Tissue Responses to Two Mini Dental Implants in Miniature Swine

Objective: To evaluate and compare histology and osseointegration of MDI Mini Dental Implant (3M ESPE, St Paul, MN) and MDL Mini Dental Implant (Intra-Lock International, Boca Raton, FL). 

Method: Premolars of four miniature swine were extracted.  After 3-month healing, the implants were inserted following manufacturers’ instructions and pertinent ISO guidelines.  Each animal received five MDI implants of Ø2.4 mm and Ø1.8 mm and three MDL of Ø2.5 mm and Ø2.0 mm.  All implants were 10 mm in length. Two pairs of randomly determined swine were sacrificed at 3 and 6 months, respectively.  The implant sites were inspected visually; and the samples with implants were harvested and randomly assigned to histopathological or histomorphometrical evaluation.

Result: All animals grew normally, and no signs of post-operative discomfort or abnormal behavior were observed in any of the animals throughout the experimental period.  Visual examination of implant areas found 4 and 11 mini implants lost at 3 and 6 months, respectively.  All remaining mini implants showed no mobility, and their peri-implant gingiva appeared healthy.  The radiographs also appeared to be normal for all mini implant sites.  Tissue responses to implants were minimal, with most at mild to moderate levels, and comparable between the MDI and MDL mini implants, regardless of their size, as examined using the Fisher Exact Test at α=0.05.  Histomorphometrical evaluation found 100% bone contact to the implant surface regardless of time of sampling, indicating excellent osseointegration of both MDI and MDL Mini Dental Implants.

Conclusion: Under conditions of the present study, overall swine tissue responses to MDI and MDL Mini Dental Implants were minimal and comparable; both the MDI and MDL Mini Dental Implants are capable of achieving significant osseointegration after 6 months. The study was supported by a grant from 3M ESPE.