Operative Dentistry Flashcards
If someone has a high smile line, what would you expect to see clinically?
All of the clinical grown and gingivae
What would you suspect from a patient with Linea Alba on buccal mucosa?
A para functional habit
What are two kinds of articular that you might mount your study casts on?
Semi-adjustable articular
Average value
What are some advantages of diagnostic wax-up
Can check;
Aesthetics
Occlusion
Shows your intentions to the patient
What phase of the treatment plan would fixed prosthodontics come under?
Reconstructive
Name two instances that a tooth would be deemed unrestorable and extraction is indicated?
Caries spread beyond the level of the alveolar crest
A horizontal fracture renders a tooth unrestorable
Name 5 reasons to place veneers?
Improve aesthetics
Change teeth shape and/or contour
Correct peg shaped laterals
Reduce or close proximal spaces and diastema’s
Align labial surfaces of instandng teeth
Name 5 reasons when not to use veneers?
Poor OH - high caries rate
Gingival recession
High lip lines
Heavy occlusal contacts
Root exposure
If extensive prep needed
Why is someone has root exposure, may you not place dentures>
Want to bond veneers onto enamel and if the root is exposed, most likely dentine and therefore will not have as good a bond
What are the 6 principles of crown preparation?
- Preservation of tooth structure
- Retention and resistance
- Structural durability
- Marginal integrity
5.Preservation of the periodontium
6.Aesthetics considerations
Define retention in relation to crown prep
Prevents removal of the restoration along the pat of insertion or the long axis of the tooth prep
Define resistance in relation to crown prep
Prevents dislodgement of the restoration by forces directed by apical or oblique direction and prevents any movement of the restoration under occlusal force
What is taper
Ideal inclination of opposing walls 6-10 degrees
Why do we not want longer walls in crown prep
Longer walls interfere with tippling displacement
What is the path of insertion with relation to fixed pros
Imaginary line along which the restoration will be place onto or removed from the prep
How are retention and path of insertion related
Retention is improved by limiting the number of paths of insertion
For structural durability to be achieved in crown prep, the restoration must contain a bulk of material that is adequate to withstand the forces of occlusion.
How is this achieved;
Through;
- occlusal reduction
- functional cusp bevel
- axial reduction
What is the minimum the occlusal reduction on the crown prep must be
2mm thick
When would you use a chamfer finish line?
Used for veneer preps
Metal based restorations usually
When would you use shoulder finish line
Usually for ceramic based
Preservation of the periodontium is one of the principles of crown preparation.
What three things should the margins of the restoration be?
- Smooth and fully exposed to a cleansing action
- Placed where the dentist can finish them and the patient can clean them
- Placed supra-gingival or at the gingival Margin where possible
What is an occasion that placement of margins in a crown prep may be sub-gingival.
When a patient has a high smile line they want to hear margins, not too high will make it hard to clean
What is the biological width of the tooth/
Height between very depth of the sulcular epithelium and the most coronal part of the alveolar bone
What is a cantilever bridge
This is a bridge that is held on at one side
What are the conventional clinical stages of indirect restorations
- Preparation
- Temporisation
- Impressions and occlusal records
- Cementation
What are two advantages of inlays compared to direct restorations
Superior materials and margins
Won’t deteriorate over time
What are disadvantages of inlays compared to direct restorations
Time and cost
What should the isthmus width in a ceramic inlay be
1.5-2mm width
What is the difference between and onlay and an inlay
Onlays are like inlays however they have cuspal coverage
