Fracture resistance and 2-body wear of 3-dimensional-printed occlusal devices

Anna-Maria Lutz; Rüdiger Hampe; Malgorzata Roos; Nina Lümkemann; Marlis Eichberger; Bogna Stawarczyk

doi:10.1016/j.prosdent.2018.04.007

Fracture resistance and 2-body wear of 3-dimensional-printed occlusal devices

J Prosthet Dent. 2019 Jan;121(1):166-172. doi: 10.1016/j.prosdent.2018.04.007. Epub 2018 Jun 29.

Authors

Anna-Maria Lutz¹, Rüdiger Hampe², Malgorzata Roos³, Nina Lümkemann⁴, Marlis Eichberger⁵, Bogna Stawarczyk⁶

Affiliations

¹ Graduate student, Dental Material Unit, Department of Prosthetic Dentistry, Ludwig-Maximilians-University, Munich, Germany.
² Research Fellow, Dental Material Unit, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany.
³ Senior Statistician, Department of Biostatistics, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.
⁴ Research Associate, Dental Material Unit, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany.
⁵ Dental Technician, Dental Material Unit, Department of Prosthetic Dentistry, Ludwig-Maximilians University, Munich, Germany.
⁶ Scientific Head, Dental Material Unit, Department of Prosthodontics, Ludwig-Maximilians University, Munich, Germany. Electronic address: bogna.stawarczyk@med.uni-muenchen.de.

PMID: 30647000
DOI: 10.1016/j.prosdent.2018.04.007

Abstract

Statement of problem: Polymeric material for 3-dimensional printing can be used to fabricate occlusal devices. However, information about fracture resistance and wear is scarce.

Purpose: The purpose of this in vitro study was to investigate the fracture resistance and 2-body wear of 3-dimensional-printed (3DP) (FotoDent splint; Dreve Dentamid GmbH), milled polymethylmethacrylate (CAM) (Temp Basic; Transpa 95H16, Zirkonzahn GmbH), and conventionally fabricated polymethylmethacrylate (CAST) (Castdon; Dreve Dentamid GmbH) occlusal devices.

Material and methods: A total of 96 occlusal devices were prepared according to the 3 different manufacturing techniques 3DP, CAM, and CAST (n=32). For each manufacturing technique, specimens were further divided into initial fracture resistance tests (n=16) and artificial aging in the mastication simulator (50 N, 37°C) with 2-body wear followed by fracture resistance tests (n=16). The fracture resistance was determined using a universal testing machine (1 mm/min). The wear was measured after 20 000 and 120 000 mastication cycles with the replica technique, mapped with a laser scanner, and quantified in R software. Data were analyzed using a 2-way ANOVA followed by a 1-way ANOVA with Scheffé or Games-Howell post hoc tests, repeated measures ANOVA with corrected Greenhouse-Geisser P values, and the Levene, Mann-Whitney, and paired t tests (α=.05).

Results: CAM presented higher initial fracture resistance than 3DP or CAST (P<.001). After mastication simulation, CAM followed by 3DP showed higher fracture resistance than CAST (P<.001). Mastication simulation decreased the fracture resistance for CAM and CAST (P<.001) but not for 3DP (P=.78). Three-dimensional-printed occlusal devices showed the highest material volume loss, followed by CAM and the lowest in CAST (P<.001).

Conclusions: Three-dimensional-printed occlusal devices showed lower wear resistance and lower fracture resistance than those milled or conventionally fabricated. Therefore, only short-term application in the mouth is recommended. Further developments of occlusal device material for 3-dimensional printing are necessary.

MeSH terms

Analysis of Variance
Dental Materials*
Dental Stress Analysis
Flexural Strength*
In Vitro Techniques
Materials Testing
Occlusal Splints*
Orthodontic Appliance Design
Polymethyl Methacrylate*
Printing, Three-Dimensional*

Substances

Dental Materials
Polymethyl Methacrylate