dat 113 pt. 2 - from quizlet

What acid and concentration is used to etch enamel?

37% phosphoric acid for about 20-30 seconds.

What appearance indicates properly etched enamel?

A frosty white appearance.

What does acid etching create in enamel?

Micropores/enamel tags that allow mechanical bonding.

Why must dentin remain slightly moist after etching?

Overdrying weakens the bond and may increase sensitivity.

Which provides a stronger and more predictable bond: enamel or dentin?

Enamel.

What is the smear layer?

A thin layer of debris left after cavity preparation.

How is the smear layer removed?

Etching.

Put the basic bonding steps in order.

Clean → Etch → Rinse → Gently dry → Primer → Adhesive → Air thin if directed → Light cure → Restoration.

Which bonding system provides the strongest dentin bond?

Etch-and-rinse.

Which bonding system requires no separate rinsing step?

Self-etch.

Which bonding system produces less postoperative sensitivity?

Self-etch.

Which bonding system is the most versatile?

Universal adhesive.

What can universal adhesives bond to?

Tooth structure, metal, and ceramic.

What is the hybrid layer?

The resin-dentin bonding zone formed when primer penetrates exposed collagen and adhesive enters and polymerizes.

What factors can interfere with bonding?

Saliva, blood, plaque/debris, overdrying dentin, inadequate bonding coverage, and failure to follow manufacturer directions.

What is microleakage?

Movement of fluids and bacteria between the tooth and restoration.

What can microleakage cause?

Recurrent caries, marginal staining, postoperative sensitivity, and restoration failure.

What are common causes of microleakage?

Polymerization shrinkage, thermal expansion/contraction, and poor bonding.

What acid is used when bonding to ceramic?

Hydrofluoric acid.

What is applied to ceramic after etching?

Silane.

What are common causes of postoperative sensitivity?

Microleakage, open dentinal tubules, overdrying dentin, poor bonding, and polymerization shrinkage.

Which composite has large particles and a rough surface?

Macrofilled composite.

Which composite provides excellent polish and esthetics but lower strength?

Microfilled composite.

Which composite provides a strong combination of strength and polishability?

Hybrid composite.

Which composite has low viscosity and flows easily?

Flowable composite.

What is a core buildup composite used for?

High-strength buildup under crowns.

What are sealants used for?

Preventing pit and fissure caries.

What are major advantages of composite resin?

Tooth colored, esthetic, conservative preparation, bonds to tooth structure, and can be completed in one appointment.

What are major disadvantages of composite resin?

Moisture sensitivity, polymerization shrinkage, lower strength than amalgam, and possible staining/discoloration.

What activates a light-cured composite?

Blue curing light.

What wavelength is associated with blue curing light in the study guide?

Approximately 470 nm.

What is chemical-cure composite?

A two-paste system that begins setting when mixed.

What substances initiate chemical-cure composite?

Benzoyl peroxide and tertiary amine.

What is dual-cure composite?

A composite that uses both light and chemical activation.

When is dual-cure useful?

When curing light cannot fully reach the material.

What effect does increasing filler have on composite?

Increases strength and wear resistance and decreases resin content and shrinkage.

Why is composite placed incrementally?

To improve depth of cure, ensure polymerization, and reduce shrinkage and tooth stress.

What are major advantages of glass ionomer?

Fluoride release, chemical bonding to tooth, and low sensitivity.

What is a disadvantage of traditional glass ionomer?

It is relatively weak with poor wear resistance.

What is RMGI?

Resin-modified glass ionomer.

What advantages does RMGI have?

Fluoride release, improved strength, and better esthetics than traditional glass ionomer.

What are compomers?

Materials combining composite-like strength with some fluoride release.

Do compomers require adhesive bonding?

Yes.

Which releases more fluoride: glass ionomer or compomer?

Glass ionomer.

What four elements make up dental amalgam?

Silver, tin, copper, and mercury.

What mnemonic helps remember the components of amalgam?

S-T-C-M: Silver, Tin, Copper, Mercury.

What is dental amalgam formed by mixing?

Alloy powder with liquid mercury.

Approximately how much mercury by weight is in dental amalgam?

About 50%.

Why are high-copper amalgams preferred?

Greater strength, better marginal integrity, less corrosion, less tarnish, and better long-term performance.

What is creep?

Permanent deformation of amalgam caused by long-term stress.

What is corrosion?

Chemical breakdown of amalgam caused by reactions with saliva and food.

What is tarnish?

Surface discoloration that makes amalgam dark and dull.

Which is mainly cosmetic: tarnish or corrosion?

Tarnish.

Which can weaken an amalgam restoration: tarnish or corrosion?

Corrosion.

What type of strength is amalgam known for?

High compressive strength.

What is a major advantage of amalgam in posterior teeth?

Excellent wear resistance and ability to withstand heavy biting forces.

Does amalgam chemically bond to tooth structure?

No. It requires mechanical retention.

What is trituration?

Mixing mercury and alloy powder in a capsule using an amalgamator/triturator.

What is amalgam's approximate working time?

About 2.5-3 minutes.

How long does amalgam take to reach its final set?

About 24 hours.

How does amalgam set?

By crystallization.

What are four important properties of amalgam?

Dimensional change, strength, creep, and corrosion/tarnish.

What is the major occupational concern involving mercury?

Inhalation of mercury vapor.

How does fluoride protect teeth?

It converts hydroxyapatite into fluorapatite.

What is fluorapatite?

A stronger, less soluble, more acid-resistant mineral.

What is the optimal water fluoridation level in the study guide?

0.7 ppm (mg/L).

What are examples of systemic fluoride?

Fluoridated water, tablets, drops, and lozenges.

What are examples of topical fluoride?

Varnish, SDF, gels, foams, rinses, and fluoride toothpaste.

What does SDF stand for?

Silver diamine fluoride.

What is chlorhexidine?

A prescription antibacterial rinse that reduces plaque and helps control oral bacteria.

What is the main difference between chlorhexidine and fluoride?

Chlorhexidine fights plaque bacteria; fluoride strengthens tooth structure.

What causes dentinal sensitivity?

Movement of fluid through exposed dentinal tubules.

What conditions can expose dentinal tubules?

Gingival recession, abrasive brushing, acid erosion, acid reflux, bulimia, bruxism, abfraction lesions, and loss of enamel or dentin.

What are common symptoms of dentinal sensitivity?

Sensitivity to cold, heat, and sweets.

What are the two main mechanisms of desensitizing agents?

Occluding dentinal tubules and reducing/desensitizing nerve responses.

What materials can be used for sensitive teeth?

Fluoride, sealants, ferric oxalate, potassium oxalate, potassium nitrate, fluoride varnish, and SDF.

What is an easy memory trick for tooth sensitivity?

Sensitivity = open dentinal tubules.

What is an easy memory trick for high-copper amalgam?

High Copper = High Performance.

What is an easy memory trick for fluoride?

Fluoride → Fluorapatite → Fewer Cavities.

What is an easy memory trick for creep?

Creep = margins creep out.