Envejecimiento dental prematuro en deportistas / Premature dental aging in athletes

El desgaste natural de los dientes ocurre dependiendo de factores como: calidad de la estructura dental, calidad de la saliva, biotipo facial que determina la fuerza de mordida; de acuerdo a estos factores locales bucales se va envejeciendo la dentadura. Pero los deportistas presentan un patrón de desgaste mayor y continuo debido al tipo de deporte que practican, las horas de entrenamiento, el consumo de bebidas con pH ácido, el cepillado dental vigoroso; todos estos factores pueden conducirlos a que desarrollen lesiones no cariosas (AU)

The natural wear of the teeth occurs depending on factors such as: quality of the dental structure, quality of the saliva, facial biotype that determines the bite force, according to these local oral factors, the teeth age. But in athletes they present a pattern of greater and continuous wear due to the type of sport they practice, the hours of training, the consumption of drinks with an acidic pH, vigorous tooth brushing; all these factors can lead them to develop non-carious lesions (AU)

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.

Stress and its role in the dentin hypersensitivity in rats.

INTRODUCTION: The perception of pain varies individually. Chronic stress leads to analgesia. The use of animal chronic mild stress model to mimic human condition was previously developed and now applied in the evaluation of pain perception in rats with dentin hypersensitivity (DH). AIMS: Using DH model induced by dentin erosion (DE) mediated by acidic solution, the present study aimed the evaluation of the interaction of chronic stress and pain induced by DH in rats with DE. METHODS: DH was induced by ad libitum 30-day intake of acidic solution. Stress was induced by the New York subway model. Body weight was weekly taken, during treatment. Groups WO (water, no stress), WS (water and stress), EO (acidic solution, no stress) and ES (acidic solution, stress) were submitted to treatments. RESULTS: After 30 days, all groups were submitted to DH test assessed by cold water stimuli in the labial surface of molars, for 5s, and the rats responses were scored as grades 0, 0.5, 1, 2, or 3. After euthanasia, blood was taken to obtain the levels of corticosterone, stomachs were observed in fresh preparations, kidneys and livers were submitted to histological evaluation. Open field model supported stress evaluation, as did corticosterone analysis. Stressed animals showed significant increase in pain perception and a decrease in locomotion frequency, tending to be more frequent in the periphery of the arena, corroborating stressed behavior and the need of protection as a pain relief. Corticosterone levels were increased in the stressed rats with dentin erosion and also corroborate present findings. Finally, reduction in weight gain was impaired in stressed group with dentin erosion. CONCLUSION: The animal model enabled the evaluation of how chronic mild stress interfered in DH pain perception.

The role of matrix metalloproteinases in dental erosion.

This review discusses the role of matrix metalloproteinases (MMPs) in the development of dentin erosion and the protective effects of MMP inhibitors, based on recent evidence from in vitro and in situ studies. MMPs are present in both dentin and saliva and play an important role in dentin erosion progression. Enzymatic removal of the organic matrix by MMPs increases the demineralization process, since the demineralized organic matrix has been shown to hamper ionic diffusion after an acidic challenge. Recent evidence from in vitro and in situ studies has shown a protective role of MMP inhibitors against dentin erosion and erosion plus abrasion. The inhibitors tested were green tea and its active epigallocatechin-gallate (EGCG), ferrous sulfate, and chlorhexidine. They have been tested in dentifrices, solutions, and gels. The latter led to a more pronounced protective effect against dentin erosion and erosion plus abrasion. The protection was long-lasting and could be observed after up to 10 days of severe erosive and erosive-plus-abrasive challenges in situ. Thus, the use of MMP inhibitors has emerged as an important preventive tool against dentin erosion. Clinical studies should be conducted to confirm the results obtained and to give support to the establishment of clinical protocols of use.

In vitro evaluation of the erosive potential of orange juice modified by food additives in enamel and dentine.

OBJECTIVES: To evaluate the erosive potential of orange juice modified by food additives in enamel and dentine. METHODS: Calcium lactate pentahydrate (CLP), xanthan gum (XG), sodium linear polyphosphate (LPP), sodium pyrophosphate tetrabasic (PP), sodium tripolyphosphate (STP) and some of their combinations were added to an orange juice. Pure orange juice and a calcium-modified juice were used as negative (C-) and positive (C+) controls, respectively. In phase 1, 15 modified orange juices were tested for erosive potential using pH-stat analysis. In phase 2, the additives alone and the combination with good results in phase 1 and in previous studies (CLP+LPP) were tested in an erosion-remineralization cycling model. In phase 3, the erosion and remineralization episodes were studied independently. Enamel was analysed by surface microhardness (SMH) and profilometry, whilst dentine by profilometry. RESULTS: In phase 1, reduction of the erosive potential was observed for all additives and their combinations, except XG alone. In phase 2, no detectable enamel loss was observed when CLP, LPP and CLP+LPP were added to the juice. XG, STP and PP had enamel loss similar to C- (p>0.05). Amongst additives, the combination CLP+LPP showed the highest SMH values followed by CLP (p<0.05). All the other groups presented SMH values similar to C- (p>0.05). For dentine, only CLP+LPP lead to surface loss values lower than C- (p<0.05). In phase 3, CLP, LPP and CLP+LPP seemed to protect against erosion; whilst none of the tested compounds seemed to interfere with the remineralization process. CONCLUSIONS: CLP and LPP reduced erosion on enamel and this effect was enhanced by their combination. For dentine, only the combination CLP+LPP reduced erosion.

In vitro alterations in dental enamel exposed to acidic medicines.

OBJECTIVE: To evaluate the effect of acidic medicines (Klaricid(®), Claritin(®), and Dimetapp(®)) on surface enamel in vitro. METHODS: Enamel blocks (n=104) were randomly distributed into two groups: G1 (pH-cycling simulating physiological oral conditions) and G2 (erosive conditions). Each group was divided into four subgroups, three to be immersed in the medicines and the control in deionized water. Specimen surfaces were evaluated for roughness and hardness at baseline and again after the in vitro experimental phase, which included 30 min immersions in the medicines twice daily for 12 days. Scanning electron microscopy (SEM) was also performed after the in vitro experimental phase. RESULTS: All medicines produced a significant reduction in hardness in G1 after 12 days (P<0.05). The three medicines promoted greater roughness after both pH-regimens - G1 and G2 (P<0.01), except for Claritin in G1. Scanning electron microscopy analysis showed erosive patterns in all subgroups. Dimetapp(®) showed the most erosion and Klaricid(®) the least, in both groups. CONCLUSION: Dimetapp(®) (lowest pH and viscosity) and deionized water (control) showed the most pronounced erosive patterns. Klaricid(®) (highest pH and viscosity) presented an in vitro protective effect against acid attacks perhaps due to its mineral content and viscosity.

Viability of using enamel and dentin from bovine origin as a substitute for human counterparts in an intraoral erosion model.

This study ascertained whether under dental erosion models that closely mimics the real-life situation enamel and root dentin from bovine origin would be reliable substitutes for human counterparts. Through a 2x2 crossover design, in a first trial, 14 volunteers wore a palatal device containing slabs of bovine and human enamel. Half of the participants ingested (4x daily, for 10 days) orange juice first, crossing over to mineral water, while the remainder received the reverse sequence. In a second trial, volunteers wore devices with slabs of bovine and human root dentin. Except for the duration of each intraoral phase, which lasted 2 rather 10 days, the experiment with root dentin run exactly as for enamel. Dental substrates were analyzed for surface microhardness. Two-way ANOVAs (α=0.05) indicated no difference between the microhardness values recorded for human and bovine enamel (p=0.1350), but bovine root dentin had lower microhardness compared to its human counterpart (p=0.0432). While bovine enamel can reliably substitute its human counterpart in in situ dental erosion models, bovine root dentin does not seem to be a viable alternative to the corresponding human tissue.

Viability of using enamel and dentin from bovine origin as a substitute for human counterparts in an intraoral erosion model

This study ascertained whether under dental erosion models that closely mimics the real-life situation enamel and root dentin from bovine origin would be reliable substitutes for human counterparts. Through a 2x2 crossover design, in a first trial, 14 volunteers wore a palatal device containing slabs of bovine and human enamel. Half of the participants ingested (4x daily, for 10 days) orange juice first, crossing over to mineral water, while the remainder received the reverse sequence. In a second trial, volunteers wore devices with slabs of bovine and human root dentin. Except for the duration of each intraoral phase, which lasted 2 rather 10 days, the experiment with root dentin run exactly as for enamel. Dental substrates were analyzed for surface microhardness. Two-way ANOVAs (α=0.05) indicated no difference between the microhardness values recorded for human and bovine enamel (p=0.1350), but bovine root dentin had lower microhardness compared to its human counterpart (p=0.0432). While bovine enamel can reliably substitute its human counterpart in in situ dental erosion models, bovine root dentin does not seem to be a viable alternative to the corresponding human tissue.

Este estudo visou avaliar, sob um modelo de erosão dental que se aproxima da realidade clínica, se o esmalte e a dentina radicular bovinos seriam substitutos viáveis aos correspondentes substratos de origem humana. De acordo com um delineamento crossover 2x2, 14 voluntários utilizaram dispositivos palatinos contendo fragmentos de esmalte humano e bovino. Metade dos participantes ingeriu suco de laranja (4x/dia, por 10 dias) e, a seguir, alternou para a ingestão de água mineral, enquanto os demais voluntários receberam a seqüência reversa. Em um segundo experimento, os sujeitos da pesquisa fizeram uso do dispositivo palatino contendo fragmentos de dentina radicular bovina e humana. Exceto pela duração de cada uma das duas fases experimentais (2 ao invés de 10 dias), utilizou-se o mesmo protocolo empregado no estudo em que se comparou o esmalte. Os substratos dentais foram avaliados quanto a sua microdureza superficial. ANOVAs a dois critérios (α=0,05) não indicaram diferença entre os valores de microdureza observados para o esmalte humano e bovino (p=0,1350), porém a dentina radicular apresentou microdureza inferior à humana (p=0,0432). Enquanto o esmalte bovino é um substituto fidedigno do substrato humano em modelos in situ de erosão dental, a dentina radicular bovina não parece ser uma alternativa viável ao tecido humano correspondente.

Effect of erosive pH cycling on different restorative materials and on enamel restored with these materials.

This in vitro study evaluated the effect of erosive pH cycling on the percentage of surface micro-hardness change (%SMHC) and wear of different restorative materials and bovine enamel restored with these materials. Eighty enamel specimens were randomly divided into eight groups according to the restorative materials and immersion media used: GI/GV-resin-modified glass-ionomer, GII/GVI-conventional glass-ionomer, GIII/GVII-resin composite and GIV/GVIII-amalgam. Over a period of seven days, groups GI to GIV were immersed in a cola drink (ERO) for 5 minutes, 3x/day and kept in artificial saliva between erosive cycles. Groups GV to GVIII were immersed in artificial saliva (SAL) throughout the entire experimental period (control). Data were tested for significant differences using ANOVA and Tukey's tests (p<0.05). For %SMHC, considering the restorative materials, no significant differences were detected among the materials and immersion media. Mean wear was higher for the resin modified glass ionomer cement when compared to conventional cement, but those materials did not significantly differ from the others. For enamel analyses, erosive pH cycling promoted higher wear and %SMHC compared to saliva. There were no significant differences in wear and %SMHC of enamel around the different restorative materials, regardless of the distance from the restorative material (50, 150 or 300 microm). In conclusion, there were only subtle differences among the materials, and these differences were not able to protect the surrounding enamel from erosion.

Abrasive wear on eroded root dentine after different periods of exposure to saliva in situ.

The effect of salivary exposure time on the abrasive wear of acid-eroded dentine was evaluated in situ. One-hundred and twenty bovine root dentine slabs were randomly assigned into six groups (A-F) and placed in intraoral palatal devices, which were worn by 10 volunteers for 4 d. On the first day, no erosive/abrasive procedures were carried out. On the following 3 d, erosive challenges were performed extraorally, two times per day, by immersing the device for 90 s in a soft drink. Subsequently, the group A specimens were immediately brushed (40 strokes), and the others were brushed after the following times: B, 20 min; C, 40 min; and D, 60 min. Group E specimens were only acid-eroded and those of group F were only brushed. Dentine wear was measured with a profilometer. anova and Dunnett's test showed that groups A-D did not differ statistically from the control group E but differed from the control group F. The lowest mean value was found for group F. Regression analysis was unable to show salivary effect on dentine wear reduction. The data suggest that the exposure time of saliva of up to 60 min has no effect on reducing the eroded dentine wear by toothbrushing.

Salivary pH changes during soft drinks consumption in children.

UNLABELLED: Dental erosion seems to have increased, perhaps partly as a result of an increase in the consumption of soft drinks. AIM: The aim of this study was to measure salivary pH, flow rate and buffering capacity before and after soft drinks intake in children with erosive lesions and to compare these to equivalent values for healthy caries-free individuals. DESIGN: The study was conducted as a case-control study using standard salivary tests. Thirty children with erosion and 30 age and sex-matched children free from erosion and active caries were included in this study. METHODS: Salivary flow rate was measured through expectoration into a graduated tube, salivary buffering capacity through colourimetric procedures and salivary pH using a digital pH meter. RESULTS: Results showed significant differences between cases and controls for salivary pH, flow rate, buffering capacity, maximum pH drop and minimum pH reached after soft drinks intake. CONCLUSIONS: It is concluded that all the factors studied are involved in dental erosion and that preventive care is mandatory for children who frequently drink these kinds of beverages.