Effectiveness of a Toothpaste with Low Fluoride Content Combined with Trimetaphosphate on Dental Biofilm and Enamel Demineralization in situ.

OBJECTIVE: The aim of the present study was to evaluate in situ whether a toothpaste with low fluoride associated with sodium trimetaphosphate (TMP) would provide similar effect to that of a 1,100 ppm F toothpaste. DESIGN: This crossover double-blind study consisted of 4 phases (14 days each), during which 10 volunteers wore oral appliances containing 4 enamel bovine blocks. The cariogenic challenge was performed by the application of a 20% sucrose solution (6×/day). The toothpaste treatments (2×/day) were: placebo, 500 ppm F, 500 ppm F plus 1% TMP, and 1,100 ppm F. At the end, enamel mineral loss and biofilm composition were analyzed. RESULTS: The toothpaste with 500 ppm F plus 1% TMP showed the lowest mineral loss (p < 0.05). Regarding the fluoride and calcium concentrations in the enamel and in the biofilm, there were no significant differences between 500 ppm F plus 1% TMP, and 1,100 ppm F toothpastes (p > 0.569), but they were significantly different when compared to toothpaste with 500 ppm F (p < 0.050). CONCLUSION: The addition of 1% TMP to a low-fluoride toothpaste reduces enamel demineralization in situ similar to a 1,100 ppm F toothpaste.

The effect of chronic treatment with fluoride on salivary activity, tooth, and bone in spontaneously hypertensive rats (SHR).

The present study evaluated the effect of chronic treatment with sodium fluoride on salivary activity, tooth, and bone in spontaneously hypertensive rats (SHR). The treatment was made with a 20-ppm NaF solution added to the drinking water for 30 days. Systolic blood pressure values were obtained by plethysmography; fluoride concentration was determined by an ion-selective electrode; calcium concentration and amylase activity were determined by commercial kits; and enamel microhardness was verified by longitudinal section. Systolic blood pressure values and animals' weight were not changed by treatment. However, the salivary flow rate-which was lowered in SHR at baseline when compared to Wistar rats-was found to be increased with the treatment with NaF. The fluoride concentration was increased in the plasma of the treated groups, even though it remained lower for the treated SHR in relation to the treated Wistar rats. Calcium concentration was decreased in the saliva and plasma of SHR treated with NaF. A reduction in the plasmatic total protein concentration was observed in SHR treated with NaF. The fluoride concentration on bone surface was found to be increased in Wistar or SHR treated with NaF. In treated SHR's femurs, it was observed a significant reduction in fluoride concentrations. Enamel microhardness of the incisor teeth was not changed by the treatment with NaF in both groups. The distribution of fluoride to the salivary glands in SHR is poor, and treatment with NaF causes a decrease in the concentration of important biochemical parameters to the salivary physiology in SHR.

In situ evaluation of a low fluoride concentration gel with sodium trimetaphosphate in enamel remineralization.

PURPOSE: To evaluate the capability of gels with low fluoride (F) concentration and supplemented with sodium trimetaphosphate (TMP) to promote in situ enamel remineralization. METHODS: Bovine enamel blocks were selected on the basis of their surface hardness after demineralization, and divided into five groups: gel without F or TMP (placebo); gel with 4,500 ppm F (4,500); gel with 4,500 ppm F + 5% TMP (4,500 5% TMP); gel with 9,000 ppm F (9,000) and gel with 12,300 ppm F (12,300). The study design was blind and cross-over: 12 subjects used palatal devices with four demineralized enamel blocks for 3 days, after topical fluoride application (TFA). Two blocks were removed immediately for analysis of the loosely bound fluoride (CaF2) and firmly bound fluoride (F) after TFA in enamel. In the remaining blocks, the percentage of surface hardness recovery (% SH), cross-sectional hardness (deltaKHN) and CaF2 and F were determined after remineralization. The results were subjected to ANOVA and Bonferroni tests (P < 0.05). RESULTS: The groups 4,500 5% TMP, 9,000, and 12,300 showed the best results with regard to % SH (P < 0.05). Lower deltaKHN values were observed in the 4,500 5% TMP and 12,300 gel groups (P < 0.05). Higher concentrations of CaF2 and F were observed in the 12,300 group, followed by the 4,500 5% TMP and 9,000 groups (P > 0.05). It was concluded that it is possible to promote enamel remineralization using gels with low fluoride concentration supplemented with TMP.

Spontaneously hypertensive rat as experimental model of salivary hypofunction.

OBJECTIVE: To analyse the salivary activity in spontaneously hypertensive rats (SHRs) evaluating biochemical parameters of saliva in 4-week-old and 12-week-old animals. DESIGN: Systolic blood pressure (SBP) was recorded by tail plethysmography. The salivary flow rate was stimulated by pilocarpine (SFR). The pH and salivary buffering capacity (SBC) were evaluated with a specific electrode. The concentrations of fluoride ([F(-)]) and calcium ([Ca(++)]) ions were determined using an electrode connected to a calibrated ion analyser. The total protein concentration was determined by Lowry method, and amylase activity by kinetic method. The salivary IgA was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: The SFR, [F(-)] and [Ca(++)] increased with age in normotensive rats, however no alteration in pH, total protein and IgA was observed between 4 and 12 weeks old Wistar rats. SBC decreased with age in Wistar rats. The SFR was not altered between SHRs in different ages and it was lower in 12 weeks old SHR when compared to Wistar rats. An increase in the protein concentration, and in the amylase activity and [F(-)] was observed with the development of SHR. Unaltered SBC, salivary IgA and [Ca(++)] were observed in 12 weeks old when compared to 4 weeks old SHR. The [Ca(++)] ions were reduced in saliva of SHR than that of Wistar rats at 12 weeks. A lower pH was observed in saliva of Wistar than that of SHR at 12 weeks. CONCLUSIONS: SHR is an experimental model of salivary hypofunction, the decreased SFR observed in SHR at different ages was associated to salivary biochemical parameter alterations.

Atenolol reduces salivary activity in pups of spontaneously hypertensive and normotensive rats treated during pregnancy and lactation.

The salivary activity in pups of spontaneously hypertensive rats (SHR) and Wistar (W) rats treated with atenolol during pregnancy, and lactation was evaluated. Atenolol's anti-hypertensive effect on the SHR rats was noticed from the beginning of treatment. Atenolol-treated SHR and Wistar rat pups showed a decrease in salivary gland weight, salivary flow, and protein concentration, with no alteration in salivary amylase activity. Atenolol's effect on salivary glands can interfere with oral health maintenance.