Objectives:Color stability of composite resins has a significant role in their durability and clinical service. Considering the increasing use of composite resins and their gradual discoloration, this study aimed to assess the efficacy of Listerine whitening mouthwash for color recovery of two discolored composite resins.Materials and Methods:This in-vitro experimental study was performed on 20 samples fabricated of Filtek Z350XT (3M ESPE, St. Paul, MN, USA) and IPS Empress Direct (Ivoclar Vivadent, Schaan, Liechtenstein) composite resins. Primary colorimetry was performed using a spectrophotometer. The samples were immersed in a coffee drink for 7 days. They were then immersed in Listerine mouthwash for 4 minutes daily for 56 days. After this period, the color change of composite resins was reevaluated. Data were analyzed using repeated-measures analysis of variance (ANOVA) and t-test.Results:The primary color change of Z350XT after immersion in coffee was 1.6 times greater than that of IPS composite (P<0.0001). The color recovery of IPS and Z350XT after immersion in the mouthwash was 1.06±0.58 (P<0.01) and 2.58±1.65 (P<0.001) units, respectively. The color change of Z350XT after exposure to the mouthwash was 25% (1.4 times) greater than that of IPS (P<0.01).Conclusion:Both composite resins experienced a clinically unacceptable discoloration after exposure to coffee (ΔE>3.3). Filtek Z350XT showed greater color change than IPS. Use of Listerine whitening mouthwash caused significant color recovery in both composite resins.

Background and Aim: The purpose of this study was to examine the effect of alcohol and non-alcohol mouthwashes on the color change of two types of bleach shade composite. Materials and Methods: Twenty-two samples of IPS empress direct composite (Ivoclar Vivadent, Schaan, Liechtenstein) and 22 samples of Vitalescence snow white composite (Ultradent Products, South Jordan, UT, USA) were prepared in 10 mm diameter and 2 mm thickness. The specimens were polished with Sof-Lex (3M ESPE, USA) abrasive papers in supra fine, fine, and medium sizes. The specimens were then stored for 24 hours in distilled water at 37°C, and an initial colorimetric assay was performed using SP64 spectrophotometer. Samples were randomly divided to be placed in 20 ml of alcohol and non-alcohol Listerine mouthwashes and were incubated at 37°C for 24 hours. The color of the specimens was again measured, and color change (ΔE) was calculated. Data were analyzed using two-way analysis of variance (ANOVA) at 95% confidence level. Results: None of the mouthwashes caused clinically significant discoloration in the samples. The effect of both mouthwashes on composite discoloration was statistically significant (P=0.0001), and the interaction between the mouthwash and type of restorative material was significant (P=0.0001). Conclusion: IAccording to the findings of this study, alcohol mouthwashes cause more discoloration in composite resins.

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One hundred elastomeric ligatures from one manufacturer were chosen for this study: 10 ligatures were tested at room temperature; the other 90 ligatures were divided into three equal groups and were stretched over stainless steel dowels. Group 1 samples were kept in artificial saliva. Group 2 samples were rinsed twice a day with 15 ml of Orthokin®, each time for 1 minute, and the Group 3 samples were rinsed twice a day with 15 ml of Oral B®, each time for 30 seconds, both samples being immersed in another artificial saliva prior to being put back in the test tubes. Each time, 10 of the samples were tested for their tensile strength at different intervals of 1, 7 and 28 days until they ruptured. One-way and two-way ANOVA and Tukey test were used for evaluation. Clinical Relevance: The aim of this study was to evaluate the in vitro effects of Orthokin®, Oral-B®, and artificial saliva on tensile bond strength of elastomeric ligatures.