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VOLUME 10 , ISSUE 3 ( July-September, 2020 ) > List of Articles
Muneera Alsobaiei, Gowri Sivaramakrishnan
Citation Information : Alsobaiei M, Sivaramakrishnan G. Shear and Flexural Strength of Resin-modified Glass-ionomer Adhesive Liner in Sandwich Restorations. Int J Prosthodont Restor Dent 2020; 10 (3):97-101.
License: CC BY-NC 4.0
Published Online: 12-04-2021
Copyright Statement: Copyright © 2020; The Author(s).
Aim: Adhesive liners used in sandwich restorations between glass-ionomer cement (GIC) and composite should have sufficient strength and bonding properties. Resin-modified glass ionomers (RMGIs) exhibit good bonding to the tooth structure, GIC, and composite. They also exhibit good mechanical and bonding characteristics compared with other unfilled resins. Hence, the present study aimed to compare the shear and flexural bond strength of sandwich restorations when resin-modified glass-ionomer liners are used sandwiching conventional GIC and composite restorations compared with unfilled resins under artificial saliva in vitro. Materials and methods: Eighty-eight specimens prepared following specific criteria for flexural (44 specimens) and shear strength (44 specimens) testing was divided into two groups consisting of RMGI and unfilled resin bonding agent sandwich restorations. Three-point bending test and the Instron universal load testing machine were used for flexural and shear testing, respectively. SPSS v.18 was used to analyze the raw data obtained and comparison between the groups. Selected samples were prepared for a scanning electron microscopy (SEM) investigation, to observe the interfaces between the GIC and composite, as well as to provide a detailed analysis of the modes of failure in the specimens. Results: Sandwich restorations using resin-modified glass-ionomer cement (RMGIC) adhesive liner showed a statistically significant increase in shear bond forces and shear strength of the final restoration compared with an unfilled resin. There was no significant difference in the flexural strength of forces between the two groups. Scanning electron microscopy results revealed cohesive failure within the GIC as a major cause of failure of these restorations. Conclusion: Resin-modified glass ionomer liners show promising results in terms of shear and flexural strength of the sandwich restoration compared with unfilled resins.