Postendodontic pain in asymptomatic necrotic teeth prepared with different rotary instrumentation techniques

OBJECTIVES: to investigate the postendodontic pain in asymptomatic necrotic teeth prepared with different rotary instrumentation techniques after single-visit root canal treatment. MATERIALS AND METHODS: A total of 60 single-rooted teeth with single root canal were treated endodontically. Teeth were divided randomly into four equaled groups (n = 15) according to instrumentation systems as follows: group I were shaped using ProTaper Universal (control group) (Dentsply/Maillefer, Ballaigues), group 2 were shaped with 2Shape (Micro-Mega) till TS2 (25.06), group 3 were shaped with XP-endo Shaper file (FKG Dentaire) till #30.04, and group 4 were shaped with Reciproc blue (VDW) till R25 (25.08). All groups were prepared according to manufacturer's instructions and obturated with lateral condensation technique. Pain levels were assessed by visual analog scale (VAS) and verbal evaluation of pain questionnaire after 6, 12, 24, 48 h, and 7 days of canal obturation. Data were then analyzed using Kruskal–Wallis and Mann–Whitney U tests at P value of 0.05. RESULTS: Postendodontic pain started after 6 h of treatment with highest values and then decreased gradually until almost vanished after 1 week of treatment, with no significant differences in VAS among studied groups (ProTaper, 2 shape, XP endo Shaper, and Reciproc Blue) after 6,12, and 48 h of treatment. On the other hand, XP endo Shaper group, showed the lowest pain values after 24 h of treatment, and the highest pain values were found in 2 shape group after 1 week with significance (P < 0.05). CONCLUSION: Root canals prepared with XP endo Shaper resulted in the lowest pain levels after 24 h of treatment. Root canal preparation with 2Sshape rotary system resulted in the highest pain levels after 1 week of treatment.