[KAP-5] Influence of Build Orientations on the Wear Resistance and Hardness of Denture Teeth fabricated by Digital Light Processing (DLP)
[Abstract]
[Objective]
With the increasing popularity of additively manufactured dentures these days1, build orientations are reported to influence the mechanical properties of these resins2-3. However, only limited studies evaluated the impact of build orientations on the wear resistance of DLP-fabricated resins. Therefore, this in-vitro study aimed to investigate the influence of build orientations on the wear resistance and hardness of denture teeth resin fabricated by digital light processing, comparing it with alternative denture teeth materials.
[Method]
Disc-shaped specimens were fabricated using a DLP printing device (Cara Print 4.0, Kulzer) and its compatible resin (dima denture teeth resin, Kulzer) with three build orientations (0°,45° and 90°). Milled specimens were prepared from milled resin (Ivotion Dent, Ivoclar Vivadent AG), PMMA specimens from prefabricated PMMA resin (Livedent FB20, GC) and composite resin specimens from prefabricated composite resin (Livedent Grace, GC). All specimens shared the same dimension of 2mm in thickness and 8 mm in diameter, with eight specimens per group (n=8). Wear resistance, in terms of wear volume, was assessed in two-body wear and three-body wear, alongside the hardness measurements by Vickers hardness testing machine (HM-100, Mitutoyo). For statistical analysis, two-way ANOVA for wear volume and one way ANOVA for hardness was performed followed by Tukey HSD test at a significant level of α = 0.05.
[Results and Discussion]
The interaction between denture teeth resins and the conditions of maximum wear volume was significant (p < 0.01). Among three build orientations, 0° build orientation exhibited the least wear volume in three body wear test and greatest hardness. When comparing all materials, 0° DLP-fabricated specimens exhibited significantly less wear volume than PMMA specimens and comparable wear volume with milled specimens while demonstrating significantly less hardness than milled specimens.
[References]
1. Infante L, Yilmaz B, McGlumphy E, et al. Fabricating complete dentures with CAD/CAM technology. J Prosthet Dent 2014;111:351-5.
2. Dizon JRC, Espera AH, Chen Q, et al. Mechanical characterization of 3D-printed polymers. Additive Manufacturing. 2018;20:44-67.
3. Shim JS, Kim JE, Jeong SH, et al. Printing accuracy, mechanical properties, surface characteristics, and microbial adhesion of 3D-printed resins with various printing orientations. J Prosthet Dent. 2020;124(4):468-75.
[Objective]
With the increasing popularity of additively manufactured dentures these days1, build orientations are reported to influence the mechanical properties of these resins2-3. However, only limited studies evaluated the impact of build orientations on the wear resistance of DLP-fabricated resins. Therefore, this in-vitro study aimed to investigate the influence of build orientations on the wear resistance and hardness of denture teeth resin fabricated by digital light processing, comparing it with alternative denture teeth materials.
[Method]
Disc-shaped specimens were fabricated using a DLP printing device (Cara Print 4.0, Kulzer) and its compatible resin (dima denture teeth resin, Kulzer) with three build orientations (0°,45° and 90°). Milled specimens were prepared from milled resin (Ivotion Dent, Ivoclar Vivadent AG), PMMA specimens from prefabricated PMMA resin (Livedent FB20, GC) and composite resin specimens from prefabricated composite resin (Livedent Grace, GC). All specimens shared the same dimension of 2mm in thickness and 8 mm in diameter, with eight specimens per group (n=8). Wear resistance, in terms of wear volume, was assessed in two-body wear and three-body wear, alongside the hardness measurements by Vickers hardness testing machine (HM-100, Mitutoyo). For statistical analysis, two-way ANOVA for wear volume and one way ANOVA for hardness was performed followed by Tukey HSD test at a significant level of α = 0.05.
[Results and Discussion]
The interaction between denture teeth resins and the conditions of maximum wear volume was significant (p < 0.01). Among three build orientations, 0° build orientation exhibited the least wear volume in three body wear test and greatest hardness. When comparing all materials, 0° DLP-fabricated specimens exhibited significantly less wear volume than PMMA specimens and comparable wear volume with milled specimens while demonstrating significantly less hardness than milled specimens.
[References]
1. Infante L, Yilmaz B, McGlumphy E, et al. Fabricating complete dentures with CAD/CAM technology. J Prosthet Dent 2014;111:351-5.
2. Dizon JRC, Espera AH, Chen Q, et al. Mechanical characterization of 3D-printed polymers. Additive Manufacturing. 2018;20:44-67.
3. Shim JS, Kim JE, Jeong SH, et al. Printing accuracy, mechanical properties, surface characteristics, and microbial adhesion of 3D-printed resins with various printing orientations. J Prosthet Dent. 2020;124(4):468-75.