[Clinical evaluation and laboratory study of ultrasonic irrigation of the root canal]

To assess the efficacy of ultrasonic irrigation of the root canal in vivo and in vitro.

Sixty anterior teeth or premolars with the diagnosis of periapical periodontitis were divided into two groups (syringe irrigation group, group S and ultrasonic irrigation group, group U) and were evaluated clinically. Sixty extracted teeth with single straight canals were selected. Forty of them were divided into two groups and were evaluated histologically. Another twenty teeth were divided into two groups and were evaluated by SEM.

Clinically, the number of lateral canals obturated in group U was more than that in group S (P < 0.01). The incidence of pain during irrigation were 13.3% in group S, and 3.3% in group U (P > 0.05). Histologically, the amount of organic debris of the root canals in group U were significantly less than that in group S (P < 0.01). By SEM study, the number of visible open dentinal tubules in group U were significantly greater than that in group S (P < 0.05).

Ultrasonic irrigation of the root canal will be a useful technique in root canal therapy.