Dental Materials Final
which organizations must approve dental materials for market?
FDA-fodd and drug administrations
what are the three dimensions of color?
what is tooth color or mixes of color?
what is intensity of color
what is lightness or darkness (grayness) of color?
what are the differences between posterior and anterior restorative material?
what are the components of porcelain? 3
crystals of feldspar
what is the greatest reason for sealant failure?
what is the greatest reason for porcelain failure?
small cracks developed from occlusal loading
what causes microleakage?
contaminants-blood, smear layer, oils
what restorative material has the least microleakage?
old alloys (due to corrosion blocking dentinal tubules)
what restoration class is the occlusal and buccal of posterior teeth and the lingual pits of anterior teeth?
what restoration class is the proximal surfaces of posterior teeth (includes the occlusal as well)
what restoration class is the proximal surfaces of incisors and canines (no incisal angle)
what restoration class is the proximal surfaces of incisors and canines, also the incisal angles?
what restoration class is the gingival third of facial or lingual surfaces of the tooth?
what restoration class is the cusp tips of posterior teeth and incisal edges of anterior teeth?
what are the effects of a high alcohol mouthwash?
when is a high alcohol mouthwash contraindicated?
with xerostomia (drying)
which four additives prevent dentinal hypersensitivity?
potassium nitrate (most common)
which topical additive acts against bacterial plaque?
what is the main ingredient in a sealant?
bisphenol A-glycidyl methacrylate (bis-GMA) or urethane dimethacrylate (UDMA)
what is the energy mechanism for polymerization?
which monomer is used in denture base?
which dental materials are polymers
what are adhesive wetting aids?
what are three different etchants?
what is the most commone etchant and what is used for?
what etchant is used for glass ionomers?
what etchant is used for porcelain?
what is the purpose of bonding?
to provide a MECHANICAL and CHEMICAL BOND for RESIN MATERIALS (or combo of both)
what 6 things increase the rate of abrasion?
speed and pressure
size irregularity and hardness
number of particles
_____ speed = _____ abrasion
what will increasing speed and pressure do to abrasion?
increase rate of abrasion
what are adverse reactions of abrasives/polishes? 3
fluoride-rich enamel layer is polished away
polish away contact and margins of restorations
exposed cementum or demineralized enamel removed
what is used for the final polish for the majority of restorations?
why should one polish fillings? 3
improves tissue health
increases longevity of fillings
how does heat affect the dental pulp?
detrimental to the pulp
what is used in the lab to polish gold?
burlew wheel on slow speed handpiece
rouge on rag wheel
which cement bond to teeth? 3
resin glass ionomer (hybrid) cement
glass ionomer have a weak bond to tooth
which cement has chmical adhesion? 2
glass ionomer cements
which cement has mechanical retention between tooth and crown? 2
what are the differences between high and low strength bases/liners?
high strength base/liner-provides THERMAL insulation and MECHANICAL support for restorations
low strength base/liner-PULP capping, stimulates secondary dentin, barrier between pulp and restoration
name the fluoride releasing cements
what are the purposes of bases/liners?
liners-seal dentin or medicate the dentinal pulp
bases-provide thermal insulation or mechanical protection of the dental pulp
which dental cement sooths pulp tissue?
zinc oxide eugenol
what are the characteristics of a base?
bases are used to provide THERMAL INSULATION OR MEHCANICAL PROTECTION for the dental pulp
includes ALL CEMENTS because cements are poor thermal conductors and have adequate compressive strength
which cement makes reparative dentin?
what are the porperites of cements that allow them to be used as bases?
poor thermal conductors, adequate compressive strength (they insulate and protect the pulp)
what is used to clean zinc oxide eugenol instruments?
alcohol or oragne solvent
what is used to clean zinc phosphate cement?
ultrasonic cleaner or solution of baking soda and water
Dental Materials Final
general questions thru dental cements