Confocal laser scanning microscopy-based evaluation of penetration depth and image analysis of root canal wall...

The complex anatomy of the root canal system often limits the effectiveness of mechanical instrumentation alone, necessitating enhanced irrigation protocols for thorough disinfection.

The aim of this study was to evaluate the effect of passive ultrasonic activation (PUI) with and without intracanal-heated sodium hypochlorite (NaOCl) on dentinal tubule penetration and root canal wall debridement.

Forty-eight extracted single-rooted human teeth were prepared and divided into three groups: conventional NaOCl irrigation, NaOCl with PUI, and intracanal-heated NaOCl with PUI. The penetration depth was assessed using confocal laser scanning microscopy, and canal cleanliness was evaluated histologically using hematoxylin and eosin staining based on standardized scoring criteria.

The group receiving intracanal-heated NaOCl with ultrasonic activation (Group III) showed significantly greater dentinal tubule penetration and cleaner canal walls across all root thirds compared to the other groups (Group I and Group II).

Intracanal heating of NaOCl combined with passive ultrasonic activation significantly enhances irrigant efficacy in terms of penetration and debridement.