Color stability and translucency of ceramic laminate veneer restoration for diastema closure: Effect of resin cement containing different photoinitiators

Abstract

Objectives: To investigate the color stability and translucency of different ceramic laminate veneers for diastema closure bonded with resin cement using different photoinitiating systems based on benzoyl germanium compounds and iodonium salts.Materials and Method: Sixty abutments were milled from a polymethyl methacrylate disc to duplicate a maxillary left central incisor tooth model that had been prepared for laminate veneer restoration. The abutments were devided into six groups (n=10) according to the ceramic type (lithium disilicate, zirconia reinforced lithium silicate, and translucent zirconia) and cement type (Variolink Esthetic LC and RelyX Veneer). Each laminate veneer was bonded to its respective abutment and stored in water for 24 hours. The color coordinates and translucency were analyzed with a reflectance spectrophotometer after cementation and after immersion in coffee solution. The translucency parameters and contrast ratio were measured. The color and the translucency differences were calculated and the data were analyzed (α=.05). The differences in color and translucency were estimated, and the results were statistically assessed (=.05). Results: Ceramic materials showed a significant impact (P ˂.001) on the color changes after coffee immersion within the Variolink Esthetic LC groups. Ttranslucent zirconia showed the highest color change, followed by zirconia reinforced lithium silicate and lithium disilicate. Among the RelyX Veneer groups, the ceramic materials showed a significant impact (P ˂.001). Translucent zirconia showed the highest color change, followed by zirconia reinforced lithium silicate and lithium disilicate. The two-way ANOVA test showed a significant interaction in color changes between ceramic type and cement type after cementation (P=.040), and after coffee immersion (P=.001). All groups showed a clinically acceptable difference in translucency parameters after coffee immersion. The two-way ANOVA test found a non-significant effect (P=.151) on translucency changes.Conclusions: Cement selection is important for the color stability and translucency of ceramic laminate veneers after coffee staining. Lithium disilicate veneer is more resistant to coffee staining than zirconia-reinforced lithium silicate and translucent zirconia veneers. Ceramic laminate veneers bonded with resin cement contain benzoyl germanium compounds (Variolink Esthetic LC) are more translucency. However, ceramic laminate veneers bonded using resin cement contain iodonium salts (RelyX Veneer) are more resistant to coffee staining. Clinical relevance: The dentists have to face challenges of predicting the final color of various ceramic laminate veneer restorations used for diastema closure and estimating its color stability after final cementation.

Influences of luting cement shade on the color of various translucent monolithic zirconia and lithium disilicate ceramics for veneer restorations

“…Factors such as the type of filler, resin matrix, photoinitiator, polymerization, and degree of conversion affect the color of resin cements. 6 As a result, comparable colors but different cement types could have a varied effect on the color of the final restoration. 22 23 Several scholars have reported higher ΔE values than the Rely X Veneer groups when using Variolink Esthetic.…”

“… 22 23 Several scholars have reported higher ΔE values than the Rely X Veneer groups when using Variolink Esthetic. 6 24 The authors attributed these high values to the presence of a different photoinitiator (Ivocerin) in Variolink Esthetic cement, which when exposed to light, reacted with monomers to promote polymerization. This phenomenon resulted in increased polymerization, improved reactivity to the curing light and increased depth of cure.…”

“…Resin cements are supplied in different shades to mask the color of the underlying tooth structure and to further aid in color matching to the adjacent natural tooth. 6 7 8 9 10 11 Therefore, the cement shade may influence the color of the overlying ceramic veneer. In fact, by using an opaque cement shade, Comba et al stated that the opacity of ceramic materials tested (Katana Zirconia and Lithium Disilicate) was influenced by the cement shade and material type; but translucency was only affected by the ceramic type and not by the shade of the cement.…”

Physical, Optical, and Mechanical Properties of Ceramic Materials after Coffee Immersion and Evaluation of Cleaning Impact with Different Oral Hygiene Tools

“…Lithium disilicate glass ceramic (LDGC), which is usually marketed as IPS e.max CAD, is made up of a 70% crystalline matrix [ 12 ]. Additionally, well-documented characteristics of its distinctive microstructure are its biocompatibility, excellent light transmission, good mechanical strength, low thermal conductivity, and abrasion resistance [ 13 , 14 ].…”

“…The perception of tooth color is acknowledged to be an intricate phenomenon, and the visual assessment of tooth color may get affected by external and internal stains, tooth mineral content, lighting, color of the lip, and assessor experience. Numerous in vitro investigations indicate that ceramics have more superior color stability compared to other dental materials [ 13 , 16 , 17 , 18 , 19 , 20 ]. Alghazali et al in 2019 evaluated the influence of Arabic coffee on the color of glazed or polished different porcelain veneers.…”