COMPARISON OF COMPRESSIVE STRENGTH OF BULK FILLED COMPOSITE AND NANO HYBRID COMPOSITE- AN IN-VITRO STUDY.

Abstract

Background
During the past 60 years, the use of composite resin for direct restorations in anterior and posterior teeth has increased significantly, largely due to the esthetic demands of patients and concerns regarding mercury in amalgam fillings. Because composite resins require little to no preparation, minimally invasive procedures can be used to preserve tooth structure and provide natural-looking results. Dental composites typically are composed of three chemical materials: an organic matrix, an inorganic matrix, and a coupling agent. Today’s composite resins produce highly esthetic, long-lasting restorations for many indications. Through an understanding of advanced layering techniques, microleakage, and fracture rate concerns can be decreased significantly. Hence it is imperative to evaluate the compressive strength of bulk-filled composite and nanohybrid composite.
Aims & Objectives To assess, evaluate and compare the compressive strength of Bulk filled composite and Nano Hybrid composite.

Materials and Methods
Study method- In-vitro study

Sample A-Ivoclar Vivadent Inc. Bulk filled composite & Tetric N-Ceram Bulk Filled Composite (Leichtenstein).
Sample B-Ivoclar Vivadent Nano filled composite & Tetric N- Ceram Nano Hybrid Composite (Leichtenstein).
The cylindrical specimens were transferred onto the Instron testing machine (Model H50KS; Instron,Redhill, Surrey,RH15DZ, UK) individually and subjected to compressive testing at a crosshead speed of 1.0 mm/minute.
Results:

A comparison of the compressive strength of the individual groups was done. There was a statistically significant difference between the groups pertaining to compressive strength. The mean score for Group B was more than Group A.
Conclusions
Within the limitation of the specific materials, testing methods, and in-vitro environment in the study, it is concluded that Nanohybrid composite material has better compressive strength as compared to bulk fill composite.

Recommendations
Further studies are needed to determine the optimal curing light intensity to obtain the best results in terms of mechanical properties for newer bulk-fill composite materials.