In vitro effect of children's toothpaste on brushing abrasion of eroded primary enamel.

PURPOSE: Emerging data have suggested that acid erosion has become an increasing clinical problem in pediatric dentistry. This study aimed to investigate the abrasive effects of two commercial toothpastes on primary enamel eroded by orange juice using an in vitro model. METHODS: Thirty enamel slabs were obtained from primary teeth and then randomly assigned to three groups (n = 8) comprising two different toothpastes: G1-control-distilled water; G2-Dentifrice A (containing no fluoride); and G3-Dentifrice B (1.100 ppmF-NaF). Each slab had one half protected to provide a control side, and the other one was subjected to treatments. The slabs were submitted to daily erosive challenges (3×/day, 2 min) in concentrated orange juice (pH 3.38) associated with abrasive challenges using a tooth-brushing machine (150 brush movements for each cycle). During the experimental period, the slabs were kept in 37 °C artificial saliva, and the experiment was carried out for 5 days. The depths of the resulting eroded areas were measured by stylus profilometry. The data were analyzed using ANOVA and the Tukey-Kramer test (α = 5%). RESULTS: Tooth loss (µm, mean ± SD) was 2.46 ± 1.18 for G1, 3.32 ± 2.12 for G2 and 2.14 ± 1.03 for G3. Therefore, the NaF dentifrice (Dentifrice B) produced significantly less mineral loss (p = 0.04) than dentifrice A. CONCLUSIONS: The findings suggest that fluoride toothpaste could protect primary enamel against erosion.

Glutamine and alanyl-glutamine accelerate the recovery from 5-fluorouracil-induced experimental oral mucositis in hamster.

INTRODUCTION: Mucositis induced by anti-neoplastic drugs is an important, dose-limiting and costly side effect of cancer therapy. AIM: To evaluate the effect of oral glutamine and alanyl-glutamine, a more stable glutamine derivative, on 5-FU-induced oral mucositis in hamsters. MATERIALS AND METHODS: Oral mucositis was induced by two intraperitoneal (i.p) administrations of 5-FU on the first and second days of the experiment (60 and 40 mg/kg, respectively) followed by mechanical trauma on the fourth day in male hamsters. Animals received saline, glutamine or alanyl-glutamine suspension (100 mM) 1 h before the injections of 5-FU and daily until sacrifice, on the 10th or 14th day. Macroscopic and histopathological analyses were evaluated and graded. Tissues from the cheek pouches were harvested for measurement of myeloperoxidase activity and glutathione stores. For investigation of serum concentration of glutamine, blood was obtained by heart puncture from anesthetized animals before sacrifice, on day 10. RESULTS: Treatment with glutamine and alanyl-glutamine reduced macroscopic and histological parameters of oral mucositis, and reduced the myeloperoxidase activity on day 14, but not on day 10. The 5-FU-induced oral mucositis significantly decreased the serum glutamine levels as well as the cheek pouch glutathione stores observed on day 10. Glutamine or alanyl-glutamine administration reversed the 5-FU effects, restoring serum glutamine levels and cheek pouch glutathione stores, observed on day 10, but did not prevent oral mucositis on the tenth day. CONCLUSION: Glutamine or alanyl-glutamine accelerated the mucosal recovery increasing mucosal tissue glutathione stores, reducing inflammatory parameters and speeding reepithelization.