الفهرس | Only 14 pages are availabe for public view |
Abstract Retention in partial denture mainly depends on the mechanical factors (clasp assembly), RPD clasps are made from the same alloy of the metal framework as Co Cr alloy, gold or titanium alloys, which is un - esthetic. One of the methods to overcome this esthetical dilemma to use tooth - colored resin clasps. Thermoplastic acetal is one of thermoplastic resins that was first introduced in 1971 as an unbreakable thermoplastic resin, it is very strong, resists wear and fracture and is quite flexible. It also exhibits high creep resistance, high fatigue endurance and is hydrophobic. It has little or no porosity which reduces the accumulationof biological material like plaque, which in turn resists odor and stains. It resist occluasl wear and is suited for maintaining vertical dimension, in addition it reduces potential for allergic reactions |