Stephen S. Wallace

Human histologic and histomorphometric analysis comparing OsteoGraf/N with PepGen P-15 in the maxillary sinus elevation procedure: a case report.

&NA; The use of the anorganic bovine bone mineral OsteoGraf/N combined with demineralized freeze‐dried bone allograft has received widespread use in sinus elevations. This composite graft material has proven to be suitable, predictable, and successful for the placement and integration of endosseous implants in the edentulous, atrophic maxilla.In this case study, the current materials and accepted methodology were compared with the latest tissueengineered bone replacement graft material, PepGen P‐15. PepGen P‐15 is a combination of OsteoGraf/N and a synthetic peptide (P‐15) that mimics the cell‐binding domain of Type‐I collagen responsible for cell migration, differentiation, and proliferation.The radiographic, histologic, and histomorphometric evaluations of the sinus grafted with PepGen P‐15 showed enhanced bone formation within a shorter time interval compared with the composite graft material of OsteoGraf/N and demineralized freeze‐dried bone allograft. (Implant Dent 2000;9:298‐302)

Clinical evaluation of freeze-dried cancellous block allografts for ridge augmentation and implant placement in the maxilla.

A number of grafting materials have been used in vertical and horizontal ridge augmentation to enable implant placement in optimal positions. Autogenous block grafts from intraoral or extraoral sites have been used with positive results. Allograft blocks with cortical bone are also used for ridge augmentation. In this case series, cancellous allograft blocks were used for horizontal augmentation of the maxilla. The observed increase in ridge width allowed subsequent implant placement after a 5-month healing period. Four months after placement, the implants were uncovered and restored. The results suggest that cancellous block allografts may be a viable alternative to autogenous block grafts or cortical allograft blocks in treatment of deficient maxillary alveolar ridges to allow subsequent implant placement in optimal position in the maxilla.

Clinical evaluation of a cancellous block allograft for ridge augmentation and implant placement: a case report.

A number of grafting materials have been used in vertical and horizontal ridge augmentation to enable implant placement in optimal positions. Autogenous block grafts from intraoral or extraoral sites have been used with positive results. Allograft blocks with cortical bone are also used for ridge augmentation. In this case report, a cancellous allograft block was used for horizontal augmentation of the maxilla. The observed increase in ridge width allowed subsequent implant placement after a 5 month healing period. After 4 months the implant was uncovered and restored as a unit in a 4-unit fixed splinted implant reconstruction. The result suggests that cancellous block allografts may be a promising alternative to autogenous block grafts or cortical allograft blocks in treatment of deficient maxillary alveolar ridges to allow subsequent implant placement in optimal position.

Postextraction ridge preservation and augmentation with mineralized allograft with or without recombinant human platelet-derived growth factor BB (rhPDGF-BB): a consecutive case series.

In an attempt to reduce postextraction alveolar bone resorption, ridge preservation and augmentation procedures have become standard-of-care treatment following tooth removal. This consecutive case series compares histologic and histomorphometric bone regenerative findings at 4 months following grafting for ridge preservation and augmentation in intact sockets and sockets with buccal wall defects. Sites were treated with mineralized allograft alone (control) or in combination with 0.3 mg/mL recombinant human platelet-derived growth factor BB (rhPDGF-BB) (test). Sites were allowed to heal for 4 months and then re-entered for trephine core biopsy and implant placement. At the end of 4 months, the mean percent remaining mineralized allograft was statistically significantly less in the test group than in the control group. The difference in mean percent vital bone between the groups showed a strong trend toward greater bone formation for the test group (41.8%) compared to the control group (32.5%) at the end of 4 months. Addition of growth factor signaling molecules to current grafting procedures may lead to accelerated bone regeneration, making it possible to successfully place implants at earlier time points.

Histomorphometric comparison of different concentrations of recombinant human bone morphogenetic protein with allogeneic bone compared to the use of 100% mineralized cancellous bone allograft in maxillary sinus grafting

The purpose of this study was to histomorphometrically evaluate the percentage of vital bone after grafting of maxillary sinuses using two different concentrations of recombinant human bone morphogenetic protein/acellular collagen sponge (rhBMP-2/ACS) combined with mineralized cancellous bone allograft (MCBA) and to compare the results to a control sinus grafted with MCBA only. Thirty-six sinuses in 18 patients had two of three of the graft combinations including: (1) control, MCBA only; (2) test one, MCBA + 5.6 mL of rhBMP-2/ACS (containing 8.4 mg of rhBMP-2); or (3) test two, MCBA + 2.8 mL of rhBMP-2/ACS (containing 4.2 mg of rhBMP-2). Histologic cores were taken 6 to 9 month following sinus augmentation. The results showed no statistically significant differences in vital bone between the two test groups compared to the control sinus group treated with MCBA alone. Future studies involving more cases and evaluating survival of implants placed in these augmented sinuses are needed to verify the results of this randomized prospective study.

Maxillary Sinus Grafting With Biphasic Bone Ceramic or Autogenous Bone: Clinical, Histologic, and Histomorphometric Results From a Randomized Controlled Clinical Trial.

Purpose:The present, randomized, controlled clinical trial compared the histologic and histomorphometric results from maxillary sinus augmentation with either biphasic calcium phosphate (BCP) (60% hydroxyapatite and 40% &bgr;-tricalcium phosphate) or autogenous bone (AB) as bone-grafting materials. Material and Methods:Ten patients received bilateral sinus elevation surgery with intraoral AB chips (control group) on one side and BCP (test group) on the contralateral side. After a healing period of 6 to 8 months, implant sites were created and trephine cores were harvested for histological and histomorphometric analysis of the grafted areas. Results:The histological examination of biopsies showed BCP particles interconnected by bridges of a vital newly formed bone. Histomorphometry demonstrated that the amount of newly formed bone in the control group (36.8%) was significantly greater than that in the BCP (28.2%) group (P = 0.0032). BCP and AB cores revealed an average of residual graft particles of 32.9% and 4.8%, respectively. The average percentage of soft tissue components was 38.9% in the BCP cores and 58.4% in the AB cores. Conclusions:Based on our findings, the amount of vital bone formation was significantly higher for AB than that for BCP. However, BCP seemed to be a biocompatible and osteoconductive material that can be used with success as a bone substitute in maxillary sinus procedures.

A Histomorphometric Comparison of Bio-Oss Alone Versus Bio-Oss and Platelet-Derived Growth Factor for Sinus Augmentation: A Postsurgical Assessment

The purpose of this study was to assess vital bone formation at 4 to 5 months and 7 to 9 months following sinus augmentation with anorganic bovine bone matrix (ABBM) with and without recombinant human platelet-derived growth factor (rhPDGF). Twenty-four subjects received bilateral sinus elevation surgery with ABBM on one side and ABBM and rhPDGF on the contralateral side. Twelve patients had core sampling at 4 to 5 months and 12 patients at 7 to 9 months postoperatively. In subjects with cores taken at 4 to 5 months, mean vital bone, connective tissue, and residual graft were 11.8%, 54.1%, and 33.6%, respectively, with ABBM alone. Cores of sinuses filled with ABBM and rhPDGF showed mean 21.1% vital bone, 51.4% connective tissue, and 24.8% residual graft. Paired t test showed a statistically significant difference in vital bone. In cores taken at 7 to 9 months, the values for ABBM alone and ABBM + rhPDGF were 21.4% vs 19.5% vital bone, 28.4% vs 44.2% connective tissue, and 40.3% residual graft vs 35.5%. There was no statistically significant difference in vital bone at 7 to 9 months after surgery. Test and control groups showed clinically acceptable levels of vital bone both at 4 to 5 months and 7 to 9 months postsurgery. However, vital bone formation was significantly greater in the 4- to 5-month sections of ABBM + rhPDGF vs the Bio-Oss alone. In the 7- to 9-month specimens, this difference disappeared. More rapid formation of vital bone with the addition of rhPDGF may allow for earlier implant placement.

Letter to the Editor Re: Kim, Nowzari, and Rich (2013).

Dear Editor, We are writing this letter with regard to an article recently published in Clinical Implant Dentistry and Related Research by Yeoungsug Kim and colleagues, entitled “Risk of Prion Disease Transmission through Bovine-Derived Bone Substitutes: A Systematic Review” (2013; 15:645–653). The aim of the article was “to assess the risk of BSE transmission through anorganic bovine bone substitutes.” This review concluded that “bovinederived graft biomaterials may carry a risk of prion transmission to patients.” There are many shortcomings with the published review paper, which fails to substantiate the conclusions reached by the authors.