Dentine Bonded Crown Flashcards
What needs to be done before starting prep?
Take silicone index and silicone impression
Index: sectioned and placed over tooth to aid reduction
Impression: used for temporary
How is the labial surface prepared?
In 2 places - labial and incisal
Must follow contour of tooth
How to start labial prep?
Use chamfer bur for depth groove - sink bur halfway - final depth should be 0.7mm-1.0mm
Ensure grooves both planes
How should incisal reduction be carried out?
1.5mm reduction - follow contour and angle of 45 degree
Better to underprepare - allow further reduction and polishing
How to finish labial prep?
Join depth grooves w/ supra-gingival finish
Need chamfer bur to achieve chamfer finish
What margin should final prep have bucally?
Chamfer margin - 0.7mm
How should contact breakthrough be acheived?
Fine stroking manner - needle bur (matrix can be placed to avoid iatrogenic damage)
More tissue will need to be taken at contact point to achieve 0.7mm margin due to bulbous nature
What taper should the prep have?
5-10 degree
What margin should final palatal prep have?
Chamfer margin - 0,7mm
Even around tooth
How should palatal aspect be prepared?
Follow contour from interproximal areas palatal
Looking for 0.7mm final reduction
Reduce cingulum following natural contour
What bur should cingulum be reduced with?
Rugby, pear
Why do margins need refining?
Ensure prep connected smoothly
No sharp line angles - can create stress conc
Can be finished w/ TC bur
What is the summary of dentine bonded crown?
Incisal reduction = 1.5mm
Buccal reduction = 0.7mm - chamfer (2 planes)
Palatal reduction = 0.7mm - chamfer (2 planes)
5-10 degree taper
Rounded internal line angles
Follow gingival contour
