Effects of chronic stress and alendronate therapy on the osseointegration of titanium implants.

ABSTRACT

PURPOSES: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.