OPERATIVE FINAL

coupling agents, fillers, resin matrix

major constituents of common dental composites

lower amount of residual monomer (ideal)

composite with HIGHER degree of conversion will have

TEGDMA

dimethacrylate monomer added to composites with better cross linking than PMMA

long working time, high degree of conversion, low abrasive wear

properties desired for light cured composites

true

T/F When dimethacrylate monomer molecules polymerize, the distance between the formed units (or intermolecular distance) becomes smaller and results in volumetric shrinkage.

polymerization shrinkage

major shortcoming of current direct composites

1% to 5% volumetric (3%)

polymerization shrinkage of most composites

A

which represents the effect of filler content on composite properties

visible blue light

most composites arer intended to be cured using

narrower emitting spectra

potential disadvantage of LED light curing units compared to conventional (QTH)

phosphric etching, rinse and dry, bonding, light cure

Bonding to enamel using a two step etch and rinse 5th generation adhesive system follows the following order:

all in one adhesive (7th gen)

this bonding agent is best described as

phosphate

functional group of MDP

suitable dentin primer

Enamel bonding was introduced as early as 1950's but successful

bonding to dentin lagged for decades because _____ was not

available.

false

T/F The primer in three-step bonding agent is a highly hydrophobic component that penetrates into the demineralized dentin.

air turbine

which handpiece are lighter in weight

electric slow speed

which hand piece has the highest torque

air driven high speed

which hand piece produces the highest pitch noise

2, 1, 3, 4

What is the appropriate sequence of cavity preparation stages?

1) Establishing retention and resistance form

2) Establishing an outline form

3) Deep caries removal

4)Application of Cavity Cleanser

latch type

type bur shank is limited to slow-speed handpieces?

deep pulpal floor, pulpal health, DEJ

Caries at the ______ may be left in consideration of prioritizing

______, while a caries-free _____ is a requirement for a

composite restoration.

caries extent, existing pit and fissure (groove) pattern

The primary guides for establishing an initial cavity outline for a

modern composite restoration is/are:

black and green

which diamond bur bands are coarser

true

T/F caries lesion activity cannot be determined by radiographic appearance except for sequential radiographic images of the same lesion over time

active caries

in normal Stephen response curees, plaque pH would be below critcal level for an extended perior of times in which situation

initial

visually non-cavitated enamel surface with shallow demineralization of dentin

mostly inorganic

human enamel is

striae of retzius

incremental growth lines or bands on tooth enamel

demineralized by acid, reduced permeability zone, remineralizable

features of caries-affected dentin

true

T/F caries lesions represent a continuum of net mineral loss

visual and radiographic exam

proximal carious lesion are best detected using

lactic acid

most potent cariogenic acid produced by strep mutans

refers to intended restoration outcome

G.V. black caries classification primarily

change in enamel opacity

earliest clinical sign of carious lesion

tactile hardness

factor commonly used to distinguish caries affected vs infected dentin

moderate

visible signs of localized enamel breakdown or signs of dentin demineralization by gray shadow under enamel

true

T/F it is unlikely to have infected dentin in initial lesion (ADA criterria)

fluoro apatite

crystal with lower solubility isotherm and better acid resistance

true

T/F lesion activity should be considered when making a decision regarding treatment

restore of individual tooth, prevention, restore of genetic abnormality, esthetic restore

conditions that fall within the scope of operative dentistry

sensory, defense, reactionary

roles of pulp

false

T/F carious lesion excavation and filling eliminates the caries process

yes

should clinical judgement be a part of assessing caries risk

moderate

radiolucency to middle 1/3 of dentin

initial

radiolucency up to outer 1/3 of dentin

bacterial penetration to dentin and enamel surface integrity loss

determinants of moderate caries lesion

true

T/F resin infiltration is based on blocking diffusion of acid

caries free DEJ

goal of restoration

initial

E1- D1 lesions

initial

resin infiltration is indicated for what lesion stage

soluble in low saturation of carbonated or other apatites

human enamel is:

specificity

diagnosing non-carious lesions as non-carious

sensitivity

diagnosing carious lesions as carious

hunter schreger bands

alternate light and dark bands in enamel, due to alternating enamel crystal orientation

dry mouth due to radiotherapy

what could cause enamel to dissolve at a higher pH than 5-5.5

hard

implies lesion on smooth surface may be arrested

food impaction, tooth and restore fracture, periodontal problems, pulp inflammation

incorrect restoration contour can lead to

polymerization shrinkage

incorrect restoration contour does NOT lead to

deep

dentin with higher permeability

S. mutans, S. sobrinus, lactobacilli

major cariogenic bacteria

false (only fluoride)

T/F carbonate and fluoride BOTH increase acid resistance

lining, small defects, PRR restoration

indication for flowable composites

water

constituent found in primer/bonding but not resin composites

higher viscosity (thicker)

higher filler load results in

addition by free radical initiation

how are dental composites polymerized

true

T/F dentin must be kept moist to allow resin infiltration

MDP

acidic monomer for decalcification and smear layer modification

smaller volume, smaller surface area, decreased C factor

concept behind incremental filling to reduce polymerization stress

radiopacity

main function of filler

2 step 6th gen adhesive

In which technique is RINSING WITH WATER NOT required after the first step of bonding to dentin?

wet bonding technique

which bonding concept is challenging in terms of “technique sensitivity”

QTH

curing unit with wider emission spectra

heat-curing

composite curing mechanism not appropriate for intraoral use

pit and fissure sealant

resin with LOWEST viscosity

true

T/F composite shrinkage is a function of di-methacrylate polymerization chemistry

TEGDMA (small structure)

composition more suitable for caries infiltration system such as icon

volume %, shrinkage

degree of composite fillers by _____ is MORE relevant, since it directly affects _____

older composites did not have radiopaque fillers

radiolucency of old, existing composites confirms

improve wear, lower solubility, increase modulus, increase strength

why is the formation of cross-linking chains important in dental composites

filler

the phase that does not react as part of the polymerization reaction

40nm to 50µm

size of fillers used today

higher volume of filler

what property of composite reduces shrinkage

higher viscosity

higher filler load results in:

coupling agent

chemically links filler particle to resin matrix

wear resistance, stain resistance, reduce crack propagation, surface integrity

functions of coupling agents

camphorquione

a photoinitiator commonly used in dental materials that enables polymerization when exposed to light.

470 nm

at what wavelength does camphorquinone absorb light to initiate polymerization

enamel

which dental surface is easier to bond to

high surface energy, rough, dryable

features of enamel that make it easier to bond to

increase surface energy for bonding

role of acid etching

37%

ideal concentration of phosphoric acid for etching enamel

link wet dentin to hydrophobic composite

role of bonding agent

true

T/F initial outline form may be different depending on the type of restorative material

convenience form

extending the outline to improve access to caries and ease of material placement

pulpal health

in deep caries what should be prioritized over complete caries removal