软质切削钴铬合金与铸造钴铬合金冠边缘适合性的比较

Comparasion of the marginal fit of soft Co-Cr alloy crown between CAD/CAM and the cast preparation

目的:探讨采用传统的失蜡铸造法和切削软质钴铬合金法制作的烤瓷冠内冠与基牙间边缘适合性的比较。方法:制备10个不锈钢牙备件。2种方法各制作10个对应的内冠,A组:失蜡铸造法组; B组:CAD/CAM切割软质钴铬合金组。采用双色硅橡胶印模法,获取A组、B组各样本界面的14个测量点间隙的大小。结果:铸造组与CAD/CAM组各测量点间隙的大小对应为:切角A(126. 79±31. 2)、(135. 67±41. 72)μm;切角B(129. 29±57. 12)、(146. 71±53. 24)μm;切缘A(172. 00±60. 33)、(172. 67±33. 46)μm;切缘B(164. 04±63. 60)、(168. 63±33. 38)μm;轴面A1(41. 38±7. 98)、(30. 54±15. 34)μm;轴面A2(42. 67±12. 49)、(30. 92±15. 69)μm;轴面B1(52. 50±12. 74)、(30. 00±9. 65)μm;轴面B2(50. 08±12. 92)、(27. 79±8. 70)μm;颈缘转角A(57. 96±29. 21)、(156. 46±37. 30)μm;颈缘中部A(66. 77±23. 35)、(135. 42±31. 18)μm;颈缘边缘A(64. 79±35. 02)、(19. 42±4. 31)μm;颈缘转角B(54. 91±19. 69)、(153. 22±33. 15)μm;颈缘中部B(63. 13±18. 05)、(131. 46±32. 56)μm;颈缘边缘B(60. 32±25. 00)、(19. 67±4. 08)μm。结论:CAD/CAM切削的软质钴铬合金冠较铸造者边缘密合性高,轴壁处和基牙顶端的间隙2组差别不大。

Objective:To investigate the marginal fit of CAD/CAM soft Co-Cr alloy and the cast Co-Cr alloy crowns to abutment teeth.Methods:10 stainless steel models for cown preparation were maded by numerical control machine.10 coping crowns were made by the lost wax casting method(group A)and 10 by CAM/CAM(group B).The crow substitues made by dual color silicone rubber impression technique were used for the measurements,the thickness of the outer layer silicone substitute for the gap space between the crown and the abutment teeth were measured at 10 marker points.Data were statistically analyzed by SPSS 19.0 software.Results:The gap thicknessof Group A and GroupB respectively were:Incisal angle A(126.79±31.2)、(135.67±41.72)μm;Incisal angle B(129.29±57.12),(146.71±53.24)μm;Incisal A(172.00±60.33),(172.67±33.46)μm;Incisal B(164.04±63.60),(168.63±33.38)μm;Axial A1(41.38±7.98),(30.54±15.34)μm;Axial A2(42.67±12.49),(30.92±15.69)μm;Axial B1(52.50±12.74),(30.00±9.65)μm;Axial B2(50.08±12.92),(27.79±8.70)μm;Inner cervical margin A(57.96±29.21),(156.46±37.30)μm;Middle cervical margin A(66.77±23.35),(135.42±31.18)μm;Outer cervical margin A(64.79±35.02),(19.42±4.31)μm;Inner cervical margin B(54.91±19.69),(153.22±33.15)μm;Middle cervical margin B(63.13±18.05),(131.46±32.56)μm;Outer cervical margin B(60.32±25.00),(19.67±4.08)μm.Conclusion:The marginal fit of soft Co-Cr alloy crown made by CAD/CAM is more adaptable than that by lost wax casting method.The gap at the axial wall and the incisal edge of this 2 groups is similar.