Influence of Atmospheric Pressure Low-temperature Plasma Treatment on the Shear Bond Strength Between Zirconia And Resin Cement

Objectives: The aim of this study was to analyze the influence of non-thermal plasma (NTP) on the zirconia shear bond strength (SBS), contact angle and to determine the fracture mode after different surface treatments and thermocycling.
Methods: One hundred sixty Y-TZP specimens were divided into two groups: G-CEM LinkAce self adhesive resin cement (GC, TOKYO, JAPAN) (group A) (n = 80); RelyX U200 Automix self adhesive resin cement (3M ESPE, St. Paul, Minn.) (group B) (n = 80). Each group was distributed into 8 groups (n=10 disks each), four control (non-NTP treated) and four experimental (NTP treated for 1min) groups ground automatically with 600 and 800 µm grit and water cooling. All groups received one of the four following treatments prior to cementation with resin cement: sand-blasting (S), Z-PRIME Plus (Bisco Inc., Schaumburg, IL, USA) (P), sand-blasting + Z-PRIME Plus (SP), or control (C), no treatment. SBS was measured in Shear Bond Tester (Bisco Inc., Schaumburg, IL, USA), and fracture sites were examined with FE-SEM. Surface wettability after surface treatments were examined additionally. SBS results were statistically analyzed by 1-way ANOVA and Independent Samples T-tests were used to compare groups on SBS.
Results: Surface activation with non-thermal plasma did not improve the shear bond strength between zirconia and resin cement. The plasma-activation tended to reveal higher bond strength if primer was used.
Conclusions: Plasma-treatment seems to be suitable to improve bond strength between zirconia and self-adhesive resin materials. However, further research is necessary to identify the influence of varying plasma-parameters.