Comparison of Clinical Efficacy of a Miswak Extract-Containing Toothpaste to a Dentifrice Containing Potassium Nitrate and to a Placebo on Dentinal Hypersensitivity: A Randomized Clinical Trial

Three toothpastes will be investigated during the study period that are 1) commercially available miswak extract-containing toothpaste; 2) commercially available toothpaste containing 5% potassium nitrate as positive control; 3) a toothpaste containing the same formulation as miswak extract except for the active ingredient (miswak extract) as negative control. Toothpastes will be dispensed in labeled containers named A,B, and C to achieve the triple masking for investigators, participants, and statisticians. Masked toothpastes will be revealed to the investigators after the statistical analyses.

After allocation, all subjects will be instructed to refrain from using any desensitizing agents for two weeks prior to the study up to the end of study period. The randomization process will be made using SPSS, the function "RAND" to assign every subject to random A, B, or C masked toothpastes. Moreover, to insure the blinded process of the study we will dispense the toothpastes in a previously prepared similar containers in separate area. Two trained examiners will read and record the scores each visit (baseline, 2-weeks, and 6-weeks). For the seek of examiners' calibration, Kappa statistic will be used to assess the inter-rater reproducibility and we will duplicate a 10% of the study results.

During each visit, teeth around the targeted tooth will be isolated with cotton rolls then the stimuli will be applied using a sharp dental explorer. It will be passed across the facial area of the tooth, perpendicular to the tooth long axis. The average of three consecutive applications will be recorded as a the reading for that tooth.