Purpose of the study: To evaluate the effectiveness of different cleaning procedures on removing the saliva and try-in paste remnants from contaminated zirconia and lithium disilicate surfaces.
Material and Methods: Fifty samples of zirconia (IPS e.max ZirCAD) and 50 samples of lithium disilicate (IPS e.max CAD) were divided into 5 groups: Group 1 – No contamination with saliva and try-in paste (control); Group 2 – Contamination followed by rinsing with water; Group 3 – Contamination followed by cleaning with NaOCL 7% for 30 seconds; Group 4 – Contamination followed by cleaning with H3PO4 35% for 30 seconds; Group 5 – Contamination followed by cleaning with Ivoclean for 30 seconds. Zirconium oxide cylinders were luted to the samples using Multilink Implant cement. After being stored for 24 hours in a deionized water bath at 370C, the samples were subjected to shear forces at a crosshead speed of 0.5 mm/min. ANOVA and Tukey’s post-hoc test were used for statistical analysis.
Results: No significant differences were observed between various groups for zirconia samples with all cleaning protocols showing shear bond strengths similar to the control groups. Group 4 showed significant improvement in shear bond strength when compared to control (p < 0.05) for lithium disilicate samples.
Conclusions: Within the limitations of this study it could be said that the application of phosphoric acid for 30 seconds is effective to clean lithium disilicate samples contaminated with saliva and try-in paste.
Authors: Luiz H. Gonzaga, Himanshu Arora, William C. Martin
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