Objectives: Tooth extraction initiates a cascade of biological events leading to the reduction of alveolar ridge volume. Alveolar ridge preservation (ARP) is a surgical treatment which aims at minimizing hard and soft tissue changes following tooth extraction. Several techniques and materials have been studied and used clinically in ARP. The selection of the biomaterials used for this technique is determined by several factors, such as features of the extraction site, inherent biomaterial properties and handling preferences by the surgeon, among others. The purpose of this study was to evaluate the efficacy of alveolar ridge preservation via the application of Easy-graft CLASSIC® (Sunstar Americas Inc.), an alloplastic bone substitute with unique handling features, following flapless posterior single tooth extraction compared to a particulate freeze-dried bone allograft (FDBA) covered with a collagen wound dressing, which has been advocated as a predictable treatment modality. The primary outcome in this study was bone volumetric reduction of the alveolar ridge assessed using cone beam computed tomography (CBCT) scans obtained at baseline and 16 weeks after tooth extraction and ARP.
Methods: This study is part of a multicenter study in collaboration with the University of Maryland School of Dentistry. Seventeen healthy adults treatment planned for a single tooth implants in the area posterior to the canines, excluding third molars, were recruited on the basis of an eligibility criteria. Patients were randomly assigned to the control group or the experimental group. Minimally traumatic extraction of the tooth was completed and the presence of an intact buccal plate of bone was verified. The control group received FDBA and the site was stabilized with a collagen wound dressing and sutures. The experimental group received Easy-graft CLASSIC® with no attempt to approximate the marginal mucosa. Healing was assessed after 1, 2, 4, 8, and 16 weeks. DICOM data was used to assess the alveolar ridge volume and linear changes from baseline to 16 weeks after ARP. Clinical measurements of the buccal gingival thickness, buccal alveolar bone thickness, keratinized gingiva, and socket dimensions were made at the time of the extraction and were subsequently analyzed for possible influences on the observed volumetric and linear outcomes.
Results: The mean alveolar ridge volume reduction from baseline to 16 weeks post operatively for the control and the experimental group was 114.96 mm3 and 94.87 mm3, respectively. These values correspond to a reduction of 9.59% for the control group and 13.04% for the experimental group. This difference did not reach statistical significance. The average loss of ridge width was 1.10mm for the FDBA and 1.24mm for the Easy-graft CLASSIC® with no statically significant differences between the two groups. The average loss of buccal bone height and lingual bone height in the FDBA group was 1.12mm and 0.63mm, respectively. Similarly, the average loss of buccal bone height and lingual bone height in the Easy-graft CLASSIC® was 1.19mm and 0.67mm, respectively. There was a weak to moderate positive correlation between buccal tissue thickness and the thickness of the buccal bone and a weak negative correlation between buccal bone thickness and alveolar ridge width reduction.
Conclusions: Within the limitations of this study, both treatment groups appear to be effective in alveolar ridge preservation and are associated with similar volumetric and linear bone reduction patterns.