Effects of Chronic Stress and Alendronate Therapy on the Osseointegration of Titanium Implants

Abstract

The purposes of this study were to evaluate the influence of chronic stress (CS) on implant osseointegration and also to analyze whether alendronate (ALN) therapy could prevent these eventual stress-negative effects. Adult male Holtzmann rats were assigned to one of the four experimental groups: AL (ALN; 1 mg/kg/week; n = 12), ALS (ALN + CS; 1 mg/kg/week; n = 12), CTL (sterile physiological saline; n = 12), or CTLS (sterile physiological saline + CS; n = 12). After 58 days of drug therapy, the ALS and CTLS groups were exposed to CS, and 2 days later all animals underwent tibial implant installation. The animals were euthanized 28 days following the operative surgical procedure. It was observed that the CTLS group presented an impairment of bone metabolism represented by lowest levels of bone-specific alkaline phosphatase and bone area fraction occupancy values. Furthermore, these animals presented a higher proportion of empty osteocytic lacunae. In contrast, the ALN therapy showed increased osseointegration and torque value parameters, regardless of stress exposition. Analysis of the data presented suggests that CS partially impairs the osseointegration of tibial implants and that ALN therapy is able to prevent these negative effects.