DD GIC, RMGICs and Composers Exam 40 Questions with Answers
when are temporary restorations used? - CORRECT ANSWER emergency patient (broken/lost
... [Show More] fillings); terminate a session; intermediate restoration; alleviate pain
what considerations should be made when considering the use of a temporary restoration? - CORRECT ANSWER duration; aesthetics; durability
what does GIC stand for? - CORRECT ANSWER glass ionomer cements
when are GICs used? - CORRECT ANSWER temporary filling material; paediatric restoration; lining and base material in deep cavities
what percentage of the GIC glass powder is silica? - CORRECT ANSWER 35-40%
what is the liquid of GIC? - CORRECT ANSWER polyacrylic acid; water
what is the powder of GIC? - CORRECT ANSWER aluminosilicate glass
what percentage of the GIC glass powder is alumina? - CORRECT ANSWER 20-30%
what percentage of the GIC liquid is polyacrylic acid? - CORRECT ANSWER 35%
how many phases are in GIC setting reaction? - CORRECT ANSWER 2 phases
what are the steps of GIC setting reaction? - CORRECT ANSWER dissolution; gelation; hardening
what kind of reaction is the GIC setting reaction? - CORRECT ANSWER acid-base reaction
which stage of GIC setting involves the release of ions from a silica case? - CORRECT ANSWER dissolution
which phase is dissolution of GIC setting? - CORRECT ANSWER phase 1
which phase is gelation of GIC setting? - CORRECT ANSWER phase 2
what does dissolution involve in GIC setting? - CORRECT ANSWER acid begins to attach to the surface of the glass particles; the polyacrylic acid ionises and becomes negatively charged which sets up a diffusion gradient; cations move out of the glass
what does gelation involve in GIC setting? - CORRECT ANSWER pH continues to rise; concentration of ions in the solution increases; cross-linking and hydrogen bonding occurs; initially hard sets it
how does increased glass composition affect GICs? - CORRECT ANSWER decreases setting and working time
how does increased particle size affect GICs? - CORRECT ANSWER increases setting time
how does tartaric acid affect GICs? - CORRECT ANSWER decreases setting time and increases working time
how does increased glass/water ratio affect GICs? - CORRECT ANSWER decreases setting time
what are the advantages of GICs? - CORRECT ANSWER aesthetics; bond chemically to enamel and dentine; radiopaque; compatible with other dental restorative materials; biocompatible
what are the disadvantages of GICs? - CORRECT ANSWER limited working time; long setting time; cracking formation; vulnerable to acids
what does RMGIC stand for? - CORRECT ANSWER resin-modified glass ionomer cement
what is the powder of RMGIC? - CORRECT ANSWER radiopaque fluoroaluminosilicate glass; pigments
what is the liquid of RMGIC? - CORRECT ANSWER polyacrylic acid; hydroxyethylmethacrylate (HEMA); water
what are the advantages of RMGICs? - CORRECT ANSWER all GIC benefits; low solubility; better aesthetics
what are the disadvantages of RMGICs? - CORRECT ANSWER polymerisation shrinkage; HEMA is cytotoxic to osteoblasts and pulpal tissues
what is the working time for GIC? - CORRECT ANSWER 2 minutes
what is the working time for RMGIC? - CORRECT ANSWER 3 minutes 45 seconds
what is the setting time for GIC? - CORRECT ANSWER 4 minutes
what is the setting time for RMGIC? - CORRECT ANSWER 20 seconds
Are GICs or RMGICs stronger? - CORRECT ANSWER RMGICs
what is a compomer? - CORRECT ANSWER a fluoride releasing composite resin
what are compomers composed of? - CORRECT ANSWER fluoroaluminosilicate glass; dimethacrylate monomer; photoinitiator; special resin; hydrophilic monomer
what is phase 1 of the compomer reaction? - CORRECT ANSWER polymerisation results in the formation of 3D acidic copolymer
what is phase 2 of the compomer reaction? - CORRECT ANSWER water uptake initiates an acid-base reaction between -COOH on the copolymer and the acid soluble glass to cause the release of fluoride
what are the properties of compomers? - CORRECT ANSWER anticariogenic activity; do not chemically bond to enamel and dentine; polymerisation shrinkage; mechanical properties
are the mechanical properties of compomers inferior or superior to composites? - CORRECT ANSWER inferior
what is the percentage polymerisation shrinkage of a compomer? - CORRECT ANSWER 2-2.5% [Show Less]