Class 1 w/extension Flashcards
Box
Dimensions of depth on the tooth.
Bur orientation - Man 1st premolar
Lingual cusp short and tiny - acts more like cingulum of mandibular canine. Buccal cusp is large - very comparble to canine in a way. Huge transverse ridge that should not be crossed if possible.
If transversed ridge crossed, pulpal floor cannot be perpendicular to axis.
Pulp chamber always follows outline - will be high up on buccal surface. If you go directly with tooth axis, you can either undermine lingual cusp or get too close to pulp.
Can’t drill with the occlusal plane, as you go right at pulp.
*Instead go at an angle between occlusal plane and long axis.
Class 1 w/extension
pit and fissures caries including occlusal and buccal/lingual surfaces of posterior teeth (molars mainly). Usually in distal pit, distolingual pit and involving distolingual groove. Do not cross oblique ridge.
Compound
Multi surfaces - class 1 w/extension or compound class 1. Either name works.
OL cavity prep
In distal pit, distolingual pit and involving distolingual groove. Do not cross oblique ridge. Maxillary molars.
OB cavity prep
Occlusal and a buccal fissure - mandibular molars.
OB DEJ
Will just barely lift up compared to normal class 1 in buccal groove.
Pulpal floor -OB
pulpal floor assumes occlusal elevation (this will go with DEJ, which will get slightly shallower) - Use a 245 to drop the box
Axiopulpal line angle
When dropping the box, you have to round the axiopulpal line angle. Follow the curvature of the buccal surface. Axial depth of 1 to 1.2 mm is ideal.
Mesial and distal walls
converging occlusaly.
Concentricity
Static test - measures if some blades were designed shorter than others. How closely single circle touches the tip of all blades. On manufactural level.
Run out
A function or a dynamic test. Push the rheostat if the bur head is displaced from its long axis when it rotates. EX - off center head or bent neck.
Accufilm - articulating paper
Marking
Study tray setup
**
330 convergent error
Don’t angle too much, it will cause rounding of wall.