Three year evaluation of a minimal invasive endodontic concept

Objectives: Recurrent infection from bacterial contamination still present in the pulpal chamber is considered to be the main cause of root canal treatment failure. The conventional chemo-mechanical approach relies on an enlargement of the root canal in order to provide access for chemical agents such as NaOCl. While the enlargement by itself contributes only little to the de-contamination of the canal, it is time consuming and may lead to additional problems such as per-forations or a spreading of bacterial content. The ability of a novel electronic device (Endox; Ly-sis) to decontaminate root canals prior to mechanical intervention gave the idea to limit the instru-mentation to only what is necessary for the obturation. Methods: 90 endodontic patients were randomly assigned to one of three different groups. In Group A instrumentation followed the rules of the step-back-technique (AMF: ISO size 30). In Group B an electric decontamination was applied prior to instrumentation and the canals were then enlarged to ISO size 25 on the entire working length. In Group C canals were instrumented up to ISO size 40. Afterwards an Er:YAG-laser-system (Key; KaVo) was used according to the manufacturer`s instructions. The canals in all groups were then filled with a sealer (Sealapex; Kerr) and lateral condensation of gutta percha. Clinical and radiological evaluation was conducted after 6 months, 1 year and three years. Results: Treatment time in Group B was by far the least compared to the other groups. One tooth from Group B had to be extracted after 1 year because of a fracture. Neither in this case nor in any other case there were signs of a failure of the endodontic therapy. Conclusions: It was concluded that a minimal invasive endodontic concept significantly reduces working time and seems to provide clinical results that are comparable to other techniques.