Evaluation of the Effect of Cavity Preparation Using Er,Cr:YSGG Laser on Microleakage of Class V Composite Restorations

The application of laser in dentistry for medical purposes such as caries removal, preparation of restorative cavities, and dental surface treatment for more effective bonding of restorative materials to the tooth has been significant. The present experimental study aimed to evaluate the effect of cavity preparation on microleakage by using erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) lasers, and to compare it with the effect of bur on microleakage in class V composite restorations.

In this experimental study, 20 intact human premolar teeth were randomly divided into 2 equal groups according to the cavity preparation technique: G1: laser cavity preparation (LCP) using a Er,Cr:YSGG laser (Bio Lase, USA), and G2: bur cavity preparation (BCP). Standard class V cavity was prepared on both lingual and buccal surfaces in two groups. The samples underwent thermocycling for 3000 times (5-55ºC) and were immersed in a methylene blue 2% solution for 24 hours. After buccolingual sectioning from the middle of the restoration, a stereomicroscope with 20 x magnification was used to measure the penetration rate of the dye and to determine the score for microleakage. Data were analyzed using SPSS (version 16) software and Mann-Whitney U test (α=5%).

According to the study results, the minimum and maximum microleakage values were observed in the occlusal and gingival margins, respectively, which were identically for both groups. Comparing two groups (BCP and LCP) revealed that there was no significant difference between them in terms of microleakage values at the occlusal and gingival margins (P>0.05).

It was concluded that cavity preparation using Er,cr:YSGG laser had microleakage values similar to those found with conventional cavity preparation (bur) method in class V composite restorations