In-vitro investigation of S-2 glass fibre aspect ratio on flexure strength, hardness and wear performance of fibre reinforced flowable dental composites

With the continuous increase in the life expectancy and changing food habits, studying the wear of human tooth is of primary importance. Fibre reinforced composites are gaining major market share among various restorative dental materials. The current experimental investigation on the flexure strength, hardness and wear performance of dental restorative composites is to understand the effect of S-2 glass fibres of low volume (5%) and aspect ratio (AR 50, 70 & 100) embedded dental resins. Specimens with nine dental systems were manufactured and tested. Flexural strength is characterised as per ISO-4049 standards and hardness by Vickers hardness. Wear investigation is carried out with a fixed load during a single test providing steady condition. Wear pattern is also analysed and micro-mechanical behaviour is investigated using laser Microscope and SEM. It is observed that inclusion of processed AR 70 S-2 glass fibres increases the mechanical properties of resin by 10.3%, 34.1% and 54.1% respectively for flexure modulus, flexure strength and Vickers hardness. Coefficient of friction for composite samples was evaluated to be around 0.65 compared with resin samples at 0.35. Fibre length of 0.35 mm (aspect ratio = 70) provided the best results which is also the critical fibre length.