Recombinant bone morphogenetic protein-2 and platelet-derived growth factor-BB for localized bone regeneration. Histologic and radiographic outcomes of a rabbit study

OBJECTIVES: Improvement in localized bone regeneration is needed to avoid the use of autogenous tissue. For that purpose, the use biologic mediators was proposed. The aim was to test whether or not one of two biologic mediators, recombinant human bone morphogenetic protein-2 (rhBMP-2) or recombinant platelet-derived growth factor (rhPDGF-BB), is superior to the other and to control groups for localized bone regeneration. MATERIALS AND METHODS: Four cylinders (height: 5 mm; diameter: 7 mm) were screwed on the parietal and frontal bones at the cranium in 12 rabbits. The cylinders either received (i) deproteinized bovine bone mineral (DBBM) mixed rhBMP-2 (DBBM/BMP-2), (ii) DBBM mixed with rhPDGF-BB (DBBM/PDGF), (iii) DBBM (DBBM), and (iv) empty control (control). Rabbits were euthanized at 2 and 8 weeks (n = 6, respectively). Conventional histomorphometric and micro-CT analyses were performed. Parametric linear mixed models were applied for the analyses with Bonferroni correction for the multiple group comparisons. RESULTS: The area of bone regeneration (histology; AAHisto ) at 2 weeks peaked for DBBM (41.91%) with statistically significantly greater values compared to DBBM/PDGF and the control group (P < 0.05). At 8 weeks, mean AAHisto values were 96.29% (DBBM/BMP-2), 46.37% (DBBM/PDFG), 39.66% (DBBM), and 35.98% (control) (DBBM/BMP-2 vs. all groups (P < 0.05)). At 8 weeks, bone regeneration was greatest for DBBM/BMP-2 (35.62%) with statistically significant differences compared to all other groups (P < 0.05). The area of bone regeneration (micro-CT; AAm-CT ) at 2 weeks amounted to 43.87% (DBBM/BMP-2), 42.81% (DBBM/PDFG), 48.71% (DBBM), and 0.96% (control). The control group demonstrated statistically significantly less AAm-CT compared to all groups (P < 0.05). At 8 weeks, mean AAm-CT values were 63.65% (DBBM/BMP-2), 50.21% (DBBM/PDFG), 44.81% (DBBM), and 4.57% (control) (P > 0.05). CONCLUSIONS: The use of rhBMP-2 significantly enhanced bone regeneration compared to all other groups including the group with rhPDGF-BB

Contour changes of peri-implant tissues are minimal and similar for a one- and a two-piece implant system over 12 years

OBJECTIVES: To assess contour changes of peri-implant tissues comparing a one- and a two-piece dental implant system over 12 years. MATERIALS AND METHODS: Patients seeking implant therapy were enrolled and randomly allocated to receive implants (a one-piece (STM) or a two-piece (BRA) system). Impressions were taken at the time of insertion of the final reconstruction (BL), after 1 year (FU-1), 5 years (FU-5), and at 12 years (FU-12). Thirty patients were included in the analysis (STM, 16; BRA, 14). Digital scans of casts were superimposed and analyzed in an image analysis program. Measurements included changes of the crown height, contour changes on the buccal side of the implants and the contralateral teeth (control). RESULTS: Contour changes at implant sites revealed a loss of - 0.29 mm (STM) and - 0.46 mm (BRA) during an observation period of 12 years. Contour changes at the corresponding tooth sites amounted to - 0.06 mm (STM) and - 0.12 mm (BRA) during the same time period. The implant crown gained 0.25 mm (STM) and 0.08 mm (BRA) in height due to recession of the marginal mucosa. The corresponding gain in crown height at the contralateral tooth sites amounted to 0.36 mm (STM) and 0.10 mm (BRA). Interproximal marginal bone level changes measured - 0.28 mm (STM) and - 1.11 mm (BRA). The mean BOP amounted to 38.8% (STM) and 48.7% (BRA) at the 12-year follow-up (FU-12). CONCLUSION: Minimal changes of the peri-implant soft tissue contour were observed at implant sites over the period of 12 years irrespective of the use of a one- or a two-piece implant system. The differences between the implant sites and corresponding teeth were clinically negligible. CLINICAL RELEVANCE: Peri-implant soft tissue stability is of high clinical relevance when monitoring dental implant sites on the long run. Clinical data on the extent of soft tissue changes around different implant systems are scarce. The present RCTs demonstrate minimal changes of the peri-implant soft tissue contour 12 years after implant insertion independent of the use of a one- or a two-piece implant system

The positive effect of tenting screws for primary horizontal guided bone regeneration: A retrospective study based on cone‐beam computed tomography data

Objectives: To radiographically evaluate the effect of the adjunctive use of tenting screws (TS) for primary horizontal guided bone regeneration (GBR). Materials & methods: Twenty-eight patients in need of staged bone augmentation were consecutively treated in a private practice. A xenogenic particulate bone substitute material (DBBM) and a resorbable collagen membrane were used in all patients. Subjects were divided into two groups: control (conventional GBR; n = 22) and test (tenting screws in conjunction with GBR - TS; n = 22). CBCT images were obtained before augmentation and after 6-8 months. CBCTs were superimposed, and linear horizontal measurements were performed. Alveolar ridge width (RW) and ridge width change (RWchange) were assessed at 1, 3, 5, and 7 mm below the bone crest. Results: Forty-four sites in 28 patients were evaluated. No differences between the groups were detected for RW at baseline (TS: 5.87 ± 2.41; control: 5.36 ± 1.65). Regarding RWchange, TS promoted an additional effect at 1 and 3 mm below the crest compared to control (p < .05; RWchange-1 TS: 3.72 ± 2.46; control: 1.25 ± 3.05; RWchange-3 TS: 3.98 ± 2.53; control: 2.50 ± 2.02). The final RW was greater in group TS compared to the control group at the 1, 3, and 5 mm level (p < .05). Conclusions: The use of tenting screws exerted a positive effect on staged GBR with a greater final RW at the 3 mm level. In addition, GBR in conjunction with TS was able to provide consistent bone augmentation at lingual/palatal sites. Keywords: alveolar ridge augmentation; bone regeneration; cone-beam computed tomography; dental implants

Localized bone regeneration around dental implants using recombinant bone morphogenetic protein-2 and platelet-derived growth factor-BB in the canine

OBJECTIVES To test whether or not one of two biological mediators (recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human platelet-derived growth factor (rhPDGF-BB)) is superior to the other and compared with control groups for bone regeneration around implants based on histomorphometrical outcome measures. MATERIALS AND METHODS Box-type defects (10 × 5 × 5 mm) were prepared on the buccal sides of the left and right edentulous ridge in ten mongrel dogs. Implants were placed at each site, the defects either received (i) bovine-derived particulated bone mineral (DBBM) mixed with rhBMP-2 and a collagen membrane (CM) (DBBM/BMP-2), (ii) DBBM mixed with rhPDGF-BB and CM (DBBM/PDGF), (iii) DBBM and CM (DBBM) and (iv) empty control (control). Animals were euthanized post-surgery at 8 weeks and 16 weeks. Histomorphometrical analyses were performed. RESULTS The mean percentages of regenerated area within total defect area amounted to 56.95% for DBBM/BMP-2, 48.86% for DBBM/PDFG, 33.44% for DBBM and 1.59% for control at 8 weeks, and 26.79% for DBBM/BMP-2, 23.78% for DBBM/PDFG, 30.21% for DBBM and 5.07% for control at 16 weeks with no statistically significant differences between the groups (P > 0.05). The mean amount of regenerated bone was 26.97% for DBBM/BMP-2, 22.02% for DBBM/PDFG, 5.03% for DBBM and 1.25% for control at 8 weeks, and at 16 weeks, these values were lower in the two groups with biological mediators (DBBM/BMP-2 = 13.35%; DBBM/PDGF = 6.96%) and only slightly increased in group DBBM (10.68%) and the control group (4.95%) compared with 8 weeks. The first bone-to-implant contact values on the buccal side were minimal for DBBM/BMP-2 (0.57 mm) and maximal for control (3.72 mm) at 8 weeks. CONCLUSIONS The use of biological mediators (rhBMP-2 and rhPDGF-BB) can increase the amount of bone regeneration at dehiscence-type defects compared with controls at 8 weeks, but not at 16 weeks due to enhanced hard tissue remodeling processes

Combined use of xenogeneic bone substitute material covered with a native bilayer collagen membrane for alveolar ridge preservation: A randomized controlled clinical trial

AIM The aim of this split-mouth randomized controlled study was to evaluate radiographic dimensional changes after tooth extraction in posterior sites treated with a ridge preservation technique or left for spontaneous healing. MATERIALS AND METHODS In a total of 18 patients, tooth extraction in posterior sites of the upper and lower jaw was performed in a split-mouth design. The post-extraction sockets were randomly assigned to the following two treatment modalities: deproteinized bovine bone mineral (DBBM) with 10% collagen (DBBM-C) covered with a native bilayer collagen membrane (NBCM) (test group) and spontaneous healing (control group). Cone beam computed tomography (CBCT) scans were performed after extractions, 3 and 6 months later. The following parameters were measured: the height of the buccal bone plate (BH), height of the palatal bone plate (PH), horizontal width of the extraction socket at 1 mm, 3 mm, and 5 mm (HW-1, HW-3, HW-5), and the horizontal width (thickness) of the buccal bone plate at 1 mm, 3 mm, and 5 mm (BHP-1, BHP-3, BHP-5). Statistical analysis was performed applying a nonparametric Wilcoxon signed-rank test. RESULTS The CBCT analysis showed a bone loss compared to baseline in test and control group. The measurements which have reached statistically significant differences at 6 months were BH (test: -2.31% vs control: -13.11%), PH (test: -2.07% vs control: -15.32%), HW-1 (test: -17.14% vs control: -32.47%), and HW-3 (test: -11.65% vs control: -28.47%). CONCLUSIONS The posterior ridge preservation technique using DBBM-C covered with a NBCM is a valid approach reducing the amount of the radiographic loss in alveolar ridge dimensions

Recombinant bone morphogenetic protein-2 and platelet-derived growth factor-BB for localized bone regeneration. Histologic and radiographic outcomes of a rabbit study

OBJECTIVES: Improvement in localized bone regeneration is needed to avoid the use of autogenous tissue. For that purpose, the use biologic mediators was proposed. The aim was to test whether or not one of two biologic mediators, recombinant human bone morphogenetic protein-2 (rhBMP-2) or recombinant platelet-derived growth factor (rhPDGF-BB), is superior to the other and to control groups for localized bone regeneration. MATERIALS AND METHODS: Four cylinders (height: 5 mm; diameter: 7 mm) were screwed on the parietal and frontal bones at the cranium in 12 rabbits. The cylinders either received (i) deproteinized bovine bone mineral (DBBM) mixed rhBMP-2 (DBBM/BMP-2), (ii) DBBM mixed with rhPDGF-BB (DBBM/PDGF), (iii) DBBM (DBBM), and (iv) empty control (control). Rabbits were euthanized at 2 and 8 weeks (n = 6, respectively). Conventional histomorphometric and micro-CT analyses were performed. Parametric linear mixed models were applied for the analyses with Bonferroni correction for the multiple group comparisons. RESULTS: The area of bone regeneration (histology; AAHisto ) at 2 weeks peaked for DBBM (41.91%) with statistically significantly greater values compared to DBBM/PDGF and the control group (P  0.05). CONCLUSIONS: The use of rhBMP-2 significantly enhanced bone regeneration compared to all other groups including the group with rhPDGF-BB