Hemalatha Konka1, K Chandrasekharan Nair2*, Vahini Reddy3 and Divya Hegde4
1Registrar Prosthodontist, Al Harkan Dental Hospital, Al Qassim, Saudi Arabia
2Professor Emeritus, Department of Prosthodontics, Sri Sankara Dental College, Akathumuri, Thiruvananthapuram, Kerala, India
3Former Professor of Prosthodontics, AECS Maaruti College of Dental Sciences, Bangalore, India
4Divya Hegde, Professor of Prosthodontics, BIDS, Bangalore, India
*Corresponding Author:K Chandrasekharan Nair, Professor Emeritus, Department of Prosthodontics, Sri Sankara Dental College, Akathumuri, Thiruvananthapuram, Kerala, India.
Received: March 07, 2022; Published: March 25, 2022
Objective: To evaluate the shear bond strength of veneering porcelain to zirconia, Lithium disilicate and Nickel chromium alloy cores.
Materials and Methods: Rectangular samples of dimension 9x4x4mm were made in three different core materials viz. Zirconia, Lithium disilicate and Nickel chromium alloy. The bonding surface of the specimens were sandblasted. Feldspathic porcelain (cerinate) was applied on the cores and fired to form a 3mm thick veneer. The specimens were embedded in an acrylic block. These specimens were subjected to shear force in a universal testing machine. Load was applied at a cross head speed of 0.5mm per minute until the specimens fractured. The force required for fracturing was recorded. The broken specimens were examined under scanning electron microscope. Data analysis was done with factorial ANOVA.
Results: The maximum bond strength was seen between lithium disilicate core and the veneering ceramic (409.4N). The Least bond strength was between Zirconia core and the veneering ceramic (284.8N). The bond strength between Nickel chromium base metal alloy core specimens and the veneering ceramic was 310.2N. SEM images of lithium disilicate specimens showed predominantly cohesive failure. SEM of Zirconia specimens showed mixed adhesive and cohesive failures. SEM of Nickel Chromium specimens showed cohesive failure. Energy dispersive microanalysis of the Lithium disilicate, metal ceramic and zirconia specimens showed mainly oxygen and silica on the surface.
Conclusions: All ceramic restorations with lithium disilicate core and feldspathic veneer can resist clinical failure due to fracture of the veneering ceramic. Delamination of the veneering ceramic can be frequent with Zirconia core.
Scanning electron microscopic analysis showed both adhesive and cohesive failures. Lithium Disilicate specimens showed predominantly cohesive failures. Multiple cracks and many pores were seen in the zirconia specimens and the failure was both adhesive and cohesive.
Electron Dispersive microanalysis showed mainly oxygen and silica as the chemical constituents present on the fractured surface.
Keywords:Zirconia; Lithium Disilicate; Nickel Chromium Alloys; Shear Bond Test; Elemental Analysis; SEM
Citation: K Chandrasekharan Nair., et al. “Shear Bond Strength of Veneering Porcelain to Different Core Materials like Zirconia, Lithium Disilicate and Nickel Chromium Alloy - An Invitro Comparative Study". Acta Scientific Dental Sciences 6.4 (2022): 137-145.
Copyright: © 2022 K Chandrasekharan Nair., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.