Removable Prosthodontics Flashcards
Which areas of anatomy provide support for upper and lower partial dentures?
Upper - Hard palate and Residual ridge
Lower - Buccal shelf, residual ridge, and retromolar pad
Outline the Kennedy classifications for removable partial dentures.
Class I = bilateral free end saddle
Class II = unilateral free end saddle
Class III = unilateral bounded saddle
Class IV = anterior bounded (crossing the midline)
What is the purpose of placing rests on anterior teeth when designing RPDs?
Bracing and indirect retention
What is the purpose of cutting rest seats?
Provide direct retention
Provides bracing and reciprocation without interfering with occlusion
What types of clasps can be used on premolars?
Gingivally approaching I-bar
Modified T-clasp
Circumferential clasp
What type of clasps can be used on molars?
Occlusal single arm clasp
Occlusal circumferential clasp
Occlusal ring clasp
What are the constituents of greenstick?
Rosin, carnauba wax, talc, stearic acid.
What is an RPI system?
A stress relieving clasp system which is used in free end saddle
designs to prevent stress on the last abutment tooth and can also
provide reciprocation.
How does an RPI work?
The rest mesially acts as an axis of rotation. As the proximal plate and I
bar rotates downwards and mesially around the axis of rotation during
occlusal load. The I bar and proximal plate disengage from the tooth/
undercuts, thus avoiding potentially traumatic torque.
Patient presents unable to tolerate new dentures having worn the old ones for 20 years, the have become loose over past 18 months were replaced.
What differences might there be between the old and the new dentures?
OVD May have changed
Path of insertion may have changed
Flange extension can be different
Palatal extension can be different
Tooth shade and shape may be different
Tooth wear may have occurred over time
Patient presents unable to tolerate new dentures having worn the old ones for 20 years, the have become loose over past 18 months were replaced.
What technique could be used to ensure he would tolerate the new denture?
Replica technique
Patient presents unable to tolerate new dentures having worn the old ones for 20 years, the have become loose over past 18 months were replaced.
Other than replacing the denture, what could have been done to improve the fit of his old dentures?
Reline the dentures with soft/hard lining material
Rebase the dentures.
What are the constituents of alginate?
Calcium sulphate, sodium phosphate, various salts of alginic acid (from brown seaweed).
What impression materials are used for primary impressions in complete
denture cases?
Impression Compound - heat reversable non-elastic material
Alginate - elastic irreversable hydrocolloid material
Why should gingival clearance be considered when designing an RPD?
Less irritation
Easier to clean gingival tissues
Better compliance
