Class II Quiz 8 Exam 3 Flashcards
Class II lesion
smooth surface lesion, in the proximals of post teeth
Once lesion hits DEJ
Takes path of least resistance so the caries spreads laterally
Why caries spread laterally
path of least resistance, once hits DEJ; form cones with tips towards pulpal tissues
Line Angle
Jcn of two walls
Jcn of three walls
point angles
Internal walls
Axial and pulpal walls
Diagnosis clinically
Chalky, opaque area, grey area in color
Best method for determining a Class II lesion
Radiograph; able to see incipient (start) lesions
When do we treat Class II lesions if previously unrestored
Cone goes through all of enamel to dentin/DEJ-consider looking at restoring
Modifying factors for restoration of Class II
poor OH, education, socioeconomic status, caries risk
Previously restored when do we treat Class II
Fractured restoration, overhang/flash, light or no proximal contacts, poor marginal integrity, non physiological contours
Indications for Class II/ radiographically
Changing…
Class II prep vision
indirect
Outline form of Class II considerations
anatomy-pits and fissures; soft and hard tissue adjacent-gingival embrasures and B and L
Resistance form of Class II
internal walls in dentin layer- because has a little more give to it than enamel b/c amalgam is brittle
90 degree cavosurface margis
Flat gingival floor/seat
Rounded internal line angles (pulpal floor and gingiva)
adequate pulpal depth
Preserve tooth structure
Retention of Class II
Dovetails, convergent proximal walls, convergent occlusal walls, proximal locks-proximal retention grooves (placed .5 mm inside DEJ)
Placement of retention grooves
.5 mm proximal lock inside the DEJ
Proximal lock is more prominent _____ than ____
gingivally than occlusal
Convenience form of Class II
Clearance-place walls in a place you can access them
Clearance aids in
Allows for easy finishing (less flash)
Lesions that deviate from normal (how to treat)
traditional prep and then just extend to affected area only
After Class II is done
Clean with air and water, re-evaluate, make any needed complications
Most detailed prep
Class II
isthmus width of Class II
1/4 of intercuspal distance
Gingival floor seat dimension axially
1 -1.5mm
Extend towards proximal surface but
DO NOT extend through the affected marginal ridge (to the mesial i.e.)
proximal trenching
forms the proximal box
makes the proximal box
axial wall, gingival floor/seat, buccal proximal wall, lingual proximal wall
Proximal trenching process
sink bur in gingival direction, then move Burr in a B-L direction, break the B and L contacts with the adjacent tooth minimally
Clearance with proximals
Remove B and L contacts with adjacent teeth
Clearance distance
.5mm or less
where is enamel thinner
gingival 1/3
enamel plate
enamel preserved to avoid adjacent tooth damage; protective, can be removed once depth is met
MArginal ridge on affected side of Class II before dropping burr
.5 mm or so
Once done with proximal trenching
clean up proximal box
Proximal box gives us
Lingual, gingival, and buccal clearance
how to measure gingival clearance
horizontally
finish the proximal box with
rotary or hand instrument
what to do with enamel/spurs
incorporate a reverse curve, remove them
Big deal for Class II amalgam preps
Round the internal line angles
