Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Department of Dentistry - Regenerative Biomaterials, Philips van Leydenlaan 25, Nijmegen, The Netherlands.
Radboud University Medical Center, Radboud Institute for Health Sciences, Department of Dentistry - Restorative Dentistry, Philips van Leydenlaan 25, Nijmegen, The Netherlands.
Dent Mater. 2021 Mar;37(3):403-412. doi: 10.1016/j.dental.2020.11.025. Epub 2021 Jan 19.
Fracture is one of the main causes for failure of resin-based composite restorations. To overcome this drawback, self-healing resin-based composites have been designed by incorporation of microcapsules. However, the relationship between their self-healing capacity and microcapsule and resin parameters is still poorly understood. Therefore, the objective of this study was to systematically investigate the effect of initiator concentration (in the resin) and microcapsule size and concentration on the self-healing performance of commercially available flowable resin-based composites.
Poly(urea-formaldehyde) (PUF) microcapsules containing acrylic healing liquid were synthesized in small (33±8μm), medium (68±21μm) and large sizes (198±43μm) and characterized. Subsequently, these microcapsules were incorporated into a conventional flowable resin-based composite (Majesty Flow ES2, Kuraray) at different contents (5-15wt%) and benzoyl peroxide (BPO) initiator concentrations (0.5-2.0wt%). Fracture toughness (K) of test specimens was tested using a single edge V-notched beam method. Immediately after complete fracture (K), the two fractured parts were held together for 72h to allow for healing. Subsequently, fracture toughness of the healed resin-based composites (K) was tested as well.
The fracture toughness of healed dental composites significantly increased with increasing microcapsule size and concentration (2wt% BPO, p<0.05). The highest self-healing efficiencies (up to 76%) were obtained with microcapsules sized 198±43 um.
commercially available resin-based composites can be rendered self-healing most efficiently by incorporation of large microcapsules (198±43μm). However, long-term tests on fatigue and wear behavior are needed to confirm the clinical efficacy.
骨折是造成树脂基复合材料修复体失败的主要原因之一。为了克服这一缺陷，通过掺入微胶囊设计了自修复树脂基复合材料。然而，它们的自修复能力与微胶囊和树脂参数之间的关系仍知之甚少。因此，本研究的目的是系统地研究引发剂浓度（在树脂中）和微胶囊的大小和浓度对市售可流动树脂基复合材料的自修复性能的影响。
合成了含有丙烯酸愈合液的聚（脲-甲醛）（PUF）微胶囊，其粒径分别为 33±8μm、68±21μm 和 198±43μm，并对其进行了表征。随后，将这些微胶囊以不同的含量（5-15wt%）和过氧化二苯甲酰（BPO）引发剂浓度（0.5-2.0wt%）掺入到常规可流动树脂基复合材料（Kuraray 的 Majesty Flow ES2）中。使用单边 V 型缺口梁法测试试件的断裂韧性（K）。在完全断裂（K）后，立即将两个断裂部分放在一起 72h 以进行愈合。随后，也测试了愈合后的树脂基复合材料的断裂韧性（K）。
愈合后的牙科复合材料的断裂韧性随着微胶囊尺寸和浓度的增加而显著增加（2wt%BPO，p<0.05）。用 198±43μm 大小的微胶囊获得了最高的自修复效率（高达 76%）。
通过掺入大尺寸（198±43μm）微胶囊，可最有效地使市售树脂基复合材料具有自修复能力。然而，需要进行长期的疲劳和磨损行为测试以确认其临床效果。
