Prosthodontics Flashcards
(48 cards)
What does RPI stand for?
R- Mesial Rest
P- Proximal guide plate
I- Gingival approaching I Bar clasp
What is the mechanism of action for an RPI?
On loading- clasp and proximal plate disengage
-> Clasp moved down and forward
-> Place moves into undercut
Relieves pressure/traumatic torque
What radiographic views can be used to asses position of an unerupted tooth?
OPT and occlusal- vertical parallax
2 PA- horizontal parallax
What complications can arise when extracting unerupted premolar tooth in very resorbed denture bearing area in a patient with OP?
MRONJ- if patient on bisphosphonates
Nerve damage
Jaw fracture
Pain, bleeding, bruising, swelling, infection, dry socket
When are the aspects to consider when designing a replacement complete lower denture, with partially erupted tooth to be kept in situ?
Extension
Support and stability
Retention
Occlusion- FWS, OVD, RVD, occlusal and incisal planes
Comfort- relief around partially erupted tooth, soft lining
Appearance- tooth shape, shade, mould
Speech- ensure patient can speak
What measurements are required for a lingual bar?
8mm in total
-> 3mm below gingival margin, 4mm height of bar, 1mm clearance to functional floor of mouth
What is the method of producing a new denture of the same spec?
Replica method
How can a loose denture be adjusted?
Reline- soft and hard
Rebase
Remake
What should you check at the try-in stage?
LIMBO
ESROCAS
What is retention?
Resistance to vertical displacement
What is stability?
Resistance to lateral displacement
How are upper complete dentures retained?
Muscular
Extension into sulcus
Adhesion and cohesion
Post dam
What is biometric guidance when setting upper and lower teeth?
Aim to place teeth in pre extraction sites
Maxillary teeth placed buccally to the ridge promotes lower denture stability
Mandibular teeth placed over the ridge
-> palatal cusps of uppers occlude with fossa of lowers
-> forces are appropriately directed
-> reduces tongue restriction
What are the aetiological factors involved in Denture stomatitis?
Poor denture hygiene
Dentures worn at night
Immunocompromised patient- diabetes
Deficiency
Old dentures
How is Denture stomatitis managed?
Take denture out at night
Clean denture with a soft brush
Steep denture- Milton (3 x 30 mins per week- not chrome)
Chlorhexidine mouthwash
Use of nystatin or fluconazole
Consider making new denture
Consider deficiency/disease that may be underlying- diabetes or haematinic deficiency
How do you restore FWS in very worn dentures?
What issue is caused by complete upper denture occluding against partial lower?
Combination syndrome- results in flabby ridge
What occurs in combination syndrome?
Bone loss from the anterior part of the maxillary ridge
Hypertrophy of the tuberosities
Papillary hyperplasia in the hard palate
Extrusion of the mandibular anterior teeth
-> Bone loss under the opposing denture base
How is flabby ridge managed?
Mucostatic impression technique
Removing fibrous tissue- less denture bearing area
Implant retained denture
What is Kennedy classification 2 modification 1?
Unilateral free end saddle with additional bounded saddle
What are the steps in the system of design used in designing partial dentures?
- Saddles
- Support
- Retention
- Bracing/reciprocation
- Connectors
- Indirect retention
- Simplification
What are the advantages and disadvantages of upper horseshoe connector?
ADV
* Wider so can be thinner
* Comfort- less edges
* Doesn’t cover any more gingival margins than full coverage
DIS
* Not as rigid
What are the ADV/DIS of upper ring connectors?
ADV
* Palate free for sensation
* Strong
* Posterior bar can act as main connector allowing anterior to be thinner
DIS
* More edges
* Difficult impression
* Less support for FES
What are the ADV/DIS of lingual plates?
ADV
* Thinner
* Provides indirect retention
DIS
* Covers gingival margin and cingulum
