Influence of the Amount of Toothpaste on Cleaning Efficacy: An In Vitro Study

Objectives The aim of this in vitro study was to test the influence of the amount of toothpaste on enamel cleaning efficacy. Materials and Methods The hydrated silica-based test toothpaste (radioactive dentin abrasion: 60.19 +/- 1.35) contained all ingredients of a regular fluoride toothpaste. The cleaning efficacy of four different toothpaste amounts (1.00 g, 0.50 g [both "full length of brush"], 0.25 g ["pea-size"], and 0.125 g ["grain of rice-size"]) diluted in 1.00 mL water were each tested for different brushing times (10, 30, 60, 120, 180, and 300 seconds) using a standardized staining model on human molars with a brushing machine. Photographic documentation and colorimetric measurements were conducted, respectively, initially, after staining and after each brushing step. Colorimetric measurements were used to calculate the stain removal (in %). Statistical Analysis Results were analyzed by one-way analysis of variance with post hoc Tukey test and Levene's test for analysis of homogeneity of variance. The level of significance alpha was set at <= 0.05. Results The cleaning efficacy decreased significantly when using smaller toothpaste amounts. Stain removal after 120 seconds brushing time was: 77.4 +/- 5.0% (1.00 g toothpaste), 75.7 +/- 3.4% (0.50 g toothpaste), 54.1 +/- 6.7% (0.25 g toothpaste), and 48.2 +/- 7.1% (0.125 g toothpaste), respectively. Conclusion In this in vitro study the cleaning efficacy of a medium-abrasive, hydrated silica-based toothpaste was analyzed. Note that 1.00 g toothpaste showed for all brushing times a significantly higher cleaning efficacy than 0.25 g toothpaste and 0.125 g toothpaste.