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Educational ObjectivesThe overall goal of this article is to provide dental profession-

als with information on tooth-colored restorations. Upon

completion of this course, the clinician will be able to do the

following:

1. Describe the early tooth-colored direct restorative

materials

2. List and compare the attributes of composite resins andglass ionomer cements

3. Describe the composition of a compomer, and compare it

to composite resins and conventional glass ionomers

4. Describe the restoratives containing nanotechnology and

the effect of nanotechnology in nano-ionomer restorations

AbstractResearchers have developed multiple tooth-colored restor-

atives in the search for a material that has optimal strength,

esthetics, handling properties and a preventive function.

Materials currently available include glass ionomer-basedmaterials, composite-based materials, compomers, giomers,

and the use of nanotechnology for composites and nano-

ionomers. Each offers benets for the individual patient case.

IntroductionThe quest for suitable tooth-colored restoratives began with

the introduction of acrylics and silicates. While weak and

offering relatively poor esthetics, as well as being difcult to

accurately mix and handle, they represented the rst efforts

at providing the clinician and patient with both esthetics and

functionality in a restoration. As researchers investigated var-ious chemistries, two main categories of direct tooth-colored

restorations evolved composite resins and glass ionomer

cements. These represented a signicant improvement over

the pre-existing options, which rapidly fell out of favor.

Figure 1. Development of early tooth-colored restoratives

1940s

Acrylics and

silicates

1950s

Composite

resins

1970s

Glass ionomer

cements

Composite ResinsComposite resins fundamentally consist of two phases: the ller

content and the monomer-based content, typically bisphenol

A glycidyl dimethacrylate (bis-GMA), tetraethyleneglycol

dimethacrylate (TEGDMA) or dimethacrylate (DMA). Set-

ting occurs strictly through polymerization of the monomers,

resulting in the llers being dispersed in the set polymer.

Early composite resins were relatively weak, with low com-

pressive strength, tensile strength and exural strength, andthey exhibited a high degree of polymerization shrinkage and

shrinkage stress. They were also poorly bonded to the clinical

site with primitive adhesive techniques, resulting in marginal

leakage and sensitivity, and subject to considerable surface

wear as a result of their relatively low surface hardness.1 Wear

resistance and strength were subsequently improved such that

posterior composites were introduced, although initially these,

too, were unsatisfactory for heavy stress-bearing situations.2

The current range of composite resin restoratives offers the

greatest strength and wear resistance of all direct tooth-colored

materials and continues to be the most esthetic option. Cur-rent adhesive techniques have resulted in improved bonding

of the tooth-adhesive and adhesive-composite interfaces,

although marginal leakage is still a consideration. Composites

typically do not contain uoride, and the uoride release from

uoride-containing composites has been found to be minimal;

at the same time, biolm adheres well and grows on rough

composite surfaces.3 Composites are now differentiated based

on ller type and load as well as unique chemistries such as

those utilized to reduce polymerization shrinkage and stress.

The physical characteristics of composites have become

well-differentiated microlled composites offer the abilityto polish and retain a high gloss and superior esthetics, while

microhybrid composites offer greater strength but result

in uneven wear due to the loss of large ller particles.4 Most

recently, nanotechnology has been introduced into composites

and is discussed later in this article.

Glass Ionomer CementsGlass ionomer cements consist of two components that

initially were available only as a powder and liquid. Funda-

mentally, these consist of uoroaluminosilicate glass particles

and an aqueous solution of polyalkenoic (or polyacrylic) acid.A major difference between glass ionomer restoratives and

composite-based restoratives is the inclusion of water in the

glass ionomer formulations and their hydrophilicity, which

results in wet contact with the tooth surface and a strong bond

over time. The setting reaction for glass ionomers is acid-

based, rather than setting through polymerization; therefore,

no polymerization shrinkage can exist. Using infrared spec-

troscopy and band-narrowing treatments to assess materials,

Arrondo et al. conrmed that glass ionomers set through an

acid-based reaction as well as cross-linking of the polycar-

boxylate with the metal ions present in the glass ionomer.5

Glass ionomer cements tolerate moist environments and are

applied to moist tooth surfaces. In addition, they adhere di-

rectly to the tooth structure and provide a solid marginal seal.

In combination, these attributes can provide for an easier and

quicker chairside experience for patient and clinician alike

compared to using composite resins. In general, however,

glass ionomer cements have lower strength than composites.

One of the main benets of glass ionomers is their ability to

release uoride. Based on studies of up to three years dura-

tion, uoride release is ongoing; the amount released exceedsthe initial uoride content of the uoroaluminosilicate glass

particles demonstrating the uptake of uoride from external

sources and has been found to be regulated by the phospho-


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rus at the glass ionomer surface.6 The uoride release from

glass ionomers has been shown to help prevent the formation

of secondary caries, by creating a zone of inhibition, and in

addition has been found to have a preventive effect on adja-

cent teeth.7 Since the main reason for replacement of direct

restorations is secondary caries, caries inhibition through

uoride release is highly desirable.

Bridging the GapAs a result of their respective attributes, resin-based com-

posites became the material of choice where strength and

esthetics were of greatest importance. Glass ionomers have

been favored in situations where caries control, the intraoral

environment and ease of placement were more important

considerations than strength and esthetics. Improving the

strength and esthetic properties of both composites and glass

ionomers became a strong focus, as well as improving specic

attributes (such as reducing polymerization shrinkage in res-

in-based composites). Researchers investigated and continueto investigate potential solutions that might offer all the ben-

ets of composites and glass ionomers but without any of the

drawbacks associated with either category. In the quest for a

single material that might meet all requirements for the ideal

restorative, composites and glass ionomers have both evolved.

Chemistry from each category has been incorporated into the

alternative restorative material, with differentiation of llers,

unique chemistries, delivery systems, curing mechanisms,

and single-layer versus multi-layer techniques.

Resin-modified Glass IonomersThe strength of glass ionomers was improved through the ad-

dition of methacrylate monomer in the aqueous polyalkenoic

acid solution as well as the addition of monomer containing

free radical double bonds in the uoroaluminosilicate-con-

taining component. This created a new subset within the

category that was named resin-modied glass ionomer

cement. The monomer sets through polymerization when

light-activated and cross-links, but does not interfere with the

acid-based setting reaction due to the limited amount added

to the glass ionomer.8,9 Light-curing of these glass ionomers

offers control whereby the initial self-setting is accelerated.

After exposure to polyalkenoic acid conditioner, resin-modi-

ed glass ionomer forms a hybrid layer at the dentin surface of

bur-cut dentin and a typical submicron gel phase can be ob-

served with transmission electron microscopy. Assessments

in laboratory testing found that the direct bonding to the

tooth structure was attributable to bonding of the gel phase

around the hydroxyapatite as well as to the hybrid layer (de-

pending on the product), which resulted in micro-mechanical

bonding through an interlocking mechanism.10 Interestingly,

and as a note of caution, no hybrid layer or gel phase is found

using the same protocol on Er:YAG laser-irradiated dentin,

nor any dentin demineralization or collagen melting.11 A sep-

arate study comparing the adhesion mechanism of bur-cut

and laser-irradiated dentin supports these results; althoughpartial demineralization was observed, there was still no

hybrid layer formation. It was also determined that the use

of glass ionomer conditioner was important for microtensile

bond strength in bur-cut dentin.12 The fracture resistance

of resin-modied glass ionomers has been found to be sig-

nicantly greater than that of conventional glass ionomers. In

addition, a reduction in particle size (of up to 10 microns) of

the uoroaluminosilicate-based component has been found

to increase fracture resistance as well as result in a smooth

surface.13 Resin-modied glass ionomers are still not a mate-

rial of choice for posterior stress-bearing areas, due to theirrelatively low surface hardness and fatigue resistance.14,15

Light-activated glass ionomers enable immediate nishing

and reduced incidence of subsequent microleakage.16

Metal-reinforced Glass Ionomers

Metal-reinforced glass ionomers include metal ions in the

mix typically silver-based alloys such as the silver-tin alloy

found in amalgam. These are used primarily for core buildups

and are also used to restore primary molars. A subset of this

category, the cermet, results from fusing the metal ions to

the uoroaluminosilicate glass particles; however, cermetsrelease less uoride than other glass ionomers.

CompomersCompomers, also known as polyacid-modied resin com-

posites, were developed from composites. They contain ller

similar to the glass particles contained in glass ionomers, di-

methacrylate monomer and polyacid, but they do not contain

water. Setting occurs through polymerization and, as with con-

ventional composites, adhesion is achieved through the man-

datory use of bonding agents rather than direct bonding to the

tooth structure.17 Based on the absence of a COO bond, it was

determined that no acid-based reaction occurs. Finally, it was

also concluded that the release of metal ions that chelate with

the methacrylate-based polymer molecules was due to dilution

of ller particles through the presence of water.5 Compomers

have lower compressive strength and exural strength, a lower

Youngs modulus (modulus of elasticity), and reduced resis-

Glassionomers

Resin-modied

glassionomers

Metal-reinforced

glassionomers and

cermets

Giomers

Nano-ionomers

Nanolledcomposites

Compomers

Microlledand

microhybridcomposite

resins

Earlycomposite

resins

NanotechnologyFigure 2. Material categories



tance to fracture and wear compared to composites, and should

not be used in stress-bearing areas.18,19,20 A study comparing

tooth-colored restorative materials found that the surface

nish of glass ionomers and compomers were both signi-

cantly poorer than that of conventional composites.21 Biolm

development is signicant on both compomer and composite

materials. The glass particles in compomers are responsible for

the uoride release from the set compomer which, while lowerthan with glass ionomers, is still ongoing.22,23,24,25,26 There have

been concerns about the release of HEMA from compomers,26

due to the risks of adverse pulpal responses in patients and

of allergy in patients and dental personnel. The amount of

HEMA released is inuenced by the individual material, depth

of cure and degree of curing.27,28 Although compomers do not

meet esthetic requirements where these demands are primary,

some offer greater polishability than glass ionomers and resin-

modied glass ionomers.18 Compomers may be suitable for

restorations where neither strength nor esthetics are primary

considerations, such as in pediatric restorations, and have alsobeen used as orthodontic bonding agents.

GiomersAnother approach has been the use of milled, silanized glass

ionomer llers that have already undergone the acid-base re-

action between uoroaluminosilicate glass and polyalkenoic

acid prior to milling. These llers are then used in a composite

resin base to provide uoride release from the llers together

with the strength and esthetics of composites and have been

found to be successful in these regards.29

NanotechnologyThe introduction of nanotechnology, initially in composites,

heralded improved esthetics without compromising strength

or wear resistance. Strength and wear resistance were also

improved, depending on the material.

Nanofilled Composite ResinsNanolled composite resins were designed to combine the

polishability and esthetics of microlled composites with

the strength and wear resistance of microhybrid composites.

They contain nanollers that are heavily loaded into the

composite; these improve the translucency and opalescence

of the composite, making it more natural looking and better

able to blend in with the surrounding area.4 The addition of

nanosized particles to composite resins increases their polish-

ability. Azevedo et al referred to the recent studies suggest-

ing that these particles should ideally be evenly dispersed

together with microllers.30 Nanolled composites offer

improved strength compared to microlled composites and

equal to or better than other composites.31 The addition of

pre-polymerized nanollers forming nanoclusters has beenfound to reduce polymerization shrinkage, further increase

strength and esthetics, and offer a smoother surface that is less

subject to wear and that wears more evenly.4

Nano-ionomersNano-ionomers were developed with the desire to combine

the proven benets of glass ionomers, in particular uoride re-

lease, with the proven benets of nanotechnology available in

resin-based composites discussed above notably improved

esthetics, surface smoothness, strength and wear resistance.

The nano-ionomer consists of one paste containing water,

polycarboxylic acid, nanollers and reactive resins. With theexception of the nanollers, these components are contained

in resin-modied glass ionomers and compomers. The other

paste contains a combination of nanollers (based on silica

and zirconia) and nano-clusters of these llers, together with

reactive resins and 27% uoroaluminosilicate glass particles.

The nano-ionomer is placed and light-cured after use of its

corresponding primer. It is essential that the primer be used

to optimize tensile shear bond strength. In assessing the in-

terface and the material, nano-clusters with a high ller load

and good distribution of the ller through the nano-ionomer

(KetacTM Nano, 3M ESPE) have been observed, togetherwith bonding through micromechanical locking.32 Korkmaz

et al. studied the shear bond strength of nano-ionomer to

enamel and dentin after use of primer with or without the ad-

dition of 37% phosphoric acid etching, with some specimens

receiving laser etching rst. It was found that the use of only

primer resulted in the greatest shear bond strength in den-

tin; in enamel, use of phosphoric acid provided the greatest

bond strength. Interestingly, as with the resin-modied glass

ionomers discussed earlier, laser treating the tooth structure

prior to use of the primer and nano-ionomer results in poor

shear bond strengths.33 The setting reaction of the nano-ionomer involves the rapid free radical polymerization of the

monomers when exposed to light-curing, followed for a much

longer time by a slower acid-base reaction involving the uo-

roaluminosilicate glass ller and aqueous acid solution. The

nano-ionomer has been found to have compressive strength at

least equal to conventional glass ionomers and resin-modied

glass ionomers, to have good exural strength and diametral

tensile strength, and to be less brittle than resin-modied

Figure 3. SEM of nano-ionomer

Courtesy of Dr. William Douglas and Dr. Daranee Tantibirojn



glass ionomers. Equivalent uoride release and recharge oc-

cur, and the inclusion of nanollers in the material results in

a smooth surface, with wear resulting in loss of the ne par-

ticles (as with nanolled composites). The end result of use

of the nanotechnology is a nano-ionomer that offers greater

strength, the esthetics of nanotechnology and the release of

uoride on an ongoing basis.

Experimental ApproachesExperimental llers such as trimethyletoxysilane and the use

of N-vinylpyrrolidone have been investigated as additives

to composites and glass ionomer cements, and the inclusion

of a methacryloyl derivative of l-proline in glass ionomers

was found to result in greater diametral tensile strength,

higher compressive strength and higher biaxial exural

strength.30,34,35 Nanosized particles of nanohydroxyapatite

and uorapatite were created and incorporated into glass

ionomer cement in another study, resulting in increased bond

strength, compressive strength, diametral tensile strengthand exural strength.36 One investigation involved creat-

ing novel llers for a resin-based composite by combining

ground cured glass ionomer with ceramic whiskers composed

of silica fused onto silicon nitride that were then silanized.

The resulting material was found to have superior exural

strength and moderate uoride release, the degree of release

inuenced by the proportions of ground glass ionomer and

ceramic whiskers.37 Experimental light-cured HEMA-free

glass ionomer cements have been studied and found to offer

promise.38 Self-etch adhesives to further strengthen adhesion

to tooth structure have also been researched for both com-posites and resin-modied glass ionomers.39

Handling and Placement

As with restorative materials themselves, substantial devel-

opments have occurred with the mixing and application of

tooth-colored restoratives. Initially, glass ionomers consisted

of powder and a water and polyacrylic acid-based liquid,

and were always hand-mixed. Similarly, early composites

consisted of two pastes and they, too, were hand-mixed.

There was no possibility of a one-component delivery sys-

tem, nor did mixing tips/double-barrel applicators exist.

Currently, a number of options are available for the handling

and application of composites and glass ionomers as well as

their derivative products. For composites, one option is a

multi-dose syringe from which the material is extruded onto

a mixing pad before being applied to the tooth; another is

direct application from a unit-dose capsule or, for owable

composites, directly into the preparation from a disposable

single-use applicator tip on a multi-dose syringe. Focus has

also been placed on the shapes of the syringes, the amount of

pressure required for extrusion of the material, the hand gripand thumb comfort during extrusion, methods for measuring

the amount extruded (such as clicks or lines representing an

average extruded dose), and the overall ease of use. Although

still available, hand-mixed dual-paste composites are difcult

to mix accurately and without the inclusion of voids. For glass

ionomers and resin-modied glass ionomers, several options

exist. These include the use of a powder and liquid, or paste-

paste (using the same hand-mixing method used for early

glass ionomers) and the use of a unit dose that is activated by

pressing on, or twisting, the unit dose and then triturated for

10 to 15 seconds (product dependent) before being applieddirectly to the preparation with or without the use of an ap-

plicator. A third option is the use of a Paste Pak that is placed

in an applicator, after which a disposable mixing tip is added

to mix premeasured amounts of each component and to dis-

pense the material onto a pad or directly to the site of use.

Figure 4. Unit doses, powder liquid, syringes

The use of predosed, as well as premixed, materials auto-

matically regulates the quality of the mix as well as the ap-propriate proportion of components. This is important, since

measuring and mixing errors can result in incorrect ratios of

two-component materials that will lead to reduced strength

and surface hardness of the nal restoration. One study found

resin-modied glass ionomers less affected than traditional

glass ionomers and other materials, but not immune to these

effects.40 Nonetheless, depending on whether a dispropor-

tionate amount of powder or liquid is used in a hand-mixing

system without premeasuring, it has been found that surface

hardness, exural strength and fracture resistance can be

affected.41,42 This led to the researchers in one investigation

advocating the use of precapsulated unit doses.42 A nano-

ionomer (Ketac Nano) utilizes a novel unit dose that does

not require activation or trituration and can be applied to the

preparation after taking it out of its foil pouch and placing it in

the matching applier (AplicapTM,3M ESPE). This approach

provides premeasured unit dosing with mixing occurring as

the material is extruded through the mixing tip built into the

unit dose itself. This system can save time and provides ease

of use. Alternatively, if preferred, the same nano-ionomer

can be dispensed as two separate premeasured pastes froma dual-paste double-barrel syringe system clicker dispenser

and hand-mixed prior to direct application to the preparation

using hand instruments.



Figures 5a and 5b. Unit dose and Aplicap

Clinical ApplicationThe two cases below illustrate the use of nano-ionomer for

anterior restorations.

Case 1.The patient presented with a large distal and buccal carious

cavity on tooth #27 which served as the support for a partial

denture clasp. An esthetic, wear-resistant restoration was

required, and it was decided to create a closed-sandwich

restoration using nano-ionomer and composite. After

applying primer (Ketac Nano), a stand-alone air syringe

was used (rather than a three-in-one air-water syringe)

to maximally air-dry the primer and avoid any possible

contamination of the site with water prior to light-curing.

Nano-ionomer (Ketac Nano) was then placed in the site forthe internal sandwich layer and light-cured, with the light-

curing tip held close to the material to ensure maximum

cure. Once cured, a soft composite nishing bur was used

to prepare the surface of the nano-ionomer, after which a

total-etch technique was used for bonding (XP Bond,

Dentsply Caulk) of the composite to the enamel. The com-

posite (FiltekTM Supreme A3, 3M ESPE) was then placed

and the composite light-cured and nished. The end result

was a durable, esthetic restoration.

Figure 6. Disto-buccal cervical lesion

Figure 7. Application of primer

Figure 8. Air-drying of primer

Figure 9. Light-curing of primer

Figures 10a and 10b. Application of nano-ionomer



Figure 11. Light-curing of nano-ionomer

Figure 12. Nano-ionomer prepared prior to composite placement

Figure 13. Finished closed-sandwich restoration

Case 2.The patient in this case was an 89-year-old woman with xero-

stomia. She presented with extensive carious cervical lesions

under a xed anterior prosthesis, indicative of high caries

activity, and the selected clinical solution was use of nano-

ionomer. Primer (Ketac Nano) was applied, dried using an airsyringe and light-cured. For the restorations, nano-ionomer

(Ketac Nano) was applied and shaped using a plastic instru-

ment prior to light-curing. The nal restorations were n-

ished using a nishing bur. To help prevent recurring caries

and to recharge the nano-ionomer with uoride, the patient

was then placed on a preventive protocol that involved the use

of ClinproTM 5000 with TCP (3M ESPE) in the morning and

Crest PRO-HEALTHTM (Procter and Gamble) toothpaste

in the evening, followed by MI PasteTM (GC America) in a

custom-made soft tray overnight.

Figure 14. Carious cervical lesions under fixed prosthesis

Figure 15. Excavation of caries

Figure 16. Application of primer

Figure 17. Application of nano-ionomer



Figures 18a and b. Final cervical restorations

SummaryTooth-colored restorations have changed greatly since

their initial introduction. Over time, these have developed

to include several types of packable composites, owable

composites, glass ionomers and compomers and the use of

nanotechnology. When selecting a material, the require-

ments for the patient and individual restorations are factors

of paramount importance.

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34 Moshaverinia A, Roohpour N, Rehman IU. Synthesis andcharacterization of a novel fast-set proline-derivative-containingglassionomercementwithenhancedmechanicalproperties.ActaBiomater.2009;5(1):498-507.

35 CulbertsonBM.Newpolymericmaterialsforuseinglass-ionomer



cements.JDent.2006;34(8):556-65.36 MoshaveriniaA,Ansari S,MoshaveriniaM,Roohpour N,DarrJA, Rehman I. Effects of incorporation of hydroxyapatite anduoroapatite nanobioceramics into conventional glass ionomercements(GIC).ActaBiomater.2008;4(2):432-40.

37 XuHH,EichmillerFC,AntonucciJM,SchumacherGE,IvesLK.Dentalresincompositescontainingceramicwhiskersandprecuredglassionomerparticles.DentMater.2000;16(5):356-63.

38 Xie D, Chung ID,WuW,Mays J. Synthesis and evaluation ofHEMA-freeglass-ionomer cements fordentalapplications.Dent

Mater.2004;20(5):470-8.39 CoutinhoE,Van Landuyt K,DeMunck J, Poitevin A,YoshidaY,InoueS, PeumansM,SuzukiK,LambrechtsP,VanMeerbeekB. Development of a self-etch adhesive for resin-modied glassionomers.JDentRes.2006;85(4):349-53.

40 Behr M, Rosentritt M, Loher H, Kolbeck C, Trempler C,StemplingerB,KopzonV,HandelG.Changesofcementpropertiescausedbymixingerrors:thetherapeuticrangeofdifferentcementtypes.DentMater.2008;24(9):1187-93.

41 BehrM,RosentrittM,LoherH,HandelG.Effectofvariationsfromtherecommendedpowder/liquidratioonsomepropertiesofresin-modiedcements.ActaOdontolScand.2006;64(4):214-20.

42 DowlingAH,FlemingGJ.Areencapsulatedanteriorglass-ionomerrestoratives better than their hand-mixed equivalents? J Dent.

2009;37(2):133-40.

Author ProfileLou Graham, DDS

Dr. Lou Graham is a graduate of Emory

Dental School. He is the past Dental

Director at the University of Chicago

and currently holds a part-time faculty

position there. Dr. Graham is an inter-

nationally recognized lecturer involved incontinuing education that focuses on incorporating current

clinical advancements through conservative dentistry. Dr.

Graham practices full time in Chicago, IL.

DisclaimerThe author(s) of this course has/have no commercial ties with the sponsors or

the providers of the unrestricted educational grant for this course.

Reader FeedbackWe encourage your comments on this or any PennWell course. For your conve-

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Questions

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answers. An immediate grade report will be provided and upon receiving a passing grade your Verication Form will be provided immediately for viewing and/or printing. Verication Forms can be viewed

and/or printed anytime in the future by returning to the site, sign in and return to your Archives Page.

1.Asresearchersinvestigatedvariousmaterials,twomaincategoriesofdirecttooth-colored restorationsevolved;thesewere_______.

a. composite resins and silicatesb. silicates and glass ionomer cementsc. composite resins and glass ionomer cementsd. acrylics and silicates

2.Themonomer-basedcontentincompos-iteresinsistypically_______.a. bis-GMAb. TEGDMAc. DMAd. any of the above

3.Settingofcompositeresins_______.a. occurs through polymerization of the monomersb. results in the llers being dispersed in the set

polymer

c. occurs through an acid-based reactiond. a and b

4.Earlycompositeresinsexhibited_______.a. low strengthb. a high degree of polymerization shrinkagec. a high level of shrinkage stressd. all of the above

5.Thecurrentrangeofcompositeresinrestorativesoffersthe_______ofalldirecttooth-coloredmaterials.a. greatest strength and wear resistanceb. lowest strength and wear resistancec. greatest strength and poorest estheticsd. none of the above

6.Compositestypically_______.a. contain iodideb. contain uoridec. do not contain uorided. a and b

7.Microlledcompositesoffer_______.a. the ability to polish the composite to a high glossb. the ability to retain a high gloss

c. superior estheticsd. all of the above

8._______isafundamentalcomponentofglassionomercements.a. Fluoroaluminosilicate glassb. Polyalkenoic (or polyacrylic) acidc. Resind. a and b

9.Theinclusionofwateringlassionomersandtheirhydrophilicityresultsin_______.a. wet contact with the tooth surfaceb. a weak bond over timec. a strong bond over time

d. a and c10.Thesettingreactionforglassionomers

is_______.a. acid-basedb. alkali-basedc. ploymerization-basedd. none of the above

11.Glassionomercements_______.a. tolerate moist environmentsb. adhere directly to the tooth structurec. are applied to moist tooth surfacesd. all of the above

12.Inthequestforasinglematerialthatmightmeetallrequirementsfortheideal

restorative,_______haveevolved.a. compositesb. acrylicsc. glass ionomer cementsd. a and c

13.Thestrengthofglassionomerswasimprovedthroughtheadditionof_______.a. methacrylate monomerb. polymer containing free radical double bonds

c. compomer particles

d. none of the above

14.Themonomerinresin-modiedglassionomers_______.a. cross-links

b. sets through polymerization when light-activated

c. does not interfere with the acid-based setting

reaction

d. all of the above

15.Thedirectbondingtothetoothstructureobservedwithglassionomerswasfound

inonestudytobeattributableto_______.a. bonding of the gel phase around the hydroxyapatite

b. the hybrid layer

c. monomer

d. a and b

16.FollowingEr:YAGlaser-irradiationofdentin,_______hasbeenobservedwiththeuseofglassionomers.a. a deeper hybrid layer

b. no hybrid layer

c. no setting reaction

d. a and c

17.Theuseofglassionomerconditioneris

importantfor_______inbur-cutdentin.a. microtensile bond strengthb. shrinkage

c. stress reduction

d. all of the above



Questions

18.Metal-reinforcedglassionomers_______.a. typically include silver-based alloys in the mixb. are used primarily for core buildupsc. can be used to restore primary molars

d. all of the above

19.Thecermet_______.a. results from fusing metal ions to uoroaluminosili-

cate glass particlesb. is a subset of metal-reinforced glass ionomersc. releases less uoride than other glass ionomersd. all of the above

20.Compomersarealsoknownas_______.a. polyacid-modied glass ionomersb. polyacid-modied acrylicsc. polyacid-modied compositesd. none of the above

21.Compomerscontain_______.a. ller similar to the glass particles contained in glassionomers

b. dimethacrylate monomer and polyacidc. no waterd. all of the above

22.Settingofcompomersoccursthrough_______.a. polymerization onlyb. an acid-based reaction onlyc. both polymerization and an acid-based reactiond. none of the above

23.Ithasbeenfoundthat_______withthemethacrylate-basedpolymermolecules

isduetodilutionofllerparticlesthroughthepresenceofwater.a. the release of metal ions that hydrateb. the release of metal ions that chelatec. the release of carboxyl bonds that chelated. all of the above

24.Compomershave_______comparedtocomposites.a. lower compressive and exural strengthb. a lower modulus of elasticityc. less resistance to fracture and weard. all of the above

25.Therehavebeenconcernsaboutthereleaseof_______fromcompomers.

a. uorideb. EDTAc. HEMAd. b and c

26.Biolmformationissignicanton_______.a. compomersb. amalgamc. compositesd. a and c

27.Agiomercontains_______.a. milled, silanized glass ionomer llersb. a composite resin basec. a silicate base

d. a and b

28.Giomershave_______.a. the strength of compositesb. the esthetics of compositesc. been shown to release uorided. all of the above

29.Theintroductionofnanotechnology_______.a. occurred initially in compositesb. heralded improved estheticsc. did not compromise strength

d. all of the above

30.Nanolledcompositeresinsweredesignedtocombinethe_______.a. polishability and esthetics of microlled compositesb. strength and wear resistance of microhybrid

compositesc. strength and wear resistance of compomersd. a and b

31.Nanollersincomposites_______.a. improve the translucency of compositesb. improve the opalescence of compositesc. make composites more natural lookingd. all of the above

32.Nanolledcompositesoffer_______microlledcomposites.a. improved strength compared tob. reduced strength compared toc. the same strength asd. none of the above

33.Theadditionofpre-polymerizednanollersformingnanoclustershasbeenfoundto_______incomposites.a. reduce polymerization shrinkageb. increase shrinkage stressc. increase strengthd. a and c

34._______arecontainedinnano-ionomers.a. Water and polycarboxylic acid

b. Nanollersc. Reactive resinsd. all of the above

35.Thenanollersinnano-ionomerarebasedon_______.a. silica and phosphateb. zirconia and phosphatec. uoride and zirconiad. zirconia and silica

36.Nano-ionomercontains_______uoroaluminosilicateglassparticles.a. 17%b. 27%c. 37%

d. none of the above

37.Primermustbeusedpriortoplacementofnano-ionomerstooptimize_______.a. compressive strengthb. tensile shear bond strengthc. exural strengthd. all of the above

38._______studiedtheshearbondstrengthofnano-ionomertoenamelanddentin.a. Korovsky et alb. Korkmaz et alc. Korbovskia et ald. none of the above

39.Theuseofonlyprimerhasbeenfoundtoresultinthegreatestshearbondstrengthto_______.a. enamelb. dentinc. cementumd. a and b

40.Theuseofphosphoricacidhasbeenfoundtoprovidethegreatestbondstrengthto_______.a. enamelb. dentin

c. cementumd. a and c

41.Nano-ionomerhasbeenfoundto______.a. have compressive strength at least equal to glass

ionomersb. have good exural and diametral tensile strengthc. be less brittle than resin-modied glass ionomersd. all of the above

42.Experimentally,theinclusionofamethacryloylderivativeofl-prolineinglassionomerswasfoundtoresultin_______.a. greater strengthb. greater polishabilityc. lower reectanced. all of the above

43.Self-etchadhesivestofurtherstrengthenadhesiontotoothstructurehavebeenresearchedfor_______.a. compositesb. gold inlaysc. resin-modied glass ionomersd. a and c

44.Earlycomposites______.a. were weakb. consisted of two pastesc. were hand-mixedd. all of the above

45._______isanoptionforthehandlingandapplicationofcomposite.a. A multi-dose syringe with a mixing pad

b. Direct application from a unit-dose capsulec. Use of a disposable tip and multi-dose syringe for

owablesd. all of the above

46.Theuseof_______isanoptionformixingglassionomers.a. a powder and liquidb. a capsulec. a Paste Pakd. all of the above

47.Measuringandmixingerrorscanresultinincorrectratiosoftwo-componentmaterialsandcanleadto_______.a. reduced strengthb. reduced surface hardness

c. reduced fracture resistanced. all of the above

48.Usingpremeasuredunitdosingwithmixingoccurringasthematerialisextrudedcan_______.a. save timeb. provide ease of usec. increase wasted. a and b

49.Researchersinoneinvestigationonthemixingofglassionomersadvocatedtheuseof_______.a. powder and liquidb. precapsulated unit dosesc. a dual paste system

d. none of the above50.The_______isafactorwhenselectinga

tooth-coloredrestorative.a. requirements for the patientb. gender of the patientc. individual restorationd. a and c


11/12

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P.O.Box116,Chesterland,OH44026orfaxto:(440)845-3447

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Educational Objectives

1. Describetheearlytooth-coloreddirectrestorativematerials

2. Listandcomparetheattributesocompositeresinsandglassionomercements

3. Describethecompositionoacompomer,andcompareittocompositeresinsandconventionalglassionomers

4. Describetherestorativescontainingnanotechnologyandtheefectonano technologyinnano-ionomerrestorations

Course Evaluation

Pleaseevaluatethiscoursebyrespondingtotheollowingstatements,usingascaleoExcellent=5toPoor=0.

1.Weretheindividualcourseobjectivesmet? Objective#1:YesNo Objective#3:YesNoObjective#2:YesNo Objective#4:YesNo

2.Towhatextentwerethecourseobjectivesaccomplishedoverall? 5 4 3 2 1 0

3.Pleaserateyourpersonalmasteryothecourseobjectives. 5 4 3 2 1 0

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8.Doyoueelthatthereerenceswereadequate? Yes No

9.Would you par tic ipate in asimilarprogramonadiferenttopic? Yes No

10.Ianyothecontinuingeducationquestionswereunclearorambiguous,pleaselistthem.

___________________________________________________________________

11.Wasthereanysubjectmatteryououndconusing?Pleasedescribe.

___________________________________________________________________

___________________________________________________________________

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___________________________________________________________________

___________________________________________________________________

ANSWER SHEET

Advances in Tooth-Colored Restorations

Name: Title: Specialty:

Address: E-mail:

City: State: ZIP: Country:

Telephone:Home(

) Ofce(

) Lic.RenewalDate:

Requirementsforsuccessfulcompletionofthecourseandtoobtaindentalcontinuingeducationcredits:1)Readtheentirecourse.2)Completeall

informationabove.3)Completeanswersheetsineitherpenorpencil.4)Markonlyoneanswerforeachquestion.5)Ascoreof70%onthistestwillearn

you3CEcredits.6)CompletetheCourseEvaluationbelow.7)MakecheckpayabletoPennWellCorp.For Questions Call 216.398.7822

AUTHOR DISCLAIMERThe author(s) of this course has/have no commercial ties with the sponsors or the providers of

the unrestricted educational grant for this course.SPONSOR/PROVIDER

This course was made possible through an unrestricted educational grant from 3MESPE. No manufacturer or third party has had any input into the development of coursecontent. All content has been derived from references listed, and or the opinions ofclinicians. Please direct all questions pertaining to PennWell or the administration ofthis course to Machele Galloway, 1421 S. Sheridan Rd., Tulsa, OK 74112 or [email protected].

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EDUCATIONAL DISCLAIMERThe opinions of ecacy or perceived value of any products or companies mentionedin this course and expressed herein are those of the author(s) of the course and do notnecessarily reect those of PennWell.

Completing a single continuing education course does not provide enough informationto give the participant the feeling that s/he is an expert in the eld related to the coursetopic. It is a combination of many educational courses and clinical experience thatallows the participant to develop skills and expertise.

COURSE CREDITS/COSTAll participants scoring at least 70% on the examination will receive a verication

form verifying 3 CE credits. The formal continuing education program of this sponsoris accepted by the AGD for Fellowship/Mastership credit. Please contact PennWell forcurrent term of acceptance. Participants are urged to contact their state dental boardsfor continuing education requirements. PennWell is a California Provider. The CaliforniaProvider number is 4527. The cost for courses ranges from $49.00 to $110.00.

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2010 by the Academy of Dental Therapeutics and Stomatology, a divisionof PennWell

COlOR0111DE

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rightsreserved.3M,ESPEandKetacaretrademarksof3Mor3MESPEAG.UsedunderlicenseinCanada.

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Call 800-634-2249 or visit www.3MESPE.com/KetacNano

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