Effect of low-calcium diet and grind diet on bone turnover of ovariectomized female rats

Objective: The variety of methodologies used to investigate ovariectomized female rats shows different results, which makes a clinical application of these results difficult. The purpose of this work was to evaluate the effect of masticatory effort reduction and of low-calcium diet on maxillary bone turnover of ovariectomized female rats. Study Design: Eighty-four female rats were divided into four groups of 21 animals each as follows: SHAM - sham-operated; OVZ - ovariectomized and fed a standard commercial diet; LCD - fed a low calcium diet, and GCD - fed a grind commercial diet. The inferior first molars were extracted bilaterally 15 days after the ovariectomy, and the animals were euthanized 3, 5 and 8 weeks after ovaries removal. The maxillae were embedded in methylmetacrilate. The results were submitted to analysis of variance. Results: The daily mineral apposition rate lowered with time and was not different between SHAM and OVZ groups. The trabecular bone volume of SHAM and OVZ animals was similar and decreased with time. The GCD animals presented the lowest means and the LCD the highest in comparison to the OVZ group. Conclusion: It was concluded that ovariectomy and a low calcium diet did not cause significant maxillary bone loss in the first molar region, and even in the absence of the antagonist tooth, they did not cause maxillary bone turnover. The grind commercial diet is a good alternative for the study of maxillary bone loss in ovariectomized female rats.