Juliana Da Costa

The effect of various dentifrices on surface roughness and gloss of resin composites

OBJECTIVES The purpose of this study was to evaluate the effect of different levels of abrasiveness (RDA) of dentifrices on the gloss and surface roughness of resin composites after toothbrushing. METHODS Sixty disk-shaped composite specimens (D=10.0mm, 2-mm thick, n=15 per material) were made of: microfill (Durafill), nanofill (Filtek Supreme), minifill hybrid (Filtek 250), and nanohybrid (Premise). One side of each specimen was finished with a carbide bur and polished with Enhance and Pogo. Five specimens of each composite were randomly assigned to one of the dentifrices, Colgate Total (CT; RDA 70), Colgate baking soda & peroxide whitening (CBS; RDA 145), and Colgate tartar control & whitening (CTW; RDA 200). Surface gloss was measured with a glossmeter and surface roughness with a profilometer before and after toothbrushing with a 1:2 slurry (dentifrice/deionised water) at 5760 strokes in a brushing machine (approximately 1Hz). Results were analyzed by three-way ANOVA/Tukeys (p<0.05). RESULTS There was a significant reduction in gloss and increase in surface roughness after brushing with all dentifrices. There was no significant difference in gloss when Durafill was brushed with any dentifrice; the other composites showed less gloss reduction when brushed with CT. Durafill, Supreme and Premise did not show significantly different surface roughness results and CBS and CTW did not produce significantly different results. CONCLUSIONS Dentifrices of lower abrasivity promote less reduction in gloss and surface roughness for composites of different particle sizes after brushing. Composites containing smaller average fillers showed less reduction in gloss and less increase in surface roughness than ones with larger fillers.

Comparison of Various Resin Composite Shades and Layering Technique with a Shade Guide

PURPOSE The purpose of this study was to compare the final shade of different shades of composites (enamel shades) over a white backing (WB) and black backing (BB), and a layering technique (enamel over dentin composite) with the corresponding Vita Classical Shade tabs (VST). MATERIALS AND METHODS Composite disk specimens enamel (N = 5) shades B1, B2, A1, and A2, and dentin (N = 1) shades A1, A2, and A3 were made. The color of the VST B1, B2, A1, and A2, enamel shade disks, and layering composites of the same brand and different brands were assessed using a colorimeter over a WB and BB. The total color difference (DeltaE*(ab) = [(DeltaL*)(2) + (Deltaa*(ab))(2) + (Deltab*(ab))(2)](1/2)) between the VST and the corresponding resin composite was calculated. The results were analyzed by one-way analysis of variance/Tukeys test (p < 0.05). RESULTS Overall, the L*, a*, and b* values of the enamel composite shades were significantly different from the corresponding VST. Only a few layered composites matched the L*, a*, and b* of the keyed VST. Out of the 72 combinations, 20 (28%) resulted in DeltaE*(ab) below the 3.3 clinically perceptible limit. CLINICAL SIGNIFICANCE Composite shades do not match well to the Vita shade guide tabs, even when the layering technique is used. As demonstrated in this study, only a few composites matched the corresponding Vita shade guide tabs. (J Esthet Restor Dent 22:114-126, 2010).

Comparison of Efficacy of an In‐Office Whitening System Used with and without a Whitening Priming Agent

PURPOSE The purpose of this study was to compare the whitening efficacy of an in-office whitening system with and without the whitening primer application and evaluate tooth and soft tissue sensitivity. MATERIALS AND METHODS This was a randomized, split-mouth design, single-blinded, clinical study. Twenty-five patients received a whitening priming agent (Power Swabs, Power Swabs Corporation, Beaverton, OR, USA) on right or left maxillary incisors prior to in-office tooth whitening with Opalescence Boost (38% hydrogen peroxide; Ultradent Products, Inc., South Jordan, UT, USA). Color was evaluated with the Bleachedguide 3D Master (Vita Zahnfabrik, Bad Sackingen, Germany) and Vita Easyshade spectrophotometer (Vident, Brea, CA, USA), after 30 minutes, 1 day, and 15 days postwhitening. After each tooth color measurement, the subjects were asked to rate their tooth and soft tissue sensitivity experience using a visual analog scale (1-10 categories). Results were analyzed by two-way repeated measurements analysis of variance/Tukeys (p<0.05); Mann-Whitney rank sum test and Kruskal-Wallis. RESULTS The teeth that were treated with the primer prior to tooth whitening did not show significant difference in ΔL*, Δa*, Δb*, ΔE* and delta shade guide from the teeth that were not treated with the primer, at the three time points evaluated (baseline versus 30 minutes after in-office treatment, baseline versus 1 day, and baseline versus 15 days). None of the subjects experienced soft tissue sensitivity, and those who experienced tooth sensitivity said it was not noticeable after 15 days postwhitening. CLINICAL SIGNIFICANCE The primer neither enhanced the whitening effect nor decreased tooth sensitivity when used before vital bleaching with Opalescence Boost (Ultradent Products, Inc., South Jordan, UT, USA). None of the subjects experienced soft tissue sensitivity, and some experienced transient tooth sensitivity.

Color and contrast ratio of resin composites for whitened teeth

OBJECTIVES The purpose of this study was to determine the optical properties, color and contrast ratio (CR) of commercially available resin composites marketed for the restoration of whitened teeth. METHODS Twenty-six resin composites designed for restoration of whitened teeth and four shade B1 (control) were evaluated. Five resin composite disks (d=12mm, h=1.54mm) were fabricated for each shade of composite and were stored in water at 37 degrees C for at least 24h. A colorimeter was used to measure specimen color over both white and black backgrounds. CIELAB and CIExyY color spaces were used. The CIELAB color notation system provides values for L*a*b*. The CIExyY system provides lightness and chromaticity values, where Y represents lightness and xy chromaticity. The contrast ratio (CR) was assessed using, CIE xyY, of the specimens against black (Yb) and white (Yw) backgrounds, with CR=Yb/Yw. The data for L*, a*, b* and CR were analyzed by one-way ANOVA, Tukeys test, and the correlation L* and CR was analyzed by Pearson correlation test (alpha=0.05). RESULTS Significantly different L*, a*, b* values and CR were observed. Premise XL2 had the highest L* and CR values and Vit-l-escence PS had the lowest. Vit-l-escence PS had the highest a* value and Point 4XL2 had the lowest, Premise XL1 had the highest b* value and Supreme WB the lowest. The L* and CR correlation was positive and statistically significant. CONCLUSIONS Composites designated for whitened teeth have different levels of color and contrast ratio. Awareness of the optical properties of the composites allows the operator to choose the appropriate materials to mimic the remaining tooth structure.

Clinically relevant issues related to preheating composites: Commentary

Resin composite is the most commonly used material for direct placement restorations. In particular, composite is now used more frequently than amalgam for direct posterior restorations. However, resin composite still suffers from some disadvantages, including the use of an adhesive interfacial bond that degrades with time, moisture, and function in the mouth, and certain key mechanical properties (e.g., modulus of elasticity) that are inferior to those of amalgam. As such, there is a concern that the resin composite should be inserted into a preparation with as few voids as possible to enhance interfacial adaptation, and maximizing the composite degree of conversion so as to maximize mechanical properties. The use of preheated composite has been suggested to aid in both of these goals. This Critical Appraisal looks at evidence in the peer-reviewed scientific literature that examines the value of inserting warm composite into cavity preparations.

Composite preheating: Effects on marginal adaptation, degree of conversion, and mechanical properties: Commentary

Resin composite is the most commonly used material for direct placement restorations. In particular, composite is now used more frequently than amalgam for direct posterior restorations. However, resin composite still suffers from some disadvantages, including the use of an adhesive interfacial bond that degrades with time, moisture, and function in the mouth, and certain key mechanical properties (e.g., modulus of elasticity) that are inferior to those of amalgam. As such, there is a concern that the resin composite should be inserted into a preparation with as few voids as possible to enhance interfacial adaptation, and maximizing the composite degree of conversion so as to maximize mechanical properties. The use of preheated composite has been suggested to aid in both of these goals. This Critical Appraisal looks at evidence in the peer-reviewed scientific literature that examines the value of inserting warm composite into cavity preparations.

In vivo temperature measurement: Tooth preparation and restorations with preheated resin composite: Commentary

Resin composite is the most commonly used material for direct placement restorations. In particular, composite is now used more frequently than amalgam for direct posterior restorations. However, resin composite still suffers from some disadvantages, including the use of an adhesive interfacial bond that degrades with time, moisture, and function in the mouth, and certain key mechanical properties (e.g., modulus of elasticity) that are inferior to those of amalgam. As such, there is a concern that the resin composite should be inserted into a preparation with as few voids as possible to enhance interfacial adaptation, and maximizing the composite degree of conversion so as to maximize mechanical properties. The use of preheated composite has been suggested to aid in both of these goals. This Critical Appraisal looks at evidence in the peer-reviewed scientific literature that examines the value of inserting warm composite into cavity preparations.

Effect of preheating resin composite on restoration microleakage: Commentary

Resin composite is the most commonly used material for direct placement restorations. In particular, composite is now used more frequently than amalgam for direct posterior restorations. However, resin composite still suffers from some disadvantages, including the use of an adhesive interfacial bond that degrades with time, moisture, and function in the mouth, and certain key mechanical properties (e.g., modulus of elasticity) that are inferior to those of amalgam. As such, there is a concern that the resin composite should be inserted into a preparation with as few voids as possible to enhance interfacial adaptation, and maximizing the composite degree of conversion so as to maximize mechanical properties. The use of preheated composite has been suggested to aid in both of these goals. This Critical Appraisal looks at evidence in the peer-reviewed scientific literature that examines the value of inserting warm composite into cavity preparations.