Investigation of the Effect of the Same Polishing Protocol on the Surface Roughness of Denture Base Acrylic Resins

Abstract

This investigation aims to determine the effect of the same polishing protocol on the surface roughness (Ra) of different resins obtained by different processing techniques. Acrylic resins obtained by CAD/CAM technology overcame the disadvantages identified in conventional materials. A total of thirty samples (six of each resin): self-cured, heat-polymerized, injection molded, CAD/CAM 3D-printed and CAD/CAM milled were prepared. JOTA® Kit 1877 DENTUR POLISH was used to polish the samples by two techniques: manual and mechanized, with a prototype for guided polishing exclusively developed for this investigation. The Ra was measured by a profilometer. The values were analyzed using ANOVA, Games–Howell post-hoc test and One-sample t-test, with p < 0.05. Manual polishing produces lower values of Ra compared to mechanized polishing, except for injected molded resins (p = 0.713). Manual polishing reveals significant differences between the resin pairs milling/3D-printing (p = 0.012) and thermopolymerizable/milling (p = 0.024). In the mechanized technique only, significant differences regarding the Ra values were found between the self-cured/3D-printed (p = 0.004) and self-cured/thermopolymerizable pair resins (p = 0.004). Differences in surface roughness values can be attributed to the inherent characteristics of the resin and the respective processing techniques.

A Different Approach to Analyzing the Surface Roughness of Prosthetic Dental Acrylic Resins

“…The surface roughness of dental acrylic resins is mainly affected by acrylic resins' inherent features, the polishing technique, and the operator's manual skills [1,4,6]. The authors of the present study propose a mechanical device for polishing acrylic resins, regardless of the individual operator's skills.…”

“…Acrylic resins are used for various applications in dentistry, such as denture base materials. The most common material used for denture base is poly (methyl methacrylate) (PMMA) [1].…”

“…The authors of the present study propose a mechanical device for polishing acrylic resins, regardless of the individual operator's skills. When assessing surface roughness, this variable should be excluded [1].…”

Surface Roughness of Polyetheretherketone Printed by Fused Deposition Modeling: A Pilot Study Investigating the Impact of Print Layer Thickness and Polishing Method

“…Its use as pre-formed blocks for milling is associated with lower porosity [29]. However, there is no consensus among authors on the best technique for polishing FDM PEEK or milled PMMA [21,[30][31][32].…”

Evaluation of the Influence of Build Orientation on the Surface Roughness and Flexural Strength of 3D-Printed Denture Base Resin and Its Comparison with CAD-CAM Milled Denture Base Resin

“…11,12 The surface roughness of the materials used as a denture base is a critical property and should be kept within acceptable values to avoid plaque accumulation, bacterial colonization, and staining. 16,17 Although avoiding surface roughness might be a complicated task in digital manufacturing due to the nature of the object production, 17,18 studies have found that surfaces with roughness values higher than 0.2 μm maximize the rate of bacterial colonization. 17,19,20 This roughness is a normal sequel to the layer-by-layer building of the object in 3D printing technology.…”