Reis A, Francci C, Loguercio A D, Carrilho M R, Rodriques Filho L E
Faculdade de Odontologia USP, Departamento de Materiais Dentários, Av Prof Lineu Prestes, 2227-Cidade Universitária, CEP 05554-900 São Paulo-SP-Brazil.
Oper Dent. 2001 May-Jun;26(3):287-94.
Fracture of anterior teeth by trauma is a common problem in children and teenagers. Complex metal-ceramic crowns with considerable loss of remaining sound structure are no longer necessary due to adhesive techniques, such as composite restorations and re-attachment techniques. This study compared the fracture strength of sound and restored anterior teeth using a resin composite and four re-attachment techniques. A "one bottle" adhesive system (One-Step, BISCO) and a dual cure resin cement (Duo-Link, BISCO) were applied. Thirty-five sound permanent lower central incisors were fractured by an axial load applied to the buccal area and randomly divided into five groups. The teeth were restored as follows: 1) bonded only = just bonding the fragment; 2) chamfer-group = after bonding, a chamfer was prepared on the enamel at the bonding line and filled with composite; 3) overcontour group = after bonding, a thin composite overcontour was applied on the buccal surface around the fracture line; 4) internal dentinal groove = before bonding, an internal groove was made and filled with a resin composite; 5) resin composite group = after a bevel preparation on the enamel edge, the adhesive system was applied and the fractured part of the teeth rebuilt by resin composite. Restored teeth were subjected to the same loading in the same buccal area. Fracture strength after restorative procedure was expressed as a percentage of the original fracture strength and the results analyzed by Kruskal-Wallis statistical analysis. The mean percentages of fracture strength were: Group 1: 37.09%, Group 2: 60.62%, Group 3: 97.2%, Group 4: 90.54% and Group 5: 95.8%. It was concluded that the re-attachment techniques used in Groups 3 and 4, as well as the composite restored group (Group 5), were statistically similar and reached the highest fracture resistance, similar to the fracture resistance of sound teeth.
外伤导致的前牙骨折是儿童和青少年中常见的问题。由于采用了复合树脂修复和再附着技术等粘结技术，对于剩余健全牙体结构大量丧失的情况，不再需要复杂的金属烤瓷冠修复。本研究比较了使用树脂复合材料和四种再附着技术修复后的健全前牙和修复前牙的抗折强度。应用了一种“单瓶”粘结系统（一步法，BISCO公司）和一种双固化树脂水门汀（双连，BISCO公司）。通过向颊侧施加轴向载荷使35颗健全的恒下中切牙发生骨折，并随机分为五组。牙齿修复如下：1）仅粘结组 = 仅粘结碎片；2）倒角组 = 粘结后，在粘结线处的釉质上制备一个倒角并用复合材料填充；3）外形超突组 = 粘结后，在骨折线周围的颊面施加一层薄的复合材料外形超突；4）牙本质内沟组 = 粘结前，制备一个内沟并用树脂复合材料填充；5）树脂复合材料组 = 在釉质边缘制备一个斜面后，应用粘结系统并用树脂复合材料重建牙齿的骨折部分。修复后的牙齿在相同的颊侧区域承受相同的载荷。修复后程序的抗折强度以原始抗折强度的百分比表示，并通过Kruskal-Wallis统计分析对结果进行分析。抗折强度的平均百分比分别为：第1组：37.09%，第2组：60.62%，第3组：97.2%，第4组：90.54%，第5组：95.8%。研究得出结论，第3组和第4组使用的再附着技术以及复合树脂修复组（第5组）在统计学上相似，并且达到了最高的抗折性，类似于健全牙齿的抗折性。
