Avaliação da alteração estrutural do esmalte dentário promovida por erosão/abrasão

Abstract

Dental wear is the non-carious loss of dental hard tissue, characterized by a multifactorial etiology with the main factor the interaction between erosion caused by acids from diet or endogenous and abrasives forces intra-oral. This dissertation consisting of two articles, which aim, respectively: (1) to critically review the available literature about the techniques of analysis of micromorphological changes in structure dental subject to erosion and/or abrasion, (2) to evaluate the effect of NaF and MFP in dentifrices available in market in the prevention of demineralization of tooth structure by erosive or erosive and abrasive process. In study 1, the scientific literature to the issue was searched using base of data nationals and internationals and manual tracing of references cited in scientific papers. In study 2, a in situ study, randomized, double-blind, crossover, slipt-mouth was conducted in three phases of 5 days each, with the participation of 15 volunteers who used palatal devices, containing 4 blocks of human tooth enamel treated with different dentifrices: control (11,2 ppm F, silica), MFP (1450 ppm F, silica) and NaF (1450 ppm F, silica). The slabs were subjected to erosion by immersion in a cola drink (Coca-Cola®) for 60 s, 4 times a day, at predetermined times. Then, the volunteers brushed their teeth, for 25 seconds and, with the device in the mouth, swished the dentifrice/saliva slurry for 60 seconds, after on side of appliance (2 blocks) was brushed with a small portion of the dentifrice by 40 brushing strokes. The enamel changes were evaluated for microhardness test and scanning electron microscopy. Data scores were submitted to ANOVA (p < 0,05). The critical review presented in study 1 showed which the literature presents different methods for analysis of dental wear, ranging from techniques well-established to techniques of recent use, therefore their expertise is needed for the development of future studies. The results of study 2 demonstrated that there was no differences in remineralization effect of fluoride dentifrices in the condition of erosion and erosion plus abrasion in relation of control group (p > 0,05). However, the harness data concerning to condition (erosion or erosion + abrasion) showed different statistically (p < 0.0001). The results of these studies indicate the knowledge about techniques of analysis of dental wear is essential for its determination. Moreover, it is imperative the realization of more studies to evaluate the fluoride effect in form of NaF or MFP, present in dentifrices available in the market using complementary techniques that allow the measurement of wear.