ABSTRACT
OBJECTIVES: Correct determination of working length is an important step for success of endodontic therapy. Conventional radiography has limitations in providing the accurate location of apical foramen. For this reason, electronic apex locators (EALs) were developed to shorten the treatment time and decrease the radiation dose. The aim of this study was to evaluate the accuracy of Root ZX EAL for working length determination in primary anterior teeth. MATERIALS AND METHODS: In this in-vitro study, 50 extracted primary anterior teeth with root resorption were selected with no obstructed canals or history of previous root canal therapy. Working lengths were measured by direct observation of actual length (AL), radiography and Root ZX EAL. A variation of ±0.5 mm from the AL was considered acceptable. The results were analyzed statistically using paired t-test and interclass correlation coefficient (ICC) at 0.05 level of significance. RESULTS: Considering an acceptable 0.5 mm margin from AL (direct measurement), the accuracy of Root ZX EAL and radiography was found to be 86% and 76%, respectively. Absolute value of error from AL was significantly lower for ZX compared to radiography (P<0.001). Interclass correlation comparing both radiography and Root ZX with AL showed strong correlations. CONCLUSION: Root ZX EAL can be used as a reliable tool for obtaining root canal length in primary anterior teeth with resorption.
ABSTRACT
OBJECTIVES: Laser irradiation has been suggested as an adjunct to traditional caries prevention methods. But little is known about the cariostatic effect of diode laser and most studies available are on permanent teeth.The purpose of the present study was to investigate the effect of diode laser irradiation combined with topical fluoride on enamel surface microhardness. MATERIALS AND METHODS: Forty-five primary teeth were used in this in vitro study. The teeth were sectioned to produce 90 slabs. The baseline Vickers microhardness number of each enamel surface was determined. The samples were randomly divided into 3 groups. Group 1: 5% NaF varnish, group 2: NaF varnish+ diode laser at 5 W power and group 3: NaF varnish+ diode laser at 7 W power. Then, the final microhardness number of each surface was again determined. The data were statistically analyzed by repeated measures ANOVA at 0.05 level of significance. RESULTS: In all 3 groups, microhardness number increased significantly after surface treatment (P<0.05). However, Microhardness change after treatment was not significantly different among groups (P >0.05). CONCLUSION: The combined application of diode laser and topical fluoride varnish on enamel surface did not show any significant additional effect on enamel resistance to caries.
