detectie carie marginala

8/3/2019 detectie carie marginala

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Early Clinic

Re-restoration of Teeth accounts for over 50% of dental work(Elderton et al.1985; Mjor and

Toffenetti 1992)caries rate declining worldwide (Downer,

1984; Rensen et al. 1985).All restorations have built in

obsolescence.

Early Clinic

Reasons for Failure of Restorationsrecurrent caries (>50%) - most common reasongiven by dentists

other technical failures restoration fracture marginal breakdowncusp fracturedefective contour (overhang, wear, open contact)poor appearance

Early Clinic

When to replace existing

restorations?

Early Clinic

Recurrent (Secondary) Decay Definition Microbiology and

Histopathology Location Clinical diagnosis Examples

Early Clinic

Definitions of recurrent caries Spread of caries at the DEJ Failure to remove all diseased tissue Marginal defects of any sort Caries at new site on previously

restored tooth Lesions at the margins of existing

restorationsEarly Clinic

Histology of Secondary Caries Described as having two

partsOuter lesionWall Lesion

Hals E. Andreassen BH. Bie T. Caries Research. 8(4):343-58, 1974.


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Early Clinic

Secondary Caries Process

Outer lesion - the enamel caries

formed on the surface enamel as a

result of new, primary attack.

Related to plaque accumulation on

the surface similar to primary

caries

Can visually assess wall lesion

Early Clinic

Secondary Caries Process

Wall lesion - which forms as a result

of leakage of bacteria, fluids or

hydrogen ions between restoration

and cavity wall.

This clinically undetectable leakage

around a restoration is referred to as

microleakage

microleakage

Cannot visually assess wall lesion

Early Clinic

Secondary Caries ProcessThe Outer Lesion - Same characteristic

features as early primary caries*Opaque white color early*Progresses through same characteristic histologic stages

incipientcavitated

Early Clinic

Microscopic Features of Incipient Caries Defined Zones

Zone 1 TranslucentZone 2 DarkZone 3 BodyZone 4 Surface

*Surface initially mineralized while

subsurfaces demineralize

*Stages based on pore sizes developing

from demineralization

*Later surface collapses and cavitates12

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Early Clinic

Secondary Caries ProcessPresence of wall lesion questionable

Since caries process follows the

enamel rods

May just be in cases where enamelrods directed to restoration interface

Or when microleakage is primary

cause of secondary decay problem

Early Clinic

Microbiology Most researchers agree that secondary

caries is the same as primary caries

adjacent to a restoration. the pellicle that forms on materials may be

different than the pellicle that forms on

tooth the initial plaque colonization may be

different


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Early Clinic

Where is recurrent caries most

likely to occur ?

Early Clinic

Location Of Secondary Caries It has been recognized by clinician for

many years (GV Black 1908) and

shown in numerous studies that

secondary caries is more prevalent at

the gingival margins of class II, III, IV

and V restorations than other surfaces.

Early Clinic

Frequency of secondary caries at

cervical and interproximal . 94% of amalgams that fail from caries

fail at these sites. Amalgams rarely

fail at occlusal surface 62% of composites fixed restorations - also would most

likely be proximal areas. Mjor IA. Operative Dentistry. 10(3):88-92, 1985

Early Clinic

Extension for Prevention Recognition of rebeginning or recurrence

of decay at cavity margins (GV Black: A

Work on Operative Dentistry. 1908) Clinical observation led to idea of

extension for prevention (Need to placemargins in areas accessible to inspection and

mechanical oral hygiene measures)

Early Clinic

Location Of Secondary Caries Relationship between proximal cavity

design and recurrent caries. Otto andRule, J Am Dent Assoc 1988;116:867-870

Difficult to determine primary vs secondary

in this particular area.

Early Clinic

Factors that predispose the gingival areas

Clinical Techniques Materials Properties Patient factors


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Early Clinic

Patient Factors Caries Risk (strep mutan count)

Oral hygieneDietGenetic predispositionFluorides

Early Clinic

Technique Factors Moisture control Access Technique

Condensationbonding

Early Clinic

Materials Properties Different materials have different potential

to seal at restoration marginsAmalgamCompositeGlass ionomers, resin modified GIs

Early Clinic

Materials Properties Amalgam Proper adaptation of amalgam at margins

Minimize voids and irregularities Proximal contours and contacts (overhangs

and open contacts) Some potential caries inhibition (corrosion

products)

Early Clinic

Materials Properties Composite Contraction on polymerization

Volume relatedAll large composite restorations leak

No ability to inhibit caries Seals well on enamel margins but poor on

dentin and cementum margins

Early Clinic

Materials PropertiesGI and RMGI Ability to inhibit recurrent caries (some

evidence but not definitive). Tend to have zero net shrinkage and seal

well.


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Early Clinic

Methods of Diagnosing Recurrent Caries Visual assessment of color Gap or defect size Hardness Bitewing radiographs

Early Clinic

Appearance of Outer Lesion Range from

white spotbrown spot with or

without softening

of mineralized

tissuefrank cavity

Early Clinic

Color Changes (amalgam) particularly difficult to

interpret adjacent to amalgam

restorations gray or blue discolorations

may indicate either a carious

lesion or corrosion or light

reflecting from the amalgam

itselfEarly Clinic

Color Changes (composite) more easily interpreted. discolorations adjacent to

composite may be a result of discolored

demineralized dentin deep

in the cavity wall or a line of stain at the

junction of the filling and

the tooth.

Early Clinic

Color Changes (composite) The development of stain around a

composite filling may indicate the

onset of early secondary caries. Transillumination is helpful in the

diagnosis of discolored dentin beneath

a tooth-colored restoration.

Early Clinic


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Early Clinic Early Clinic



Secondary caries and Margin defects A ditched amalgam has

long been regarded with

suspicion by clinicians and

are often replaced as a

preventive measure toavoid plaque stagnation

and secondary caries

activity


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Early Clinic

Marginal Gap or Defect Size No good correlation between gap size

and recurrent decay Larger gaps (>250 m) more likely to

accumulate plaque Plaque accumulations may be decisive

factor

Early Clinic

A catch on a restoration interface

is not synonymous with caries.

Early Clinic

Hardness The clinical parameters that correspond

to heavily infected dentine was

softness to probing, hard and medium-hard areas being

very lightly infected with micro

-organisms. Only frank cavitation was a good

predictor of caries at the DEJ

Early Clinic

Bitewing Radiographs limited value because of shadowing effect

of restorative materials (amalgam)restorative materials should therefore be same

radiopacity as tooth to maximize detection improve caries diagnosis significantly

compared to other methodsPoor sensitivity 30-50%Good specificity 90%+

Early Clinic

Decay can be more rapid under

composite resin restorations

Early Clinic

Conclusions: (recurrent caries) Initiation and progression similar to

primary caries Microbiology similar to primary caries Secondary caries rarely found inocclusal areas Most often found in gingival areas Margin gaps or ditching not good

indicator of 2 caries


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Early Clinic

Conclusions: (recurrent caries) Multiple modes of evaluation Frank cavitation, hardness, bitewings are

considered best clinical indicators Color better for composite than amalgam Patient caries risk assessment counts

Early Clinic

Replacing Amalgam Restorations

Early Clinic

Amalgam Removal Technique Isolation (rubber dam) High-vac suction Copius water spray Remove in chunks if possible

High-speed grinding releases mercuryvapors (concern)

Early Clinic

Mount Extracted Tooth

Early Clinic


Early Clinic



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Early Clinic

Amalgam removal Use 330 carbide Other special

designs just forrapid removal

34 330

Early Clinic

Amalgam removal Channel throughthe center of the

isthmus frommesial fossa todistal fossa at thedepth of thedentin or base ofpulpal floor

Early Clinic

Amalgam removal Separate box

from isthmus by

extending to

buccal and ling

walls at depth of

pulpal floor or

baseEarly Clinic

Amalgam Removal Technique Try to remove in

large pieces do not pry hard

enough to breakinstrument-youpay)

Early Clinic

Amalgam Removal Technique

Early Clinic

Amalgam Removal Technique Boxes are

generally locked

in mechanically

due toconvergence of

B-L walls


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Early Clinic

Amalgam Removal Technique Section box

portion in half

Early Clinic

Amalgam Removal Technique Remove pieces

Early Clinic

Amalgam Removal Technique Remove pieces

Early Clinic

Amalgam Removal Technique Determine where

or if recurrent

caries is present Base needed? Restore

detectie carie marginala

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