Background: Recently, universal single-shade resin composites have become increasingly available in the dental market. The modification of their composition can have an inadvertent effect on their physical and surface properties, and subsequently determinantal effect on their clinical function and longevity. Therefore, this study aimed to evaluate the effect of different finishing and polishing (F/P) systems on surface roughness (Ra), surface gloss (GU), and Vickers microhardness (VMH) of universal single-shade RBCs. Materials and methods: Four commercial RBCs were used; the universal single-shade RBCs were Omnichroma, Charisma® Diamond ONE, and Vittra APS Unique, and a conventional nanocomposite Filtek™ Z250 XT was used as a control. The 3 F/P systems were Sof-Lex™ XT, Enhance®/PoGo®, and Diacomp® Plus Twist. A total of 160 discs were used for the 3 F/P system groups for all RBCs (n = 10). After F/P, the Ra, GU, and VMH were assessed. The data were analyzed using 2-way ANOVA at p-value < 0.05. Results: Significant differences were found among the four RBCs and the 3 F/P systems (p < .000). Omnichroma showed the lowest Ra and acceptable GU, but the lowest VMH. Charisma showed the highest Ra, acceptable GU, and VMH. Vittra showed acceptable Ra, GU, and VMH and Filtek showed the highest GU, VMH, and acceptable Ra. Conclusion: Although conventional nanohybrid RBC (Filtek Z250 XT) showed better GU and VMH values, the universal single-shade RBCs demonstrated comparable surface properties. The highest GU & VMH and lowest Ra were achieved by Diacomp followed by Enhance and Soflex.

This in vitro study compared the color change (∆E) and biaxial flexural strength (BFS) of two resin nanoceramics (LU and CS) and two polymer-infiltrated ceramic networks (VE and CU) after different surface finishing protocols. A total of 192 discs (12 × 1.2 mm²) were prepared from the materials (n = 48) and then polished with 1200-grit silicon carbide paper, followed by roughening with a 30 µm grit diamond bur. According to the surface finishing applied, the discs from each material category were categorized into four groups: control group (no finishing), polishing (MP), glazing (OG), or a combination of MP and additional polishing (MP+PP). Following surface finishing, all the discs were immersed in a coffee beverage to simulate one year of clinical use. A spectrophotometer and universal testing machine were used to measure the ∆E and BFS, respectively. Fractographic analysis was performed using scanning electron microscopy images. Multivariate analysis of variance was used for the statistical analysis, followed by one-way ANOVA and post hoc Dunnett’s test (a = 0.05). The ∆E and BFS were significantly impacted by material type and surface finishing (p ≤ 0.05). Irrespective of the materials and finishing, untreated LU and OG-treated VE specimens demonstrated the highest (2.98 ± 0.36) and lowest (1.21 ± 0.33) color changes. Regarding BFS, untreated CU and OG-treated CS specimens demonstrated the lowest (121.88 ± 2.08 MPa) and highest (174.17 ± 3.83 MPa) values. Surface finishing using glazing resulted in the highest BFS and lowest ∆E compared to other surface finishing protocols for the tested materials. VE demonstrated the least color changes, and CS showed the highest BFS following surface finishing of the materials tested. Surface finishing is material dependent; thus, it is critical to use the best surface finishing protocol in a clinical setting.

This study presents an evaluation of the microtensile bond strength (µTBS) and microleakage (ML) of a bulk-fill (BF) composite, Ormocer, and Alkasite in comparison to the conventional composite bonded to caries-affected dentin (CAD) in deciduous dentition. Eighty-four human primary molars displaying carious lesions involving the middle third of dentin were included. CAD was exposed, and the teeth were randomly assigned to four groups based on the type of restorative material used: Group 1 (conventional composite), Group 2 (BF composite), Group 3 (Alkasite), and Group 4 (Ormocer). Sample storage and artificial aging were performed. Dye penetration, a universal testing machine, and a stereomicroscope were used for microleakage, µTBS, and failure mode assessment. The interface was evaluated by scanning electron microscopy (SEM). µTBS and ML results were analyzed using a one-way analysis of variance (ANOVA) and Tukey’s post hoc tests (p < 0.05). Group 1 (conventional composite) exhibited the highest microleakage and lowest bond strength. The minimum ML and maximum μTBS values were demonstrated by Group 4 (Ormocer). Ormocer and Alkasite proved to be better alternatives to conventional composites in terms of ML and bond strength in deciduous dentition.

Objectives: This study investigated the effects of three over-the-counter (OTC) whitening products, whitening pen (WP, Dazzling White Instant Whitening Pen, Dazzling White, Grand Rapids, MI, USA), whitening mouthwash (MW, Colgate Optic White, Colgate-Palmolive, New York, NY, USA), and whitening toothpaste (TP, Crest 3D White, Procter & Gamble, Cincinnati, OH, USA), on the microhardness, gloss retention, and surface roughness of a nanofilled resin composite (Filtek Z350 XT Universal Restorative, 3M ESPE). Methods: Composite resin specimens were prepared and subjected to treatment with WP, MW, or TP. Microhardness, gloss retention, and surface roughness were measured before and after treatment. Data were subjected to statistical analysis, with normality assessed by Shapiro–Wilk testing. Parametric data were summarized as mean ± SD, and differences were evaluated using paired t-tests and one-way ANOVA with a significance level of p ≤ 0. 05. Results: All whitening products significantly altered the tested surface properties. Microhardness decreased in all groups (MD [95% CI]: 2.28 [1.84–2.71] for WP, 5.05 [4.22–5.88] for MW, and 3.09 [2.35–3.83] for TP; p < 0.001), with the greatest reduction observed in the MW group. Gloss retention also declined significantly (MD [95% CI]: 9.52 [6.28–12.76] for WP, 17.97 [14.92–21.01] for MW, and 18.92 [15.64–22.21] for TP; p < 0.001), with TP and MW showing greater loss compared to WP. Surface roughness increased significantly within each group (MD [95% CI]: −0.07 [–0.10 to −0.04] for WP, −0.23 [–0.30 to −0.16] for MW, and −0.25 [–0.38 to −0.13] for TP; p < 0.001), although no significant differences were found among groups in post-treatment values. Conclusions: OTC whitening products adversely affected the optical and mechanical properties of Z350 XT universal composite resin. Whitening MW caused the most pronounced microhardness reduction, while MW and TP induced greater gloss loss than WP. Clinicians should consider the potential impact of whitening products on resin composite restorations when advising patients on their use.