Long-term preservation of ridge dimension following tooth extraction and ridge preservation: A randomized controlled trial of healing at 4- and 12-month healing time points.

BACKGROUND: To date, the efficacy of ridge preservation in the maintenance of the residual alveolar ridge dimension beyond 6 months after treatment is unknown. The purpose of this study was to compare the differences in alveolar ridge dimensional change following ridge preservation between 4- and 12-month healing time points using cone-beam computed tomography (CBCT). METHODS: Fifty seven patients planned for tooth extraction and implant placement were enrolled. Following extraction, ridge preservation was performed. CBCT scans were taken within 72 hours following extraction with a customized resin stent containing a fixed radiographic marker. At either 4 months (short-term, ST group) or 12 months (long-term, LT group) after ridge preservation, patients had a second CBCT taken and an implant placed. Changes in ridge height and width were measured using the standardized radiographic marker. RESULTS: No significant differences were detected between the ST and LT groups in loss of buccal and lingual ridge height. Similarly, when adjusted for baseline ridge width, no significant differences were detected in ridge width loss at 3, 5, and 7 mm apical to the crest between the ST and LT groups. CONCLUSIONS: The efficacy of ridge preservation in the maintenance of ridge width and height at the 12-month time point is similar to that of the 4-month time point. Clinicians may feel confident that a delay in implant placement for up to a year has no significant negative impact on the height and width of the healed ridge.