Aim:The aim of this study is to evaluate the effect of alcohol and nonalcohol containing mouth rinses on the color stability of a nanofilled resin composite restorative material.Materials and Methods:A total of 120 samples of a nanofilled resin composite material (Tetric N-Ceram, Ivoclar Vivadent AG, FL-9494 Schaan/Liechtenstein) were prepared and immersed in distilled water for 24 h. Baseline color values were recorded using Color Spectrophotometer 3600d (Konica Minolta, Japan). Samples were then randomly distributed into six groups: Group I - distilled water (control group), Group II - Listerine, Group III - Eludril, Group IV - Phosflur, Group V - Amflor, and Group VI - Rexidin. The postimmersion color values of the samples were then recorded, respectively.Results:Significant reduction in the mean color value (before and after immersion) was observed in nonalcohol containing mouth rinses (P < 0.001).Conclusion:All mouthrinses tested in the present in-vitro study caused a color shift in the nanofilled resin composite restorative material, but the color shift was dependent on the material and the mouthrinse used. Group VI (Rexidin) showed maximum color change.

Introduction:The objective of this study was to evaluate dentinal defects formed by new rotary system — Protaper next™ (PTN).Materials and Methods:Sixty single-rooted premolars were selected. All specimens were decoronated and divided into four groups, each group having 15 specimens. Group I specimens were prepared by Hand K-files (Mani), Group II with ProTaper Universal (PT; Dentsply Maillefer), Group III with Hero Shaper (HS; Micro-Mega, Besancon, France), and Group IV with PTN (Dentsply Maillefer). Roots of each specimen were sectioned at 3, 6, and 9mm from the apex and were then viewed under a stereomicroscope to evaluate presence or absence of dentinal defects.Results:In roots prepared with hand files (HFs) showed lowest percentage of dentinal defects (6.7%); whereas in roots prepared with PT, HS, and PTN it was 40, 66.7, and 26.7%, respectively. There was significant difference between the HS group and the PTN group (P < 0.05).Conclusion:All rotary files induced defects in root dentin, whereas the hand instruments induced minimal defects.

No abstract

No abstract