Acquired enamel pellicle protects gastroesophageal reflux disease patients against erosive tooth wear

Abstract The objective of this study was to compare the protein profile of the acquired enamel pellicle (AEP) formed in vivo in patients with or without gastroesophageal reflux disease (GERD), and with or without erosive tooth wear (ETW). Twenty-four volunteers were divided into 3 groups: 1) GERD and ETW; 2) GERD without ETW; and 3) control (without GERD). The AEP formed 120 min after prophylaxis was collected from the lingual/palatal surfaces. The samples were subjected to mass spectrometry (nLC-ESI-MS/MS) and label-free quantification by Protein Lynx Global Service software. A total of 213 proteins were identified, or 119, 92 and 106 from each group, respectively. Group 2 showed a high number of phosphorylated and calcium-binding proteins. Twenty-three proteins were found in all the groups, including 14-3-3 protein zeta/delta and 1-phosphatidylinositol. Several intracellular proteins that join saliva after the exfoliation of oral mucosa cells might have the potential to bind hydroxyapatite, or participate in forming supramolecular aggregates that bind to precursor proteins in the AEP. Proteins might play a central role in protecting the dental surface against acid dissolution.

Knowledge and attitudes related to erosive tooth wear of professional wine tasters: a cross-sectional study / Conhecimentos e atitudes relacionadas ao desgaste dentário erosivo de provadores de vinho profissionais: um estudo transversal

Objective: this study aimed to evaluate knowledge and attitudes of professional wine tasters about erosive tooth wear. Material and Methods: two questionnaires were applied to 56 wine tasters during the 25th National Evaluation of Wines - Safra 2017 in Bento Gonçalves, Rio Grande do Sul. Descriptive data analysis and the Fisher's exact test were performed (p < 0.05). Results: for the analysis, 56 volunteers aged 25-76 years were included. Most of the volunteers reported attending dentist once a year (55.35%) and their teeth become sorer after ingesting liquids or acid foods (32.14%) over time. The majority (82.14%) believe wine tasting may have teeth effects and have already heard about erosive tooth wear (51.78%). However, when asked about symptomatology, more than half (53.57%) reported not to know. Brushing teeth immediately after ingesting something (37.5%) and increasing the brushing frequency (33.92%) were the most cited treatment options. The habit of using mouthwash solutions was significantly associated with the professionals age (p = 0.039). Conclusion: the volunteers reported a high intake of acid substances and, although most of them reported to consult dentist regularly and have already heard about erosive tooth wear, knowledge about this condition is still limited among these professionals. (AU)

Objetivo: o objetivo desse estudo foi avaliar o conhecimento e as atitudes de provadores de vinho profissionais relacionadas ao desgaste dentário erosivo. Material e Métodos: dois questionários foram aplicados a 56 provadores de vinho durante a 25ª Avaliação Nacional de Vinhos - Safra 2017 no município de Bento Gonçalves, Rio Grande do Sul. Foi realizada a análise descritiva dos dados e o teste Exato de Fisher (p < 0.05). Resultados: na análise foram incluídos 56 voluntários com idade entre 25 e 76 anos. A maioria dos voluntários relatou frequentar o dentista uma vez por ano (55,35%) e que seus dentes, com o passar do tempo, tornaram-se mais doloridos ao ingerir líquidos ou alimentos ácidos (32,14%). Mais da metade (82,14%) acreditam que as provas de vinho podem causar algum efeito sobre os dentes e já ouviram falar em desgaste dentário erosivo (51,78%). Porém, quando questionados sobre a sintomatologia, a maioria (53,57%) afirmou não ter conhecimento. Escovar os dentes imediatamente após ingerir algo (37,5%) e aumentar a frequência de escovação (33,92%) foram as opções mais compreendidas como tratamento. Utilizar soluções para bochecho esteve significativamente associado à idade dos profissionais (p=0,039). Conclusão: provadores de vinho profissionais relataram alta ingestão de substâncias ácidas e, embora a maioria consulte pelo menos uma vez por ano o dentista e já tenha ouvido falar a respeito do desgaste dentário erosivo, o conhecimento sobre essa condição ainda é limitado entre esses profissionais. (AU)

Metabolic effect of low fluoride levels in the islets of NOD mice: integrative morphological, immunohistochemical, and proteomic analyses

Abstract Fluoride (F) has been widely used to control dental caries, and studies suggest beneficial effects against diabetes when a low dose of F is added to the drinking water (10 mgF/L). Objectives This study evaluated metabolic changes in pancreatic islets of NOD mice exposed to low doses of F and the main pathways altered by the treatment. Methodology In total, 42 female NOD mice were randomly divided into two groups, considering the concentration of F administered in the drinking water for 14 weeks: 0 or 10 mgF/L. After the experimental period, the pancreas was collected for morphological and immunohistochemical analysis, and the islets for proteomic analysis. Results In the morphological and immunohistochemical analysis, no significant differences were found in the percentage of cells labelled for insulin, glucagon, and acetylated histone H3, although the treated group had higher percentages than the control group. Moreover, no significant differences were found for the mean percentages of pancreatic areas occupied by islets and for the pancreatic inflammatory infiltrate between the control and treated groups. Proteomic analysis showed large increases in histones H3 and, to a lesser extent, in histone acetyltransferases, concomitant with a decrease in enzymes involved in the formation of acetyl-CoA, besides many changes in proteins involved in several metabolic pathways, especially energy metabolism. The conjunction analysis of these data showed an attempt by the organism to maintain protein synthesis in the islets, even with the dramatic changes in energy metabolism. Conclusion Our data suggests epigenetic alterations in the islets of NOD mice exposed to F levels comparable to those found in public supply water consumed by humans.

Optimizing the formation of the acquired enamel pellicle in vitro for proteomic analysis

Abstract Saliva is the major contributor for the protein composition of the acquired enamel pellicle (AEP), a bacteria-free organic layer formed by the selective adsorption of salivary proteins on the surface of the enamel. However, the amount of proteins that can be recovered is even smaller under in vitro condition, due to the absence of continuous salivary flow. Objective This study developed an in vitro AEP protocol for proteomics analysis using a new formation technique with different collection solutions. Methodology 432 bovine enamel specimens were prepared (4x4 mm) and divided into four groups (n=108). Unstimulated saliva was provided by nine subjects. The new AEP formation technique was based on saliva resupply by a new one every 30 min within 120 minutes at 37ºC under agitation. AEP was collected using an electrode filter paper soaked in the collection solutions according with the group: 1) 3% citric acid (CA); 2) 0.5% sodium dodecyl sulfate (SDS); 3) CA followed by SDS (CA+SDS); 4) SDS followed by CA (SDS+CA). The pellicles collected were processed for analysis through LC-ESI-MS/MS technique. Results A total of 55 proteins were identified. The total numbers of proteins identified in each group were 40, 21, 28 and 41 for the groups CA, SDS, CA+SDS and SDS+CA, respectively. Twenty-three typical AEP proteins were identified in all groups, but Mucin was only found in CA and CA+SDS, while three types of PRP were not found in the SDS group. Moreover, a typical enamel protein, Enamelin, was identified in the CA+SDS group only. Conclusion The new technique of the in vitro AEP formation through saliva replacement was essential for a higher number of the proteins identified. In addition, considering practicality, quantity and quality of identified proteins, citric acid seems to be the best solution to be used for collection of AEP proteins.

Do commercial whitening dentifrices increase enamel erosive tooth wear?

Abstract Objective This in vitro study evaluated the effect of commercial whitening dentifrices on erosive tooth wear (ETW) of bovine enamel samples, in comparison with commercial regular dentifrices. Methodology Sixty bovine crowns were embedded in acrylic resin, polished and then had their baseline profile determined. They were randomly assigned to 5 groups (n=12/group), according to the type of commercial dentifrice to be tested: GI - Crest Anti-cavity Regular; GII - Crest 3D White; GIII - Colgate Total 12 Clean Mint; GIV - Colgate Optic White; GV - Placebo (negative control, fluoride-free dentifrice). The samples were submitted to daily erosive and abrasive challenges for 3 days. The erosive challenges were performed 3 times a day by immersing the specimens in 0.1% citric acid solution (pH 2.5) for 90 s. Each day after the first and last erosive challenges, the specimens were subjected to the abrasive challenge for 15 s, using a toothbrushing machine (Biopdi, São Carlos, SP, Brazil), soft toothbrushes and slurry (1:3 g/ml) of the tested toothpastes (1.5 N). The specimens were kept in artificial saliva between the challenges. The final profile was obtained and the ETW (µm) was calculated. Data were analyzed by Kruskal-Wallis and Dunn's tests (p<0.05). Results All dentifrices tested significantly reduced the enamel wear in comparison with the Placebo, except GIII. The median (95% CI) ETW was 1.35 (1.25-1.46)bc for GI, 1.17 (1.01-1.34)cd for GII, 1.36 (1.28-1.45)ab for GIII, 1.08 (1.04-1.14)d for GIV and 2.28 (2.18-2.39)a for GV. Conclusion When dentifrices from the same manufacturer were compared, the whitening dentifrices led to similar or less wear than the regular ones.