Pull-off Force of Four Different Implant Cements Between Zirconia Crowns and Titanium Implant Abutments in Two Different Abutment Heights

Int J Periodontics Restorative Dent. 2022 May-Jun;42(3):e67-e74. doi: 10.11607/prd.4926.

Abstract

This study evaluated the pull-off force between titanium abutments and zirconia crowns that were bonded using four different cements and two abutment heights (AHs). In total, 24 titanium abutments (3-mm AH: n = 12; 5-mm AH: n = 12; taper: 7.5 degrees) and 24 zirconia crowns were designed, manufactured, cemented with one of four dental cements (one temporary, two semi-permanent, one permanent), stored in water for 24 hours, and thermocycled (37,500 cycles, equal to ~4 years in vivo). The pull-off force needed to separate the abutment and crown in each combination was determined eight times per combination of cement type and abutment height. Statistical analysis was conducted at a significance level of P < .05. The permanent self-adhesive composite cement showed a high pull-off force with a risk for crown fracture (mean: 381 N for 3-mm AH; 617 N for 5-mm AH). In contrast, the temporary zinc-oxide cement showed frequent premature decementation after thermocycling (mean: 14 N with 3-mm AH; 28 N with 5-mm AH). Both semi-permanent methacrylate-based cements ranked between the other cements (mean: 31 N/37 N for 3-mm AH; 120 N/72 N for 5-mm AH). Statistically significant differences were found between all cements (ANOVA P < .001). The abutment heights differed significantly for all cements (P < .005) except for the temporary zinc-oxide cement. Methacrylate-based cements were the most reliable cements for semi-permanent mounting of zirconia crowns on titanium abutments. They provide sufficient retention to avoid unintended loosening and are weak enough to remove the crown without causing damage.

MeSH terms

  • Crowns
  • Dental Abutments
  • Dental Cements
  • Dental Implants*
  • Dental Materials
  • Dental Prosthesis, Implant-Supported
  • Dental Stress Analysis
  • Glass Ionomer Cements
  • Humans
  • Materials Testing
  • Methacrylates
  • Oxides
  • Titanium*
  • Zinc
  • Zirconium

Substances

  • Dental Cements
  • Dental Implants
  • Dental Materials
  • Glass Ionomer Cements
  • Methacrylates
  • Oxides
  • Zirconium
  • Titanium
  • Zinc
  • zirconium oxide