Effect of 9.3 μm CO2 and 2.94 μm Er:YAG Laser vs. Bur Preparations on Marginal Adaptation in Enamel and Dentin of Mixed Class V Cavities Restored With Different Restorative Systems

This study aimed to compare marginal adaptation in enamel and dentin before after aging of laser vs. bur-prepared mixed class V cavities restored by different restorative systems. Seventy two caries-free human molars were distributed nine experimental groups; prepared using lasers: a handpiece -integrated 2.94 μm Er:YAG at 4.5 W, 300 mJ, 0.75 50 mJ with 15 Hz (LiteTouch, Light Instruments, Israel) novel CO 2 12.95 19.3 4.1 6.11 671 (Solea 9.3 μm, Convergent Dental, USA). Cavities conventional diamond burs (Intensiv, Switzerland) red contra angle high speed under maximal water cooling served as control. simulation dentinal fluid three self-etching universal adhesives combination nanohybrid composites, applied layers: Scotchbond Universal Filtek Supreme XTE (3M, USA), G-Premio BOND Essentia (GC, Japan), OptiBond Harmonize (Kerr, After restorations' polishing simultaneous thermal (5–50°C, min each) mechanical loading (max. 49 N; 200,000 cycles), replicas restoration margins examined SEM × 200 magnification. Percentages continuous (CMs) quantified the fatigue test statistically compared (two-way ANOVA Fisher's least significant difference [LSD] post hoc test). Significant differences found almost all groups between results test, well preparation tools materials ( p < 0.05). Traditional bur preparations are confirmed gold standard dentin, tested systems provide more than 80% CM loading. can be equally effective SBU/Filtek XTE. ablation could not convincing Marginal has been highly dependent on substrate showed impaired adhesion, especially enamel. Universal/Filtek highest most stable values CM. The other device substrate.