Evaluation of the diffusion of calcium hydroxide-based medicaments through the dentinal tubules and apical foramen: A mass spectrometry study

AIMS: This mass spectrometry study investigated the diffusion of hydroxyl and calcium ions from a calcium hydroxide intracanal medicament (Pulpdent(®)) when used alone or mixed in equal parts with a steroid–antibiotic paste (Ledermix(®)). MATERIALS AND METHODS: The pH (using pH meter) and calcium ion concentration (using inductively coupled plasma-mass spectrometry) of the diffused medicaments were assessed using endodontically prepared human extracted teeth with either a sealed or a patent apex, at time intervals of 1, 3, 8, 24, and 168 h. STATISTICAL ANALYSIS: A one-way ANOVA was used to explore differences between and within groups, with Tukey–Kramer/Games–Howell posttests. RESULTS: In both situations tested, Pulpdent(®) showed greater release of both calcium and hydroxyl ions than when mixed in equal parts with Ledermix(®). Greater initial release of both ions occurred in roots with a patent apex, but by 1 week there was no significant difference between the two. If a 50:50 combination of Pulpdent(®) paste and Ledermix(®) paste is used, there is a lower release of calcium ions and hydroxyl ions than using Pulpdent(®) paste alone. CONCLUSION: With both Pulpdent(®) paste alone and Pulpdent(®) paste mixed equally with Ledermix(®) paste, the major pathway for movement of hydroxyl ions and calcium ions is diffusion through the dentine of the root, with the apex playing only a minor role.