Assessing the Efficacy of Novel Fiber-Reinforced Dual-Cure Luting Resins

Lippo Lassila; Sufyan Garoushi; Enas Mangoush; Pekka K Vallittu; Eija Säilynoja

doi:10.4317/jced.61396

Assessing the Efficacy of Novel Fiber-Reinforced Dual-Cure Luting Resins

J Clin Exp Dent. 2024 Mar 1;16(3):e333-e342. doi: 10.4317/jced.61396. eCollection 2024 Mar.

Authors

Lippo Lassila¹, Sufyan Garoushi¹, Enas Mangoush¹, Pekka K Vallittu^{1

2}, Eija Säilynoja^{1

3}

Affiliations

¹ Department of Biomaterials Science and Turku Clinical Biomaterial Center -TCBC. Institute of Dentistry, University of Turku, Finland.
² Wellbeing Services County of South-West Finland, Turku, Finland.
³ Research Development and Production Department, Stick Tech Ltd - Member of GC Group, Turku, Finland.

Abstract

Background: Dual-cure resin-based luting materials are increasingly favored in clinical applications due to their capacity to establish a strong bond with natural tooth structure and restorations. This study aimed to examine certain physical and handling characteristics of newly developed experimental dual-cure luting resins reinforced with short fibers (SFRCs) and compare them with commercially available dual-cure luting resins.

Material and methods: Seven dual-cure luting materials were tested (Relyx Ultimate, Duo-Link, eCEMENT, Variolink Esthetic, G-CEM LinkForce, experimental SFRC1, experimental SFRC2). Fourier transform infrared spectroscopy (FTIR) was utilized to determine the degree of monomer conversion (DC%) in the self and light-curing protocol. A rotating disk rheometer measured viscosity at room temperature (22°C) and simulated mouth temperature (35°C). Fracture toughness, flexural strength, and flexural modulus were evaluated using a 3-point bending test. Each luting resin was subjected to the examination of its surface microstructure using scanning electron microscopy (SEM). Analysis of variance (ANOVA) at a significance level of (p = 0.05) was conducted to analyze data.

Results: It was revealed that DC% of the tested dual-cure resins was significantly (p< 0.05) affected by the curing mode, the dual-cure SFRC2 having the highest and Relyx having the lowest DC (64%, and 41% respectively). The viscosity of all tested materials decreased with increasing temperature. SFRC2 demonstrated the highest fracture toughness (2.3 MPa m1/2), while Relyx Ultimate, Duo-Link, and eCEMENT exhibited the lowest values (≈ 1 MPa m1/2)(p< 0.05). Both SFRCs and G-CEM link-force exhibited the highest flexural strength values, and SFRCs resulted in the highest flexural modulus values (p<0.05).

Conclusions: The experimental fiber-reinforced dual-cure luting resins exhibited superior DC%, fracture toughness, and flexural properties, yet, SFRC2 showed the highest viscosity at elevated temperature. These results highlight the capability of short fiber reinforcement to enhance the mechanical properties of dual-cured resin-based luting materials without compromising handling characteristics. Key words:Dual-cure luting resin; short fibers; degree of conversion; viscosity; fracture toughness; flexural properties.