ABSTRACT
Objective To evaluate the clinical effect of Wy 10 whitening combined with enamel microabrasion on bleaching dental fluorosis.Methods Forty patients with dental fluorosis were in-cluded and divided into two groups (20 each):group A was treated with Wy 10 whitening and enamel microabrasion,and group B only with Wy 10 whitening.Efficacy was measured according to the Vita classical shade guide before and after treatment.Sensitivity between groups was also tested.Results The effective rate of group A was significantly higher than that of group B (x2 =5.096,P＜0.05).The sensitive rates were 20.0％ (4/20) and 15.0％ (3/20) in group A and group B,respectively.No significant difference was found between the two groups in sensitivity (P＞0.05).Conclusions Wy 10 whitening combined with enamel microabrasion is an effective and safe method for bleaching dental fluorosis.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of different length and diameters on the stability of mini implant and to select optimal length and diameter using continuous variation of parameters.</p><p><b>METHODS</b>To perform 3-dimensional finite element analysis, finite element models of a maxilla, and mini implants with length of 6-12 mm and diameters of 1.2-2.0 mm were generated. Load of two different forces were applied to the head of mini implant. One type was horizontal force (HF), the other was composite force (CF). The maximum equivalent stress (Max EQV) in maxilla and the maximum displacement (Max DM) of mini implant were evaluated.</p><p><b>RESULTS</b>The Max EQV in maxilla and Max DM of mini implant decreased as length and diameter increased. When length was more than 9 mm, the evaluation indexes were small and had a less change. Datas indicated that diameter played a more important role in reducing target, and was a more effective parameter in reducing Max EQV when CF was loaded.</p><p><b>CONCLUSION</b>From biomechanical point of view, the choice of the length should not be more than 9 mm. When CF is loaded using the mini implant, diameter exceeding 1.2 mm are optimal design for mini implant.</p>