Abstract

X-ray microtomography (micro-CT) was used to assess the densities of white-spot lesions (WSL) treated with either a fluoride-free paste, or 0.21 or 1.1% NaF toothpastes containing functionalized tricalcium phosphate (TCP). Bovine enamel specimens were ground, polished and demineralized to form WSL. Specimens (N=10) were treated with one of the following NaF silica-based toothpastes in a 10-day pH cycling model: (1) Tom’s of Maine (0% NaF), (2) Clinpro® Tooth Crème (0.21% NaF plus TCP), and (3) Clinpro® 5000 (1.1% NaF plus TCP). Each day consisted of four 2 min treatments, one 4 h acid challenge (pH=5.0), and immersion in artificial saliva (pH=7.0) between these events. After cycling, specimens were analyzed using micro-CT. Statistical analysis (Student’s t-test, Welch t-test or Tukey HSD test) was performed at the 95% confidence level. Compared to sound enamel, significantly (p<0.05) lower densities in WSL were only found at 24 µm from Clinpro Tooth Crème, and at 36 µm from Clinpro 5000. In contrast, the densities measured at 12, 24, 36, and 48 µm from the fluoride-free toothpaste were lower (p<0.05) than sound enamel. Micro-CT analyses revealed NaF toothpastes containing TCP led to increased WSL densities relative to the fluoride-free toothpaste.

Key words: Toothpaste, microtomography (micro-CT), density, remineralization.