Comparison of Postoperative Pain After Root Canal Preparation, in Single and Multiple Visits, With Reciprocating and Rotary Single-File Systems: A Randomized Clinical Trial.

Subjects allocation and randomization method:

• All diagnoses and treatment procedures will be performed by a single operator in one visit or multiple visits to eliminate or minimize individual variability in the treatment between clinicians.
• Total of 160 patients, as per the inclusion criteria will be intervened. This will be divided into two groups as follows:

1. Group A (n=80) single visit.
2. Group B (n=80) multiple visits.

• Group A and B will be subdivided into two groups (each group=40) based on the motion of the files to be used either Reciprocation EOF (Edge one Fire file) or Rotational motion PN (ProTaper Next files). Each subgroup will be divided based on either the tooth is vital or non-vital (each subgroup=20) as shown in study design (Figure 1).

(Figure 1)

• A pulpal and periapical diagnoses will be done for each tooth on taking careful history, clinical and radiographic examination based on the American Association of Endodontists (AAE 2008) diagnostic guidelines.
• The treatments in groups A or B by ProTaper Next or Edge one Fire will be randomized with sequentially numbered opaque sealed envelopes (SNOSE) with 40 patients in PN group and 40 patients in EOF group with allocation sequence and assigning to intervention which will be done by blinded second investigator at the time of cleaning and shaping, concealed from operator to reduce bias.