Marginal adaptation in enamel and dentine of mixed class V cavities prepared with a Quantum Square Pulse Er:YAG laser
CUMD, University of Geneva, Geneva, Switzerland
Izabella Nerushay, Anastasia Ryabova, Ivo Krejci
Objective: To evaluate marginal adapta2on of mixed class V composite restora2ons in cavi2es prepared with the new highly efficient Quantum Square Pulse (QSP) mode Er:YAG laser (LightWalker, Fotona),
compared to diamond bur prepara2on. Methods: Best laser parameters with the noncontact handpiece were determined in a pretest by SEM micromorphological evalua2on of enamel and den2ne by varying pulse length, power and water spray seOngs. 21 extracted caries-‐free human third molars were subsequently randomly equally distributed into Gr. 1: Laser 300mJ/12Hz; Gr. 2: Laser 300mJ followed by 120mJ/12Hz and Gr. 3: Diamond bur. All cavi2es were restored with Clearfil SE Bond (Kuraray) and Clearfil AP-‐X (Kuraray) composite under den2nal fluid simula2on. SEM marginal adapta2on analysis at 200x magnifica2on was performed on replicas before and a`er thermo-‐mechanical cyclic loading (TML). Results: The mean % of "con2nuous margin" before/a`er TML in enamel were Gr.1: 86.7/80.6; Gr.2: 95.7/88.6; Gr.3: 96.1/93.1 (ANOVA; p>0.05/>0.05) and in den2ne Gr.1: 97.3/88.5; Gr.2: 96.7/93.4; Gr.3: 91.6/81.0 (ANOVA; p>0.05/>0.05) Conclusions: No significant differences in % "con2nuous margin" were detected for laser prepared cavi2es in comparison to bur prepared cavi2es, both in enamel and den2ne, before and a`er loading. Among the two laser groups, there was a trend towards bemer marginal adapta2on in enamel with 300mJ/120mJ compared to 300 mJ only.