Peri-implant Tissue after Osseointegration in Diabetes in Rat Maxilla

Histological and histometric evaluations were done to investigate the effects of streptozotocin-induced diabetes on peri-implant tissue after osseointegration in the rat maxilla. Titanium screw implants were immediately inserted into the sockets after extraction of left upper first molars of 4-week-old male Wistar rats. Rats were divided into three groups. Rats in group I and group It were sacrificed at 4 and 8 weeks after implantation, respectively, and rats in group DM, in which streptozotocin was injected intraperitoneally at 4 weeks after implantation, were sacrificed at 8 weeks after implantation. Histological and histometric evaluations were carried out for decalcified specimens with EDTA and undecalcified ground specimens. Newly formed bone contacted the implant surface directly in the three groups. No significant difference in the bone-implant contact rate was found among the three groups. However, moderate inflammatory cell invasion and dilatation of capillaries were observed in the proper lamina around the implants. The bone height was significantly less in the DM group than in group I, while significance was not found between group DM and group It. These results suggested that hyperglycemia for 4 weeks after osseointegration affected the marginal bone level, whereas it did not influence the bone-implant contact rate.