Improved Root-filling Quality among General Dental Practitioners using NiTi Rotary Instrumentation

Objectives: Epidemiological studies indicate that a high frequency (30-50%) of root-fillings performed by general dental practitioners (GDPs) are technically defective. It is suggested that new technologies such as NiTi rotary instrumentation (NTRI) will facilitate treatment procedures and thus improve root-filling quality. The present study investigated the effect of a NTRI educational program administered to a group of GDPs on the technical quality of root-fillings. Methods: 148 dentists within the Public Dental Service of Gothenburg, Sweden, were introduced to the GT system (Maillefer/Dentsply). The dentists were assigned at random to three intervention groups: a 4-hour lecture (L-group, n=40); a 4-hour lecture plus a full day hands-on course (LH-group, n=40); or a control group receiving no instruction (n=68). Radiographs of two root filled molar teeth per dentist were selected at random before the start of the education program and after a 6-month clinical learning period. A total of 566 radiographs (1222 roots) were submitted and analysed. Using length, seal and shape of root-fillings a 5-level variable was created, with categories ranging from “excellent” through “unacceptable” . Results: The rate of “excellent” root-fillings in the L-group increased from 28% to 47% (p=0.015), and in the LH-group from 29% to 46% (p=0.04). The increase was most pronounced in curved canals. No statistically significant differences were seen among controls. In the L-group the rate of “unacceptable” root-fillings were 16% and 15% before and after training, respectively (p=0.78). In the LH- group the frequency decreased from 15% to 8% (p=0.11). Among controls corresponding values were 19% and 19%, respectively. Conclusions: Introducing NTRI to GDPs may increase the rate of good quality root-fillings. The proportion of “unacceptable” root-fillings were equal or slightly lower in all three groups after the 6-month period, but not to a statistically significant degree.