Assessment of oxidative stress in saliva of children with dental erosion.

OBJECTIVE: To evaluate oxidative stress in saliva of children with dental erosion as compared to children with no erosion. METHODS: One single examiner, trained and prepared to make diagnosis of dental erosion according to the Basic Erosive Wear Examination index, selected 40 children aged 4 to 6 years, who attended a pediatric dentistry prevention clinic. Two groups were formed - one comprising children with dental erosion (n=22), and another with no dental erosion (n=18). The quantity of dental biofilm was verified using the Simplified Index of Oral Hygiene, and unstimulated saliva was collected for biochemical analyses. The following were assessed in saliva: flow rate, buffering capacity, pH, and total protein concentration. Malondialdehyde levels were also verified to determine oxidative stress and total antioxidant status. RESULTS: The quantity of biofilm was smaller in children with mean dental erosion±standard deviation (0.76±0.25), as compared to those with no dental erosion (1.18±0.28). There was no statistical difference in saliva parameters of oxidative stress in children with dental erosion. CONCLUSION: The activity of oxidative stress in saliva did not influence dental erosion process when in its early stages.

Assessment of oxidative stress in saliva of children with dental erosion / Avaliação do estresse oxidativo da saliva de crianças com erosão dentária

ABSTRACT Objective To evaluate oxidative stress in saliva of children with dental erosion as compared to children with no erosion. Methods One single examiner, trained and prepared to make diagnosis of dental erosion according to the Basic Erosive Wear Examination index, selected 40 children aged 4 to 6 years, who attended a pediatric dentistry prevention clinic. Two groups were formed - one comprising children with dental erosion (n=22), and another with no dental erosion (n=18). The quantity of dental biofilm was verified using the Simplified Index of Oral Hygiene, and unstimulated saliva was collected for biochemical analyses. The following were assessed in saliva: flow rate, buffering capacity, pH, and total protein concentration. Malondialdehyde levels were also verified to determine oxidative stress and total antioxidant status. Results The quantity of biofilm was smaller in children with mean dental erosion±standard deviation (0.76±0.25), as compared to those with no dental erosion (1.18±0.28). There was no statistical difference in saliva parameters of oxidative stress in children with dental erosion. Conclusion The activity of oxidative stress in saliva did not influence dental erosion process when in its early stages.

RESUMO Objetivo Avaliar o estresse oxidativo da saliva de crianças que possuíam erosão dentária, comparadas àquelas que não apresentavam esta situação. Métodos Um único examinador, treinado e calibrado para o diagnóstico de erosão dentária, segundo o índice de Basic Erosive Wear Examination, selecionou 40 crianças de 4 a 6 anos de idade que frequentavam uma clínica de prevenção de odontopediatria. Dois grupos foram formados - um com aquelas que apresentavam erosão (n=22) e outro sem erosão (n=18). A quantidade do biofilme dental foi obtida utilizando o Índice de Higiene Oral Simplificado, tendo sido feita a coleta de saliva não estimulada para as análises bioquímicas. O fluxo salivar, a capacidade tampão da saliva, o pH salivar e a proteína total da saliva foram avaliados. Também foi verificado o valor do malondialdeído para determinação do estresse oxidativo e o total antioxidante. Resultados A quantidade de biofilme foi menor nas crianças, com erosão dentária média±desvio padrão (0,76±0,25) comparadas àquelas sem erosão dentária (1,18±0,28). Não houve diferença estatística nos parâmetros salivares de estresse oxidativo em crianças com erosão dentária. Conclusão A ação do estresse oxidativo na saliva não influenciou na erosão dentária, quando ainda nos estágios iniciais.

Dental erosive wear assessment among adolescents and adults utilizing the basic erosive wear examination (BEWE) scoring system.

OBJECTIVES: To investigate erosive tooth wear and related variables among adolescents and adults in Israel, utilizing the new basic erosive wear examination (BEWE) scoring system, in an attempt to contribute to the ongoing review, evaluation, and further development of an international standardized index. MATERIAL AND METHODS: A cross-sectional, descriptive, and analytic survey was conducted among 500 subjects of five age groups. Dental erosion was measured according to the new BEWE scoring system. Independent variables included gender, age, origin, education, employment status, and diet. A backward stepwise linear regression model was applied to identify significantly associated variables. RESULTS: Fifty percent of the survey subjects demonstrated erosive tooth wear; among them, 10 % had distinct erosion of over 50 % of the dental surface. Total BEWE score differences by age groups were statistically significant; as the age increased, the mean total BEWE scores increased (p < 0.001). The association between acidic foods and erosion was evident among the younger population (p = 0.038). In a multiple regression model, age (p < 0.001) and diet (p = 0.044) achieved statistical significance as variables associated with dental erosive wear. CONCLUSIONS: Our study is one of the first to use the BEWE scoring system in an epidemiological survey among adolescents and adults. It was found that the BEWE index is straightforward, easy to conduct, and comfortably accepted by the examinees. CLINICAL RELEVANCE: The present findings, together with further international research, should contribute toward continued evaluation of the BEWE system as an international standard and thereby, toward more optimal understanding, evidence-based treatment, and prevention of dental erosive wear.

Effects of enamel abrasion, salivary pellicle, and measurement angle on the optical assessment of dental erosion.

The present study assessed the effects of abrasion, salivary proteins, and measurement angle on the quantification of early dental erosion by the analysis of reflection intensities from enamel. Enamel from 184 caries-free human molars was used for in vitro erosion in citric acid (pH 3.6). Abrasion of the eroded enamel resulted in a 6% to 14% increase in the specular reflection intensity compared to only eroded enamel, and the reflection increase depended on the erosion degree. Nevertheless, monitoring of early erosion by reflection analysis was possible even in the abraded eroded teeth. The presence of the salivary pellicle induced up to 22% higher reflection intensities due to the smoothing of the eroded enamel by the adhered proteins. However, this measurement artifact could be significantly minimized (p<0.05) by removing the pellicle layer with 3% NaOCl solution. Change of the measurement angles from 45 to 60 deg did not improve the sensitivity of the analysis at late erosion stages. The applicability of the method for monitoring the remineralization of eroded enamel remained unclear in a demineralization/remineralization cycling model of early dental erosion in vitro.

An in vitro assessment of the effect of load and pH on wear between opposing enamel and dentine surfaces.

OBJECTIVE: Previous in vitro studies have described the wear characteristics of specimens in which enamel has been opposed to enamel and dentine opposed to dentine. The aim of this study was to assess the characteristics of wear between specimens in which enamel was opposed to dentine at loads simulating attrition and at pH values simulating different erosive environments. It was hypothesized that enamel would wear more slowly than dentine under all conditions. DESIGN: Opposing enamel and dentine specimens from 57 human third molar teeth were worn in electromechanical machines with various loads (32, 62 and 100 N) and lubricants (pH 1.2, 3.0 and 6.1). Tooth wear was quantified by measuring reduction in dentine volume over time using a 3D profilometer. Qualitative assessment was also carried out using scanning electron microscopy. RESULTS: Dentine wear increased with increasing load, and dentine wear was faster at pH 1.2 than at pH 3.0 or 6.1 for all loads tested. Interestingly, enamel wore more rapidly than dentine at pH 1.2 under all loads. At pH values of 3.0 and 6.1, enamel wear rates were not measurably different from zero and they were less than wear rates for opposing dentine specimens at all loads. Micrographic assessment showed extensive surface destruction of dentine wear facets due to erosion at pH 1.2. Dentine wear facets were smoother at pH 3.0 that at pH 6.1. CONCLUSIONS: When enamel wears against dentine in an acidic environment enamel will wear more rapidly at very low pH, while under less acid conditions dentine will wear faster than enamel.

An assessment of stress analyses in the theory of abfraction.

Wedged-shaped lesions at the cemento-enamel junction of teeth have been attributed primarily to biomechanical loading forces that cause flexure and failure of enamel and dentin. This theory, termed abfraction, remains controversial. This review examined studies on mechanical properties of enamel and dentin and studies on bite forces and mastication as background information. Abfraction is based principally on a few early finite element analysis and photoelastic models showing stress concentration at the dental cervical area without actually showing enamel and dentin fracture. However, a review of more recent dental stress analyses has been contradictory. Particularly, analyses of the periodontal ligament and alveolar bone, not modeled in previous studies, have shown that those structures may dissipate occlusal loading forces from the cervical areas. In addition, some models may not fully represent intricate dental anatomy and complex occlusal function. Therefore, the key basis of the abfraction theory may be flawed.

Assessment of enamel erosion and protective effect of salivary pellicle by surface roughness analysis and scanning electron microscopy.

PURPOSE: To assess dental erosion caused by 0.1% and 1.0% citric acid in vitro and to estimate the protective influence of experimentally formed salivary pellicle. MATERIALS AND METHODS: Bovine enamel slabs (n = 80) were polished and embedded in epoxy resin. For the formation of pellicle layer 40 specimens were immersed for 24 h in pooled human saliva. Erosion was caused by immersion in citric acid solution for 1, 5, 10 and 30 min. Erosive alterations on the pellicle-covered and non-covered enamel specimens were scored as a change (delta) of surface roughness parameters Ra, Rt and RzDIN using contact profilometer and observed in scanning electron microscope. RESULTS: Profilometric analysis of eroded enamel specimens emphasized the aggressiveness of even low concentrated citric acid with a short period of challenge. The change of roughness parameters after 1-min immersion in 0.1% citric acid were 16.4, 182.6 and 132.2 nm for deltaRa, deltaRt and deltaRzDIN, respectively, and 54.8, 516.6 and 258.2 nm after 1-min immersion in 1.0% citric acid. Changes of the surface roughness were dependent on the exposure time and concentration of acidic solution. Pellicle layer significantly reduced the extent of erosive destruction, which was additionally documented on SEM-micrographs. Residual pellicle-like structures were detected after 5 min of immersion in 0.1% citric acid. However, there were no significant differences in pellicle-covered and non-covered enamel slabs measured profilometrically for 1.0% citric acid with 10 min and 30 min exposure time. CONCLUSION: The findings confirm the property of pellicle layer to resist against erosive influence of organic acids, which is, however, limited by duration of acidic treatment and concentration of erosive agent.