The effect of diode compared to Erbium: YAG lasers on radicular dentin micro hardness during root canal treatment (a comparative in vitro study)

The sterilization of root canals is the most important cause of endodontic treatment success. Nowadays the use of laser in sterilization of the root canals has increased, therefore, the aim of this in vitro study is to evaluate and compare the effect of different lasers used for root canals sterilization on dentin micro hardness.

The sample of this study consisted of 30 recently extracted, single-rooted canal, permanent human teeth. The root canals were prepared using rotary Protaper system, then the sample was randomly divided into three equal groups of 10 teeth each, according to the laser type used: (Group 1: Diode 810 nm laser + 5.25% sodium hypochlorite (NaOCl), Group 2: Erbium: YAG (Er: YAG) 2940 nm laser + 5.25% NaOCl, and group 3 (control group): was irrigated only with 5.25% NaOCl. Each root was then sectioned longitudinally, then embedded in acrylic block, and polished to record dentin Vickers hardness (VH). Data were analyzed using one-way ANOVA and Bonferroni statistical tests with (P-value ≤ 0.05) as the level of significance.

results showed that there were significant differences between VH of sample irradiated with diode 810 nm and NaOCl, meaning that diode 810 nm laser treatment had increased dentin micro hardness. Samples irradiated with Er: YAG increased dentin micro hardness, however there were no statistically significant differences between its VH and NaOCl group. Group 1 showed to attain better micro hardness than group 2 during endodontic sterilization.

The diode 810 nm laser outperformed both Er: YAG 2940 nm and 5.25% NaOCl in terms of increasing the microscopic hardness of dentin during endodontic treatment.