In Situ Investigation of the Remineralizing Effect of Saliva and Fluoride on Enamel Following Prophylaxis Using Sodium Bicarbonate

Abstract

Objectives:This in situ study evaluated the effect of saliva, associated or not with fluoride, on enamel previously submitted to prophylaxis using sodium bicarbonate.Methods:The study was conducted on enamel blocks submitted to in vitro prophylaxis using sodium bicarbonate. The blocks were randomly divided into 2 groups (G1/G2) and mounted on intraoral appliances wore by 10 volunteers. G1 blocks were directly exposed to saliva in situ, while blocks in G2 were exposed to saliva with fluoride (rinsing with 0.2% NaF solution during the initial minute). Enamel alterations were evaluated using surface microhardness and profilometry. Enamel hardness data were analyzed by ANOVA and Tukey tests and surface wear was evaluated using paired t test (P<.05).Results:No significant differences were found between G1 and G2 for enamel hardness and wear. The wear after prophylaxis was not different from the wear after the in situ stage. Baseline mean values of enamel hardness, after prophylaxis and after the in situ stage were 340±16.6, 329±35.7 and 354±37.8 for G1 and 338±15.6, 312±46.3 and 340±21.8 for G2, respectively.Conclusions:It was concluded that saliva alone exhibited a similar effect to saliva associated with fluoride; after 4h of in situ remineralization, there was no recovery in height of the enamel structure that had been lost due to the application of sodium bicarbonate.

Tooth enamel properties and morphology after microabrasion: an in situ study

“…Microabrasion with H 3 PO 4 + pumice or HCl + silica demonstrated a decrease in SMH values, with statistically‐significant differences when compared with the analysis performed before microabrasion, as previous mentioned . SMH analysis after different times of saliva exposure demonstrated the progressive action of saliva, as the exposed surface was less mineralized. There was a significant increase in the SMH value, which varied according to the amount of time in the presence of saliva and the microabrasion system used.…”

“…Moreover, the mechanical application recommended for the microabrasion technique can emphasize these effects . Enamel microhardness and roughness can be influenced by a combination of the abovementioned factors, as described in previous studies . However, most of these studies have not considered the protective capacity of the oral environment, due to the presence of saliva and its components.…”

“…The acid component used in the microabrasion system could be associated with a mineral loss of the enamel surface . In addition, the abrasive component could increase mineral loss, which is characterized by tooth wear . Moreover, the mechanical application recommended for the microabrasion technique can emphasize these effects .…”

“…The presence of fluoride in the oral environment is another factor that might cause remineralization of the enamel surface . In addition to the fluoride present in saliva, fluoride from toothpaste can prevent demineralization by forming a layer of calcium fluoride on the enamel surface . Most studies of enamel alterations due to microabrasion have an in vitro design, and have not considered the protective properties of the oral environment, mainly related to saliva .…”

“…Most studies of enamel alterations due to microabrasion have an in vitro design, and have not considered the protective properties of the oral environment, mainly related to saliva . Thus, an in situ model might simultaneously simulate intraoral events and standardize experimental conditions . Analysis of the enamel surface by evaluating microhardness is a very sensitive method for assessing the mineral content at a specific site where most of the mineral exchange is likely to occur in the demineralization or remineralization processes of enamel …”