Analysis of Bone Volume Changes Following Lateral Guided Bone Regeneration.
Abstract: INTRODUCTION. Despite numerous reports in the literature on guided bone regeneration (GBR), there are no human randomized trials providing data on lateral ridge augmentation on pristine sites comparing absorbable and non-absorbable membranes. The current literature does not provide evidence-based criteria to guide a clinician select one technique for lateral GBR over the other. Due to la... read moreck of data, it was complex to design randomized clinical trial in order to get scientific outcomes. The aims of the present study were a quantitative and qualitative comparison of bone changes after lateral GBR procedures compared to baseline level between absorbable and non-absorbable membranes. The quantitative changes in bone volume were detected by a 3D digital software. The qualitative comparison derived from a histological analysis of bone core samples collected from the site of augmentation. MATERIALS & METHODS. The study population was 20 subjects, 10 for the absorbable membrane (Group 1) and 10 for the non-absorbable one (Group 2). The study received IRB approval. The inclusion criteria were systemically healthy subjects (>18 years old), non-smokers, presenting with at least one mandibular Kennedy Class III defects with 1 or 2 posterior adjacent missing teeth. A preoperative polyvinyl siloxane (PVS) impression of the edentulous mandible was poured into a stone cast that was subsequently scanned and digitalized. The crestal soft tissue thickness was measured by a periodontal probe and guided by a customized stent. After full thickness flap reflection, grafting material (FDBA) was placed in the defect and covered with one of the two membranes in randomized order. Three and six months postoperative stone casts were obtained and scanned. At the end of six months, the three models were compared using a dedicated 3D software in terms of volumes gained after GBR. After six months, dental implants were placed in the areas of augmentation. During the procedure a core sampling was collected for analysis by histomorphometry to compare the two groups. RESULTS. Analysis of volumetric changes between baseline (0 months) and time of implant placement (Visit 4 at 6-8 months) detected a mean changes of 434,78 mm3 (SD ± of 136,67 mm3) and 284,21 mm3 (SD ± 96,31 mm3) for Group 1 and 2, respectively. Bone changes in Group 1 between baseline and 3 months were 500.34 mm3 (SD ± 163,398 mm3) while they were -65,55 mm3 (SD± 44,25 mm3) between 3 and 6 months. In Group 2 (Cytoplast membranes) bone changes between baseline-3 months and 3- 6 months were 310,68 mm3 (SD ± 145,42 mm3) and -26,46 mm3 (SD ±53,37 mm3), respectively. The soft tissue had a mean thickness of 1,26 mm (SD ± 0,44 mm), which decreased, by 0,02 mm (SD ± 0,38 mm) at 6 months. Lateral bone gain had a mean of 2,82 mm (SD ± 1,02 mm). Histomorphometric analysis showed a mean of 44,39% of new bone, old bone and residual graft compared to the total area of the specimens. Group 1 specimens had a mean of 41,27% while for Group 2 was 48,59%. CONCLUSIONS. From the present pilot study, it could be concluded that absorbable and non-absorbable membranes provided sufficient bone for implant placement as planned prosthetically. No further grafting was needed after the initial augmentation. The results showed higher incidence of complications but lower graft resorption from 3 to 6 months for non-absorbable membrane Group. Specimens harvested from the non-absorbable group showed more mineralized tissue (bone and residual graft) compared to the absorbable Group.
Thesis (M.S.)--Tufts University, 2016.
Submitted to the Dept. of Periodontology.
Advisor: Yong Hur.
Committee: Bjorn Steffensen, Charles Hawley, Hans Peter Weber, Yumi Ogata, and Matthew Finkelman.
Keywords: Dentistry, Computer science, and Histology.read less