Dual Rinse® HEDP increases the surface tension of NaOCl but may increase its dentin disinfection efficacy.

The aim of this study was to evaluate the surface tension and the antimicrobial activity in infected dentin of a NaOCl solution combined with an etidronate powder (Dual Rinse® HEDP), compared to pure NaOCl and the classic NaOCl + EDTA irrigating sequence, respectively. The surface tension of three irrigants was measured by Wilhelmy technique. To evaluate the antimicrobial activity of the solutions, 26 human teeth were contaminated for 5 days with E. faecalis. After bacterial contamination, ten samples were irrigated with NaOCl followed by EDTA, another ten with NaOCl/Dual Rinse® HEDP, and four were used as positive controls. Two specimens not contaminated were used as negative controls. After live/dead BacLight staining, samples were examined by CLSM for analyzing % of residual live and dead cells. Comparison of bacterial viability between and within groups was performed using the Mann-Whitney test for independent samples and the Wilcoxon signed-rank test, respectively. The mean surface tension of EDTA was significantly lower than that of the other irrigants tested (p < 0.001). Conversely, the surface tension of NaOCl/Dual Rinse® HEDP solution was significantly higher than that of all the other solutions (p < 0.001). Residual bacterial viability in the NaOCl/Dual Rinse® HEDP (1.71%) was significantly lower (p = 0.019) than in the NaOCl + EDTA group (3.77%). All of the experimental groups showed significantly lower proportion of viable bacterial cells than the positive control group (p < 0.01). Clinical relevance adding etidronate to NaOCl increases its antimicrobial effect in dentinal tubules even though increases its surface tension.

Effects of curcumin-mediated antimicrobial photodynamic therapy associated to different chelators against Enterococcus faecalis biofilms.

BACKGROUND: The aim of this study was to evaluate curcumin-mediated antimicrobial photodynamic therapy (aPDT) action combined or not with ethylenediaminetetraacetic acid (EDTA) and hydroxyethylidene bisphosphonate (HEBP) on Enterococcus faecalis biofilms. METHODS: Enterococcus faecalis biofilms were grown on dentin bovine discs in brain heart infusion (BHI) medium with 1% glucose, in aerobic conditions at 37°C for 7 days. Then, they were randomly distributed to one of experimental conditions, as follows: control, 75 J.cm-2 LED, 600 µmol.L-1 curcumin, 17% EDTA, 18% HEBP, 600 µmol.L-1 curcumin plus 75 J.cm-2 LED, 600 µmol.L-1 curcumin plus 17% EDTA, 600 µmol.L-1 curcumin plus 18% HEBP, 600 µmol.L-1 curcumin plus 17% EDTA and 75 J.cm-2 LED or 600 µmol.L-1 curcumin plus 18% HEBP and 75 J.cm-2 LED. The viability of microorganisms and the vitality of biofilms were determined by colony forming unit counts and confocal scanning laser microscopy (CSLM), respectively. Statistical analysis was conducted by Kruskal Wallis and Dunn's post-hoc tests (α = 0.05). RESULTS: The results showed that all combinations of aPDT with chelators significantly reduced the viability of microbial cells and the vitality of biofilms in comparison to control, even when considering deeper layers of biofilms. CONCLUSION: The combination of curcumin with EDTA and HEBP similarly improved the effect of aPDT on E. faecalis biofilms.

Effect of Temperature, Concentration and Contact Time of Sodium Hypochlorite on the Treatment and Revitalization of Oral Biofilms.

Background and aims. Increasing the temperature of sodium hypochlorite (NaOCl) enhances its dissolution and antibacterial properties. However, the high resistance of multi-species biofilms could restrict the effect of the solution regardless of its temperature, enabling the long-term recovery of the surviving bacteria. The aim of this study was to investigate if the increase of temperature of NaOCl improves its antibacterial and dissolution ability on oral biofilms and if the post-treatment remaining bacteria were capable of growing in a nutrient-rich medium. Materials and methods. Forty dentin blocks were infected intra-orally for 48 hours. Then, the specimens were treated with 1% and 2.5% NaOCl at room temperature (22ºC) and body temperature (37ºC) for 5 and 20 min. The percentage of live cells and the biovolume were measured pre- (control) and post-treatment and after the biofilm revitalization. Four confocal 'stacks' were chosen from random areas of each sample. Statistical analysis was performed using Kruskal-Wallis and Dunn tests. Statistical significance was defined at P <0.05. Results. All the NaOCl groups were effective in dissolving the biofilm at any temperature, concentration and contact time without statistical differences among them (P >0.05). The 1%-NaOCl for 5min was not able to significantly kill the bacteria, regardless of its temperature and contact time (P >0.05). Conclusion. The temperature variation of the NaOCl was not relevant in killing or dissolving bacterial biofilms. Twenty-four hours of reactivation did not appear to be enough time to induce a significant bacterial growth.

Effect of different radiopacifying agents on the physicochemical properties of white Portland cement and white mineral trioxide aggregate.

INTRODUCTION: The aim of this study was to evaluate the pH, calcium ion release, setting time, and solubility of white mineral trioxide aggregate (WMTA) and white Portland cement (WPC) combined with the following radiopacifying agents: bismuth oxide (BO), calcium tungstate (CT), and zirconium oxide (ZO). METHODS: Fifty acrylic teeth with root-end filling material were immersed in ultrapure water for measurement of pH and calcium release (atomic absorption spectrophotometry) at 3, 24, 72, and 168 hours. For evaluation of setting time, each material was analyzed according to the American Society for Testing and Materials guidelines 266/08. The solubility test was performed according to American National Standards Institute/American Dental Association specification no. 57/2000. Solubility, setting time, and pH values were compared by using analysis of variance and Tukey test, and the values of calcium release were compared by the Kruskal-Wallis and Miller tests. The significance level was set at 5%. RESULTS: The pH and calcium release were higher at 3 and 24 hours. WPC was the material with the higher values for both properties. WMTA had the greatest solubility among all materials (P < .05). All radiopacifiers increased the setting time of WPC, and WMTA had the shortest setting time among all materials (P < .05). CONCLUSIONS: All materials released calcium ions. Except for WPC/CT at 168 hours, all materials promoted an alkaline pH. On the basis of the obtained results, ZO and CT can be considered as potential radiopacifying agents to be used in combination with Portland cement.

Factors related to self-perceived need for dental treatment in adolescents, adults, and elders in a city in Northeastern Brazil. / Fatores relacionados à autopercepção da necessidade de tratamento odontológico em adolescentes, adultos e idosos em um município do nordeste do Brasil

Objective: to identify factors related to self-perceived need for dental treatment in adolescents, adults, and elders in a small city in Northeastern Brazil. Methods: Data from a cross-sectional study with a sample of 139 individuals were assessed. Data collection included oral examinations and interviews concerning demographic and predisposing characteristics, and availability of financial resources. In a hierarchical model, Poisson regression analysis was used. Results: Out of the total sample, 85.5%, 84.5%, and 38.5% of the adolescents, adults, and elders, respectively, reported the need for dental treatment. The self-perception of this need was lower among elders who had not received information on how to avoid oral problems, and among the edentulous. On the other hand, it was higher amongst those who self-rated their oral health as fair/poor/very poor. Conclusions: These results highlight the importance of self-rated oral health and the access to preventive information on oral problems in modulating the individual concept of dental treatment need. Moreover, they point to the need for greater attention to the elderly group, mostly edentulous that showed lower perceived need.

Análisis comparativo de la extrusión apical de dentina producida por diferentes técnicas de instrumentación / Comparative analysis of dentin apical extrusion through different root canal techniques

Objetivo. El propósito de este estudio fue comparar el material sólido extruido por el foramen apical usando las técnicas manuales Step Back, regon y las rotatorias, Sistema K3 Endo, Sistemas Protaper y sistema F.K.G. RaCe. Material y métodos. Sesenta y cinco dientes unirradiculares fueron utilizados siendo 15 para cada uno de los grupos. El material extruído en las diferentes técnicas fue recogido en papel de filtro (Whatman®) sometidos a secado en estufa y pesado en balanza digital de alta precisión. A través del test ANOVA se observó la diferencia existente entre los diferentes grupos estudiados y el test paramétrico de Tukey fue aplicado para el análisis comparativo de los grupos entre sí. Resultados. El análisis de los resultados mostró extrusión de material por el foramen en todas las técnicas testadas.siendo que Step Back promovió la mayor cantidad de material extruido siendo significante en relación a las demás que fueron equivalentes estadísticamente. Conclusiones. No fue observada diferencia significativa entre la técnica de Oregon y las rotatorias siendo que entre estas el sistema K3 Endo proporcionó el menor índice de extrusión (AU)

Objective. The purpose of this study was to conpare the solid material extruded through the apical foramen using manual techniques Step Back, Oregon and rotary systems: K3 Endo, ProTaper and FKG RaCe. Material and methods. Sixty-five single-root teeth were used with 15 for each of the groups. The extruded material of different techniques was collected in filter paper (Whatman®) submitted to oven drying and weighing in high precision digital scale. Through ANOVA test was observed the difference between the different studied groups and the Tukey parametric test was applied to the comparative analysis of the groups together. Results. The analysis of the results showed extrusion material through the foramen in all techniques. Step Back promoted the most significant being extruded material in relation to the others that were statistically equivalent.Conclusions. No significant difference was observed between the technique of Oregon and rotary systems; among these being that K3 Endo system provided the lowest rate of extrusion (AU)