The preventive effects of systemic casein phosphopeptides on the resorption of roots in rats

Abstract

Introduction: Root resorption is a well documented side effect of orthodontic treatment. The aim of this study is to assess the potential for casein phosphopeptides (CPPs) to create an environment in which teeth are less susceptible to root resorption following orthodontic tooth movement. Method: Thirty one eleven week old, Wistar rats, were used in this experiment. Experimental and control animals were given the same diet of nutrigel (Troy Laboratories Pty. Ltd, NSW, Australia) mixed with rat chow with the same frequency and had free access to water throughout the whole experimental period. The 14 experimental rats received a diet supplemented with 40mg CPP per 100g of rat while the 17 control rats did not receive any supplements in their diet. The rats underwent a 2-week period of acclimatization with their respective diets followed by a two week experimental period after which the animals were euthanized and the samples were harvested. The tooth movement appliance was a 150cN sentalloy® (GAC Australia) closed coil spring (wire diameter 0.22mm, eyelet diameter 0.56 mm) applied from the maxillary incisor randomly to the right and left first maxillary molar. A volumetric analysis of the extent of root resorption on the mesial root of the first maxillary molar was examined using a micro CT scan. Results: The rats which received dietary CPP did not have a significant reduction in overall root resorption (p=0.28) although the results did reveal that dietary CPP appeared to lower the average root resorption by about a 15%. Dietary CPP was also found to have no statistically significant effect on decreasing tooth movement (p=0.42) although the average tooth movement was reduced by about 15%. Conclusions: CPP seems to have a variable effect on the volumetric quantification of root resorption. While on average, there was less root resorption observed in rats fed dietary CPP, individual variability makes this effect statistically insignificant. Similarly, CPP did not have a statistically significant effect on reducing tooth movement. Although it is possible that CPP may have a beneficial effect on reducing cementum solubility, this may be counteracted by its anabolic effect on bone mass which explains the variability observed in this study.