【摘要】 目的:比较传统型和新型微型固位体粘结固定义齿的抗疲劳破坏能力。方法:将人前磨牙和磨牙各20颗间隔10mm配对包埋于树脂中建立单个磨牙缺失模型。随机等分为2组,分别进行传统的邻面轴沟、支托牙体预备和邻面备洞粘结预成微型固位体。制作Ni-Cr合金固定义齿,用树脂粘结剂PanaviaF粘结于模型上,经冷热循环机械载荷(TCML)咀嚼模拟疲劳实验后,用体视显微镜观察粘结面破坏、微渗漏情况并作非参数Mann-Whitney统计学检验。结果:实验过程中传统邻面轴沟固位组有2个双端、1个单端固位体完全脱落;微型固位体固位组无固位体脱落。传统组微渗漏程度高于微型固位体组,有显著性统计学差异(P=0.046)。破坏和裂纹多发生在粘结剂-金属界面。结论:微型固位体固位的粘结固定义齿的抗疲劳破坏能力优于传统的邻面轴沟固位型粘结固定义齿。更多还原

【Abstract】 Objective:To compare the fatigue failure characteristics of conventional resin-bonded fixed partial dentures (C-RBFPDs) with that of a new type RBFPDs incorporating mini-anchor attachment (Crownless Bridge Work system, CBW). Methods:Ten Ni-Cr alloy conventional RBFPDs and ten Ni-Cr alloy CBW RBFPDs were respectively bonded to the acid-etched abutment teeth. All the specimens were fixed on a thermocycling and mechanical loading (TCML) chewing simulator. After thermocycling and dynamic mechanical loading (6 000× 5 ℃/55 ℃, 6×10~6×50 N, 1.7 Hz), the specimens were immersed in a 10 ml/L gentian violet solution for 24 hours,then rinsed and incised. Section surfaces were observed with an optical microscopic. Failure and crack characteristics at the metal-resin-enamel adhesion interfaces were assessed with a 4-level dye penetration microleakage scale. Statistical differences were identified with Mann-Whitney test (α = 0.05 ). Results:There were two conventional RBFPDs de-bonded completely and one with single retainer loosen from the abutment teeth. No de-bonding was found in the CBW RBFPDs group. The degree of microleakage in the conventional RBFPD group was significantly higher than that in CBW RBFPD(P=0.046). Cracks occurred mostly between the metal-resin interfaces in both groups. Conclusion:CBW RBFPDs are stronger in the resistance of fatigue failure than the conventional RBFPDs.更多还原