الفهرس 
Effect of erosion and/or abrasion challenge on surface microhardness of ormocer-based and highly-filled versus conventional flowable resin composites :In vitro study
contentsOnly 14 pages are availabe for public view
 |  | from | 98 |  |  |
| | | from | 98 | | |
Abstract
Objectives: This study is designed to evaluate the surface microhardness of ormocer-based and highly filled flowable resin composites in comparison to the conventional flowable resin composite, before and after erosion and/or abrasion challenge. Methods: resin composite discs were prepared by packing each of the intervention and control materials in Teflon moulds (3x3) followed by standardized light curing. Then all specimens were finished and polished and then stored in distilled water for 24 hours. Specimens subjected to erosive challenge were immersed in an acidic solution at 37oC, while those with abrasive challenge were subjected to a standardized procedure of tooth brushing using an electrical toothbrush, either with or without an abrasive toothpaste. The third subgroup were subjected to an erosive followed by an abrasive challenge either without toothpaste or with an abrasive toothpaste. All specimens were tested for surface microhardness using Vicker{u2019}s microhardness tester at baseline and after the challenges. Results: All interventions with all challenges whether erosion, abrasion or erosion plus abrasion with or without toothpaste, showed a statistically significant decrease in surface micro-hardness. Conclusions: Ormocer-based flowable composite had the best chemical resistance to erosion among all the materials, while conventional and highly filled flowable composites are more capable of resisting abrasion