Restorative - Crowns and treatment planning Flashcards
Outline the overall assessment stages? (from when you first see the patient)
C/0 HPC PMD PDH SH/FH E/O I/O
What is contained within the E/O?
You are checking for abnormalities as soon as you first see the patient. symmetry TMJ M.O.M Lymph nodes Smile
What does a high lip line mean?
When the patient smiles you can see the gingivae all the way up to the apex of the tooth.
What is the vermillion zone?
The sharp demarcation between the lips and the skin
Outline the steps in an I/O?
Checking of all the soft tissues Soft palate, hard palate, lateral border of the tongue, tongue and floor of the mouth. Perio - BPE Dentition - Charting of the teeth Occlusion - If GF or CG If the teeth retrude or protrude and their lateral movements. Incisal relationship. Inter arch and inter tooth space.
Special investigation?
Study casts photographs Radiographs Sensibility tests - EPT and thermal 6PPC Facebow
When are face bows utilised in fixed pros?
Facebows are important for any pros work involving the canines or where the vertical dimension is being altered.
Radiographic assessment?
Grade radiograph Tooth present Apical pathology bone levels Caries Large restorations and RCT Assess possible abutment teeth
What are the 5 stages of overall treatment planning?
IIRRM Immediate Initial (disease control) Re-elevaluation Re-constructive Maintenance
What treatment is carried out in the immediate phase of treatment?
Relief of symptoms
Consider endo
Consider immediate denture/bridge
What treatment is carried out in the initial phase of treatment?
OHI and diet advice HPT Ex of hopeless teeth management of caries and failed restorations endodontics denture design and wax-up for FP
What treatment is carried out in the re-evaluation phase of treatment?
Re-evaluation of periodontal status
Confirm denture/ bridge design
What treatment is carried out in the re-constructive phase of treatment?
Perio surgery (if OH is good) Fixed and removable prosthodontics
What treatment is carried out in the maintenance phase of treatment?
Supportive periodontal care and review of restorations
Why do patients need to have good OH before they can think about FP?
As if they don’t arrest the disease in the mouth and have good OH then the chances of restoration failure are much greater
Alternatives to FP?
Implants
Internal bleaching of teeth (colouration problem)
RPD
Why is over the preparation of a crown bad?
It weakens the tooth increases the chances of failure
Also increases the chances of pulpal damage or exposure.
What are the problems with under preparation of crowns?
Aesthetically won’t look as good and functionally will make it feel bulking in the mouth.
Also makes plaque control difficult as cleansing of the teeth isn’t as good.
What can you include in your design to increase retention of the crown?
Taper - 6’ on opposing wall
One path of insertion
grooves
Long walls
Name some key qualities of good crown margins?
Smooth and fully exposed to allow cleansing action
Should be clearly visible to the dentist to allow for any finishing and so the patient can easily clean.
Should be 0.5mm supragingival
Define biological width?
It is the Junctional epithelium + Connective tissue length about the alveolar crest.
What would happen if the margins of the crown encroached on the biological width?
There would be possible bone loss as the gingivae would become inflamed as an inflammatory response
Would also make it very difficult to clean this area
At what landmark does the tooth become unrestorable if caries reaches it?
The crestal bone.
The patient should be informed if they are close to this point and told about the poor prognosis.
For a crown preparation, what are the 3 types of reductions?
Axial
Occlusal (functional cusp)
occlusal (non-functional cusp)
Finishing line
What are the two main types of finishing lines?
Chamfer
Shoulder
What crown material is best suited for bruxists?
MCC
What material is worst for bruxists and why?
All ceramics are harder than tooth tissue and won’t be worn down but the opposing teeth will. Affecting the ICP relationship
When considering what crown material to use what should you consider?
Aesthetic (anterior or posterior)
Amount of tooth tissue reduction
If you’re a bruxist
Lip line
What kind of preps require the most amount of tooth reduction?
All ceramic -porcelain bonded to zirconia or alumina framework
What is the axial reduction on metal crowns?
0.5mm
What is the axial reduction on MCC?
1.5mm
