Influence of Human Saliva on the Development of Artificial Erosions

Abstract

It was hypothesized that saliva from patients with erosion exhibits lower protective efficacy compared to saliva from patients without erosion, based on in vitro enamel softening studies. A total of 645 enamel specimens were distributed among seven experimental groups. Saliva was gathered from each of 10 volunteers without clinical signs of dental erosion and from 10 patients exhibiting severe erosive defects. Aliquots of 50 ml of saliva from each patient were mixed with sour drops or citric acid, respectively. Pooled saliva, sour drops and citric acid mixed with water served as controls. The enamel specimens were soaked in the respective mixture for 5 min and were subsequently incubated in pure saliva for 2 min. This cycle was repeated three times, then the specimens were kept in 100 ml of saliva for 8 h. Surface microhardness was evaluated at the beginning of the experiment and after each cycle. During the experiments, microhardness decreased significantly in all groups except for the pure saliva group. For sour drops and citric acid mixed with saliva from patients without erosion, the final microhardness was higher compared to the mixture of the two erosive compounds with saliva from patients with erosion. The storage of saliva for 8 h resulted in a certain amount of rehardening, with the highest level of rehardening being observed in the group that was least demineralized (sour drops plus saliva from patients without erosion). It is concluded that salivary components play a crucial role in the development of dental erosion.

Influence of Intrinsic Factors on Erosive Tooth Wear in a Large-Scale Epidemiological Study

“…Since it seems that especially the components of saliva play a crucial role in the development of dental erosion [Hellwig et al, 2013], it has been suggested that changes in the saliva in late pregnancy and during lactation may temporarily predispose women to dental erosion [Laine, 2002]. In addition to possible changes in salivary parameters, there is an increased risk for vomiting and GERD, so we hypothesized that multiple pregnancies could increase the risk for erosive tooth wear.…”

“…In addition, most prevalence studies include only a small number of cases, and the criteria for both erosive tooth wear and associated conditions differ remarkably, making it difficult to draw conclusions [Schlueter and Tveit, 2014]. Furthermore, there seem to be individual differences in susceptibility to erosive wear, probably mainly due to saliva secretion and its associated properties [Moazzez et al, 2004;Hellwig et al, 2013;Hara and Zero, 2014].…”

Do pediatric medicines induce topographic changes in dental enamel?

“…Salivary buffering and changes in oral pH are complex, 19,20,21 and many concomitant factors can influence the potential of substances to promote changes in tooth topography, such as endogenous pH lower than 5.5, flow and salivary buffering, and higher titratable acidity. 3,6,8,11,19,21 Nevertheless, the evaluation of these factors alone cannot determine whether a drug does have such potential.…”

Effects of brushing timing after erosive challenge on enamel loss <i>in situ</i>: White light interferometer and nanoindentation study

“…Differences between methodological approaches for evaluating the surface hardness changes of eroded enamel after human saliva exposure may result in different findings; for instance a microhardness test in a previous study was performed with a load of 50 g 6) while the nanoindentation test in the current study used a force of 10 mN (approximately 1 g). Apart from methodological differences among studies, the contrast in findings may also be related to the dynamic nature of remineralization and difference in remineralization ability and composition of saliva among different subjects 34) . Nevertheless, the positive effects of the initial intraoral exposure on nanoindentation hardness are significant and remarkable.…”