Influence of sterilization on the retention forces of lithium disilicate and polymer-infiltrated ceramic-network crowns bonded to titanium base abutments: An in-vitro study

Clin Oral Implants Res. 2024 Apr;35(4):377-385. doi: 10.1111/clr.14234. Epub 2024 Jan 3.

Abstract

Objectives: The aim of this study was to evaluate the effect of sterilization on the retention forces of lithium disilicate (LD) and polymer-infiltrated ceramic network (PICN) crowns bonded to titanium base (Ti-base) abutments.

Materials and methods: Forty LD and 40 PICN crowns were milled and then bonded to 80 Ti-bases with two resin composite cements: Multilink Hybrid Abutment (mh) and Panavia V5 (pv) for a total of 8 groups (n = 10). Half of the specimens (test) underwent an autoclaving protocol (pressure 1.1 bar, 121°C, 20.5 min) and the other half not (control). Restorations were screw-retained to implants, and retention forces (N) were measured with a pull-off testing machine. The surfaces of the Ti-bases and the crowns were inspected for the analysis of the integrity of the marginal bonding interface and failure mode. Student's t-test, chi-square test, and univariate linear regression model were performed to analyze the data (α = 0.05).

Results: The mean pull-off retention forces ranged from 487.7 ± 73.4 N to 742.2 ± 150.3 N. Sterilized groups showed statistically significant overall higher maximum retention forces (p < .05), except for one combination (LD + mh). Sterilization led to an increased presence of marginal gaps and deformities compared to no-sterilization (p < .001), while no statistically significant relationship was found between failure mode and sterilization (p > .05).

Conclusions: Sterilization may have a beneficial effect on the retention forces of LD and PICN crowns bonded to titanium base abutments, although it may negatively influence the integrity of the marginal bonding interface.

Keywords: CAD–CAM; bonding; implant dentistry; pull‐off; retention force; sterilization; titanium base abutment.

MeSH terms

  • Ceramics
  • Computer-Aided Design
  • Crowns
  • Dental Abutments
  • Dental Porcelain
  • Dental Stress Analysis
  • Materials Testing
  • Polymers*
  • Titanium*
  • Zirconium

Substances

  • lithia disilicate
  • Titanium
  • Polymers
  • Dental Porcelain
  • Zirconium