In situ effect of a sodium bicarbonate solution on enamel after simulation of endogenous dental erosion.

Uma das medidas recomendadas para o controle da progressão de lesões de erosão dental de origem intrínseca é o enxágüe bucal com solução de bicarbonato de sódio, visando à neutralização de ácidos gástricos presentes na boca. Contudo, a prescrição de tal solução faz-se em bases empíricas. Assim, este estudo avaliou, através de um modelo in situ, o efeito de uma solução de bicarbonato de sódio no controle da erosão dental causada por desafios ácidos endógenos. Este estudo caracterizou-se por um experimento do tipo cross-over 2x2, composto por duas fases experimentais de 5 dias cada. Após um período de lead-in de 2 dias, quatorze voluntários utilizaram dispositivos intrabucais contendo, em cada lado (direito e esquerdo), um fragmento de esmalte bovino polido, esterilizado e delimitado de modo a obter áreas hígidas de referência. Duas vezes ao dia, um dos espécimes foi exposto, ex-vivo, à solução de ácido clorídrico (0,01 M, pH = 2) por 2 min. Imediatamente após, os aparelhos foram reinseridos na boca e os voluntários realizaram enxágüe bucal com solução de bicarbonato de sódio ou água deionizada por 1 min. Após um período de wash-out de 2 dias, os voluntários iniciaram a segunda fase empregando a substância alternativa para o enxágüe bucal. Ao término das duas etapas, foram avaliadas a profundidade de desgaste através de perfilometria ótica e a microdureza Knoop. ANOVA e o teste de Tukey demonstraram que o desgaste do esmalte foi significativamente reduzido quando se empregou a solução de bicarbonato de sódio para o enxágüe bucal. Para a microdureza, ANOVA demonstrou apenas presença de diferença significativa em função da condição do substrato (p < 0,0001). Os espécimes erodidos apresentaram valores de microdureza significativamente menores do que o grupo não submetido ao desafio ácido. O enxágüe bucal com solução de bicarbonato de sódio controlou a erosão no esmalte submetido a simulações de episódios erosivos endógenos.One of the recommended measures to control dental erosion of intrinsic origin is the oral rinse with sodium bicarbonate solution, which has been suggested to neutralize the gastric acid regurgitated into the oral cavity. However, the efficacy of this prescription has not yet been proved. Therefore, the aim of this study was to evaluate in situ the effect of a sodium bicarbonate rinse in the control of dental erosion in enamel exposed to gastric acid-like solution. This study comprised two experimental legs. After a 2-day lead-in period, fourteen volunteers wore palatal devices containing two polished, sterilized enamel slabs. Throughout the experimental period of 5-d, one of the two specimens was exposed twice daily extra-orally to hydrochloric acid solution (0,01 M, pH=2) for 2 min. Immediately after, devices were reinserted in the mouth and volunteers rinsed their oral cavity with a sodium bicarbonate solution or deionized water for 60s. In the second leg of this study, after a 2-day washout period, appliances were refilled with a new set of enamel specimens and participants were crossed over to receive the alternate rinse. The wear depth accessed using optical profilometry and Knoop surface microhardness were evaluated. Analysis of Variance (ANOVA) and Tukey\'s test demonstrated that wear of enamel was significantly reduced when a sodium bicarbonate solution was used to rinse the oral cavity following erosive episodes. For microhardness, ANOVA demonstrated only significant differences in function of the enamel condition (p < 0,0001). The eroded specimens presented microhardness values significantly lower than the group not submitted to the acid challenge. Sodium bicarbonate rinse controlled erosion of enamel caused by gastric acid-like solution

Potential effect of sodium bicarbonate-containing dentifrice in controlling enamel erosion in situ

Purpose: To assess, by a crossover 2 x 2 in situ study, the speculated protective role of a sodium bicarbonate-containing toothpaste in controlling erosive lesions. Methods: Bovine enamel slabs were sterilized, and submitted to baseline Knoop microhardness measurements. After a 3-day lead-in period, 14 volunteers wore palatal acrylic appliances containing six enamel slabs (three on each side), for 4 consecutive days. On the first day, appliances with contained specimens were placed in the oral cavity to allow salivary pellicle formation. On the subsequent days, half of the enamel slabs were immersed extraorally in a lemonade-like soft drink for 90 seconds, twice daily. On both of these occasions, the appliance was dipped in toothpaste slurry of either a sodium bicarbonate-containing toothpaste or a regular counterpart for 60 seconds. Following a 3-day washout period, a new set of enamel slabs were mounted and the volunteers started the second period using the alternate dentifrice. Results: ANOVA (alpha = 0.05) showed no statistically significant difference between enamel treated with regular and sodium bicarbonate-based dentifrices, regardless of whether specimens were eroded or not (P=0.8430). Acid-challenged specimens revealed lower microhardness values than uneroded samples. (Am J Dent 2008;21:300-302).CAPESCNPqFAPESP[#2006104550-1

Control of erosive tooth wear: possibilities and rationale

Dental erosion is a type of wear caused by non bacterial acids or chelation. There is evidence of a significant increase in the prevalence of dental wear in the deciduous and permanent teeth as a consequence of the frequent intake of acidic foods and drinks, or due to gastric acid which may reach the oral cavity following reflux or vomiting episodes. The presence of acids is a prerequisite for dental erosion, but the erosive wear is complex and depends on the interaction of biological, chemical and behavioral factors. Even though erosion may be defined or described as an isolated process, in clinical situations other wear phenomena are expected to occur concomitantly, such as abrasive wear (which occurs, e.g, due to tooth brushing or mastication). In order to control dental loss due to erosive wear it is crucial to take into account its multifactorial nature, which predisposes some individuals to the condition