The effect of Er, Cr : YSGG laser on the reduction of the root canal bacteria in cases with contracted endodontic access cavity design : An in-vitro study /

Abstract

There is minimal scientific evidence concerning the effect of contracted endodontic access cavity design (CEC) combined with Erbium, Chromium: yttrium-scandium-gallium garnet (Er,Cr:YSGG) laser on intracanal bacterial biofilm reduction. So, the aim of the present in-vitro study was to compare the antimicrobial efficacy of sodium hypochlorite and Er,Cr YSGG laser on E.faecalis biofilm reduction when employing two different endodontic access cavity designs in maxillary first premolar teeth. Sixty intact maxillary first premolar human teeth were randomly allocated into two main equal groups (n=30) according to the access cavity design utilized. Group 1, traditional access cavity preparation and Group 2, contracted access cavity preparation. Following access cavity preparation initial root canal preparation was performed, teeth were then sterilized, and inoculated with E.faecalis for 21 days. Colony forming units (CFUs) per milliliter counts were determined after inoculation to ensure biofilm growth. Mechanical preparation was performed using ProTaper Gold rotary NiTi system up to size F2. The first bacteriological sample (S1) was obtained following mechanical preparation. The teeth of each main group were further divided into 3 equal subgroups (n=10) according to the final disinfection protocol. Group A, irrigation using Saline solution; Group B, irrigation with 5.25% NaOCl and 17% EDTA; Group C, (Er,Cr: YSGG) Laser irradiation. A second bacteriological sample (S2) was obtained following the final disinfection protocol. Microbiological quantification was performed for samples using paper points and CFU. The results showed that only NaOCl completely eradicated E.faecalis bacterial biofilm in both cavity designs. Er,Cr: YSGG laser subgroups (1C and 2C) showed significantly higher bacterial reduction in comparison to saline irrigated groups (1A and 2A). Access cavity design had a significant effect on bacterial biofilm reduction in both subgroups; saline irrigated samples (A) and laser irradiated groups (C) in which traditional access cavity design exhibited higher bacterial reduction than contracted access cavity design, however, the design had no influence on bacterial reduction when NaOCL irrigation was used