摘要
目的研究氢氟酸凝胶处理时间对可切削玻璃陶瓷粘接后断裂强度的影响。方法收集人离体磨牙50颗,垂直牙长轴磨除牙合面釉质;将CEREC Blocs可切削玻璃陶瓷瓷块加工成片状试件后,随机分成5组,每组10片,用质量分数9.5%的氢氟酸凝胶进行处理,处理时间分别为30 s(B组)、60 s(C组)、120 s(D组)、240 s(E组),A组为对照组,不用氢氟酸凝胶处理;用VariolinkN粘接系统将处理后的瓷片与离体牙进行粘接,万能试验机上测试瓷片的断裂载荷,对数据进行单因素方差分析和LSD检验。结果 A组、B组、C组、D组、E组试件断裂载荷值分别为(1 774±153)N、(2 190±180)N、(2 336±173)N、(2 097±174)N、(2 075±202)N。5组试件断裂载荷均数间的差异有统计学意义(F=13.5,P<0.001)。LSD检验结果显示A组断裂载荷值均小于其余各组,差异均有统计学意义(P<0.05);C组载荷值大于D、E组,差异有统计学意义(P<0.05)。结论氢氟酸处理可提高试件粘接后的断裂强度,处理时间超过120 s后断裂强度下降,但仍高于不作氢氟酸处理组。
Objective To evaluate the fracture strength of cemented machinable glass ceramic after being etched with hydrofluoric acid for different time periods and provide guides for clinical hydrofluoric etching. Methods 50 human mo-lars were collected, and occlusal enamel was removed. Sirona CEREC Blocs were processed into plate-shape, divided in-to 5 groups and etched with hydrofluoric acid for 30 s （ Group B） , 60 s （ Group C） , 120 s （ Group D） and 240 s （ Group E） respectively, while Group A remained untreated. Then all specimens were cemented onto the collected molars with Variolink？ N cement system. Fracture loads were measured with a universal testing machine. The results were analyzed by one-way ANOVA and LSD test. Results Fracture loads of Group A to E were （ 1 774 ± 153） N, （ 2 190 ± 180） N, （ 2 336 ± 173） N, （ 2 097 ± 174） N, （ 2 075 ± 202） N respectively. Significant differences of fracture load were observed among five groups （ F=13. 5, P〈0. 001） . LSD test showed that fracture load of Group A was lower than the other groups and fracture loads of Group D and E were significantly lower than Group C （ P＆lt;0. 05） . Conclusion Hydrofluoric acid etching increased fracture strength of cemented Sirona CEREC Blocs specimens, but fracture load decreased after being etched for more than 120 s, which was still higher than those untreated.
出处
《广东牙病防治》
2015年第11期575-577,共3页
Journal of Dental Prevention and Treatment
基金
佛山市院市合作项目(2014HT10008)
关键词
离体牙
断裂强度
可切削玻璃陶瓷
氢氟酸
Isolated tooth
Fracture strength
Machinable glass ceramic
Hydrofluoric acid
