[Effect of 2 bleaching therapies on decoloring of stained dental fluorosis]

To evaluate the clinical performance of at-home bleaching and its application in combination with cold-light bleaching for esthetic management of fluorosed teeth，providing guidance for clinicians to choose the right treatment regimen and communicate with patients successfully.

We divided 43 cases with stained dental fluorosis into 2 groups, with 22 cases in the at-home bleaching group and 21 in the combination therapy group. Stained spots were chosen and colorimetric assay was performed using CMYK colorimetric table before treatment. According to the color of the splash, the light and shade were divided into light grade, medium grade and heavy grade. The CMYK data of the selected point and complete decolorization ratio (stain decolorization rate) were recorded after cold-light bleaching, every 2 weeks and half a year later. Meanwhile, tooth sensitivity was recorded using visual analogue scale (VAS). Statistical analysis was performed using SPSS 17.0 software package.

In the combination therapy group, the decolorization rates of light, medium and heavy stains were 73.44%, 8.70% and 0% immediately after cold-light bleaching respectively. At 2 weeks, in the at-home group, the postoperative decoloring rate was 64.17% in the light grade group and 4.44% in the medium grade group, respectively. In the combination therapy group, the postoperative decoloring rate was 100% in the light grade group and 63.04% in the medium grade group, respectively (P＜0.01). The postoperative decoloring rate in the heavy grade group was 0%. At 4 weeks, in the at-home group, the postoperative decoloring rate was 100% in the light grade group, 73.33% in the medium grade group and 11.40% in the heavy grade group, respectively. In the combination therapy group, the postoperative decoloring rate was 100% in the medium grade group and 53.00% in the heavy grade group, respectively (P＜0.01). At 6 weeks, in the at-home group, the postoperative decoloring rate was 100% in the medium grade group and 76.32% in the heavy grade group. In the combination therapy group, the postoperative decoloring rate was 94.00% in the heavy grade group (P＜0.01). At 8 weeks, the postoperative decoloring rate was 95.61% in the heavy grade group of at-home group. Half a year after treatment, bleaching decoloration rate had no significant difference compared with that at the end of treatment (P＞0.05). Tooth sensitivity was 45.45% in the at-home group and 80.95% in the combination therapy group (P＜0.05).

Fluorosed teeth show significantly better esthetic appearance after both the at-home bleaching and the combination therapy at 6-8 weeks, and can maintain stable for a long time. Cold-bleaching has faster decoloration speed, with the final decolorization rate of the stains unchanged. In addition, it increases the incidence of postoperative sensitivity of teeth.