Comparison of marginal leakage and retentive strength of implant‑supported milled zirconia and cobalt‑chromium copings cemented with different temporary cements

Abstract

Background: Few studies assessed the effect of coping material (particularly milled metal copings)
on the retentive strength of cements and reported contradictory results. Thus, this study aims
to assess the marginal leakage and retentive strength of implant‑supported milled zirconia and
cobalt‑chromium (Co‑Cr) copings cemented with different temporary cements.
Materials and Methods: In this in vitro study, Zirconia and Co‑Cr copings were fabricated on 100
straight titanium abutments. Each group of copings was divided into five subgroups (n = 10) for the
use of different cements: permanent zinc‑phosphate (ZP) cement, temporary zinc oxide eugenol
cement (temp bond [TB]), calcium hydroxide‑based temporary cement (Dycal [DC]), polymer‑based
eugenol‑free acrylic‑urethane temporary cement (Dentotemp [DT]), and methacrylate‑based
temporary cement (Implantlink [IL]). The retentive strength and marginal leakage of restorations
were assessed. Data were analyzed by one‑way ANOVA, Tukey, and Fisher’s exact tests ( = 0.05).
Results: In the Co‑Cr group, the retentive strength values (in Newtons) were as follows:
ZP (411.40 ± 5.19) >DC (248.80 ± 5.01) >IL (200.10 ± 5.06) >DT (157.90 ± 5.19) >TB (98.50 ± 6.88).
This order was as follows in the zirconia group: ZP (388.70 ± 5.35) >DC (226.60 ± 5.08)
>IL (179.00 ± 3.71) >DT (136.00 ± 4.88) >TB (78.60 ± 3.50). All pairwise comparisons were
statistically significant (P < 0.001). The difference in marginal leakage was not significant among the
groups (P = 0.480).
Conclusion: The type of coping material and cement type significantly affected retentive strength,
but not marginal leakage, of implant restorations. Milled Co‑Cr copings showed higher retentive
strength than zirconia copings, and ZP cement followed by DC yielded the highest retention.
Key Words: Computer‑aided design, dental cements, dental prosthesis, implant‑supported

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Hamid Neshandar Asli: Pubmed,Google Scholar