Early Application of Er,Cr:YSGG Laser in Endodontics: Effects on Patency Achievement and Debris Reduction

A crown-down instrumentation approach has been recommended to prevent debris extrusion from infected root canals. The aim of this study was to investigate the impact of a crown-down irrigation approach involving application of an early step of laser-activated irrigation (LAI) before establishing initial patency or completing instrumentation. Additionally, the impact of early LAI on time required to achieve initial patency and canal cleanliness was investigated and compared to conventional needle irrigation (CNI).

One hundred twenty roots of extracted permanent maxillary molars were treated with a LAI or CNI irrigation protocol using 3% sodium hypochlorite (NaOCl) early in chemo-mechanical preparation. Time required to achieve initial patency was recorded. A scanning electron microscopic (SEM) investigation was conducted using 10 root canals from each irrigation protocol and five additional control root canals. The debris remaining on the root canal walls was scored and compared.

No significant difference was found for time required to establish initial patency between LAI and CNI groups (p = .534). In the SEM investigation, a significant difference in the debris scores among LAI, CNI, and control groups (p < .001) was found. The LAI group had significantly lower debris scores than the control and CNI groups (p < .001).

Early implementation of the laser in the chemo-mechanical preparation had no measurable impact on time required to establish initial apical patency. However, early LAI with NaOCl resulted in a significant reduction in the amount of root canal wall debris compared to CNI and control groups.