Biomedical subjects

Michael Rohrer

Publications and source records attributed to Michael Rohrer.

3 recordsLinked to original sources

PubMed2005

Maxillary sinus augmentation using a peptide-modified graft material in three mixtures: a prospective human case series of histologic and histomorphometric results.

This prospective study assessed vital bone quality and quantity after grafting maxillary sinuses with anorganic bone mineral containing a cell binding peptide (ABM/P-15) in combination with DFDBA (Mix I), hydrogel/ABM/P-15 (Mix II), or PRP (Mix III). Fifteen maxillary sinuses in 12 patients were grafted with the ABM/P-15 mixtures and after 4 to 5 months, cores were taken and analyzed histologically and histomorphometrically. Fifty-nine screw-type implants were placed. Mixes containing a spacer material (Mix I and II) produced greater average vital bone, more mature bone, and more interconnected bone bridges from the cortical (oral) end to the most apical portion, compared to a mix that lacked a spacer material (Mix III). None of the 59 implants failed with any graft material up to 5 months following implant placement. The study demonstrates that new trabecular bone is formed after grafting ABM/P-15 in the sinus floor; that more vital bone is formed when ABM/P-15 is mixed with a spacer material than without; and that implants can be successfully placed.

Adult↗

PubMed2004

Extraction sockets and implantation of hydroxyapatites with membrane barriers: a histologic study.

The purpose of this pilot study was to investigate the effect on extraction socket healing when an absorbable hydroxyapatite (AH) and a nonabsorbable anorganic bovine bone mineral (ABB) covered with either an acellular dermal matrix allograft (ADMA) or expanded polytetrafluoroethylene (ePTFE) membrane barrier were left exposed to the oral cavity. Following tooth extraction, a total of 16 sockets in 15 patients with deficient buccal plates of > or =5 mm were randomly divided into 4 treatment groups: 1) AH covered with ADMA, 2) AH covered with an ePTFE membrane, 3) ABB covered with ADMA, and 4) ABB covered with an ePTFE membrane. Primary coverage was not attempted or obtained in any of the 16 treated sockets. Six to 8 months postextraction at the time of implant placement, histologic cores of the treatment sites were obtained. These cores were processed, stained with Stevenel's blue/van Gieson's picro fuchsin, and histomorphometrically analyzed. Vital bone, connective tissue and marrow, and residual graft particles were reported as a percentage of the total core. The mean vital bone was 34.5% (AH with ADMA), 41.7% (ABB with ADMA), 27.6% (ePTFE and AH), and 17.8% (ePTFE and ABB). The average percentage of vital bone in the 8 sockets covered with ADAMA was 38% compared with an average percentage vital bone of 22% in the 8 sockets covered with ePTFE membrane barriers. Because of the small number of specimens in the 4 groups, statistical analysis was not possible. However, in this pilot study, ADMA-covered sites resulted in more vital bone present 6 to 8 months postsocket treatment than obtained in the ePTFE-covered sites regardless of bone replacement materials used. Further research is warranted to see if these results show a similar difference in bone-to-implant contact after implant placement.

Adult↗

PubMed2002

Histological comparison of healing extraction sockets implanted with bioactive glass or demineralized freeze-dried bone allograft: a pilot study.

BACKGROUND: Various materials have been used immediately following tooth extraction to fill and/or cover the socket in an attempt to limit or prevent ridge resorption. The purpose of the present pilot study was to establish a reliable model to investigate the effect of various bone graft and bone replacement materials on extraction socket healing. This study also compared healing extraction sockets 6 to 8 months postimplantation of a bioactive glass (BG) or demineralized freeze-dried bone allograft (DFDBA) to an unfilled socket control (C). METHODS: Following tooth extraction, a total of 30 sockets in 19 patients were randomly divided into 3 treatment groups: 10 sockets received BG, 10 sockets DFDBA, and 10 sockets served as unfilled controls. Primary coverage was achieved by flap advancement over each socket. Six to 8 months postextraction at time of implant placement, histological cores of the treatment sites were obtained. These cores were processed, undecalcified sections prepared and stained with Stevenel blue/van Gieson's picric fuchsin, and histomorphometrically analyzed. Vital bone, connective tissue and marrow, and residual graft particles were reported as a percentage of the total core. RESULTS: A model system was described in humans and used to evaluate the healing response in the 3 treatment groups. Results concluded that mean vital bone present was 59.5% for BG-, 34.7% for DFDBA-, and 32.4% for C-treated sites. These differences were not statistically significant. However, the residual implant material was significantly higher in DFDBA-treated (13.5%) versus BG-treated sockets (5.5%). CONCLUSIONS: Although the differences in percent vital bone were not statistically significant among the 3 treatment groups in this pilot study, BG material was observed to act as an osteoconductive material which had a positive effect on socket healing at 6 to 8 months postextraction. Further research following implant placement in treated and control sockets is warranted to determine if bone implant contact is improved in BG-filled versus unfilled sockets.

Adult↗