Biofilm in Endodontics: In Vitro Cultivation Possibilities, Sonic-, Ultrasonic- and Laser-Assisted Removal Techniques and Evaluation of the Cleaning Efficacy

Incomplete and inadequate removal of endodontic biofilm during root canal treatment often leads to the clinical failure. Over the past decade, biofilm eradication techniques, such as sonication of irrigant solutions, ultrasonic and laser devices have been investigated in laboratory settings. This review aimed to give an overview of endodontic biofilm cultivation methods described in papers which investigated sonic-, ultrasonic- and Er:Yag laser-assisted biofilm removal techniques. Furthermore, the effectiveness of these removal techniques was discussed, as well as methods used for the evaluation of the cleaning efficacy. In general, laser assisted agitation, as well as ultrasonic and sonic activation of the irrigants provide a more efficient biofilm removal compared to conventional irrigation conducted by syringe/needle. The choice of irrigant is an important factor for reducing the bacterial contamination inside the root canal, with water and saline being the least effective. Due to heterogeneity in methods among the reviewed studies, it is difficult to compare sonic-, ultrasonic- and Er:Yag laser-assisted techniques among each other and give recommendations for the most efficient method in biofilm removal. Future studies should standardize the methodology regarding biofilm cultivation and cleaning methods, root canals with complex morphology should be introduced in research, with the aim of simulating the clinical scenario more closely.

Automated summary

Incomplete and inadequate removal of endodontic biofilm during root canal treatment often leads to clinical failure. This review provides an overview of endodontic biofilm cultivation methods and discusses the effectiveness of sonic-, ultrasonic-, and Er:Yag laser-assisted biofilm removal techniques. Laser assisted agitation, as well as ultrasonic and sonic activation of the irrigants, are more efficient in biofilm removal compared to conventional irrigation. The choice of irrigant also plays a role in reducing bacterial contamination inside the root canal. Standardization of methodology and introduction of root canals with complex morphology in research are needed for better comparison and recommendations for the most efficient method in biofilm removal.