Class I Amalgam Restorations Flashcards
cavitated lesions in pits and fissures (class I) are _____ or _____ to detect in the early stages
difficult
impossible
Is a “catch” of an explorer in a deep fissure a reliable indication of a carious lesion?
no
How are class I caries with a need for surgical intervention detected?
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)
how are questionable class I lesions in a caries active patient?
Surgical exploration and restoration of questionable site (therapeutic tx aimed at reducing caries risk)
Especially if pt has other pit and fissure cavities
how are questionable class I lesions in a caries free/inactive pt treated?
Monitoring
If a class I cavitation within a pit/fissure is STRONGLY suspected, what can be done?
A small round bur is used to explore fissure system (exploratory procedure)
When exploring a fissure system with a small round bur, what indicates the presence of carious lesions?
Walls of pit/fissure will turn opaque white
Voids (cavities) dropping into dentin
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?
bonded composite resin
How can caries be prevented when thre are contiguous (adjacent, touching) SOUND pits and fissures?
close it with a pit and fissure sealant
Combined composite resin/sealant
Preventive resin restoration
Combined composite resin/sealant restoration
Closes contiguous, sound pits/fissures
Lesion-specific cavity prep for class I lesions
Lesion-specific cavity prep
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
What restorative material is a good option for when cavitation of a pit/fissure is large enough to be obvious clinically/radiographically?
amalgam - preferred
Cast gold
indirect porcelain
composite resin
What are the advantages to using amalgam for a class I?
most economical choice
2nd best in terms of longevity (1st is cast gold)
amalgam restorations require a ________ cavity prep
material specific
Material specific cavity prep
various design features of the cavity are dictated by physical requirements of the restorative material
eg. amalgam
KaVo DIAGNOdent
Laser light
Induces fluorescence of carious tooth tissue and quantifies it
CANNOT DETECT CARIES: interproximally, around composite restorations, beneath sealants
Outline form of class I amalgam preps
smooth flowing, gentle curves
Why is it advantageous for class I amalgam preps to have a smooth flowing outline form with gentle curves?
angular contours chip during condensation
Angular contours concentrate stresses, leading to restoration fracture during function
Easier to find when carving back fresh amalgam
Angular irregularities - invagination
Sharp angle in the outline form at where the triangular ridge of a cusp meets the cavity prep
Susceptible to fracture during condensation
Angular irregularities - evagination
Sharp, angular extension in a prep
Difficult to condense into
In a class I amalgam prep, extension is a balance between…
Conservation of tooth structure and the room for access/visibility
The extension of class I amalgam preps is trying to accomplish what?
- all infected tissue removed, no unnecessary tissue removed
- remove unsupported enamel
- include contiguous fissures, pits, restorations
Why must unsupported enamel be removed in a class I amalgam prep?
enamel not supported by dentin is weak and will fracture under function
Why must contiguous fissures, pits, and restorations be included in a class I amalgam prep?
Act as conduits for cariogenic microorganisms that cause secondary caries
Max restoration lifespan
What are the 3 types of extension in a class I amalgam prep?
Bucco-lingual extensions
mesio-distal extension
occlusal (pulpal floor) depth
Features of bucco-lingual extension in a class I amalgam prep
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
