Problem Solving in Denture Design Flashcards
Why may you want to modify a survey line?
If not enough of an undercut on teeth you hope to clasp
What can be done to modify a survey line?
Add composite buccally to create more favourable survey line giving better undercuts for retention
Why is composite used when modifying survey lines?
Least invasive
-> Teeth can be crowned to alter survey line but this causes damage to teeth
What are the common types of precision attachments used when added retention of a denture is required?
Ball on post- for retained roots (may have to try coping first)- component on denture fits around ball and clips into socket (like implant retained denture but with real tooth)
Tube-locks can be added into crowns- denture slots in on certain POI
What are the issues with precision attachments?
Metal wears out
Attachment becomes loose in acrylic
Difficult to repair or replace
-> keep note of which ball and attachment that you use (order, reference numbers etc)
Tube locks are casts as integral part of Co/Cr denture
-> issue if these warp or become damaged
In what situations are 2 part dentures useful?
If there is gross soft tissue/bone loss due to resorption (periodontitis) and unaesthetic undercuts/defects
If there is different POI anteriorly and posteriorly
How do 2 part dentures work?
Co/Cr denture made for posterior region
Pins on anterior section slot into chrome (different POI) to replace teeth at front
What can be to alter acrylic to suit patients of different ethnicity?
Use minute stains to incorporate racial pigmentation
When are swing lock dentures used?
Kennedy class 1(when only anterior teeth remain)
and sometimes class 2
-> if poor undercuts on canines and survey lines cannot be modified
-> if denture with free end saddles not tolerated
Can be helpful if patient has prominent mandibular tori
How do swing lock dentures work?
Acrylic section engages bony undercut below labial surface of anteriors
Lingual bar is present
This clips around teeth and locks into place
What are the issues with swing lock dentures?
Demanding for technician
Good OH is essential- can contribute to caries and periodontal disease
What connector can be used for lingual tilted teeth? (Potentially due to mandibular resection)
Buccal bar
What can be done to make dentures better for bruxists?
Adding metal backings to teeth
Using Co/Cr- reduces fracture
Metal Occlusal surfacea
Cross-linked teeth (expensive)- better wear resistance
Acrylic post dam AND Co/Cr palate- improved retention, less chance of fracture at midline
What is the issue with bruxism in edentulous patients?
Can still cause fracture of the denture (typically down the middle) as they do not stop habit despite having no teeth
-> add metal backings to teeth (requires additional tooth trial stage)
