. Defects filled with DFDB (mesial area offirst molar) ular PHA (distal area offirst molar).

and gran-

401

Figure 6. Six months postsurgery. The level of attachment is measured using the same acrylic occlusal Stent that was used initially. Table 1. Pocket

Depth

in Millimeters

Center A

Initial

8.42 8.76 4.33 4.32

(Means

PHA ± 0.28 ± 0.24 ± 0.20 ± 0.16

6 Months

A

Mean

Change (Initial-6 month)

A

4.08 4.44

0.32* 0.24*

Mean Difference

A

0.50 0.42

0.18 0.16

(PHA-DFDBA)

SE)

±

NS S

DFDBA 8.33 ± 0.26 8.68 ± 0.24 4.75 ± 0.17 4.66 ± 0.18 3.58 4.02

t t

0.28* 0.22*

P= 0.02 P- 0.03

Statistically significant PsO.OOOl 12 Number of paired defects NS Not statistically significant "

=

=

=

Table 2.

(Means

Figure 5.

Closure

of flap

with silk

Changes ±

cross mattress sutures.

done 1 week postoperatively and a new dressing was placed for an additional week. Following the surgical procedure the patients were seen weekly for 1 month and then at 3 and 6 months post operatively. Post-surgical care included reinforcement of oral hygiene, root debridement, and supragingival scaling and polishing whenever necessary. Six months after initial surgery, all clinical parameters (Fig. 6) and standardized radiographs were repeated and surgical reentries performed. The surgical reentry consisted of a reflection of a full thickness flap. Any changes in the morphology of the bony defects were assessed and osseous measurements were taken as in the initial surgery. Student's paired tests were done to evaluate the results. Since this study was carried out in two different centers, the results were analyzed independently. was

RESULTS All surgical areas healed without incident and there was no apparent clinical difference in the healing patterns between PHA and DFDB sites. The presurgical pocket depths were

Probing Attachment

Levels in Millimeters

PHA

Center Mean

and suture removal

in

SE) Measured from Acrylic Stent

gain (Initial-6 months)

A

Mean difference

A

(PHA-DFDB)

2.67 3.10

±

0.58 0.98

±

±

±

0.22* 0.22* 0.17 0.18

DFDB

2.08 2.12 =

=

0.10* 0.16* 0.006 0.001

'Statistically significant PsO.0001 similar in both groups of defects at both centers; means at each center ranged from 8.33 mm to 8.76 mm (Table 1). Pocket depth reductions were significant for all four groups of defects with a slightly greater reduction seen in the PHA groups at both centers (Table 1). Probing attachment level changes showed the same pattern at both centers with a statistically significant greater improvement in PHA treated defects over that seen with DFDB (Table 2). The amount of gingival recession seen was very similar with both materials, no statistically significant difference was found between the two (Table 3). This pattern was the same at both centers. All four areas underwent some loss of crestal bone following the surgery. There was a greater loss seen in those

J Periodontol

402

July 1990

TREATMENT OF PERIODONTAL DEFECTS

Table 3. Changes in Gingival Recession in Millimeters (Means + SE) Measured from Acrylic Stent

Center

Change (Initial-6 months)

A

Mean Difference

A

Mean

(PHA-DFDB) 'Statistically significant

DFDB

PHA

-1.42 -1.34

0.28* 0.20*

0.08 0.56

0.16 0.14

1.50 1.90

± ±

0.33 0.19

Mean difference

(PHA-DFDB)

0.11 0.12

0.14 0.14

-0.50 -0.50 P P

=

=

Gingival

Fluid Initial 6 months Mean change Mean difference

Sulcular

Initial Index 6 months Mean change Mean difference

0.15*

0.12t

PHA

3.25 3.42

0.92 0.96

(PHA-DFDB)

'Statistically significant

0.18t 0.06

1.42 ± 0.14 0.62 ± 0.21 0.79 ± 0.18* P 0.17 =

13.45 130.42 ± 12.53 40.66 ± 8.90 8.95 11.93* 89.75 ± 14.23* =.093 11.39

124.92

36.17 88.75 -1.00 1.42 0.17 1.25 0.08

±

± ± ±

0.12 0.07 0.13* 0.08

1.38 ± 0.14 0.21 ± 0.07 1.17 ± 0.15* 0.34 =

Mobility

Initial 6 months Mean change Mean difference

1.33 ± 0.19 0.92 ± 0.15 0.41 ± 0.15 0.25 ±0.13

1.16 ± 0.17 1.00 ± 0.17 0.16 ± 0.11 0.08 =

(PHA-DFDB)

Center

Mean difference

0.13 0.21

(PHA-DFDB) Tooth

Table 5. Changes in Osseous Defect in Millimeters (Means + SE) Measured from Acrylic Stent

(Initial-6 month)

DFDB

(PHA-DFDB)

Bleeding

0.04 0.02

1.33 0.62 0.70 -0.08

SE) (Center A)

(PHA-DFDB)

'Statistically significant PsO.001 -(•Statistically significant P