Masking ability of bleach‐shade resin composites using the multilayering technique

Abstract

Objective Evaluate the masking ability of bleach‐shade resin composites applied by multilayering techniques over colored substrates. Materials and methods Disc‐shaped specimens were fabricated from bleach‐shade resin composites using different multilayering techniques. Substrates were produced in opaque ceramic discs simulating colored substrates (A2, A3, A3.5, C2, C3, C4) and a bleached tooth (0M1). Color coordinates were obtained using a reflectance spectrophotometer. Color difference was calculated by CIEDE2000 using coordinates of 0 M1 ceramic as standard reference. Data were analyzed by one‐way ANOVA and Tukey's post‐hoc test (p ≤ 0.05). Masking ability interpretation was based on perceptibility and acceptability thresholds. Results All combinations presented ΔE00 above the acceptable threshold (ΔE00>1.8), ranging from 2.49 to 7.42, regardless of the restorative system, multilayering strategy or substrate color. Multilayering combinations placed over A2, A3 and A3.5 were moderately (1.8<ΔE00≤3.6) and clearly unacceptable (3.6<ΔE00≤5.4), combinations associated with C2, C3 and C4 were clearly unacceptable and, extremely unacceptable (ΔE00>5.4). Lower ΔE00 was observed for combinations with 0.5 mm extra white enamel layer (2.49), or 1.0 mm white dentin layer (2.69), over A2 and A3.5 substrates. Lightness difference showed the greatest contribution to ΔE00. Conclusions Bleach‐shade resin composite systems applied by the multilayering technique were not able to ensure effective masking ability. Clinical significance Bleach‐shade resin composites applied with different combinations of the multilayering technique were not effective in masking colored substrates. Alternative strategies, techniques and dental materials should be explored to obtain acceptable masking.

Masking Ability of Bleach Shade Composite Resins in Different Thicknesses

“…However, few studies have been conducted on the optical properties of bleach shade composites [ 32 ]. In a recent study, which examined the masking ability of bleach shade composite resins in different layering techniques, it was observed that they cannot mask the different background colors [ 33 ].…”

Influence of manufacturing technique on the color of zirconia restorations: Monolithic versus layered crowns

“…Three brands of 3Y‐TZP zirconia were selected to fabricate 45 anterior crowns with 1 mm labial thickness, using three different manufacturing techniques: (a) monolithic ( n = 5), (b) cut‐back and enamel layering (bi‐layer) ( n = 5), (c) cut‐back and dentine and enamel layering (tri‐layer) ( n = 5). The sample size was based on the results from previous studies 33–37 . The zirconia and the veneering ceramics used in this study are presented in Table 1.…”

“…The sample size was based on the results from previous studies. [33][34][35][36][37] The zirconia and the veneering ceramics used in this study are presented in Table 1.…”

Masking Ability of Monolithic and Layered Zirconia Crowns on Discolored Substrates

“…Although extensive research has been recently conducted on the masking ability of restorative materials [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ], there is still missing information on how color differences might impact visual perception when translucent restorations are evaluated over different discolored substrates. Furthermore, there is little information about the colorimetric behavior of monolithic and layered zirconia crowns in combination with various abutment colors.…”

“…Furthermore, there is little information about the colorimetric behavior of monolithic and layered zirconia crowns in combination with various abutment colors. Most studies evaluated the masking ability using rectangular or disc samples [ 12 , 13 , 15 , 16 , 17 , 19 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ], which do not reproduce the clinical conditions met in the oral cavity.…”