Volumetric Analysis of Ridge Preservation Using Bio-Oss® Collagen: A Retrospective Cohort Study Based on CBCT and Panoramic Radiographs

Background and Objectives: Tooth loss affects quality of life and chewing ability and is associated with natural ridge resorption after extraction. Implants are a viable option for the anchorage of removable or fixed prostheses. Successful implant placement requires adequate bone availability. To minimize bone loss after extraction and to avoid the need for additional augmentation before implant placement, ridge preservation techniques are employed. The aim of this study was to assess volume changes in extraction sockets after ridge preservation with a collagen-based bovine/porcine xenogenic material, Bio-Oss® Collagen (Geistlich, Switzerland), in molar and premolar regions. Materials and Methods: A retrospective study was designed and implemented. Subjects who underwent tooth extraction and consecutive ridge augmentation with Bio-Oss® Collagen between 2018 and 2022 and complied with the inclusion criteria were selected. The volume of the tooth root prior to extraction (alveolar socket volume surrogate) was estimated from pre-extraction CBCT scans and panoramic radiographs (predictor variable). The volume of the socket after extraction and ridge preservation was measured in CBCT datasets (outcome variable). The results were tabulated and analyzed (p < 0.05). Results: The study sample was composed of 80 subjects (37 female, 43 male; 20 premolars, 60 molars; average age: 59 ± 12.5 years). Of those, 60 cases qualified for comparative analyses (27 female, 33 male; 15 premolars, 45 molars; avg. age 59 ± 12.7 years). Compared with the pre-extraction alveolar socket volume in this subset of 60 subjects (maxillary premolar: 195.20 ± 33.40 mm3, maxillary molar: 470.41 ± 99.92 mm3, mandibular premolar: 220.42 ± 102.03 mm3, mandibular molar: 544.76 ± 137.32 mm3), ridge preservation cases still exhibited a volume loss of approximately 3–18% due to residual resorption depending on the location of the augmentation site (volume after ridge preservation: maxillary premolar: 192.07 ± 63.50 mm3, maxillary molar: 381.96 ± 81.38 mm3, mandibular premolar: 199.86 ± 73.70 mm3, mandibular molar: 475.85 ± 152.26 mm3. The highest resorption rates were observed in maxillary molar sites (approximately 18%), whereas maxillary premolar sites showed the lowest rates (around 3%). Conclusion: The study demonstrates that ridge preservation with the xenograft Bio-Oss® Collagen (Geistlich, Switzerland) can reduce ridge resorption following tooth extraction.