THE EFFECT OF A FLUORIDATED TOOTHPASTE ON DENTINAL LESIONS IN PLAQUE-FILLED GROOVES - AN INTRAORAL CROSSOVER STUDY

Recently, we introduced an intra-oral dentin demineralization model-to evaluate the efficacy of a fluoridated toothpaste at plaque-retention sites with limited access to salivary components and fluoride. Usage of the fluoridated toothpaste reduced mineral loss from grooves in sou nd dentin by 15% compared with a non-fluoridated toothpaste (Lagerweij et al., 1997). In the current study, preformed dentinal lesions were subjected to similar toothpaste treatments. To improve the power of th e model in discriminating between toothpaste groups, we changed the de sign from monadic to crossover to reduce the influence of variation be tween the participants. Two sets of specimens were placed in the parti al prostheses of 29 participants who used a toothpaste containing eith er 1000 ppm fluoride or no fluoride during two consecutive six-week pe riods. Changes in mineral content were analyzed by transverse microrad iography. The average mineral loss after the nonfluoride period was 17 85 vol% x mu m (SD 2399), and 1335 vol% x mu m (SD 2039) after the flu oride period, a 25% inhibition in demineralization. Analysis of varian ce showed that the demineralization was significantly influenced not o nly by the type of treatment (p < 0.001 level), but also by the partic ipant (p < 0.001), the width of the groove (p < 0.001), and the depth into the groove where changes in mineral content were measured (p < 0. 017). Twenty-one percent of all the lesions showed remineralization. N o significant difference in the extent or the occurrence of reminerali zation was found between the treatments.