Abstract：
Literature reports indicate that during bracket removal there can be enamel damage. We compare the shear bond strength (SBS) and tooth enamel loss of four adhesive systems and identify the Ca/P ratio. Then a total of 20 premolars were divided into four groups of five each. After prophylaxis, photographs were taken at 35× with a scanning electron microscope (SEM) and analyzed with X-ray spectroscopy (EDS) at 250×. Brackets were bonded with Transbond™ MIP(G1), Transbond™ PLUS SEP(G2), Enlight(G3) and Stylus®(G4) adhesives, 24 h after were debonded with a Instron universal testing machine at 1 mm/min. All the brackets were photographed with the SEM. The amount of lost enamel was measured with AutoCad. All the results were measured with a significance level p < .05. The SBS general average at debonding was 7.94 ± 2.26 MPa, meanwhile the SBS for G1, G2, G3 and G4 was 9.38 ± 1.46, 6.28 ± 0.69, 9.08 ± 2.45 and 7.04 ± 2.64 MPa respectively. 90% of the samples had no enamel loss, 10% had enamel loss. Only two samples in G1 presented an enamel loss area of 0.34mm2 and 0.80mm2 respectively. From EDS analysis, the Ca/P ratio was 1.6 ± 0.05, 1.61 ± 0.03, 1.64 ± 0.83 and 1.59 ± 0.07 for G1, G2, G3 and G4 respectively; no statistically significant differences were found. We conclude that no association was found between the Ca/P ratio and enamel damage when brackets are removed. HIGHLIGHTS: Where enamel is lost, we observe fractures, steps, horizontal and vertical enamel loss. There is a loss of tooth enamel from 0.34 to 0.80 mm2 with Transbond PLUS SEP. Structural loss of enamel is almost inevitable during the separation of the bracket.
摘要：
文献报告表明，在支架移除期间，可能会损坏牙釉质。我们比较了四种粘合剂系统的剪切粘合强度（SBS）和牙釉质损失，并确定了Ca/P比。然后将总共20颗前磨牙分为四组，每组五个。预防后,用扫描电子显微镜（SEM）以35倍拍摄照片，并用X射线光谱（EDS）以250倍进行分析。支架用Transbond™MIP(G1)粘合,Transbond™PLUSSEP(G2),Enlight(G3)和Stylus®(G4)粘合剂，24小时后,用Instron通用测试机以1mm/min脱粘。所有支架均用SEM拍照。用AutoCad测量损失的釉质的量。所有结果均以显著性水平p<.05测量。脱粘时的SBS总平均值为7.94±2.26MPa,同时，G1，G2，G3和G4的SBS分别为9.38±1.46，6.28±0.69，9.08±2.45和7.04±2.64MPa。90%的样品没有牙釉质损失，10%有牙釉质损失。G1中只有两个样品分别呈现0.34mm2和0.80mm2的牙釉质损失面积。从EDS分析来看，G1，G2，G3和G4的Ca/P比分别为1.6±0.05，1.61±0.03，1.64±0.83和1.59±0.07。差异无统计学意义。我们得出的结论是，去除托槽后，Ca/P比与牙釉质损伤之间未发现关联。亮点:搪瓷丢失的地方，我们观察骨折,steps,水平和垂直釉质损失。使用TransbondPLUSSEP，牙釉质损失从0.34到0.80mm2。牙釉质的结构损失在支架的分离期间几乎是不可避免的。
