Avaliação de desempenho estético e estabilidade de cor de duas resinas compostas monocromáticas: um estudo in vitro

Abstract

Monochromatic resins promise to change their color after polymerization, matching the tooth. These resins have a chromatic technology related to the composition of filler particles of special size and shape that would be capable of generating a chameleon effect to copy the color of the restored tooth. However, recent studies indicate color variations (ΔE) greater than the reference (ΔE<3.7) for clinical acceptability. This study aimed to verify the adaptation and color stability of two monochromatic composite resins. Fifty-four upper anterior stock teeth (Vita Zahnfabrik, Sackingen, Germany) in shades A1, A2 and A3 prepared with class III (CLIII) and class V (CLV) cavities were used. The restorations were made with Omnichroma (OMC) resin (Tokuyama, Tokyo, Japan) and Vitra APS Unique (Dental Group, Joinville, Brazil) (T0). Using digital color analysis software, the ΔE between the tooth and restoration was calculated using the CIEDE2000 formula. The teeth were immersed for 14 days in whole grape juice and a new analysis was performed to compare color stability (T1). The results showed that there was no difference in the mean ΔE00 for restorations made with OMC (MT0=3.79 [±1.24]; MT1=11.59 [±5.48]) and Unique (MT0=4.46 [±1.92]; MT1=12.05 [±4.38]) at T0 and T1 (p<0.05). The mean ΔE00 value of restorations performed with OMC (MT1=11.59; MT0=3.79 t=-8.02) and Unique (MT1=12.05; MT0=4.46 t=-12.09) resin at T1 was higher than the mean ΔE00 value at T0 (p<0.05). The comparison of the different chromas of the Unique composite resin at T0 showed that the mean ΔE00 of chroma A1 (MT0=3.11 [±0.91]) was lower than that of chroma A3 (MT0=6.08 [±1.70]) (p=0.0001). And the mean ΔE00 of chroma A2 (MT0=4.17 [±1.75]) was lower than that of chroma A3 (p=0.011). The mean ΔE00 of class III preparations (MT0= 5.46 [±2.02]; MT1=14.58 [±4.31]) presented higher values than CLV preparations (MT0= 3.46 [±1.19]; MT1=9.52 [±2.72]), for restorations made with Unique composite resin at T0 and T1, and for those made with Omnichroma composite resin (CLIII, MT 1=14.36 [±5.26]; CLV, MT1=8.82 [±4.23]) at T1 (p<0.05). Conclusion: the monochromatic resins evaluated did not present satisfactory results for clinical acceptability of color in all cases, both presented pigmentation after exposure to the pigmenting agent, and the class III preparation presented worse results after pigmentation.