Effect Of Non-Thermal Air Plasma Treatment On Shear Bond Strength Of Adhesive Resin Cement To Zirconia

Document Type : Original Article


1 Lecturer Fixed Prosthodontics Department, Faculty of Dentistry, Fayoum University, Egypt.

2 Lecturer Fixed Prosthodontics Department, Faculty of Dentistry, Beni Suef University, Egypt.

3 General Oral and Maxillofacial Surgery Practioner, Private Institution,Egypt.


Purpose: The purpose of the present study was to analyze the effect of non-thermal air plasma treatment on shear bond strength and failure mode of self-adhesive resin cement to zirconia.
Materials& Methods: Forty eight zirconia plates were prepared from IPS e.max ZirCad blocks (Ivoclar Vivadent, Schaan, Liechtenstein) and classified into four groups (n=12) according to surface treatment; group CO (control) without any surface treatment, group SD was treated with 50 µm alumina sandblasting, group PL used air atmospheric pressure plasma device (Piezobrush® PZ2, Relyon plasma GMBH, Regensburg, Germany) & group SP which was a combination of 50 µm alumina sandblasting followed immediately with atmospheric plasma treatment. Zirconia specimens were immediately centered with Relay X Unicem (3M ESPE) resin cylinders of 3.7 mm diameter and 2 mm height. Shear bond strength test was performed 8 days after water storage at 37˚C using a computer controlled materials testing machine (Model 3345; Instron Industrial Products, Norwood, USA). A scanning electron microscope (Quanta 250 Field Emission Gun, Netherlands) was used to determine failure mode with all morphological and structural changes. Average surface roughness (Ra) was calculated with different surface treatments. Energy Dispersive X-ray (EDX) analysis was used for chemical changes evaluation. Data were analyzed with one-way ANOVA followed by Tukey’s post hoc test when the ANOVA test was significant.
Results: A significant difference between different surface treatments (P=0.010) was recorded with the highest shear bond strength value in SP group and the lowest value with untreated surface CO gp. All groups showed mixed failure mode which was mainly cohesive except for CO gp. Surface roughness was increased with sandblasting and decreased after plazma treatment. EDX analysis showed increase oxygen on plazma treated surface.
Conclusion: Non thermal air plasma treatment can be used for increasing zirconia surface treatment especially when accompanied with 50 µm AL2O3 sandblasting.
Clinical significant: Non thermal air plasma treatment alone or in combination with sandblasting can be considered as a good clinical protocol for cementing zirconia restorations.