Pellicle modification with natural bioproducts: Influence on tooth color under erosive conditions.

Salivary pellicle was modified with bioproducts and we assessed the change in tooth color and the protection of enamel to erosion. Human enamel specimens were assigned to one of three solutions: grape seed extract or black tea (bioproducts), or deionized water (negative control); after which one half the specimens underwent erosive challenges. The specimens underwent 15 cycles involving salivary pellicle formation (10 min, 37°C), incubation in solution (2 min, 25°C), subsequent pellicle formation (90 min, 37°C). Half of the specimens was kept in a humid chamber and the other half was submitted to erosion (2 min, 1% citric acid). After 15 such cycles, the pellicle was removed. Tooth color and the surface reflection intensity were assessed after every five cycles and after pellicle removal. For non-eroded specimens, the exposure to bioproducts promoted significantly greater color change than the deionized water, with increases in yellow appearance. After pellicle removal, the color was similar in all non-eroded specimens. The bioproducts increased the surface reflection intensity over cycles. For the erosion-exposed specimens, erosion itself resulted in color change. Black tea and deionized water resulted in increased yellow appearance. Exposure to the bioproducts resulted in higher relative surface reflection intensity values over time, but only grape seed extract resulted in higher relative surface reflection intensity value at the time of pellicle removal. The bioproducts caused transient staining effect, which was reduced after pellicle removal. For enamel submitted to erosion, grape seed extract resulted in less color change and better protection of enamel against erosion than black tea or water

Adhesive interface degradation : what are the consequences to restorations longevity?

Objetivo: Este estudio tiene por objetivo comparar el rendimiento de diferentes sistemas adhesivos en relación con la degradación hidrolítica y presentar posibles alternativas para minimizar o evitar esa degradación. Material y método: Una revisión de la literatura fue realizada a través de la base de datos PubMed. Se utilizaron las siguientes palabras claves durante la búsqueda: hydrolytic degradation, dentin, hybrid layer degradation, collagen. Conclusión: La degradación hidrolítica está directamente relacionada con los sistemas adhesivos simplificados. Substancias y técnicas están siendo desarrolladas con el fin de mejorar la estabilidad de la interfaz adhesiva, minimizando los efectos de la hidrólisis, sin embargo, los estudios con evidencia clínica sobre la aplicabilidad de los mismos todavía son escasos.The aim of this article is to discuss the hydrolytic degradation of different adhesive systems and alternatives to minimize or avoid degradation. The review of literature was performed using the PubMed database. The keywords used were: hydrolytic degradation, dentin, hybrid layer degradation, collagen. It can be concluded that hydrolytic degradation has been related to simplified adhesive systems. Substances and techniques are being studied to improve the bonded interface stability and minimize the hydrolysis effects, however, clinical evidence related to their applicability is scarce.Fil: Cintra Mailart, Mariane. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Bogado Escobar, Lorena. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil)Fil: Poletto, Adriana . Universidad Nacional de Cuyo. Facultad de OdontologíaFil: Bühler Borges, Alessandra. Universidad Estadual Paulista "Júlio de Mesquita Filho" (Brasil

Protection of calcium silicate/sodium phosphate/fluoride toothpaste with serum on enamel and dentin erosive wear

Objective: To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. Methodology: Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva – 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS – Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (μm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). Results: For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. Conclusion: The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW

Minimal intervention in dentistry : which is the best approach for silorane composite restoration repairs?

This study aimed to evaluate surface treatments, adhesives and composites for repairing silorane based restorations. One hundred and twenty truncated cones (2 mm smaller diameter and 4 mm larger diameter) made of silorane composite were divided in 12 g

The effects of anti-oxidant agents as neutralizers of bleaching agents on enamel bond strength

The aim of this study was to investigate the neutralizer effect of antioxidant agents on the bond strength of bleached enamel. Buccal enamel surfaces of 80 bovine incisors were divided into eight groups. The negative control group (NC) received no bleaching treatment and the other groups were bleached with 35% hydrogen peroxide gel for 30min., activated with a photocuring unit. Ten specimens were selected for the positive control group (PC) and received no anti-oxidant agents. The remaining bleached specimens received one of the six anti-oxidant agents, for 20min (10% Sodium Ascorbate–SA; Catalase–CA; Glutathione Peroxidase–GP; Acetone–AC; Ethanol–ET; 7% Sodium Bicarbonate– SB). Bonds were formed and shear bond test was carried out after 24h. The data were analyzed by one-way ANOVA and Tukey’s tests (α =5%). The PC group showed significantly lower bond strength mean than the NC group. All of the experimental groups showed bond strength means significantly lower than the NC group. The CA group showed significantly higher bond strength mean than the bleached PC group and the groups SA, GP, AC, ET and SB showed no significant differences compared to PC group. It was concluded that only the Catalase application resulted in significant increase of bond strengths in relation to the PC group and that none of the treatments was able to completely neutralize the deleterious effects of bleaching on bond strength

Surface roughness of packable composite resins polished with various systems

Purpose: The aim of this study was to evaluate the surface roughness of four packable composite resins, SureFil™ (Dentsply, Petrópolis, Rio de Janeiro, Brazil), Prodigy Condensable™ (Kerr Co., Orange, CA, USA), Filtek P60™ (3M do Brasil, São Paulo, Brazil), and ALERT® (Jeneric/Pentron, Inc., Wallingford, CT, USA) and one microhybrid composite resin (Filtek Z250™, 3M do Brasil) after polishing with four finishing systems. Materials and Methods: Twenty specimens were made of each material (5 mm in diameter and 4 mm high) and were analyzed with a profilometer (Perthometer® S8P, Perthen, Mahr, Germany) to measure the mean surface roughness (Ra). The specimens were then divided into four groups according to the polishing system: group 1 - Sof-Lex™ (3M do Brasil), group 2 - Enhance™ (Dentsply), group 3 - Composite Finishing Kit (KG Sorensen, Barueri, São Paulo, Brazil), and group 4 - Jiffy Polisher Cups® (Ultradent Products, Inc., South Jordan, UT, USA). The specimens were polished and then evaluated for Ra, and the data were subjected to analysis of variance, analysis of covariance, and Tukey's test (p = .05). Results: The mean Ra of SureFil polished with Sof-Lex was significantly lower than that of KG points. Prodigy Condensable polished with Enhance showed a significantly less rough surface than when polished with Sof-Lex. Filtek P60 did not exhibit a significant difference with the various polishing systems. For ALERT the lowest mean Ra was obtained with Sof-Lex and the highest mean Ra with KG points. Regarding Filtek Z250, polishing with KG and Jiffy points resulted in a significantly lower mean Ra than when polished with Enhance. Conclusions: Packable composite resins display variable roughness depending on the polishing system used; the Sof-Lex disks and Jiffy points resulted in the best Ra values for the majority of the materials tested