Alveolar Ridge Preservation in Posterior Maxillary Teeth for Reduction in the Need for Sinus Floor Elevation Procedures. A Pilot Study

Objectives: The research aims to compare the changes in vertical ridge dimensions and evaluate the potential need for sinus augmentation with or without ridge preservation in the posterior maxilla following tooth extraction.
Methods: 19 extraction sites were included in this piolot study, comprising of 9 control (no grafting) and 10 test (grafting) sites. Test extraction sites were randomised for ridge preservation with two types of deproteinised bovine bone mineral (DBBMs) xenografts, either Bio-Oss^® (6 sites) or Bio-Oss Collagen^® (4 sites) (Geistlich, Switzerland). Computed tomography (CT) scans were taken before extraction and at four months following extraction to compare changes in vertical ridge dimensions (mid-, buccal and palatal ridge height) and sinus volume. The need for lateral window sinus augmentation was determined based on the criteria for residual mid-ridge height less than 5mm at the post-extraction site.
Results: In the test (ridge preservation) group, there were significant reductions of both buccal and palatal ridge height (p<0.05) but no significant changes in the mean of mid-ridge heights (p=0.491) four months post-opertively. In contrast, the control group had significant reductions in all vertical ridge dimensions (p<0.05). The inter-group analysis revealed that the mean change in the mid-ridge height in the test group (-0.5±2.0mm) was significantly less than that in the control group (-2.7±0.9mm) (p=0.008). However, there was no significant difference in mean buccal and palatal ridge height changes between the control and test groups (p>0.0.5). Furthermore, there was a statistically significant difference in the mean change in sinus volume between the groups (p=0.03), where the control group demonstrated an increase in sinus volume (0.7±0.7cm³) while the ridge preservation group demonstrated a decrease in sinus volume (-0.3±0.7cm³) after four months. Based on the residual mid-ridge height criteria (<5mm), 8 out of 9 (89%) control sites would require lateral window sinus augmentation as opposed to 3 out of 8 (38%) sites in the test group.
Conclusions: Within the limitations of this study, the alveolar ridge preservation in posterior maxillary teeth significantly reduced the amount of vertical mid-ridge dimensional changes and the need for sinus augmentation compared to untreated extraction sites.