Histologic evaluation of an allogeneic mineralized bone matrix in the treatment of periodontal osseous defects.

The aim of this study was to evaluate the potential of an allogeneic bone matrix to regenerate new bone, cementum, and periodontal ligament around a previously diseased root surface. Four patients with severe chronic periodontitis and teeth with hopeless periodontal or restorative prognoses participated in this study. One tooth with a severe intraosseous defect was selected per patient. At baseline, measurements of probing depth, gingival recession, and clinical attachment level were obtained. Following flap reflection, a root notch was placed at the apical extent of the calculus; the root was debrided, and the allogeneic bone graft material was placed into the defect. After a minimum of 6 months of healing, the teeth were removed en bloc and prepared for histologic examination. Two of four teeth demonstrated regeneration of new bone, cementum, and periodontal ligament. One tooth healed by new connective tissue attachment, and another by junctional epthelium.

Living cellular construct for increasing the width of keratinized gingiva: results from a randomized, within-patient, controlled trial.

BACKGROUND: The standard of care for increasing keratinized gingiva adjacent to teeth that do not require root coverage is the free gingival graft (FGG). A pilot study indicated that the use of a living cellular construct (LCC) could be effective in this clinical scenario. METHODS: A pivotal, multicenter, randomized, within-patient, controlled, open-label trial was conducted (N = 96 patients). After removing the mucosa and keratinized gingiva from the test site, either an LCC or FGG was applied. The primary efficacy endpoint was the ability of the LCC to regenerate ≥2 mm keratinized gingiva at 6 months. Secondary measures were the same color and texture as the adjacent tissue, a 1-mm width of keratinized gingiva at 6 months, patient treatment preference, surgical site sensitivity at 1 week, and patient-reported pain after 3 days. Safety was assessed by reports of adverse events. RESULTS: At 6 months, the LCC regenerated ≥2 mm of keratinized gingiva in 95.3% of patients (81 of 85 patients; P <0.001 versus a 50% predefined standard). As expected, the FGG generated more keratinized gingiva than the LCC (4.57 ± 1.0 mm versus 3.2 ± 1.1 mm, respectively). The gingiva regenerated with the LCC matched the color and texture of the adjacent gingiva. All patients achieved ≥1 mm keratinized gingiva with the LCC treatment by 6 months, and more patients preferred treatment with the LCC than with the FGG. No difference in sensitivity or pain was noted between the treatments. The treatments were well tolerated, and reported adverse events were typical for this type of periodontal surgery. CONCLUSION: The use of an LCC may provide a safe and effective therapy for augmenting the zone of keratinized gingiva.

Periodontal regeneration using an anabolic peptide with two carriers in baboons.

BACKGROUND: Various growth proteins have been used to encourage periodontal tissue regeneration. The purpose of this pilot study is to evaluate the periodontal regeneration achieved with the use of a synthetic anabolic peptide (AP) combined with either beta-tricalcium phosphate (beta-TCP) or an absorbable collagen sponge (ACS) as the carrier. METHODS: Periodontal defects were created bilaterally adjacent to four mandibular teeth in five baboons. Plaque was allowed to accumulate around wire ligatures placed into the defects. After 2 months, the wire ligatures were removed, and a notch was placed at the base of the defect. The four teeth were randomly treated with one of the following treatments: 1) saline + ACS serving as the control, 2) AP + ACS, 3) saline + beta-TCP serving as another control, or 4) AP + beta-TCP. The baboons were sacrificed 5 months post-treatment, and histomorphometric analyses were performed under masked conditions. RESULTS: At 5 months post-surgery, the mean length of new cementum for sites treated with AP + ACS, AP + beta-TCP, saline + ACS, saline + beta-TCP amounted to 3.32 +/- 1.7 mm, 3.86 +/- 1.0 mm, 2.87 +/- 1.3 mm, and 3.15 +/- 1.9 mm, respectively. The mean width of new cementum for the corresponding values was 52.5 +/- 14.7 microm, 54.5 +/- 24.2 microm, 37.4 +/- 12.7 microm, and 48.9 +/- 12.4 microm, respectively. The mean width of new periodontal ligament for corresponding values was 246 +/- 140 microm, 166 +/- 26 microm, 251 +/- 92 microm, and 240 +/- 91 microm. No statistically significant difference was observed for any of the parameters among groups in this pilot study. CONCLUSIONS: Preclinical studies showed that AP has positive anabolic effects on bone cells. In this study, no adverse tissue reactions were observed in the AP-treated sites, including root resorption, ankylosis, or a foreign body reaction. The cementum length and width were greater in the sites treated with AP versus sites treated with a control; however, these differences were not significant in the small number of animals used. Further research is needed to define the potential of AP as a periodontal therapeutic agent.

Clinical and histologic evaluation of calcium-phosphate bone cement in interproximal osseous defects in humans: a report in four patients.

This study evaluated the clinical and histologic results of a calcium phosphate bone cement in the treatment of human periodontal intraosseous defects. Four patients with chronic advanced periodontitis in whom treatment with complete dentures was planned were recruited. The cement was implanted in one defect per subject with a presurgical probing depth of at least 7 mm and a radiographic bone defect of 4 mm or more. Patients were seen every 2 weeks for periodontal maintenance. At 6 months, clinical measurements were repeated and the tooth was removed en bloc for histologic processing. Results demonstrated that all defects resulted in probing depth reduction and, at three of the four defects, in clinical attachment level gain. However, no site showed periodontal regeneration. There was no new bone formation. New cementum and connective tissue were limited to 0.2 mm or less. Large deposits of the bone cement were noted encapsulated in connective tissue.

Clinical and histologic evaluation of non-surgical periodontal therapy with enamel matrix derivative: a report of four cases.

BACKGROUND: Enamel matrix derivative (EMD) is a composite of proteins that was demonstrated histologically to work as an adjunct to periodontal regenerative surgical therapy. The purpose of this study was to evaluate the clinical and histologic effects of EMD as an adjunct to scaling and root planing. METHODS: Four patients with severe chronic periodontitis and scheduled to receive complete dentures were accrued. Probing depth and clinical attachment levels were obtained. Unlimited time was allowed for hand and ultrasonic instrumentation. A notch was placed in the root >or=1 to 2 mm from the apical extent of root planing. EMD was inserted into the pocket, and a periodontal dressing was placed. Patients were seen every 2 weeks for plaque control. At 6 months post-treatment, soft tissue measurements were repeated, and the teeth were removed en bloc and prepared for histomorphologic analysis. RESULTS: Probing depth reduction and clinical attachment level gain were obtained in three-fourths of the specimens. Three of the four specimens analyzed histologically demonstrated new cementum, bone, periodontal ligament, and connective tissue attachment coronal to the notch. In one specimen, the gingival margin had receded below the notch. CONCLUSIONS: The results were unexpected and may represent an aberration. However, the substantial reduction in deep probing depths and clinical attachment level gain in three of four specimens, in addition to the histologic findings of new cementum, new bone, a new periodontal ligament, and a new connective tissue attachment, suggest that EMD may be useful as an adjunct to scaling and root planing in single-rooted teeth.

Histological and clinical evaluation of recombinant human platelet-derived growth factor combined with beta tricalcium phosphate for the treatment of human Class III furcation defects.

Four patients with chronic advanced periodontitis participated in this study. At least one mandibular first molar had to have a hopeless periodontal and prosthetic prognosis. Clinical measurements were made, and the furcation defects were surgically exposed. A notch was placed through the calculus on both the mesial and distal roots. The furcal area was root planed with diamond-tip ultrasonic instruments. The furcations were grafted with a combination of recombinant human platelet-derived growth factor and beta tricalcium phosphate. A collagen barrier for guided tissue regeneration was used on both the facial and lingual surfaces. The flaps were coronally positioned and sutured. All patients were followed at 2-week intervals for 6 months. At 6 months, all teeth demonstrated a reduction in probing depth and a gain in clinical attachment. One tooth demonstrated a Class II furcation involvement, while through-and-through furcation involvement was still evident on the other three experimental teeth. The teeth were removed en bloc and processed for histologic evaluation. Three root surfaces demonstrated periodontal regeneration, an additional three showed new attachment, and one surface revealed junctional epithelium as measured from the base of the calculus notch. The notch area could not be identified on one surface of one specimen.

Comparison of clinical, periapical radiograph, and cone-beam volume tomography measurement techniques for assessing bone level changes following regenerative periodontal therapy.

BACKGROUND: Intraoral radiographs (IRs) provide a two-dimensional view of osseous structures, whereas cone-beam volumetric tomography (CBVT) images are viewable in three dimensions. The aim of this investigation was to compare the measurements from digital IR and CBVT images to direct surgical measurements for the evaluation of regenerative treatment outcomes. METHODS: Digital IR and CBVT images were taken prior to initial bone grafting and at the 6-month reentry surgery for 35 intrabony defects. After defect debridement, direct bony defect measurements were made with a periodontal probe. These same measurements were made on the IR and CBVT images and then compared to the direct surgical values. RESULTS: CBVT correlated strongly with surgical measurements (r = 0.89 to 0.95), whereas IRs correlated less favorably (r = 0.53 to 0.67). IR measurements were significantly less accurate compared to CBVT for all parameters investigated and underestimated surgical measurements from 0.6 +/- 2.3 mm to 1.5 +/- 2.3 mm. No significant difference for the distance from the cemento-enamel junction (CEJ) to the alveolar crest (P = 0.66 for initial measurement and P = 0.92 for reentry), defect fill (P = 0.14), or defect resolution (P = 0.09) was seen between CBVT and surgical measurements; however, there was a significant difference for the distance from the CEJ to the base of the defect, with CBVT measurements underestimating the surgical measurements by 0.5 +/- 1.1 mm for reentry (P <0.01) and 0.9 +/- 0.8 mm for the initial measurement (P <0.01). CONCLUSIONS: Overall, compared to direct surgical measurements, CBVT was significantly more precise and accurate than IRs. If supported by further research, CBVT may obviate surgical reentry as a technique for assessing regenerative therapy outcomes.

Evaluation of a mineralized cancellous bone allograft for the treatment of periodontal osseous defects: 6-month surgical reentry.

This study evaluated the effectiveness of a mineralized cancellous bone allograft (Puros) for the treatment of human periodontal osseous defects. Twenty patients with chronic periodontitis each contributed at least one intrabony defect. The surgical procedure consisted of flap reflection, debridement of the defect, root planing, and placement of the bone graft in the defect, followed by flap closure. Clinical and surgical measurements were taken at baseline and at the 6-month surgical reentry. The average probing depth reduction was 4.8 +/- 1.3 mm and average gain in clinical attachment levels was 4.2 +/- 1.5 mm; both changes were statistically significant. The average percent bone fill was 66.8% +/- 26.2% and average percent defect resolution was 71.5% +/- 25.5%. Mineralized cancellous bone allograft appears to be an effective material for the treatment of osseous defects in patients with chronic periodontitis.

Clinical evaluation of demineralized freeze-dried bone allograft with and without enamel matrix derivative for the treatment of periodontal osseous defects in humans.

BACKGROUND: Beneficial clinical effects have been demonstrated with the addition of enamel matrix derivative (EMD) to demineralized freeze-dried bone allograft (DFDBA) compared to EMD alone. The purpose of this study was to evaluate the effectiveness of DFDBA combined with EMD compared to DFDBA alone in the treatment of intraosseous defects of chronic periodontitis. METHODS: Thirty-two patients with 41 intrabony defects > or = 3 mm were randomly assigned to one of two treatment groups. Intrabony defects were treated with DFDBA alone or in combination with EMD. Soft tissue measurements included probing depth (PD), gingival recession, and clinical attachment level (CAL). Hard tissue measurements included height of the alveolar crest, defect depth, and defect morphology. Following 6 months of healing, all measurements were repeated with the use of a surgical reentry procedure on 29 patients. Data were analyzed to determine PD reduction, CAL gain, change in recession, crestal resorption, defect fill, defect resolution, percentage of defect fill, and percentage of defect resolution. RESULTS: Analysis of soft and hard tissue measurements demonstrated a statistically significant difference from baseline within each group (P <0.001); however, there was no statistically significant difference between the groups. CONCLUSION: Both treatments were shown to be safe and effective therapy for periodontal defects; however, the addition of EMD to DFDBA provided no statistically significant improvement to the soft and hard tissue parameters measured.

Human histologic and clinical evaluation of recombinant human platelet-derived growth factor and beta-tricalcium phosphate for the treatment of periodontal intraosseous defects.

This study histologically evaluated recombinant human platelet-derived growth factor-BB (rhPDGF-BB) in combination with beta-tricalcium phosphate (beta-TCP) for the treatment of human intraosseous periodontal defects. Eight patients, each with two teeth treatment planned for extraction, were enrolled. Presurgical measurements included probing depth, clinical attachment level, and recession. Initial surgery consisted of flap reflection, debridement, placement of a root notch through the base of calculus, scaling and root planing, root biomodification with 50 mg/mL tetracycline, grafting with rhPDGF-BB + beta-TCP, and complete wound closure. One tooth in each patient was treated with 0.3 mg/mL of rhPDGF-BB + beta-TCP, and the other tooth was treated with 1.0 mg/mL of rhPDGF-BB + beta-TCP. After a minimum of 6 months of healing, postsurgical clinical measurements were made, and teeth were removed en bloc. Soft tissue healing was uneventful. Histologic evaluation demonstrated new bone, cementum, and periodontal ligament coronal to the reference notch in 13 of the 16 teeth. Six of the eight 0.3-mg/mL sites and seven of the eight 1.0-mg/mL sites demonstrated periodontal regeneration. This study provides proof of principle that 0.3 mg/mL and 1.0 mg/mL of rhPDGF-BB and beta-TCP can promote periodontal regeneration in human intraosseous periodontal defects.

Modified-release subantimicrobial dose doxycycline enhances scaling and root planing in subjects with periodontal disease.

BACKGROUND: Previous studies showed that adjunctive subantimicrobial dose doxycycline (SDD; 20 mg, twice daily) provides significant clinical benefits to scaling and root planing (SRP). A modified-release SDD formulation containing 40 mg doxycycline (SDD-40) to be taken once daily has been developed. The aim of this study was to investigate the efficacy of SDD-40 when used as an adjunct to SRP for the treatment of periodontitis. METHODS: A 9-month, double-masked, randomized, placebo-controlled, multicenter study was conducted to test the efficacy of adjunctive SDD-40 in 266 subjects with periodontitis. Subjects were treated by SRP and randomized to receive SDD-40 or placebo for 9 months with evaluations at 3, 6, and 9 months. RESULTS: Adjunctive SDD-40 provided significantly greater clinical benefits than placebo at all time points. At month 9, at sites with baseline probing depths (PD) > or =6 mm, 72% to 76% of sites in the SDD-40 group demonstrated clinically significant PD reductions and clinical attachment level (CAL) gains > or =2 mm compared to 56% to 58% of sites in the placebo group (P <0.0001); 48% to 52% of sites in the SDD-40 group demonstrated PD reductions and CAL gains > or =3 mm compared to 32% of sites in the placebo group (P <0.0001). In moderate sites (baseline PD 4 to 6 mm), adjunctive SDD-40 provided significant clinical benefits compared to placebo for mean CAL (all time points: P <0.05), PD (3 months: P = 0.002; 6 and 9 months: P = 0.001), and bleeding on probing (BOP) (3 months: P <0.01; 6 months: P <0.02; 9 months: P <0.05). In deep sites (baseline PD > or =7 mm), SDD-40 provided significant benefits over control for mean CAL (3 months: P <0.05; 6 and 9 months: P <0.01), PD (all time points: P <0.001), and BOP (3 months: P <0.05; 6 months: not statistically significant; 9 months: P <0.05). Compliance with study medication was high (>92%) with no significant differences in adverse events between groups and no evidence of microbiologically significant changes or development of antibiotic resistance in the subgingival flora in either group. CONCLUSION: SDD-40 used as an adjunct to SRP resulted in significantly greater clinical benefits than SRP alone in the treatment of periodontitis.

The effect of ultrasound on bone dimensional changes following extraction: a pilot study.

BACKGROUND: Because of bone resorption following tooth extraction, preservation of adequate bony dimension is performed often for subsequent treatment with dental implants. This study evaluated a novel, non-invasive treatment using ultrasound to accelerate healing following extraction to minimize alveolar bone loss. The objective of this study was to evaluate the effect of ultrasound on the dimensional healing changes of alveolar bone following tooth extraction using cone-beam volumetric tomography (CBVT). METHODS: This randomized, split-mouth trial involved 12 subjects requiring extraction of two contralateral erupted permanent teeth. Baseline CBVT scans were captured 7 to 10 days following extraction, after which time ultrasound therapy commenced in test sites. Ultrasound therapy was delivered for 20 minutes using a piezoelectric transducer for 10 sessions over the subsequent 4 weeks. Follow-up radiographic scans were obtained at 4 weeks and 3 months postextraction. Analyses of variance and covariance were performed to assess dimensional changes over the 3-month healing period. RESULTS: Analysis of dimensional changes in all measures of vertical height and horizontal width demonstrated no statistically significant differences between the ultrasound and control groups from baseline to 3 months postextraction. Evaluation of correlations between dimensional changes demonstrated a moderately strong correlation (r = 0.67; P = 0.023) in the ultrasound group between the change in buccal vertical height and the baseline crestal ridge width. Analysis of the change in buccal vertical height relative to baseline crestal width demonstrated a statistically significant benefit to ultrasound compared to control (P = 0.016). This benefit was more pronounced in wider sockets compared to narrow sockets. CONCLUSIONS: In this pilot study, there was no significant benefit to ultrasound in absolute bony dimensional changes following tooth extraction. There was a significant interaction between the treatment rendered (ultrasound versus control) and the change in buccal ridge height relative to baseline ridge width at the crest and 3 mm apical to the crest. This benefit was apparent in wide sockets compared to narrow sockets; however, the clinical importance of these relative dimensional changes in the ultrasound group are difficult to determine given the inclusion of all tooth types in a pilot study with a small sample size.

The efficacy of subgingival calculus removal with endoscopy-aided scaling and root planing: a study on multirooted teeth.

BACKGROUND: The dental endoscope was developed to facilitate visualization of the subgingival environment as an aid in diagnosis and non-surgical root debridement. The purpose of this study was to determine whether endoscopy-aided scaling and root planing (SRP) resulted in a greater reduction of residual calculus compared to SRP alone in multirooted teeth. METHODS: Twenty-four patients were enrolled and contributed 35 tooth pairs (70 teeth in total). Each tooth per pair was randomly assigned to receive endoscopy-aided SRP (test) or SRP alone (control). Both teeth were extracted immediately after treatment, washed with water, and stained with methylene blue. The percentage of residual calculus was determined via stereomicroscopy and digital image software by a single masked examiner. RESULTS: Overall, there was 1.16% (P = 0.097) less residual calculus at test versus control sites. At interproximal surfaces, test roots had 2.63% less residual calculus than control roots (P = 0.003), whereas test roots had slightly more residual calculus than controls at buccal/lingual surfaces (0.36%; P = 0.652). There were no statistically significant differences in residual calculus between groups at deeper probing depths or at sites with deep furcation invasions. Only at shallower interproximal sites with probing depths < or =6 mm was significantly less residual calculus seen in roots treated with endoscopy (P = 0.020). Treatment time decreased significantly as operator experience increased; however, no significant improvement in residual calculus levels was noted with greater experience. CONCLUSION: Within the confines of this study, the use of the endoscope as an adjunct to traditional SRP provided no significant improvement in calculus removal in multirooted molar teeth.

The effectiveness of subgingival scaling and root planing: an evaluation of therapy with and without the use of the periodontal endoscope.

BACKGROUND: A fiber-optic periodontal endoscope was developed to aid in the visualization of subgingival structures and to improve the diagnosis and management of periodontal diseases. The purpose of this study was to determine whether use of the periodontal endoscope with scaling and root planing (SRP) resulted in a decrease in residual calculus compared to SRP alone. METHODS: Fifteen subjects with 50 tooth pairs participated in this study. Each tooth per pair was randomized to receive SRP with or without the endoscope. Teeth were extracted, and a stereomicroscope and digital image analysis was used to determine percent residual calculus present in a masked fashion. RESULTS: There was 2.14% (P < 0.001) more residual calculus at control versus test sites. At buccal/lingual and interproximal surfaces, mean differences in residual calculus were 1.30% (P <0.015) and 2.93% (P < 0.001), respectively. Test treatment time decreased significantly as operator experience increased. There were no statistically significant differences between residual calculus for test and control teeth at shallower probing depths; however, at deeper probing depths, the use of the endoscope resulted in significantly less residual calculus. CONCLUSIONS: The use of the periodontal endoscope resulted in a statistically significant overall improvement in calculus removal during SRP, which was most evident in deeper probing depths. The clinical significance of this level of improvement is unknown.

Application of periodontal tissue engineering using enamel matrix derivative and a human fibroblast-derived dermal substitute to stimulate periodontal wound healing in Class III furcation defects.

BACKGROUND: Enamel matrix derivative (EMD) has been shown to promote several aspects of periodontal regeneration in vitro and in vivo. Recently, a bioengineered tissue (DG) was developed to promote wound healing of chronic skin ulcers. This pilot study sought to assess the effects of EMD and DG, alone or in combination, on periodontal wound healing in surgically created Class III furcation defects. METHODS: Six female baboons received bilateral ostectomy of approximately 10 mm around the first and second mandibular molars to achieve Class III, subclass C furcation defects. Wire ligatures and cotton pellets were left in place for 2 months to maintain the depth of the defects and promote plaque accumulation. Each furcally involved molar was then assigned to one of four treatments: open flap debridement (OFD), OFD plus EMD, OFD plus DG, or OFD plus DG and EMD. This resulted in six total sites per treatment group. Seven months after defect creation and 5 months after treatment, and after no oral hygiene, tissue blocks of the mandible were taken for blinded histometric analysis to assess parameters of periodontal regeneration adjacent to furcal root surfaces and from the mid-furcal aspect (i.e., new bone, new connective tissue attachment, new epithelial attachment, and new cementum formation). RESULTS: Histometric analysis demonstrated differential regenerative responses with respect to treatment within each animal. However, statistically significant differences between treatments from all six animals were not observed (P >0.20, mixed-model analysis of variance). EMD-treated sites presented mildly positive regenerative results and no negative responses. Both DG only and combination therapy demonstrated similar or less than positive responses relative to OFD controls. CONCLUSION: The descriptive analysis may suggest a positive effect of enamel matrix proteins and a negative effect of DG used alone or in combination with enamel matrix proteins on the regeneration of Class III furcation defects in baboons.

Histologic and clinical evaluation of an allogeneic bone matrix for the treatment of periodontal osseous defects.

The objective of this study was to evaluate the potential of an allogeneic bone matrix (Grafton, Osteotech) to regenerate new bone, new cementum, and a new periodontal ligament around teeth previously contaminated by bacterial plaque. Four patients with chronic advanced periodontitis and who were scheduled for full-mouth extraction were enrolled in the study. One patient dropped out from the study before any therapy began. One tooth with an intraosseous defect in each patient was selected for treatment. Measurements of probing depth, gingival recession, and clinical attachment level were made. After flap reflection, a root notch was placed at the apical level of calculus, the root was debrided, and allogenic bone matrix was inserted into the defect. After 6 months of healing, the teeth were removed en bloc and evaluated histologically for a new attachment apparatus. Two of the three teeth demonstrated regeneration of new bone, cementum, and periodontal ligament.

Platelet-derived growth factor stimulates bone fill and rate of attachment level gain: results of a large multicenter randomized controlled trial.

BACKGROUND: Growth factors are generally accepted to be essential mediators of tissue repair via well-established mechanisms of action that include stimulatory effects on angiogenesis and cellular proliferation, ingrowth, differentiation, and matrix biosynthesis. The aim of this study was to evaluate in a large-scale, prospective, blinded, and randomized controlled clinical trial the safety and effectiveness of purified recombinant human platelet-derived growth factor (rhPDGF-BB) mixed with a synthetic beta-tricalcium phosphate (beta-TCP) matrix for the treatment of advanced periodontal osseous defects at 6 months of healing. METHODS: Eleven clinical centers enrolled 180 subjects, each requiring surgical treatment of a 4 mm or greater intrabony periodontal defect and meeting all inclusion and exclusion criteria. Subjects were randomized into one of three treatment groups: 1) beta-TCP + 0.3 mg/ml rhPDGF-BB in buffer; 2) beta-TCP + 1.0 mg/ml rhPDGF-BB in buffer; and 3) beta-TCP + buffer (active control). Safety data were assessed by the frequency and severity of adverse events. Effectiveness measurements included clinical attachment levels (CAL) and gingival recession (GR) measured clinically and linear bone growth (LBG) and percent bone fill (% BF) as assessed radiographically by an independent centralized radiology review center. The area under the curve (AUC), an assessment of the rate of healing, was also calculated for CAL measurements. The surgeons, clinical and radiographic evaluators, patients, and study sponsor were all masked with respect to treatment groups. RESULTS: CAL gain was significantly greater at 3 months for group 1 (rhPDGF 0.3 mg/ml) compared to group 3 (beta-TCP + buffer) (3.8 versus 3.3 mm; P = 0.032), although by 6 months, this finding was not statistically significant (P = 0.11). This early acceleration of CAL gain led to group 1 exhibiting a significantly greater rate of CAL gain between baseline and 6 months than group 3 as assessed by the AUC (68.4- versus 60.1-mm weeks; P = 0.033). rhPDGF (0.3 mg/ml)-treated sites also had significantly greater linear bone gain (2.6 versus 0.9 mm, respectively; P < 0.001) and percent defect fill (57% versus 18%, respectively; P < 0.001) than the sites receiving the bone substitute with buffer at 6 months. There was less GR at 3 months in group 1 compared to group 3 (P = 0.04); at 6 months, GR for group 1 remained unchanged, whereas there was a slight gain in gingival height for group 3 resulting in comparable GR. There were no serious adverse events attributable to any of the treatments. CONCLUSIONS: To our knowledge, this study is the largest prospective, randomized, triple-blinded, and controlled pivotal clinical trial reported to date assessing a putative periodontal regenerative and wound healing therapy. The study demonstrated that the use of rhPDGF-BB was safe and effective in the treatment of periodontal osseous defects. Treatment with rhPDGF-BB stimulated a significant increase in the rate of CAL gain, reduced gingival recession at 3 months post-surgery, and improved bone fill as compared to a beta-TCP bone substitute at 6 months.

Histologic evaluation of mineralized and demineralized freeze-dried bone allograft for ridge and sinus augmentations.

The objective of this study was to quantify new bone formation from biopsies of demineralized freeze-dried bone allograft (DFDBA) and freeze-dried bone allograft (FDBA) following ridge and sinus augmentations. Ninety-three patients who received maxillary sinus or ridge augmentation grafts agreed to core biopsies of their grafts when the implants were placed. Samples ranged from 6 to 36 months postgrafting. These samples were sectioned, stained, and examined histomorphometrically Seventy-two FDBA and 21 DFDBA samples were examined, and the mean percentages of new bone formed were 41.89% and 41.74%, respectively. There was no statistical difference, irrespective of graft site.

Immediate and early loading of SLA ITI single-tooth implants: an in vivo study.

PURPOSE: The purpose of this investigation was to determine whether early and immediate loading of dental implants resulted in adverse consequences as determined clinically, radiographically, and histologically. MATERIALS AND METHODS: In a canine model, 48 sand-blasted, large-grit, acid-etched (SLA) surfaced implants were placed at 4 different times before definitive restoration and loading. These times were 3 months (group A), 21 days (group B), 10 days (group C), and 2 days (immediately) (group D) before loading. Each implant was restored at the same time with a single gold screw-retained crown. Immediately after restoration all crowns were placed in function. Standardized periapical radiographs were made 1, 2, and 3 months after restoration. At the end of the study, block sections were obtained for histologic examination. Changes in crestal bone height on the mesial and distal aspects of each implant and the change in bone density of the coronal 3 mm of crestal bone were recorded. Primary, secondary, and total bone-to-implant contact; bone marrow-to-implant contact; and connective tissue-to-implant contact were evaluated histologically. RESULTS: All implants were osseointegrated at the end of the study; no clinical failures of integration were noted. The changes in crestal bone heights for groups A, B, C, and D (means +/- SE) were 0.02 +/- 0.07 mm, 0.30 +/- 0.08 mm, 0.15 +/- 0.08 mm, and 0.35 +/- 0.18 mm, respectively. Total bone-to-implant contact for the 4 groups was 69.1%, 71.3%, 74.6%, and 75.2%, respectively (P > .57). DISCUSSION: Under the conditions of this study no statistically significant differences were noted between the 4 different loading protocols for any of the parameters recorded. This finding is consistent with other recent studies and case reports. CONCLUSION: The findings of this study indicate that early and immediate loading of single-unit SLA surfaced implants was possible in this model. (More than 50 references.)