Evaluation of dynamic hardness and elastic modulus of four resin composites by dynamic micro-indentation method” -an invitro study

Introduction: Restorative dentistry has became more exciting with the introduction of tooth coloured restorative materials such as composites and ceramics. Many advances in these materials have been introduced into the market in the recent past, making it difficult for a clinician to choose any particular type. The knowledge regarding mechanical properties like dynamic hardness, elastic modulus, wear resistance etc of a material is essential for a clinician to choose. Micro indentation hardness testing is a convenient way of investigating the mechanical properties of a small volume of material.
Aim: This study aims to compare dynamic hardness and elastic modulus of four commercially available resin composites.
Matrails & Method: Four commercially available resin composites Filtek Z350xt, Swisstec, Charisma Smile, Tetric N-Ceram Were taken. Twenty disc shaped specimens were prepared from four resin composites and divided into four groups of five specimens each. The specimens were tested for mechanical behaviour using dynamic micro indentation hardness tester. Results: The results were analysed using SPSS version 23, descriptive statistics, ANOVA test with post hoc scheffe test done for intergroup comparison of the hardness and elastic modulus.
Conclusion: The dynamic micro-indentation method is a useful technique for determining the mechanical behavior of dental resin composites as brittle material. Within the limitations of this in vitro study, maximum dynamic hardness is seen in Charisma smile and the least dynamic hardness is seen in Filtek Z350XT. And maximum elastic modulus is seen in Charisma smile and the least dynamic hardness is seen in Swisstec.