Histological and histomorphometric evaluation of immediate implant placement on a dog model with a new implant surface treatment.

PURPOSE: The aim of this study was to evaluate crestal bone resorption and bone apposition resulting from immediate post-extraction implants in the canine mandible, comparing a conditioned sandblasted acid-etched implant surface with a non-conditioned standard sandblasted implant surface. MATERIAL AND METHODS: In this experimental study, third and fourth premolars and distal roots of first molars were extracted bilaterally from six Beagle dog mandibles. Each side of the mandible received three assigned dental implants, with the conditioned surface (CS) on the right side and the non-conditioned surface (NCS) on the left. The dogs were sacrificed at 2 (n=2), 4 (n=2) and 12 weeks (n=2) after implant placement. RESULTS: The microscopic healing patterns at 2, 4 and 12 weeks for both implant types (CS and NCS) yielded similar qualitative bone findings. The mean crestal bone resorption was found to be greater for all implants with NCS (2.28+/-1.9 mm) than CS (1.21+/-1.05 mm) at 12 weeks. The mean percentage of newly formed bone in contact with implants was greater in implants CS (44.67+/-0.19%) than with the NCS (36,6+/-0.11%). There was less bone resorption with the CS than the NCS. CONCLUSION: The data show significantly more bone apposition (8% more) and less crestal bone resorption (1.07 mm) with the CS than with the NCS after 12 weeks of healing. This CS can reduce the healing period and increase bone apposition in immediate implant placements.