Optimizing dental resin polymerization: the impact of multiple wavelength light-curing units

Abstract

Objective: This study aims to evaluate the influence of variable wavelengths on the polymerization and degradation of microhybrid dental composites with different photoinitiator systems. Material and Methods: Three types of resin were analyzed: EMPRESS DIRECT TRANS 30 (IVOCLAR) (ED) with an alternative photoinitiator, VITTRA APS (FGM) (VA) utilizing an APS system and Z100 (3M) (Z) containing only camphorquinone. Vickers microhardness (DV), compressive strength (RC), and solubility (S) tests were conducted, creating the following groups with 10 samples per group: A1: ED light-cured by monowave, A2: ED light-cured by biwave, B1: VA light-cured by monowave, B2: VA light-cured by biwave, C1: Z light-cured by monowave, C2: Z light-cured by biwave. Results: RC (Mpa): A1: 249.88 (36.73), A2: 174.31 (19.68), B1: 240.78 (26.17), B2: 207.7 (35.6), C1: 268.74 (31.15), C2: 202.77 (31.56). S: A1: 0.0005, A2: 0.0001, B1: 0.0005, B2: 0.0005, C1: 0.0004, C2: 0.0002. DV (HV): A1: 35.59 (4.88), A2: 37.97 (4.27), B1: 70.33 (12.75), B2: 73.64 (9.7), C1: 129.59 (12.85), C2: 128.33 (18.91). Groups A and E showed significantly higher compressive strength than B and (A/B; P=0.0007, E/F; P=0.0035, ANOVA followed by Tukey test). No significant difference was detected between groups C and D. Conclusion: The correct association between wavelength and photoinitiator is important for compressive strength. The APS system showed compatibility with both types of LCUs.

KEYWORDS

Chemical Waste Degradation; Composite resin; Compressive strength; Dental Curing Lights; Hardness.