Randomization and allocation concealment
tooth
Participants were randomly assigned with equal allocation to the four arms using a computer-generated list of random numbers in blocks of four. Allocation concealment was guaranteed by managing envelopes that are opaque, successively numbered and sealed till the date of candidate attendance. Once the patient consented to be included in the study, the envelope was opened, and each tooth was given the assigned treatment. The envelopes were prepared by a staff member not involved in any of the phases of the clinical trial.