Effect of working length measurement by electronic apex locator or digital radiography on postoperative pain: a randomized clinical trial.

INTRODUCTION: The aim of this study was to evaluate the effect of working length determination methods, electronic apex locator and digital radiography, on postoperative pain. METHODS: Two hundred twenty patients with asymptomatic single-rooted vital teeth were randomly assigned to 2 groups according to the method used for working length determination, the radiographic group and the electronic apex locator group. After working length determination, chemomechanical preparation was performed in a crown-down technique with ProTaper instruments. A master cone radiograph was taken. Canals were obturated with gutta-percha and sealer by using a lateral compaction technique. Postoperative pain was assessed after 4, 6, 12, 24, and 48 hours by using a 4-point pain intensity scale. In addition, patients were asked to record the number of days necessary to achieve complete pain resolution. RESULTS: Postoperative pain during the 4-hour to 48-hour interval studied was not significantly different (P > .05) between groups. The mean times for pain dissipation in the radiographic and electronic apex locator groups were 3.37 ± 2.79 and 3.88 ± 3.34 days, respectively. The difference between groups was not statistically significant (P > .05). CONCLUSIONS: There is no difference in postoperative pain between working length measurement methods by using an electronic apex locator or digital radiography. The reduced exposure to radiation by using apex locator may be a factor that influences a dentist's decision to choose the electronic apex locator over radiography.

Comparision of two different preparation protocol of Ni-Ti Rotary PathFile-ProTaper instruments in simulated s-shaped canals.

INTRODUCTION: The aim of this study is to compare the root canal transportation with the PathFile-ProTaper recommended protocol, PathFile-ProTaper modified protocol and stainless steel K-flexofiles. METHODS: Forty-five ISO 15, 0.02 taper S-shaped Endo Training Blocks were divided randomly into three groups of 15 each and prepared as follows: PathFile-Protaper recommended protocol, Pathfile-Protaper modified protocol and manual preparation with K-Flexofiles. The amount of transportation was assessed by scanning the blocks before and after preparation and superimposing the images. The cutting effects of the instruments from the inner and outer aspects of the root canals were measured and statistically analyzed with the One-way Anova test and Tukey HSD test. RESULTS: Manual preparation caused significantly more transportation than both PathFile-Protaper systems. There was no significant difference regarding transportation between the two Pathfile-Protaper protocols. CONCLUSION: The modified Pathfile-Protaper protocol transported the canal similar to the recommended Pathfile-Protaper protocol. It may be suggested that, while working safety remains unchanged, the shaping procedure and consequently working time can be shortened with fewer instruments. The results of this study can help clinicians to reduce the preparation time with the PathFile-ProTaper rotary system while the preparation quality remains the same.