A Study to Investigate the Stain and Plaque Removal Capability of Two Experimental Potassium Nitrate Dentifrices

The purpose of this study is to determine whether spherical silica can achieve similar or greater extrinsic dental stain and plaque removal, in comparison to dentifrices containing higher concentrations of standard abrasive silica, and how the addition of 5% sodium tripolyphosphate (STP) enhances cleaning capability.

This proof of principal (PoP) single centre, randomised, examiner blind, four-treatment arm, parallel design study will be conducted in healthy participants with a propensity for extrinsic dental stain (based on the judgement of the examiner) on the facial surfaces of the anterior teeth. This study will be used to evaluate and compare the extrinsic dental stain and plaque removal of an experimental low abrasivity 0.5% spherical silica dentifrice and a marketed low abrasivity 6% standard silica abrasive dentifrice, and an experimental moderate abrasivity 1% spherical silica / 5% STP dentifrice and a marketed high abrasivity 16% standard abrasive silica / 5% STP dentifrice. Stain will be assessed using an established clinical measure of extrinsic dental stain - the MacPherson modification of the Lobene stain index (MLSI). Particpants will be stratified by baseline MLSI score (total MLSI (area \[A\] × intensity \[I\]) for the facial surfaces of the 4 anterior assessment teeth). Plaque will be assessed using an established clinical measure of plaque - the Turesky Modification of the Quigley Hein Index. Stain and plaque will be assessed at intervals over an 8 week treatment period. Plaque will be assessed at baseline and Week 8 only.