Effects of different pH values of citric acid solutions on the calcium and phosphorus contents of human root dentin.

In a group of mandibular incisors, the calcium and phosphorus contents of the cervical, middle, and apical thirds of the roots were determined using an electron microprobe analyzer, before and after treatment with citric acid solutions of different concentrations. The treated surfaces were examined using a scanning electron microscope. The relative calcium and phosphorus loss values obtained from the samples treated with pH 0.8, 1.1, 1.3, 1.5, and 1.7 solutions were significantly different from those obtained in the control group. The demineralizing effect of the pH 0.8 and pH 1.3 solutions was the same, with both of these being less effective than the pH 1.1 solution.