Effect of Different Glass-Ceramics and Resin Cement Curing Modes on the Color Stability of Sectional Laminate Veneers Following Artificial Aging.

Abstract

Background:The purpose of this study is to evaluate the effect of two glass ceramic materials and resin cement curing modes on the color stability of sectional porcelain laminate veneers following artificial aging. Methods: Forty sound human maxillary central incisors were prepared to receive sectional laminate veneers (SLVs) with a thickness of 0.5-0.7 mm. Prepared teeth were randomly divided into 2 equal groups according to ceramic materials used (N=20) as follows: Group I: IPS e.max press. Group II: Celtra press. Each main group was randomly subdivided into 2 equal subgroups according to resin cement used: light and dual cure resin cements (Relyx Veneer) (Relyx Ultimate) respectively. All samples were subjected to 10,000 cycles of thermo-cycling. Color change was measured by laboratory spectrophotometer before and after thermocycling. All the collected data were statistically analyzed by One-way ANOVA followed by Tukey's post hoc test. Results: Color change between restoration and natural side of each sample before and after artificial aging did not reveal significant difference (P<0.05). IPS e.max press showed significant lower color stability with dual and light cure resin cement (ΔE 3.48-ΔE 3.4) than Celtra press (ΔE 2.6-ΔE 3.05). Light cured resin cement used with Celtra press showed statistically significant higher ΔE value than dual cured cement (P>0.05). Conclusions: Celtra press glass ceramic is more color stable than IPS e.max press. Resin cement and aging process influenced the color stability of sectional laminate veneers. Results were clinically accepted for all tested materials in reference to natural teeth (ΔE<3.5). The results may help the patient to aesthetically correct their anterior teeth with a suitable material providing strength and natural teeth looking, in addition to conservation of tooth structure, with optimum esthetics.

Effect of resin cement type on the final color of high translucent zirconia before and after thermocycling: an in vitro study.

“…The color change in Group CH was significantly higher, indicating that dualcured resin-cement lacking amine initiator was more color stable upon cementation. 13, 29 Our results came in agreement with Abdalahalim et al, 30 who found that light-cured resin-cement (RelyX veneer) showed higher color change than amine-free MDPcontaining dual-cured cement (RelyX ultimate) after cementation. However, our results did not coincide with Ural et al, 13 who found that amine-free MDPcontaining dual-cured resin-cement (RelyX ultimate) showed higher color change than lightcured cement (NX3) after cementation.…”

“…Such findings might be attributed to the presence of TEGDMA (in ZR-Cem) and Bis-GMA (in Choice2), which are susceptible to high degree of water sorption upon thermocycling and subsequently hydrolytic degradation causing hydrolysis of polymer bonds, leading to color change. 25,30,35 Bis-GMA in the cement and the adhesive used also has an inherent tendency to turn yellow, especially when exposed to heat. 34 Additionally, in Choice2, these changes might be attributed to presence of camphorquinone, which although useful in initiating the polymerization reaction, it is a yellowish compound that degrades and causes cement discoloration over time.…”