Abstract: PURPOSE: The purpose of this study was to explore the effect of Nd:Yap laser combined with composite resin filling on reducing hypersensitivity of dental wedge-shaped defect. METHODS: Seventy cases, 144 teeth with sensitive wedge-shaped defects were selected. The patients were randomly divided into 2 groups and treated as below: 35 cases, 74 teeth in group A were treated with composite resin directly； 35 cases, 70 teeth in group B were treated with Nd:Yap laser combined with composite resin. After treatment, the effective rates under clinical examination standard (immediately, 1, 3 and 6 months after treatment) in both groups were collected and statistically analysed with SPSS 13.0 software package. RESULTS: In group A, one and 2 teeth fillings fell off 3 months and 6 months after treatment,respectively. In group B, one and 1 tooth fillings fell off 3 months and 6 months after operation. There was no significant difference between the two groups (P>0.05). The effective rates of desensitization were 95.71%，91.43%，87.14% and 81.43% in group B, respectively, which were significantly higher than those in group A (82.43%，78.38%，72.97% and 64.86%)(P<0.05). CONCLUSIONS: Nd:Yap laser combined with composite resin filling can treat sensitive wedge-shaped defect effectively and improve the symptoms of tooth sensitivity significantly .

Key words: Wedge-shaped defect, Nd:Yap laser, Tooth hypersensitivity