Influence of a microgrooved collar design on soft and hard tissue healing of immediate implantation in fresh extraction sites in dogs.

Objective: This study compared the alveolar bone reduction after immediate implantation using microgrooved and smooth collar implants in fresh extracted sockets.

Material And Methods: Four mongrel dogs were used in this study. The full buccal and lingual mucoperiosteal flaps were elevated and the third and fourth premolars of the mandible were removed. The implants were installed in the fresh extracted sockets. The animals were sacrificed after a 3-month healing period. The mandibles were dissected and each implant site was removed and processed for a histological examination.

Results: During healing, the marginal gaps in both groups, which were present between the implant and the socket walls at implantation, disappeared as a result of bone filling and resorption of the bone crest. The buccal bone crests were located apical of its lingual counterparts. At the 12-week interval, the mean bone-implant contact in the microgrooved group was significantly higher than that of the turned surface group. From the observations in some of the microgrooved groups, we have found bone attachment to the 12 mum microgrooved surface and collagen fibers perpendicular to the long axis of the implants over the 8 mum microgrooved surface.

Conclusion: Within the limitations of this study, microgrooved implants may provide more favorable conditions for the attachment of hard and soft tissues and reduce the level of marginal bone resorption and soft tissue recession.