Microcomputed tomographic analysis of the alveolar ridge alteration around extraction sites with and without immediate implants placement: in vivo study.

BACKGROUND: The aim was to assess the alveolar ridge alteration around extraction sites with and without immediate implants according to extraction socket classification (ESC) using microcomputed tomography (micro-CT). MATERIAL AND METHODS: Ten beagle dogs (mean age and weight: 24 +/- 0.83 months and 13.8 +/- 0.49 kg, respectively) were randomly divided into three groups according to the ESC. In Group 1 (ESC-I), bilateral first and third premolars were extracted and replaced with immediate implants. In Group 2 (ESC-II), two adjacent premolars were extracted with one immediate implant placement in the mesial socket in the maxilla and in the distal socket in the mandible. In Group 3 (ESC-III), three adjacent teeth were extracted and an immediate implant was placed in the central socket. Primary closure was achieved using resorbable sutures. Buccal sites with dehiscence defects were excluded. After 4 months, subjects were sacrificed and alveolar ridge widths were measured at 1 mm interval in axial and sagittal views, using micro-CT in sites with and without immediate implants. RESULTS: In sites without immediate implant placement, alveolar ridge width was significantly higher in Group 1(6.1 +/- 1.35mm) than Group 3 (4.14 +/- 1.53 mm) (p <.05). In sites with immediate implant placement, the alveolar ridge width was higher among sites in Group 1 (6.4 +/- 3.8 mm) than Group 2 (4.8 +/- 0.46 mm) (p < .05) and Group 3 (5.02 +/- 0.84 mm) (p <.05). Overall, between each corresponding group in both sites with and without immediate implant placement at 1 mm thickness, there was no significant difference in the alveolar ridge widths. CONCLUSION: With the exception of Group 1 (ESC-I), immediate implant placement did not prevent or minimize bone remodeling in extraction sites according to ESC.