Objective: An earlier clinical study demonstrated that brushing with a commercial Arm & Hammer dentifrice containing baking soda physically removed significantly more plaque than brushing with either of two commercial dentifrices which did not contain baking soda. However, little has been done to confirm these results and to compare baking soda-containing dentifrices with more recently commercialized non-baking soda dentifrice formulations. The objective of this study was to compare commercial dentifrices containing 20% to 65% baking soda and commercial dentifrices without baking soda in enhancing plaque removal efficacy of tooth brushing.
Methods: Five randomized, controlled, blinded, crossover clinical studies were performed among healthy adult volunteers who provided informed consent. After approximately 24 hours without oral hygiene, subjects with sufficient plaque were enrolled in the study phase. Plaque was scored before and after supervised brushing for one minute using the Turesky, et al. modification of the Quigley-Hein Plaque Index at six sites per tooth according to Soparkar's modification as described by Lobene, et al. In each study, wash-out periods with a regular dentifrice not evaluated in the study separated each product treatment.
Results: In all studies, every dentifrice exhibited a significant (p < 0.0001) reduction in 24-hour plaque scores. Between-group comparisons of whole mouth plaque scores in all five studies demonstrated that brushing with baking soda dentifrices resulted in statistically greater (p < 0.01) reductions in whole mouth mean plaque scores than brushing with dentifrices that did not contain baking soda. Results on other tooth surfaces, such as facial, lingual, proximal, and gingival surfaces also demonstrated statistically greater (p < 0.05) reductions in mean plaque scores for the baking soda-containing dentifrices as compared to the baking soda-free dentifrices. In three of the studies comparing different levels of baking soda, brushing with dentifrices with higher concentrations of baking soda consistently removed numerically more plaque than those containing lower levels. In one of these three studies, the difference in plaque removal between the baking soda dentifrices reached statistical significance. The results suggest a positive relationship between plaque removal efficiency and baking soda concentration.
Conclusion: The collective results from the five controlled clinical studies on over 270 subjects reported in this paper, consistently demonstrate that Arm & Hammer baking soda dentifrices enhanced plaque removal effectiveness of tooth brushing to a significantly greater extent than the non-baking soda dentifrice products.