In vitro effect of toothpaste with low fluoride combined with sodium trimetaphosphate on dentine erosion.

PURPOSE: This study sought to evaluate in vitro the effect of a dentifrice containing sodium trimetaphosphate (TMP) combined or not with low fluoride (500 ppm NaF) on dentine erosion of intrinsic origin. METHODS: Human root dentine blocks were selected based on surface microhardness and randomly allocated into five groups (n = 12): negative control (0 ppm F; no TMP); F500 (500 ppm NaF); F1500 (1500 ppm NaF-positive control); TMP (1% TMP); and F + TMP (500 ppm NaF + 1% TMP). The blocks were submitted to erosion cycles (3 ×/day) for 3 days (0.01 M HCl, pH 1.5-30 s), treatment (1 min-1:3 p/p dentifrice/distilled water) and remineralization (artificial saliva/120 min). Dentine alterations were determined according to the percentage of microhardness loss (%HL), surface loss (SL) and surface analysis by scanning electron microscopy. The data were analyzed using one-way ANOVA (p < 0.05). RESULTS: The values of SL and %HL in each group were, respectively: negative control (1.36 ± 0.36; 57.29 ± 14.14), F500 (1.46 ± 0.28; 65.66 ± 5.11), F1500 (1.52 ± 0.36; 61.66 ± 5.15), TMP (1.45 ± 0.45; 62.08 ± 3.83) and F + TMP (1.38 ± 0.42; 63.38 ± 6.47). There was no statistically significant difference in all the parameters (p = 0.873 and p = 0.152). CONCLUSION: The dentifrices containing TMP combined or not with fluoride were not able to prevent dentine erosion.

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.

Photodynamic antimicrobial chemotherapy and ultraconservative caries removal linked for management of deep caries lesions.

BACKGROUND: Ultraconservative removal of carious tissue is becoming increasingly highlighted for management of deep caries lesions, and combined with an antimicrobial photochemistry-based treatment modality (PACT), this approach can be enhanced favoring dental tissue repair and preservation. The aim was to investigate the effectiveness of PACT using a light emitting diode (LED) associated with a photosensitizer toluidine blue ortho (TBO) on deep caries lesions. METHODS: For that, a single blind, randomized, controlled, split-mouth clinical trial where 45 patients with at least two deep carious lesions on permanent posterior teeth was performed. The primary intervention was deep caries lesion management with disinfection of remaining dentin tissue using PACT. Bacterial counts were measured following treatments as the main outcome. The remaining dentinal samples of each lesion were treated with either non-PACT-control or PACT. The PACT procedure were characterized by 100 µg mL(-1) TBO followed by 94J cm(-2) LED irradiation. Samples of dentin were collected before and immediately after treatments for microbiological analysis of total viable bacteria, mutans streptococci and Lactobacillus spp. counts. Microbial reduction was data were submitted to unpaired t test (α=5%). RESULTS: PACT led to statistically significant reductions in mutans streptococci (1.08 ± 1.20 log), Lactobacillus spp. (1.69 ± 1.37 log), and total viable bacteria (1.07 ± 1.01 log) compared to the control, which showed log reductions respectively of 0.05 ± 0.49, 0.52 ± 0.89, and 0.47 ± 0.77 for the same microorganisms. CONCLUSION: Dentin from deep carious lesions treated with PACT showed a decrease in cariogenic microbial load.