Studies on the development of new soft resin-based denture for elderly person in need of care

我们开始开发新的软树脂基义齿，吸收机械刺激到义齿下的粘膜，使老年人感到舒适。首先选定了甲基丙烯酸2-乙基己基酯（EHMA）与甲基丙烯酸甲酯（MMA）共聚物，并通过初步的压缩试验表明该共聚物具有一定的力学效应。其次，采用本研究设计的试验方法，对衬里用软树脂所需的柔软模量、松弛应力率和压缩后尺寸回复率进行了研究。结果表明，当EHMA成分比超过80%时，材料的柔软模量呈指数增长。松弛应力率在EHMA 60%以上的范围内达到满意值。尺寸回复率方面，60%和70%的EHMA共聚物表现为弹性回复率，80%、90%和100%的EHMA共聚物表现为粘弹性回复率。大于80%的共聚物在30秒后的尺寸回复率约为100%。因此，我们认为这种延迟在临床上是没有问题的。通过这种方式，EHMA效应得到了认可。作为应用，制作上、下全口义齿进行试验。方法如下。在此之前，将EHMA-MMA薄片在70℃下加热制成牙槽嵴石膏模型。在义齿法的最后阶段，将树脂面团填充到上熟化瓶中，形成的EHMA-MMA薄片涂在义齿的粘膜侧。将固化烧瓶设置为烧瓶固位体，在70℃下聚合EHMA-MMA软树脂基义齿。通过这种方法，丙烯酸树脂与EHMA-MMA片材之间的界面被化学粘合。因此，由于软性树脂基义齿具有粘弹性，可以通过义齿分散和放松咀嚼力，因此可以避免患者的粘膜疼痛，这是非常值得期待的。少

We began development of new soft resin-based denture absorbing mechanical stimulation to a mucous membrane under denture, which was comfortable to an elderly person. First a copolymer of 2-ethylhexyl methacrylate (EHMA) and methyl methacrylate (MMA) was selected especially, and it was suggested that the copolymer might have a mechanical effect by preliminary compression tests. Secondly, modulus of softness, relaxation stress rate and ratio of dimensional recovery after compression to be necessary for soft resin for lining were investigated by test method devised in this study. As a result, the modulus of softness exponentially increased when the EHMA composition ratio exceeded 80%. As for the relaxation stress rate, a satisfied value was shown in range of more than EHMA 60%. As for the ratio of dimensional recovery, copolymers of EHMA 60% and 70% showed behavior of elastic recovery, whereas copolymers of EHMA 80%, 90% and 100% showed behavior of viscoelastic recovery. However, copolyme … More rs of more than EHMA 80% showed the ratio of dimensional recovery of about 100% after 30 second. Therefore, we judged that such the delay was clinically no problem. In this manner, the EHMA effect was recognized. As application, upper and lower complete denture was made for trial. The method is as follows. Beforehand, EHMA-MMA sheet was adapted to plaster model of an alveolar ridge by heating at 70℃. After packed resin dough to upper curing flask at final stage of denture method, the formed EHMA-MMA sheet was applied to mucous membrane side of denture. And the curing flask was set to flask retainer, and the EHMA-MMA soft resin-based denture was polymerized at 70℃. By the way, the interface between an acrylic resin and EHMA-MMA sheet were chemically bonded. Consequently, as the soft resin-based denture having viscoelastic property was able to disperse and relax a force of mastication through denture, It was expected very much that a patient might be able to evade a pain of mucous membrane. Less