Clinical study of single-visit root canal treatment with a nickel-titanium (Ni-Ti) rotary instrument combined with different ultrasonic irrigation solutions for elderly patients with chronic apical periodontitis.

The study involved 300 elderly patients with chronic periapical periodontitis. The patients were randomly assigned into three groups. The treatment for group A used a Mtwo Ni-Ti rotary instrument combined with ultrasonic irrigation of a 2.5% NaOCl solution. The group B used the same instrument combined with ultrasonic irrigation of an active silver ion antibacterial solution. The group C used the same instrument combined with syringe irrigation of a 2.5% NaOCl solution. The root canal fillings were performed immediately after canal preparation. Twenty-four hours after the procedure, patients self-assessed pain levels according to the VAS table. The three groups returned after seven days so their postoperative acute reactions could be evaluated clinically. After six and twelve months, efficacy was evaluated. The self-assessed pain levels for group A and B were significantly lower than group C. The incidence of postoperative acute reactions after seven days for group A and B were significantly lower than those of group C. The effective rates after six and twelve months did not differ among these groups. The single-visit root canal treatment with a nickel-titanium rotary instrument combined with ultrasonic irrigation for elderly patients with chronic periapical periodontitis achieved short and long term efficacy and stability.