Efficacy of a single session protocol for endodontic treatment in primary teeth: in vivo study.

AIMS: To determine the efficacy of a single session protocol (SSP) in the reduction of septic content of primary teeth root canals and identify the persistence of bacterial species associated with unsuccessful treatment. METHODS: Primary teeth root canals (16) with pulp necrosis and peri-radicular lesions were treated. Samples were collected at baseline (T1), and after chemo-mechanical preparation, before filling (T2). Identification of the microorganisms was determined using checkerboard DNA-DNA hybridisation. STATISTICAL ANALYSIS: Wilcoxon test was applied for comparison of mean number of species, proportion and mean count of each species between the evaluation times. RESULTS: Significant reductions were found in the mean number of bacteria species between T1 and T2 (p < 0.05), but not for the reduction in proportion (p > 0.05). There was a reduction (6.0-4.6) of the mean number of species associated with failure, without statistical significance. CONCLUSION: The SSP was capable of significantly reducing the septic content, even though, many of the bacteria associated with failure persisted at the time of root canal filling.

Electronic determination of root canal working length in primary molar teeth: an in vivo and ex vivo study.

AIM: To evaluate in vivo and ex vivo the accuracy of an electronic apex locator in primary molar teeth with or without root resorption. METHODOLOGY: Fifteen primary molar teeth with 30 root canals were divided into two groups: roots without resorption (n = 13) and roots with resorption (n = 17). Root canals were measured with the Root ZX apex locator in vivo, and then after tooth extraction, each canal was measured electronically ex vivo. The actual root canal length was measured visually, with the placement of a K-file into the most cervical edge of either apical foramen or resorption. The Student's t-test was applied for statistical analysis at a 5% significance level. RESULTS: The electronic apex locator was precise in 69% and 65% of the cases with and without root resorption, respectively (tolerance = ± 0.5 mm), in vivo and 69% and 77%ex vivo. When the tolerance was ± 1 mm, however, these figures increased to 92% and 94% for root canals with and without resorption, respectively, in vivo and ex vivo. No significant difference was observed between the resorbed and non-resorbed root canals measured using the Root ZX. CONCLUSION: The Root ZX apex locator was accurate in determining in vivo and ex vivo the working length ± 1 mm in primary molar teeth in over 90% of roots regardless of the presence of root resorption.