Temporary Dressings and Crowns Flashcards
If a therapist or hygienist places a temporary dressing, what must they do?
- have had appropriate training and competent to do so
- inform the patient and record it in the notes
- advise the patient of the treatment you have carried out, explain it is temporary and they will require an appointment for a permanent restoration
Why place a temporary dressing?
- restore appearance
- prevent sensitivity
- prevent food packing
- prevent sharp edges
- prevent bacterial contamination
- restore occlusion
- prevent damage to rest of tooth
- prevent gingivae growing into cavity
What temporary materials are available?
- zinc oxide eugenol
- polycarboxylate cement
- glass ionomer
Give some features of zinc oxide eugenol cements:
- poor abrasion resistance and soluble
- not for long term
- non-irritant to pulp
- obtundent effect on inflamed pulp
- tastes of oil of cloves
- white and opaque
- affects the curing of composite
- easy to mix, place and shape
What is unmodified zinc oxide eugenol and its properties?
Zinc oxide and eugenol:
- cheap
- not strong
- slow setting >24 hours
- seldom used
What is accelerated zinc oxide eugenol?
Zinc and magnesium oxide, zinc acetate and eugenol
- faster setting than unmodified (5 mins)
- not strong
e.g. Sedanol
What is resin reinforced zinc oxide eugenol?
Zinc and magnesium oxides, hydrogenated rosin + eugenol and polystyrene
- stronger than unmodified and accelerated
- sets within 5 mins
e.g. Kalzinol
What is polymer reinforced zinc oxide eugenol?
Zinc oxide and zinc acetate + eugenol and polymethyl methacrylate beads
- hardest ZnOE cement
- sets within 5 mins
e.g. IRM - Intermediate Restorative Material
What is polycarboxylate cement and its properties?
Zinc and magnesium oxides + polyacrylic acid (dehydrated)
- fluoride release
- good strength
- adheres to dry tooth substance
e.g. Poly F plus
What is glass ionomer and its properties?
Aluminosilicate glass + polyacrylic acid (dehydrated)
- releases fluoride
- bonds to dry tooth substance
- tooth-coloured
- good strength
e.g. Chemfill, Fuji
- Moisture control imperative necessary to protect using manufacturers varnish or vaseline
- susceptible to acid erosion - avoid fizzy drinks straight after placement
How do you place a temporary dressing?
- isolate with cotton wool rolls and saliva ejector
- remove any debris from cavity with an excavator or cotton wool pledget in tweezers
- dry carefully
- assess size of the cavity
- choose material
- mix enough material
- place material in cavity with flat plastic
- remove excess and shape
- check occlusion
What material can a therapist or hygienist use to recement a crown?
Temp bond - patient must be told this is a temporary cement, and an appointment with a dentist must be made
What types of crown may you come across?
How do you go about recementing it?
Jacket crown or post crown:
- clean out crown
- check the prep
- does the crown reseat easily
- can the patient go into occlusion
- load crown with temp bond
- seat
- recheck occlusion
- wait until temp bond sets
- remove excess cement
