Debris Removal Using a Hydroxyapatite Nanoparticle-Containing Solution (Vector Polish) with Sonic or Ultrasonic Agitation

Chemomechanical preparation of the root canal system is considered to be the most important part of root canal treatment, including both mechanical removal of tissue remnants and dentine chips, and chemical elimination of biofilm and microorganisms. A number of different solutions and agitation techniques have been proposed for that purpose. It was the aim of the present study to investigate whether root canal cleanliness can be improved by using a hydroxyapatite nanoparticle-containing solution with and without sonic or ultrasonic agitation. Seventy-four single-rooted teeth were divided into four experimental groups (n = 15) and two control groups (n = 7). All teeth were split longitudinally and a groove and three holes were cut into the root canal wall and filled with dentinal debris. Final irrigation was performed using sodium hypochlorite or a hydroxyapatite nanoparticle-containing solution (Vector polish) activated with a sonically or an ultrasonically driven endodontic file. Two calibrated investigators rated the remaining debris using a four-score scale. The results were analyzed using a non-parametric test with alpha < 0.05. Sonic and ultrasonic irrigation with sodium hypochlorite cleaned the grooves and holes well from debris. The hydroxyapatite nanoparticles activated by a sonic file cleaned grooves and holes equally well. Ultrasonically activated nanoparticles performance was clearly inferior. The syringe control-group left large amounts of debris in grooves and holes. The use of the hydroxyapatite nanoparticles used in this study did not improve removal of debris.

Automated summary

The study investigated the impact of using a solution containing hydroxyapatite nanoparticles and sonic or ultrasonic agitation on root canal cleanliness. Results showed that sonic and ultrasonic agitation with sodium hypochlorite effectively cleaned debris from the root canal, and using sonic agitation with hydroxyapatite nanoparticles had a similar cleaning effect. However, ultrasonically activated nanoparticles performed poorly in comparison.