Influence of photodynamic therapy, different final irrigants, and ultrasonic activation on the bond strength of glass fiber posts to root dentin.

OBJECTIVE: To evaluate the influence of photodynamic therapy (PDT), different final irrigants, and ultrasonic activation (US) on the bond strength of glass fiber posts (GFP) to root dentin. METHODS: One hundred twenty bovine roots were divided into 12 groups according to PDT application, the type of final endodontic irrigant, and US. The samples were divided into 12 groups (n = 10): G1-DW(distilled water); G2-DW+US; G3-17% EDTA; G4-17% EDTA+US; G5-17% GA (glycolic acid); G6-17% GA+US; G7-PDT+DW; G8-PDT+DW+US; G9-PDT+17% EDTA; G10-PDT+17% EDTA+US; G11-PDT+17% GA; G12-PDT+17% GA+US. After cementing the glass fiber posts with resin cement, roots were sectioned into 2-mm-thick slices. One slice from the cervical third and another from the middle third were used for the push out test (PO), and the other two for the diametral compression test (DC). Thus, 10 samples were obtained per third for each mechanical test (n = 10). Kruskal-Wallis and Student-Newman-Keuls tests were used to analyze PO and DC data, and Pearson's correlation test was used to verify the relationship between the variables. Failure patterns were analyzed with chi-square test. RESULTS: Significant differences were found in the PO test among the experimental groups (p < 0.001; power=1.00). PDT improved bond strength when using EDTA. PDT and US increased bond strength when using GA. Favorable failure patterns occurred more frequently in Group GA+US. There was no correlation between data obtained with PO and DC tests (r = 0.112; p = 0.729). CONCLUSION: PDT provided the highest bond strength values of GFP to root dentin when associated with GA and US or when associated only with EDTA.

Influence of ultrasonic activation on antimicrobial activity of a new final irrigant containing glycolic acid: An in vitro study.

This study evaluated the influence of ultrasonic activation (US) on the antimicrobial activity of a new final irrigant containing glycolic acid (GA). Extracted teeth were used, being 70 to counting of colony-forming units (CFUs) and 35 to confocal laser scanning microscopy. Samples were inoculated with Enterococcus faecalis and divided into 7 groups: distilled water + US; 17% EDTA; Qmix; 17% GA; 17% EDTA + US; QMix + US; and 17% GA + US and kept in contact with test solution for 1 min in the groups with or no US. In the CFUs, the highest bacterial reduction was observed in QMix + US group, followed by QMix and GA + US. In the confocal evaluation, the lowest number of viable cells was observed in EDTA + US, with no statistical difference from QMix, QMix + US and GA + US (P > 0.05). The use of US improves the antimicrobial activity of EDTA and GA, being statistically different from the isolated use of these final irrigants in both evaluation tests.

Antimicrobial activity of intracanal dressings composed by natural products associated to chlorhexidine and its influence on dentinal colour change / Avaliação da ação antimicrobiana de medicações intracanais à base de produtos fitoterápicos associados à clorexidina e sua influência na alteração de cor da estrutura dentinária

Purpose: evaluate the antimicrobial activity of intracanal dressings and their influence on dentinal colour changes. Material and methods: eighty single-rooted human extracted teeth were decoronated and divided into eight groups (n=10) according to intracanal dressing protocols inserted into the root canals: G1­distilled water (DW); G2­2% chlorhexidine gel (CHX); G3­calcium hydroxide (Ca[OH]2)+DW; G4­grape seed extract (GSE)+DW; G5­ginger extract (GE)+DW; G6­Ca(OH)2+CHX; G7­GSE+CHX; and G8­GE+CHX. The antimicrobial activity was evaluated by colony-forming units (CFUs) counting and dentinal colour changes was evaluated by digital spectrophotometry. Data were statistically analysed by One-way ANOVA followed by Tukey´s post hoc test (antimicrobial evaluation) and non-parametric Wilcoxon followed by the Mann- Whitney-U test (colour change evaluation) (α=0.05). Results: the highest bacterial reduction was observed in groups 4, 6, 7 and 8, with no significant difference between them (p<0.05). Groups 4 and 7 showed the highest medians of dentinal colour change (p<0.05). Conclusion: the addition of CHX improved the antimicrobial activity of GE-based intracanal dressing, with no effect in GSE-based intracanal dressing; moreover, these protocols induced significant dentinal colour changes. (AU)

Objetivo: avaliar a atividade antimicrobiana de medicações intracanais e sua influência na alteração da cor dentinária. Materiais e métodos: oitenta dentes humanos extraídos unirradiculares foram seccionados e divididos em oito grupos (n = 10), de acordo com os protocolos de medicação intracanal inseridos nos canais radiculares: água destilada G1 (DW); G2-2% de gel de clorexidina (CHX); hidróxido de cálcio G3 ­ (Ca [OH] 2) + DW; extrato de semente de uva G4 (GSE) + DW; extrato de gengibre G5 (GE) + DW; G6- Ca (OH) 2 + CHX; G7 ­ GSE + CHX; e G8-GE + CHX. A atividade antimicrobiana foi avaliada por contagem de unidades formadoras de colônias (UFCs) e as alterações de cor dentinária foram avaliadas por espectrofotometria digital. Os dados foram analisados estatisticamente por ANOVA one-way, seguida pelo teste post hoc de Tukey (avaliação antimicrobiana) e Wilcoxon não paramétrico, seguido pelo teste de Mann- Whitney-U (avaliação da mudança de cor) (α = 0,05). Resultados: a maior redução bacteriana foi observada nos grupos 4, 6, 7 e 8, sem diferença significativa entre eles (p < 0,05). Os grupos 4 e 7 apresentaram as maiores medianas da alteração da cor dentinária (p < 0,05). Conclusão: a adição de CHX melhorou a atividade antimicrobiana da medicação intracanal baseado em GE, sem efeito na medicação intracanal baseado em GSE; além disso, esses protocolos induziram alterações significativas na cor dentinária.(AU)

Predictors of dental erosions in patients evaluated with upper digestive endoscopy: a cross-sectional study.

The most studied medical condition related with dental erosions is gastroesophageal reflux disease (GERD). The aim of this study was to assess other predictors of dental erosions besides GERD in outpatients referred for upper digestive endoscopy. In a cross-sectional study, we prospectively evaluated 235 patients who underwent upper digestive endoscopy. Patients were interviewed and examined by a trained dentist before the endoscopies, addressing dental health as well as clinical information and food intake. Dental erosion was classified using Basic Erosive Wear Examination score. Potential predictors for dental erosions were: gender, age, chronic use of antidepressants and proton pump inhibitors (PPI), diabetes mellitus, body mass index, heartburn and acid regurgitation scores, chocolate intake, reflux esophagitis and hiatal hernia. Overall prevalence of dental erosions was 23.4%. The most parsimonious Poisson regression model for dental erosions considered age, chocolate intake and acid regurgitation as predictors. Dental erosions were associated with acid regurgitation in patients younger than 50 years [adjusted prevalence ratio (PR) = 1.8 (95% CI 1.1-2.9)] and with chocolate intake in patients older than 50 years [PR = 2.1 (95% CI 1.2-3.9]. The surfaces most eroded were palatine/lingual (n = 25) and occlusal (n = 25), followed by vestibular (n = 5). In outpatients evaluated with upper digestive endoscopy, the variables associated with dental erosions were age younger than 50 years, acid regurgitation and chocolate intake. Referral for dental evaluation should be considered for young patients with GERD and frequent acid regurgitation.