DENTAL MATERIALS

Sealants are mechanical or chemical bonding?

MECHANICAL bonding

Sealants material is retained with what acids?

35-38% phosphoric acid

Sealants can penetrate to form what kind of pores?

'tags' or microscopic pores

indications of sealants

-Moderate to high risk caries

- incipient caries or existing pits and fissures susceptible to decay

T/F Sealants are Secondary preventative service

FALSE

* Primary Preventative service

Contraindication of sealants

tooth surface having frank caries or on surfaces that have well-coalesced pits and fissures

T/F: Self-curing or auto polymerized sealants are available and do not require polymerization thru a curing light ( commonly found in school based/public health setting )

TRUE

T/F: Advantage of polymerized material (curing light is used ) that mixing is required

FALSE

* No mixing is required ( more working time!)

T/F: Tarnish is irreversible while corrosion can be reversed through polishing

FALSE

* Tarnish: discoloration on a metal or slight loss of the surface: reversible thru polishing

Corrosion: Chemical/electrical process in which a solid ( metal ) is attacked by the environment agent. irreversible

To function properly, a restoration must be what properties to withstand the forces of mastication

- must be hard ( hardness )

- strong ( yield strength )

- stiff ( elastic modulus )

what property is important for the requirement of impressions and restorative materials

Dimensional stability

what property is important to measure of how much heat and cold are transmitted to pulpal and soft tissues under a restoration

Thermal conductivity

T/F Enamel and dentin are good thermal conductors

FALSE

* They are poor thermal conductors

composites + ceramics are good

what property is a result of thermal expansion from eating/drinking cold/hot food/liquid and is associated with secondary caries and sensitivity?

Percolation

A term that refers to excess material, especially with amalgam which if not excessive can bB removed/ contour

Flash

Cements are used for ____ and commonly composed of ____ or glass powder and an acidic liquid or eugenol

Cements are used for CEMENTATION OF RESTORT. and as BASES and commonly composed of ZINC OXIDE or glass powder and an acidic liquid or eugenol

temporary cement or base material

Zinc-oxide-eugenol

T/F: ZOE and Varnish can be used with composite materials

FALSE

* Cannot be used with composite materials!

T/F: Liners do not provide thermal protection

True

resin and compomer cements are composed of what?

- Dimethacrylate ( Bis-GMA ) resin

- Glass filler used to bond all-ceramic restort. and special dental appliance

Athletic mouth gaurds are fabricated from what type of material? examples?

Thermoplastic material

* poly ( vinyl acetate ) - polyethylene polymer also known as ethylene vinyl acetate ( EVA ) acrylic

poly ( vinyl acetate ) - polyethylene polymer also known as what ?

ethylene vinyl acetate ( EVA ) acrylic

T/F: Mouthguards can cause prominent inflammation that tapers off between the molars

FALSE

*Mouthguards can cause prominent inflammation that tapers off between the CENTRALS

Sealants and mouth guards are considered to be as what kind of preventative services ?

Primary preventative services

sealant placement TECHNIQUE most directly impacts what of a sealant?

impacts RETENTION of sealants

what are the 3 classification for material by their use

• Preventative/Therapeutic materials

• Restorative

• Auxiliary

A material’s ability to conduct temp. changes; transfer heat

Thermal conductivity

shrinkage or expansion of a material; usually expressed as a percentage of an original length or volume

Dimensional change ( THERMAL DIMENSIONAL CHANGE )

The production of HEAT resulting from the reaction of the components of some materials when they are mixed

Exothermic reaction