PRS02 - Lecture 3 - Replacing Missing Teeth Flashcards
What should be the first option for patients with missing teeth? (2)
No treatment
If the patient is happy to leave it and it doesnt affect quality of life
What is the shortened dental arch approach? (2)
When the patient has 10 pairs of occluding teeth
Replacing the missing teeth may cause more problems than it solves
What are the 3 indications for replacing missing teeth?
Aesthetics
Function - cutting food (anterior), grinding food (posterior), speech
Close gaps - prevent instability, drifting, or over-eruption of opposing teeth
What are the 7 methods of replacing missing teeth?
No treatment
Acrylic denture
Colbalt-chrome denture
Minimal preparation bridge
Conventional bridge
Compound bridge
Implant
What are the advantages of replacing missing teeth? (7)
Aesthetics
Function
Occlusion
Speech
Periodontal splinting/orthodontic retention
Feeling of completeness
Restoring OVD
What are the disadavantages of replacing missing teeth? (4)
Damage to pulp + adjacent teeth
Plaque retention -> ↑ risk of caries + periodontal disease
Cost - expensive
Time consuming -> no. visits + uncomfortable (i.e. surgical procedure)
Explain the importance of the verbal history when replacing missing teeth (6)
Complaints Of (C/O)
Aesthetic or Functional
Medical History (MH)
Allergies (i.e. alginate)
Dental History (DH)
Caries risk
Motivation
Family History (FH)
Reason for loss of teeth (i.e. periodontal disease or caries)
Intra-oral (I/O)
Individual teeth for abutments (dentures + bridges)
Saddles (implants + denture support)
Mucosal support (acrylic denture)
Tooth support (cobalt-chrome denture)
Shape of ridge
Occlusion
Investigations
PA radiographs - perio + endo status of abutment teeth
Occlusion -> produce study models + check space available for replacing teeth
What needs to be stablised before treating missing teeth? (3)
Diet
OHR
Periodontal disease + caries
What are the advantages and disadvantages of a removable partial denture? (5:3)
Advantages (5)
Most conservative prosthesis
Keeps space open between adjacent teeth (prevent drifting + functions as provisional)
Maintains bone levels (via masticatory forces)
Relatively cheap
Easy to clean
Disadvantages (3)
↓ Retention (compared to fixed options)
Plaque retentive (i.e. covers palatal aspect)
Makes people self-consious (young)
What are the 2 types of partial denture? (3:5)
Acrylic (3)
Likely to cover whole palate -> ↑ retention
↓ Hygiene (plaque + food trap)
↑ Risk of periodontal disease + caries of sound teeth.
Cobalt-chrome (5)
Strong in 3 cross sections -> ↑ retention
Saddles and flanges are made from -> acrylic
Rest seats need to be placed on abutment teeth (in this case canines)
↑ invasive -> tooth needs to be prepped (i.e. rest seats)
↓ aesthetics - I bars may be able to be seen (anteriors)
What are Bridges?
Fixed prosthesis used to replace one or more teeth by sticking the artificial tooth/teeth -> adjacent natural teeth.
What are the 3 materials that can be used for bridges?
Metal -> least destructive, strong and cheap.
Ceramic -> aesthetic, small spans, breakability.
Metal-ceramic -> strength + aesthetics
If the missing teeth is caused by trauma (i.e. sports related) – why is ceramic bridges the best option? (3)
Ceramic bridges are more weaker (↑ breakability)
↓ strain on abutment teeth
↓ chances of fracturing roots of abutment teeth from recurrent trauma.
What criteria does the patient need to fit before a dental bridge can be placed? (3)
Low BPE
Good OHR
Strong + vital abutment teeth
Define terminology used for bridges
Abutment
Retainer
Pontic
Span
Pier
Unit
Connector
Abutment = tooth to which a bridge is attached
Retainer = crown, or restoration, that is cemented to abutment
Pontic = artificial tooth that’s part of a bridge
Span = space between natural teeth
Pier = abutment tooth standing between and supporting 2 pontic (each pontic with a further abutment)
Unit = retainer or pontic when applied to bridge.
Connector = connects a pontic -> retainer or 2 retainers to eachother. (can be fixed or moveable)
Describe Minimal Preparation bridges (8)
1) Unrestored or minimally prepared abutment teeth (for cingulum rests, guide planes, utilise as much of palatal/lingual surfaces).
2) Pontic has a metal wing that is bonded superficially (i.e. enamel) to palatal/lingual surface of abutment teeth.
3) Using resin cement (thus the abutment has to be etched)
4) However – it is crucial that the abutment tooth is: (6)
Vital
Upright (to allow axial loading)
Sufficient attachment levels + root support
Edentulous area needs to be sufficient width (to fit pontic)
Need to clear inter-occlusal splace
Prepare palatal abutment teeth to provide space for retainer
Describe Conventional bridges (1)
Extensive crown peparations on abutment teeth (to retain bridge)
Describe fixed-fixed bridge design (6)
1) Used when you have parallel abutment teeth
2) Made up of a minimum of 3 units (rigid connector at each end)
3) Abutment teeth rigidly splinted + preparations must be parallel
4) Retainer should approximately have same retention
5) Occlusal surface of abutment must be fully covered.
6) Not indicated for short spans -> large amount of teeth need to be removed.
Describe fixed-moveable (4)
1) Used when it is difficult to obtain parallel abutments.
2) Made up of :
Major retainer with rigid connector (distal end of pontic)
Minor retainer with moveable connector (on mesial abutment) -> allows vertical movement.
3) 2 parts are cemented separately
4) More expensive than fixed-fixed
Describe Cantilever bridges
1) Most common design for minimal preparation bridges.
2) Made up of:
One retainer that is attached to one abutment (distal) tooth
3) Good when the other abutment tooth is being used for another prosthesis (i.e. denture).
What are the 4 different types of pontic designs?
Hygienic (wash-through) pontics -> no contact with soft tissues -> easiest to clean but ↓ aesthetics (cant be used on anteriors)
Bullet shaped -> slightly makes contact with alevolar ridge but not tooth shaped (limited to areas where the gingival third of the tooth doesnt show.)
Saddle/ridge concave -> largest area of contact with soft tissues, best aesthetics (used for anteriors + posteriors) but hardest to clean.
Ridge-lap (modified ridge-lap) -> Buccal surface looks like natural tooth. Lingual/palatal surface cut away (convex) making it easier to clean.
What is a Rochette design? (4)
Part of the minimal preparation bridge
The metal retainer has holes (perforated)
Composite is placed in the holes and laps over the edge -> ↑ mechanical retention
It was a historical concept prior to the development of adhesive cements
