Effect of Thermo-mechanical Cycling on Fracture Resistance of Different CAD/CAM Crowns: An In Vitro Study

J Contemp Dent Pract. 2024 Jan 1;25(1):29-34. doi: 10.5005/jp-journals-10024-3619.

Abstract

Aim: To evaluate the effect of thermo-mechanical cycling (TMC) on fracture resistance of different computer-aided design/computer-aided manufacture (CAD/CAM) crowns.

Materials and methods: A total of 42 CAD/CAM crowns were fabricated on epoxy resin maxillary first premolar teeth and divided into three groups (n = 14) according to the material used: IPS e.max CAD (Ivoclar Vivadent) lithium disilicate (LD), Vita ENAMIC (VE) (VITA Zahnfabrik), Tetric CAD (Ivoclar Vivadent). Also, each group was subdivided into two equal subgroups according to TMC (n = 7). Subgroups (O) without TMC and subgroup (W) with TMC (5-55°C, 30 second, 75,000 cycles). All samples in each group were cemented with a universal bond (Tetric N bond universal) and adhesive resin cement (Variolink Esthetic DC) (Ivoclar Vivadent). Subsequently, the samples were loaded to failure in a universal testing machine at a crosshead speed of 1 mm/min, and the fracture pattern and the fracture resistance in each group were recorded.

Results: Fracture resistance was analyzed by one-way analysis of variance (ANOVA) test, followed by Tukey's post hoc test for pairwise comparison. Fracture resistance showed a significant difference between the tested groups before and after TMC; IPS e.max CAD has the highest value (1233.35 ± 97.72, 1165.73 ± 199.54 N) followed by Tetric CAD (927.62 ± 42.5, 992.04 ± 53.46 N) and Vita ENAMIC has lowest value (506.49 ± 74.24, 354.69 ± 90.36 N).

Conclusion: Thermo-mechanical cycling affected the fracture resistance of both polymer-based CAD/CAM crowns.

Clinical significance: For dental practitioners, both IPS e.max CAD and Tetric CAD can be used clinically for posterior teeth, providing satisfactory results and resistance to fracture. How to cite this article: Elmokadem MI, Haggag KM, Mohamed HR. Effect of Thermo-mechanical Cycling on Fracture Resistance of Different CAD/CAM Crowns: An In Vitro Study. J Contemp Dent Pract 2024;25(1):29-34.

Keywords: Ceramic-polymer; Composite resin; Computer-aided design/computer-aided manufacture; Fracture resistance Thermo-mechanical cycling..

MeSH terms

  • Acrylic Resins*
  • Ceramics / chemistry
  • Composite Resins*
  • Computer-Aided Design
  • Crowns
  • Dental Porcelain
  • Dental Restoration Failure
  • Dental Stress Analysis
  • Dentists*
  • Esthetics, Dental
  • Humans
  • Materials Testing
  • Polyurethanes*
  • Professional Role*

Substances

  • Vivadent
  • Dental Porcelain
  • Acrylic Resins
  • Composite Resins
  • Polyurethanes