L2 Flashcards
ACC
To increase strength, you need bulk. - All ceramic, no metal.
ACC advantages
Superior esthetics
Excellent translucency
Best color stability
Biocompatibility
Silica based on ceramic restorations can be bonded to tooth structure
Conservative restoration would be inadequate
Enough tooth structure to support the restoration
Favorable occlusal load
Don’t absorb moisture
ACC disadvantages
Brittle
Proximal and lingual reduction
Margin adaptation (this has improved recently).
Critical cavosurface angle
Not for FDP abutment (certain types can be used anteriorly)
Opposing tooth wear, not as much of a problem as feldspathic porcelain
More conservative prep can be used
Unfavorable occlusal load
Parafunctional activity
ACC uniform reduction of
1mm except for 2 areas - top, near CEJ (where it is curved - if it were uniform, it would be undercut).
Porcelain is brittle, so your cavosurface margin should be
90 degrees -like amalgam.
770.8M
1.2 mm diam
256.8M
1.0 m diam
747.6M
0.6mm diam
ACC requires a
shoulder.
702.8M
1.0mm flat shoulder bur, tapered
515.7M
1.0 mmm diameter flat shoulder bur, not tapered
285.5M
football bur
862M
round top
ACC prep sequence
Make putty guide
Incisal edge reduction
Facial and lingual guiding grooves 1st and 2nd planes
Facial and lingual reductions and break contact
Remove unsupported structure, “lipping”
Refine, check with reduction guide
Incisal reduction
2mm
Facial reduction
1.2 mm
Circumferential finishline
1.0+
Lingual clearance (concave)
1.0mm
Outline (finishline, margin)
0.5mm above free gingiva
Direct provisional
fixed or removable dental prosthesis or max-facial prosthesis, designed to enhance esthetics, stabilization or other function for a limited time.
Biologic:
no sensitivity or pain no swollen or bleeding gums feels like a tooth long lasting, no cavities insulation for vital tooth and pulp recovery ideal margin sealing gingival recovery proper interproximal and occlusal contact anti-carious, prevent secondary decay
Mechanical:
Able to chew without worrying fractures and/or dislodging crowns Keep everything in place Resist functional load Resist removal force Maintain interabutment alignment
Esthetics
Looks like a real tooth Easily add and subtract easy to finish and polish color compatibility color stability translucency
Provisional requires
External surface form (ESF)
- Represents definitive restoration form
- Determined in diagnostic stage
- Outer contour of the restoration
Tissue surface form (TSF)
- Represents prepared hard and soft tissue that receive the restoration
- Internal contour of the restoration
