Pimentel Maria Isabel Guimarães Carvalho Ribeiro, Kantovitz Kamila Rosamilia, Turssi Cecília Pedroso, Amaral Flávia Lucisano Botelho do, Basting Roberta Tarkany, Martins Leandro de Moura, França Fabiana Mantovani Gomes
Faculdade São Leopoldo Mandic, School of Dentistry, Department of Restorative Dentistry, Campinas, SP, Brazil.
Universidade Federal do Amazonas - Ufam, Department of Restorative Dentistry, Manaus, AM, Brazil.
Braz Oral Res. 2025 Feb 7;39:e13. doi: 10.1590/1807-3107bor-2025.vol39.013. eCollection 2025.
This study evaluated the microtensile bond strength (μTBS) and fracture pattern of direct composite resin reinforced with polyethylene fiber (Ribbond®) on dentin substrate after thermomechanical cycling (TMC). Dentin blocks (dentin thickness=2 mm) were obtained from forty human third molars and randomly divided into four groups (n=10) according to type of restoration (composite resin with or without Ribbond®) and to whether they were or were not subjected to TMC (100,000 cycles of 50 N / 2 Hz / 1-minute baths of 5 and 55ºC). The 1-mm-thick square-shaped specimens were submitted to μTBS testing in a universal testing machine at 0.5 mm/min. The fracture patterns were assessed by stereoscopic magnifying glass (30X magnification). The μTBS (in MPa) and failure pattern data were subjected to the generalized linear model and G tests (a=0.05). Neither the polyethylene fiber nor TMC had any statistically significant effect (p=0.196 and p=0.136, respectively) on the μTBS of the composite resin to dentin. Adhesive failures were more prevalent in the composite resin group compared with the Ribbond-containing group when subjected to TMC. Additionally, the composite resin containing Ribbond® showed a higher proportion of cohesive failures in composite resin than the resin groups not containing this fiber, irrespective of TMC. It was concluded that reinforcing the direct layer of composite resin with Ribbond® polyethylene fiber did not influence the adhesive resistance to dentin, even when subjected to TMC. However, its incorporation did result in a higher frequency of cohesive failures in resin after TMC.
本研究评估了热机械循环（TMC）后，聚乙烯纤维（Ribbond®）增强的直接复合树脂与牙本质基质之间的微拉伸粘结强度（μTBS）和断裂模式。从40颗人类第三磨牙获取牙本质块（牙本质厚度 = 2 mm），并根据修复类型（含或不含Ribbond®的复合树脂）以及是否进行TMC（50 N / 2 Hz / 5和55ºC的1分钟水浴，共100,000次循环）随机分为四组（n = 10）。将1 mm厚的方形试样在万能试验机中以0.5 mm/min的速度进行μTBS测试。通过立体放大镜（30倍放大）评估断裂模式。μTBS（以MPa为单位）和失效模式数据进行广义线性模型和G检验（α = 0.05）。聚乙烯纤维和TMC对复合树脂与牙本质之间的μTBS均无统计学显著影响（分别为p = 0.196和p = 0.136）。进行TMC时，与含Ribbond的组相比，复合树脂组的粘结性失败更为普遍。此外，无论是否进行TMC，含Ribbond®的复合树脂在复合树脂中显示出比不含该纤维的树脂组更高比例的内聚性失败。得出的结论是，用Ribbond®聚乙烯纤维增强复合树脂的直接层即使在进行TMC时也不会影响对牙本质的粘结抗性。然而，其加入确实导致TMC后树脂中内聚性失败的频率更高。
