Purpose To evaluate resin cement bond strength after removal of salivary contamination from a zirconia surface using different cleaning solutions and air‐borne particle abrasion. Materials and methods One‐hundred and twenty zirconia specimens (KATANA STML, Noritake) were prepared and divided into 12 groups (n = 10). Groups were subjected to a notched‐edge shear bond strength test (ISO 29022) to analyze the bonding efficiency of a resin cement (Panavia V5, Kuraray Noritake Dental Inc.) before and after contamination with saliva. Group 1 (control) was prepared and cemented without salivary contamination. Group 2 was coated with ceramic primer (Clearfil Ceramic Primer Plus, Kuraray Noritake Dental Inc.) then subjected to salivary contamination then tested. Group 3 was contaminated, cleaned by air‐borne particle abrasion, ceramic primer and resin cement applied, and tested. Groups 4 to 12 were contaminated, and then different cleaning solutions (water, 4.5% hydrofluoric acid, 35% phosphoric acid, Ivoclean, KATANA cleaner, Zirclean, sodium hypochlorite 4%, and 7.5%) were used to decontaminate the zirconia surface, followed by ceramic primer, resin cement application, and tested. One‐way ANOVA and Tukey post‐hoc analysis was used to analyze the data. Results One‐way ANOVA showed statistical differences among cleaning procedures (p < 0.001, F = 13.48). Air‐borne particle abrasion was the only group which provided a bond strength (21 ± 2.8 MPa) that was not statistically different than the control group in which no contamination occurred (25.3 ± 3.3 MPa) (p = 0.247). The use of hydrofluoric acid and zirconia cleaning solutions resulted in bond strengths values which were not statistically different from each other (17.5‐19.1 MPa). Conclusion Air‐borne particle, zirconia cleaning solutions and hydrofluoric acid are feasible to decontaminate the zirconia surface from saliva prior to bonding the restoration.

Objective To determine color and translucency stability of present‐day resin‐based restorative materials. Materials and methods Disk‐shaped (1.0 × 10 mm) resin composites (Filtek Universal, 3M ESPE; Spectra ST, Dentsply Sirona; Gradia Direct X, GC America; Estilite Quick, Tokuyama; Harmonize, Kerr; ACTIVA Bioactive‐Restorative, Pulpdent) were prepared and divided into four staining groups (n = 5); coffee (55°C), grape juice (5°C), deionized water (25°C) and thermocycling (20 000 cycles, 5°C to 55°C with a 30‐second dwell time). Spectrophotometer measurements were taken at baseline and 14 days for each group and the color stability (CIEDE2000) and changes in the translucency parameter (RTPCIEDE2000) and luminous transmittance of each composite were determined. A 2‐way analysis of variance (ANOVA) using maximum likelihood estimations was used for analysis for these changes, with subsequent pairwise comparisons using Bonferroni‐corrected Student's t tests and an experiment‐wise α = 0.05. Results A significant interaction (P < .0001) between material and treatment was found for each change in the esthetic property tested over 14 days. Multiple significant differences between materials for each treatment and between treatments for each material were identified. Conclusions The severity of color change and translucency of resin‐based materials are dependent on their type, mostly affected by the coffee staining medium. Nano‐filled resin composite is most resistant to color change and with stable translucency after artificial aging. Clinical Relevance Nano‐filled resin composite may be the most esthetically durable resin‐ based restorative material. Micro‐hybrid resin composite and resin‐modified glass ionomer restorative material are susceptible to color change and losing their translucency. Hot coffee solution may shorten the esthetic lifespan of a resin‐based material.

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Objective Compare optical properties of a bisacryl‐, composite‐, and ceramic‐resin restorative materials pre and post artificial aging. Methods Bisacryl‐resin (LuxaCrown [LC], DMG), resin‐composite (Filtek Supreme Ultra, [Filtek SU] 3M ESPE), and ceramic‐resin (Enamic, VITA Zahnfabrik) specimens were prepared. The L*, C*ab, and hab values were measured pre and post artificial aging to determine color stability (CIEDE2000) and changes in contrast ratio (CR), transmittance block, and relative translucency parameter. The datasets were analyzed using 2‐way ANOVA followed by pairwise comparisons. Results Color difference data showed a significant interaction between materials and treatments [F(6:60) = 375.04, P < .0001] with Enamic being most color stable material and coffee having most effect on color stability. CR data showed a significant interaction between materials and treatments [F(6:60) = 4.12, P = .0016]. LC showing most change in CR values with coffee treatment. Change in transmittance blocked by Filtek SU and LC was greater for coffee treatment than that by each of the other treatments (P < .0001). Filtek SU and LC, coffee produced a greater decrease in relative translucency than that each of the other treatments (P < .0001). Conclusions Resin‐based materials demonstrate optical properties that encourage their use for direct/indirect restorative options. Color stability and translucency of these materials are proportionally related. Clinical significance Understanding the optical properties of resin‐based materials provides help in material selection and provides insight into clinical performance and esthetic longevity. The optical stability of certain bisacryl‐resin is better than what was previously determined for these restorative materials.

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SUMMARY Objective: Resin-based materials used in restorative dentistry are introduced at a fast pace with limited knowledge about their properties. Comparing properties of these materials from different restorative categories is lacking but can help the clinician in material selection. This study aimed to compare mechanical properties and wear resistance of bis-acryl-, composite-, and ceramic-resin restorative materials. Methods and Materials: Bisacryl-resin (Bis-R, LuxaCrown, DMG), composite-resin (Com-R, Filtek Supreme Ultra, 3M Oral Care), and ceramic-resin (Cer-R, Enamic, VITA Zahnfabrik) specimens were prepared for mechanical tests: fracture toughness (FT) with and without initial thermomechanical loading using a mastication simulator, flexural strength (FS), and flexural modulus (FM), compressive strength (CS), and volumetric wear loss measurement. The datasets for FT and wear resistance were each analyzed using two-way ANOVA followed by pairwise comparisons or Tukey testing as appropriate. The datasets for FS, FM, and CS were analyzed using one-way ANOVA followed by the Tukey test. Results: Analysis of FS, FM, and CS showed significant differences between materials, with all pairwise comparisons between materials showing significance. Analysis of FT resulted in a significant interaction between the material and treatment, with analysis of wear loss showing a significant interaction between the material and the number of cycles. Conclusions: Cer-R demonstrated superior FT, CS, and wear resistance compared to Bis-R and Comp-R materials. Fracture toughness of Bis-R increased after thermomechanical loading.

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