2. Materials and Methods
Wong-Baker’s FACES pain, pain
The study was conducted from March 2018 to April 2019 at the Department of Endodontics, Qassim University in Saudi Arabia after obtaining the approval from the institutional review board at the university (EA/6008/2018). This was a single-centered, single-blind randomized controlled clinical trial. The trial was registered with the Australia and New Zealand clinical trial registry (clinical trial number: ACTRN12622001513707). The participants were enrolled for the trial after being provided with complete information about the clinical trial and signing written informed consent. The primary outcome of the study was to measure the efficacy of three intra-canal medicaments on post canal preparation pain at 0, 4, 48, 72, 96 hrs, postoperatively. Efficacy of intra-canal medicament was defined as a reduction in the mean pain score values at time intervals of 0, 4, 48, 72, and 96 hrs, respectively, using Wong-Baker’s FACES pain rating scale (WFPRS). WFPRS is six-point scale comprising six faces (no hurt; hurts a little bit; hurts a little more; hurts even more; hurts a whole lot; hurts worst). The scale corresponds to 0, 2, 4, 6, 8, 10 on the numeric rating scale, and is used in combination with it (The sample size was calculated by utilizing PASS software version11 (Microsoft, Redmond, WA, USA). Two independent sample 