In vitro wear of posterior composited subjected to chemical, thermal and mechanical stresses
Al-Daly, Huda M
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The objective of this study was to compare the resistance of new posterior composite resins to in vitro wear by exposing them to mechanical, chemical and thermal factors. Flat rectangular specimens were processed of five posterior composites, one conventional composite and amalgam. The cured specimens were stored in water at 370 C for seven days, dried and weighed. All samples were thermocycled between 40 C – 750 C for 540 one minute cycles, except those in group F. One group of specimens was exposed to 60,000 strokes of brushing without chemical treatment. A second group of specimens was chemically stressed by exposure to 75% ethyl alcohol, before and during tooth brushing. After stressing the specimens were washed,dried, and weighed. The volume loss was calculated employing the weight loss data density of each material. Statistic analysis of the volume loss showed difference among the 8 groups. Amalgam showed the least volume loss of all groups,followed by material E (Marathon)l material A (P-30), and material F (Ful-Fil). Material B (Herculite) showed the highest volume loss. Amalgam was not affected by chemical treatment, while composite wear resistance decreased with exposure to ethyl alcohol. Thermocycling also reduced wear resistance of the composite materials.
PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact email@example.com.Includes photographs.Thesis (M.Sc.D.)--Boston University, Henry M. Goldman School of Graduate Dentistry, 1986 (Operative)Bibliography : leaves 67-76.
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