Abstract
The impact of different NiTi systems, such as ProTaper Gold, NeoEndo Flex, Hyflex EDM, Reciproc Blue and WaveOne Gold, on postoperative pain of single-rooted teeth following root canal retreatment is of interest to dentist. Additionally, the study aims to ascertain whether age, gender and tooth localization adhering to retreatment with various rotary and reciprocating instruments significantly affect postoperative pain. Root canal re-treatment with 5 (five) distinct rotary or reciprocating NiTi systems did not significantly affect postoperative pain or painkiller consumption. Postoperative pain levels in this trial peaked on the first day and then dramatically declined each subsequent day.