Analysis of aerosol generation during Er:YAG laser-assisted caries treatment: A randomized clinical trial

Background. Maintaining biosafety in dental practice involves the effective elimination of aerosols produced during dental treatment. Objectives. To assess the quantity of aerosols and aerobic bacteria in the air during the treatment of caries. Materials and methods. The study involved 60 patients with a total of 60 molar teeth (n = 60) in the mandible who were divided into 2 groups based on caries treatment method. Group 1 (G1, n = 30) received treatment with a conventional dental turbine (W&H Synea TA-98LC; W&H, Burmoos, Austria), while group 2 (G2, n = 30) underwent treatment with an Er:YAG (erbium-doped yttrium aluminium garnet) laser (LightWalker, Fotona, Slovenia). Measurements of aerosol particles between 0.3 mu m and 10.0 mu m near the operator's mouth were taken using the PC200 laser particle counter (Trotec GmbH, Schwerin, Germany). The number of aerobic bacteria in the air was determined using 60 Petri plates with a microbiological medium (Columbia agar with 5% sheep blood) and the sedimentation method. A control group (G3) was established to measure initial aerosol levels and initial total number of bacteria colony-forming units (CFUs) before each treatment. Results. In G1 (dental turbine), the median value of aerosol particles was 57,021 (42,564-67,568), while in G2 (Er:YAG laser), it was significantly lower at 33,318 (28,463-35,484) (p < 0.001). The median total bacteria count per cubic meter of air in G1 (conventional dental turbine + high volume evacuator (HVE)), G2 (Er:YAG laser + HVE) and G3 (control group before caries treatment) were 734 (420-988), 158 (96-288) and 48 (32-74), respectively, with a statistically significant difference between the groups (p < 0.001). Conclusions. The use of Er:YAG laser during caries treatment resulted in a 41.6% reduction in aerosol amounts and a 78.5% decrease in the total bacterial count (TBC) compared to treatment with a dental turbine.