Accelerated aging effects on color and translucency of flowable composites.

OBJECTIVES: To evaluate the effect of accelerated aging on color and translucency parameter of composites. MATERIALS AND METHODS: Filtek Supreme Ultra Flowable, shades A1, A3, White, Tetric EvoFlow, shades A1, A3, Bleach, and Filtek Z250 shades A1, A3, B1 were evaluated. Color and translucency were recorded using a spectrophotometer after 24-hour storage (baseline) and after accelerated aging. The data were analyzed by analysis of variance. RESULTS: Fisher's PLSD intervals for comparisons among products and shades were 0.4, 0.1, 0.3, and 0.4 for ΔL*, Δa*, Δb*, and ΔE*, respectively. The data showed significant ΔE* and ΔL* main effects for composite product and shades (p < 0.001) and their interactions (p = 0.008 and p = 0.03), respectively. Tetric EvoFlow displayed the smallest aging-dependent color shift followed by Filtek Z250 and Filtek Supreme Ultra Flowable. Accelerated aging did not significantly affected the composites for translucency (p > 0.05). CONCLUSION: The effects of aging on color of resin composites were composite and shade dependent. Translucency was not affected by accelerated aging. CLINICAL SIGNIFICANCE: The effects of aging on color of resin composites were composite and shade dependent.

Comparison of three adhesive systems in class II composite restorations in endodontically treated teeth: Influence of Er:YAG laser conditioning and gingival margin levels on microleakage.

BACKGROUND: Dental surface conditioning by Er:YAG laser is currently being investigated, as not all of the mechanisms and effects of this technique have been clearly studied. Thus, the aim of the present study was to assess the cervical microleakage of Class II resin composite restorations in endodontically treated teeth following either the respective conventional conditioning or additional Er:YAG laser conditioning, in association with varied adhesives. MATERIAL AND METHODS: Standardized mesial-occlusal-distal cavities (two gingival walls positioned in dentin and enamel, respectively) were created in 60 extracted human premolar teeth. Following the completion of the endodontic therapy, the teeth were grouped into six categories based on conditioning modality and adhesive strategy as follows: group 1-37% phosphoric acid/Adper Single Bond 2 (ASB2); group 2-Er:YAG laser/37% phosphoric acid/ASB2; group 3-Clearfil SE Bond (CSE); group 4-Er:YAG laser/CSE; group 5-Adper Easy One (AEO); and group 6-Er:YAG laser/AEO. Specimens were submitted to thermocycling and dye penetration, followed by longitudinal sectioning. The dye penetration was evaluated using a stereomicroscope. One specimen from each group was assessed under a scanning electron microscope for adhesive interface analysis. RESULTS: No significant differences were found between the conditioning modalities, nor between the adhesive systems at both margins. Groups 1 and 2 showed a lower degree of microleakage in the enamel vs. dentin (p = 0.002). Group 2 showed a significantly lower incidence of microleakage in enamel vs. dentin (p = 0.005). CONCLUSIONS: CSE and AEO were comparable with that of ASB2 regarding sealing ability. Additional Er:YAG laser conditioning may be beneficial before ASB2 application in enamel. Key words:Endodontically treated teeth, etch-and-rinse adhesive, Er:YAG laser, gingival level, sealing ability, self-etch adhesive.

The effect of mouth rinses on the color stability of sonicfill and a nanohybrid composite.

PURPOSE: The aim of this study was to evaluate the effects of 4 mouth rinses on the color stability of two different resin composites. MATERIALS AND METHODS: A2 shade sonic-activated bulk fill material SonicFill (Kerr) and conventional nanohybrid composite Filtek Z550 (3M ESPE) were used. Forty disc-shaped specimens (10 mm x 2 mm) were fabricated for both composites and finished using 400-grit SiC paper and polished. After polishing and immersing in distilled water for 24h all specimens were subjected to color measurements. The baseline color values (L*, a*, b*) of each specimen were measured with a colorimeter. Following baseline measurement each composite group was divided into 5 groups: Oral-B Pro Expert Clinic Line Alcoholfree (Oral-B) group, Listerine Tooth Defense Rinse (Listerine) group, Pharmol Zn Mouth rinse (Çözümilaç) group, Nilera Mouth rinse (Nilera) group and Distilled water (control) group. The specimens were incubated in mouth rinses (20 ml) at 37°C for 12 hours and subjected to color measurement. Two-way ANO VA was used for statistical analysis (p<0.05). RESULTS: SonicFill showed significantly higher discoloration when exposed to Oral-B Pro Expert Clinic Line Alcohol-free, Listerine Tooth Defense Rinse and Pharmol Zn Mouth rinse. The color differences of two resin composites were not statistically significant for distilled water and Nilera Mouth rinse. CONCLUSION: Within the limits of this study it can be concluded that the SonicFill showed higher discoloration than nanohybrid resin composite Filtek Z550.