Synergistic effect of dentinal tubule occlusion by nano-carbonate apatite and CO₂ laser in Vitro

Objective: The aim of this study was to evaluate the occluding effects of a combination of dentifrice containing nano-carbonate apatite (n-CAP) and a CO₂ laser on dentinal tubules, and to assess the acid resistance of the occluded dentinal tubules produced. Background data: A number of experiments have been conducted recently to relieve the symptoms of dentin hypersensitivity (DH) using a laser in combination with desensitizing products. Materials and methods: One hundred and twenty specimens with exposed dentinal tubules were divided into four groups: the control, n-CAP, laser, and combined groups. Thirty specimens in each group were reassigned into three different conditions: baseline, treatment for occluding dentinal tubules, and acid challenge (pH 4.0 acetate buffer solution for 3 min). At the end of each phase, all specimen surfaces were evaluated by scanning electron microscope (SEM). Results: The combined group had a significantly smaller mean dentinal tubule area than the control group, and the fewest reopened dentinal tubules after acid challenge. Conclusions: The combined therapy is a promising means of treating DH patients in the clinic.