LIGHT-CURING DISTANCE AND RESIN THICKNESS EFFECTS ON THE SHORTFIBER–REINFORCED RESIN COMPOSITES' DEPTH OF CURE

Objective: This study evaluated the light-curing distance and resin thickness effects on the depth of cure of short fiber–reinforced resin composites (SFRCs).Methods: Fifteen SFRC specimens with a diameter of 6 mm and thickness of 4 mm were divided into groups (n=5) with light-curing distances of 0, 2, and 4 mm. Another 15 specimens with a diameter of 6 mm and thicknesses of 3, 4, and 5 mm (n=5) were subjected to a 0-mm light-curing distance. Microhardness tests were conducted using a Vickers hardness tester (load: 200 g; dwell time: 15 s), and the depth of cure was assessed by calculating the hardness ratio of the bottom to the top surface (%). Statistical tests included one-way analysis of variance (ANOVA) followed by post hoc Fisher's LSD tests.Results: The depths of cure with 0-, 2-, and 4-mm light-curing distances were 79.0±0.7%, 77.0±0.6%, and 75.0±0.8%, while those with thicknesses of 3, 4, and 5 mm were 81.0±1.0%, 78.2±1.0%, and 34.4±2.0%, respectively. Significant differences (p<0.05) in the depth of cure were found in all groups.Conclusion: A depth of cure >80% was only attained with a 3-mm resin thickness and 0-mm light-curing distance