Class I Amalgam Restorations

Question 1

cavitated lesions in pits and fissures (class I) are _____ or _____ to detect in the early stages

Answer 1

difficult

impossible

Question 2

Is a “catch” of an explorer in a deep fissure a reliable indication of a carious lesion?

Answer 2

no

Question 3

How are class I caries with a need for surgical intervention detected?

Answer 3

dark/light halo showing through enamel surrounding pit/fissure
Radiolucency on BWs in subjacent dentin (but class I's are not always visible in xrays)

Question 4

how are questionable class I lesions in a caries active patient?

Answer 4

Surgical exploration and restoration of questionable site (therapeutic tx aimed at reducing caries risk)
Especially if pt has other pit and fissure cavities

Question 5

how are questionable class I lesions in a caries free/inactive pt treated?

Answer 5

Monitoring

Question 6

If a class I cavitation within a pit/fissure is STRONGLY suspected, what can be done?

Answer 6

A small round bur is used to explore fissure system (exploratory procedure)

Question 7

When exploring a fissure system with a small round bur, what indicates the presence of carious lesions?

Answer 7

Walls of pit/fissure will turn opaque white

Voids (cavities) dropping into dentin

Question 8

In class I caries, if the destruction extends in a few spots into the dentin but the lateral extension is minimal, what material would likely be used to restore it?

Answer 8

bonded composite resin

Question 9

How can caries be prevented when thre are contiguous (adjacent, touching) SOUND pits and fissures?

Answer 9

close it with a pit and fissure sealant

Combined composite resin/sealant

Question 10

Preventive resin restoration

Answer 10

Combined composite resin/sealant restoration
Closes contiguous, sound pits/fissures
Lesion-specific cavity prep for class I lesions

Question 11

Lesion-specific cavity prep

Answer 11

Prep where the size, shape, and position of the cavity are dictated by the caries lesion and NOT by the physical requirements of the restorative material

Question 12

What restorative material is a good option for when cavitation of a pit/fissure is large enough to be obvious clinically/radiographically?

Answer 12

amalgam - preferred
Cast gold
indirect porcelain
composite resin

Question 13

What are the advantages to using amalgam for a class I?

Answer 13

most economical choice

2nd best in terms of longevity (1st is cast gold)

Question 14

amalgam restorations require a ________ cavity prep

Answer 14

material specific

Question 15

Material specific cavity prep

Answer 15

various design features of the cavity are dictated by physical requirements of the restorative material
eg. amalgam

Question 16

KaVo DIAGNOdent

Answer 16

Laser light
Induces fluorescence of carious tooth tissue and quantifies it
CANNOT DETECT CARIES: interproximally, around composite restorations, beneath sealants

Question 17

Outline form of class I amalgam preps

Answer 17

smooth flowing, gentle curves

Question 18

Why is it advantageous for class I amalgam preps to have a smooth flowing outline form with gentle curves?

Answer 18

angular contours chip during condensation
Angular contours concentrate stresses, leading to restoration fracture during function
Easier to find when carving back fresh amalgam

Question 19

Angular irregularities - invagination

Answer 19

Sharp angle in the outline form at where the triangular ridge of a cusp meets the cavity prep
Susceptible to fracture during condensation

Question 20

Angular irregularities - evagination

Answer 20

Sharp, angular extension in a prep

Difficult to condense into

Question 21

In a class I amalgam prep, extension is a balance between…

Answer 21

Conservation of tooth structure and the room for access/visibility

Question 22

The extension of class I amalgam preps is trying to accomplish what?

Answer 22

• all infected tissue removed, no unnecessary tissue removed
• remove unsupported enamel
• include contiguous fissures, pits, restorations

Question 23

Why must unsupported enamel be removed in a class I amalgam prep?

Answer 23

enamel not supported by dentin is weak and will fracture under function

Question 24

Why must contiguous fissures, pits, and restorations be included in a class I amalgam prep?

Answer 24

Act as conduits for cariogenic microorganisms that cause secondary caries
Max restoration lifespan

Question 25

What are the 3 types of extension in a class I amalgam prep?

Answer 25

Bucco-lingual extensions
mesio-distal extension
occlusal (pulpal floor) depth

Question 26

Features of bucco-lingual extension in a class I amalgam prep

Answer 26

extends far enough up B/L grooves to remove contiguous tissures and to terminate on gentle contours

minimal extension between triangular ridges - optimal isthmus width