An In Vitro Analyses of Three Body Wear Simulation in Four Posterior Resin Composites

Bharat, N (2012) An In Vitro Analyses of Three Body Wear Simulation in Four Posterior Resin Composites. Masters thesis, Ragas Dental College and Hospital, Chennai.


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Wear resistance of composite restorative materials has been a major concern especially when used as an posterior restorative material. The purpose of this study was to evaluate and compare the wear resistance of four newer posterior resin composites materials by three body wear simulation method. Wear was evaluated by measuring the amount weight loss using a highly sensitive physical balance, surface roughness was measured with a contact type surface profilometer and the wear surface characterized was by scanning electron microscope and optical microscope. Four newer posterior resin composite materials used in the study was methacrylate based nanohybrid posterior composite filtek z350 (3M ESPE), a silorane based composite filtek silorane p90 (3M ESPE), Ormocer based composite admira (VOCO) and packable composite surefil (DENTSPLY). The four posterior composites evaluated in the study were categorized as, group 1filtekz 350, group 2 - filtek silorane p-90 ,group 3 admira, group 4 surefil. The wear instrumentation used was a Dry abrasion tester, customized with stainless steel wheel, and distilled water was used as lubricant. Test instrument was designed such that a flat test sample is pressed radially against a wheel with a force of 20N. Abrasive media was introduced into the contact area between the sample under test and the wheel such that the wheel carries the abrasive media between the sample and the wheel creating a three body wear. The intial weight of each specimen was measured in milligrams using a highly sensitive physical balance. Material wear was measured by the loss of material at every 5000 cycles from 5000 cycles till 30000cycles. The samples were evaluated for surface roughness at every 5000 cycles from 5000 cycles till 30000 cycles by using contact type surface profilometer. The wear surface was analyzed with optical microscope and Scanning electron microscope to characterize the wear pattern. One-Way ANOVA followed by TUCKEYS post hoc test was used for statistical analysis at the 0.05 significance level. The mean weight loss values at the end of 30000 cycle was found to be highest in group 4 and weight loss values was found to be lowest in group1 with significance level of 1%. The mean wear depth values at the end of 30000 cycle was found to be highest in group 4 and lowest in group 1 with a significance level of 1% and this findings were confirmed by scanning electron microscope findings. CONCLUSION: From the results of the present study it can be concluded that: 1. Particle size plays a major role on the wear resistance of dental composites. FILTEKZ-350 a nano hybrid composite with a filler particle size of 5-20nm revealed least weight loss at the end of 30000 cycles when compared with other newer posterior resin composites namely silorane, ormocers and packable composites used in this study. 2. An interesting observation made in the present study was that the percentage volume of filler revealed a linear relationship of the filler particles to the wear resistance of that material. FILTEKZ350 with 88%filler volume had the least amount of weight loss when compared with other materials used in the study 3. Another valuable finding observed was the correlation between the filler particle size and the Ra, values that measures the wear depth. (in μm).

Item Type: Thesis (Masters)
Uncontrolled Keywords: Three Body Wear Simulation, Four Posterior Resin Composites.
Subjects: DENTAL > Conservative Dentistry and Endodontics
Depositing User: Subramani R
Date Deposited: 24 Mar 2020 05:34
Last Modified: 24 Mar 2020 05:34

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