The effect of different methods of cleansing temporary cement (with and without eugenol) on the final bond strength of implant‑supported zirconia copings after final cementation: An in vitro study

Abstract

Background: The temporary cement remaining inside the dental prosthesis can act as a source of
microbial colonization and contamination and decrease the final cement retention. Consequently,
complete removal of temporary cement before permanent cementation is suggested. This study
aimed to assess the effect of different cleaning methods for removing temporary cement on the
tensile bond force (TBF) of permanently cemented implant‑supported zirconia copings.
Materials and Methods: In this in vitro study fifty titanium abutments were screwed onto 50
analogs with 30 Ncm torque into in acrylic resin blocks. Each abutment was scanned separately, and
50 zirconia copings were designed and milled. Permanent resin cement was used to cement copings
of control group (N = 10). Copings were divided into two temporary cementation types that in each
group, two cleansing methods were used: Temp‑S (temporary cement with eugenol and sandblasted
after debonding), Samples of the control group were placed in the universal testing machine, and the
TBF values were recorded. Samples of the test groups after debonding and cleaning the abutments
were subjected to cement with permanent resin cement, aging, and removing. Levene test, two-way
analysis of variance (ANOVA), and Tamhane post hoc tests were applied. α = 0.05.
Results: The highest and lowest TBF values were found for the TempNE‑SU (554.7 ± 31.5 N) and
Temp‑S (492.2 ± 48 N) groups, respectively. The two groups of isopropyl alcohol baths in ultrasonics
in combination with sandblasting showed statistically higher TBF values than the other two groups
that used only sandblasting (P < 0.001) and had similar values compared to the control group.
Conclusion: Sandblasting combined with immersion in an ultrasonic bath containing isopropyl
alcohol resulted in statistically similar values to the values of cementation with resin cement from
the beginning. However, cleaning the inside of the copings only by sandblasting method reduced
the values of the final retention force in comparison to cement with permanent resin cement
from the beginning.
Keywords: Cleaning methods, permanently cemented implant, temporary cement removal,
tensile bond force, zirconia