Abdelaziz Khalid M, Saleh Ahmed A
Department of Restorative Dental Sciences, College of Dentistry, King Khalid University, PO Box 3263, Abha 61471, Saudi Arabia.
J Dent Sci. 2018 Dec;13(4):378-385. doi: 10.1016/j.jds.2018.08.003. Epub 2018 Sep 1.
BACKGROUND/PURPOSE: The longevity of bonded composite restorations could be affected by the utilized adhesive-composite application techniques. This in vitro study aimed to evaluate the influence of adhesive-composite application modalities on their bonding values to tooth structure and on the failure resistance of the performed restorations on loading.
Resin composite studs, 2 mm in diameter and 4 mm high, were bonded in 2 groups to flattened enamel and dentin surfaces of 80 extracted premolars using pre-cured (PC) and co-cured (CC) self-etch resin adhesive. Studs in each group were built-up in 4 subgroups using either multiple increments of nano-filled composite (IF, control) or single increment of preheated nano-filled (PH), bulk-fill (BF) and sonic-activated bulk-fill composites (SF). Another 80 premolars with standard class II cavities were also restored using the same adhesive-composite application modalities. All specimens were then stressed on a universal testing machine to assess the composite-tooth shear bond strength and the resistance of the performed restorations to failure. The modes of specimens' failure were also assessed following each test.
The PC adhesive provided higher bond strength to dentin (p < 0.05) and comparable bond strength to enamel in comparison to the CC one (p>0.05%). Both PH and BF composites showed lower bond strength to dentin in presence of PC adhesive (p < 0.05). Comparable bond strengths were noticed for PH, BF and SF composites to dentin in presence of CC adhesive (p > 0.05). PH and SF restorations presented the highest resistance to failure (p < 0.05).
Both incrementally and bulky-inserted composites offer clinically acceptable bond strength in presence of pre-cured resin adhesive. Both Preheated and sonic-activated composite restorations offer the highest resistance to failure on loading. The preheating procedure renders regular composite material suitable for bulk-fill applications.
背景/目的：粘结复合树脂修复体的使用寿命可能会受到所采用的粘结剂 - 复合树脂应用技术的影响。本体外研究旨在评估粘结剂 - 复合树脂应用方式对其与牙体组织粘结强度以及修复体加载时抗折性能的影响。
使用预固化（PC）和共固化（CC）自酸蚀树脂粘结剂，将直径2毫米、高4毫米的树脂复合树脂柱粘结到80颗拔除前磨牙的磨平釉质和牙本质表面，分为2组。每组树脂柱再分为4个亚组，分别使用多次增量的纳米填充复合树脂（IF，对照组）或单次增量的预热纳米填充（PH）、大块充填（BF）和超声激活大块充填复合树脂（SF）。另外80颗有标准II类洞的前磨牙也使用相同的粘结剂 - 复合树脂应用方式进行修复。然后在万能试验机上对所有标本施加应力，以评估复合树脂与牙齿的剪切粘结强度以及修复体的抗折性能。每次测试后还评估标本的断裂模式。
与CC粘结剂相比，PC粘结剂对牙本质的粘结强度更高（p < 0.05），对釉质的粘结强度相当（p > 0.05%）。在PC粘结剂存在下，PH和BF复合树脂对牙本质的粘结强度均较低（p < 0.05）。在CC粘结剂存在下，PH、BF和SF复合树脂对牙本质的粘结强度相当（p > 0.05）。PH和SF修复体的抗折性能最高（p < 0.05）。
在预固化树脂粘结剂存在下，增量式和大块插入式复合树脂均提供临床上可接受的粘结强度。预热和超声激活的复合树脂修复体在加载时具有最高的抗折性能。预热程序使普通复合树脂材料适用于大块充填应用。
