Effect of finishing and polishing methods on surface roughness of autopolymerized acrylic resins

ABSTRACT Objective : To evaluate the surface roughness of two makes of autopolymerized acrylic resin (Classic Dencor® and Duralay®) with two different methods of finishing and polishing (conventional and using the Dhpro® finishing & polishing kit). Methods : A total of 20 specimens (10 of each make) was obtained using Zetalabor®--Zhermak condensation silicone molds. After polymerization, 20 blocks of resin were divided in two and subjected to two types of finishing and polishing, one at each end. The types of finishing and polishing were as follows: conventional (lathe) and using the Dhpro® finishing & polishing kit. Once finished and polished, the specimens were subjected to surface roughness testing using a roughness meter and were analyzed via the Student’s t-test. Results : There is a statistically significant difference between the forms of polishing, unrelated to the brand of acrylic resin. Conventional polishing achieved a level of 0.12 µm for both resins and the DhPro® polishing presented roughness a little above 0.2 µm. Conclusion : Conventional polishing is superior to the DhPro® kit, as it achieves lower levels of roughness. There is no significant difference between the acrylic resins in terms of surface roughness after the finishing and polishing processes.

摘要 目的：评估两种品牌自凝丙烯酸树脂（autopolymerized acrylic resin，Classic Dencor®与Duralay®）分别采用两种不同打磨抛光工艺（传统车床法与Dhpro®打磨抛光套件）后的表面粗糙度。方法：本研究采用Zetalabor®—Zhermak品牌缩聚硅橡胶模具制备共计20件试样，每种品牌各10件。聚合固化完成后，将20块树脂坯料均分，每块试样的两端分别采用两种打磨抛光方式处理：传统车床法与Dhpro®打磨抛光套件法。待打磨抛光工序完成后，使用粗糙度仪对试样进行表面粗糙度测试，并通过学生t检验（Student’s t-test）进行统计分析。结果：不同抛光方式间存在具有统计学意义的差异，且该差异与丙烯酸树脂品牌无关。传统车床抛光法处理后，两种树脂的表面粗糙度均为0.12 µm；而采用DhPro®套件抛光后的粗糙度略高于0.2 µm。结论：传统车床抛光法优于Dhpro®打磨抛光套件，可获得更低的表面粗糙度。经打磨抛光处理后，不同品牌的丙烯酸树脂在表面粗糙度维度上无显著统计学差异。