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Comparison of Wear Resistance of Hawley and Vacuum Formed Retainers: An in-vitro Study | ||
| Journal of Dental Biomaterials | ||
| مقاله 7، دوره 3، شماره 2، مرداد 2016، صفحه 248-253 اصل مقاله (551.99 K) | ||
| نوع مقاله: Original Article(s) | ||
| نویسندگان | ||
| Vahid moshkelgosha1؛ Mehrdad Shomali2؛ Masoomeh Momeni* 3 | ||
| 1Orthodontic Research Center and Department of Orthodontics, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. | ||
| 2Orthodontic Research Center, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran | ||
| 3Students Research Committee, School of Dentistry, International Branch, Shiraz University of Medical Sciences, Shiraz, Iran. | ||
| چکیده | ||
| Statement of Problem: As a physical property, wear resistance of the materials used in the fabrication of orthodontic retainers play a significant role in the stability and long term use of the appliances.Objectives: To evaluate the wear resistance of two commonly used materials for orthodontic retainers: Acropars OP, i.e. a polymethyl methacrylate based material, and 3A-GS060, i.e. a polyethylene based material.Materials and Methods: For each material, 30 orthodontic retainers were made according to the manufacturers’ instructions and a 30×30×2 mm block was cut out from the mid- palatal area of each retainer. Each specimen underwent 1000 cycles of wear stimulation in a pin on disc machine. The depth of wear of each specimen was measured using a Nano Wizard II atomic force microscope in 3 random points of each specimen’s wear trough. The average of these three measurements was calculated and considered as mean value wear depth of each specimen (µm).Results: The mean wear depth was 6.10µm and 2.15µm for 3A-GS060 and Acropars OP groups respectively. Independent t-test showed a significant difference between the two groups (p < 0.001). The results show Polymethyl methacrylate base (Acropars) is more wear resistance than the polyethylene based material (3A-GS060).Conclusions: As the higher wear resistance of the fabrication material can improve the retainers’ survival time and its cost-effectiveness, VFRs should be avoided in situations that the appliance needs high wear resistance such as bite blocks opposing occlusal forces.Key words:Hawley Retainer, Vacuum-formed Retainer, Wear Resistance | ||
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