Effect of diabetes mellitus and insulin therapy on bone density around osseointegrated dental implants: a digital subtraction radiography study in rats

Objectives: To evaluate the effect of diabetes mellitus (DM) and insulin therapy on bone density around osseointegrated dental implants by digital subtraction radiography (DSR). Material and methods: Forty implants were placed in tibiae of 40 adult rats. After a healing period of 2 months, the animals were divided into four groups of 10 animals each: a 2‐month control group, sacrificed at time (A), a diabetic group (D), an insulin‐treated group (I) and a 4‐month control group (C). During 2 months, group I received subcutaneous doses of insulin, whereas groups C and D received only saline. The animals in groups D, I and C were thereafter sacrificed. The glucose plasma levels (GPLs) were monitored throughout the experiment. Film radiographs were taken at implant surgery and on the day of sacrifice. The radiographs were digitized, and bone density in regions of osseointegration (OR) around the implants was evaluated by quantitative DSR between baseline and final images. Differences in shades of gray among the groups were assessed using ANOVA. Results: GPLs were within normal range for groups A, C and I and higher for group D. There was a significant difference in mean gray shade values in the OR of subtraction images between groups D (122±7) and I (136±5) (P