Assessment and Planning of the Edentulous Pt

Question 1

What does evidence suggest the best tx is for the edentulous mandible?

Answer 1

In the mandible a conventional denture is no longer the most appropriate choice for prosthodontic tx - but a 2 implant overdenture should become the first choice of tx for edentulous mandibles

Question 2

Indications for progressing to implant retained overdentures on the NHS?

Answer 2

Instability despite a well adapted set of dentures
Denture intolerance - gag reflex (reduce palatal coverage)
- Ongoing pain with well adapted dentures

Question 3

Clinical assessment of the edentulous patient for implants?

Answer 3

Denture:
In place:
- Ridge adaptation
- Margins - if underextended and overextended = instability
- Occlusal stability
- Overclosure
= If not suitable fit = remake denture
Outside the mouth
- Assess denture thickness: thickness for locator housing, supragingival component of locator abutment and overlying denture = minimum of 8.5mm from tip of teeth to fitting surface of denture (if do not have this = risk of hole in denture where abutment is coming through) 

Mandible
Residual ridge: enough for implant?
- Buccolingual width
- Variation in crestal contour (may limit available space for denture, may need to be addressed surgically)
- Mentalis insertions and exostoses = prominences from mentalis insertion = more bone here = no room for denture flange = denture causes an ulcer
- Mental nerve: risk of damage? - influences how far distal implants can be placed, superficial mental foramen may make a crestal incision a risk of nerve injury

Denture vs mandible - see if they are in harmony with eachother - may still be problem if they do not with implants
- Do neutral zone and residual risk coincide?

Radiograph assessment

• OPT
• If concerned about thickness of mandible = CT scan

Question 4

What are the minimum space requirements for a: bar attachment, ball attachment and locator attachment?

Answer 4

Bar attachment: 15mm
Ball attachment: 10mm
Locator attachment: 8.5mm

Question 5

What is a healing abutment replaced with?

Answer 5

A locator abutment

Question 6

What locator pressing pack inserts are used for retention?

Answer 6

Blue insert (lightest), then pink if not enough retention, then clear insert if not enough retention

Question 7

What is the function of an O-ring?

Answer 7

Goes around neck of locator abutment to protect it