EFFECT OF PREHEATED RESIN COMPOSITE LUTING AGENT ON FLEXURAL STRENGTH OF LITHIUM DISILICATE CERAMIC AT CEMENT-CORE INTERFACE

Abstract

Objective: This study aimed to evaluate the effect of a pre-heated resin composite luting agent on the biaxial flexural strength of lithium disilicate ceramic bonded to a resin composite substrate, simulating immediate dentin sealing or composite core build-up.

Materials and Methods: Fifty-two heat-pressed, crystallized, and glazed lithium disilicate discs (diameter = 10 mm, thickness = 1 mm) were fabricated and randomly assigned to four groups (n = 13) based on the luting agent used: (1) pre-heated resin composite at 68°C (PRC), (2) dual-cured resin cement (DC), (3) light-cured resin cement (LC), and (4) high-strength flowable resin composite (HSF). Biaxial flexural strength was evaluated for all specimens. Data normality was assessed using the Shapiro-Wilk test (α = 0.05). Differences among groups were analyzed using one-way ANOVA followed by post-hoc multiple comparison tests.

Results: The flexural strength of lithium disilicate ceramics varied significantly depending on the luting material applied. Mean biaxial flexural strength values increased in the following order: LC < DC < PRC < HSF. The PRC group exhibited significantly higher flexural strength compared to the DC and LC; however, no significant differences were observed between DC and LC groups.

Conclusion: Pre-heated resin composite as an alternative luting agent provides comparable or superior mechanical support to lithium disilicate restorations compared to conventional resin cements, offering clinical guidance for material selection to optimize restoration durability.

Keywords: Pre-Heated Resin Composite, Lithium Disilicate, Biaxial Flexural Strength, Luting Agent, Resin Cement