Special Technique CD Flashcards
What is denture security?
Combination denture retention and stability
What is denture retention?
Ability to resist force in axial direction - away from denture bearing tissue
How is retention achieved in complete denture?
Peripheral seal
Cohesion between denture and oral mucosa
SA denture bearing area
How is retention achieve in partial denture?
Tooth undercut
Cohesion between denture and mucosa
What can compromise retention of full denture?
Poor denture adaptation to underlying tissue
Unfavourable supporting anatomy
Dry mouth
Ingress air - lack posterior seal
What is unfavourable anatomy?
Fibrous ridge
Atrophic alveolus
What is denture stability?
Ability resist force displacing dentures other than axial - resistance lateral and antero-posterior movement
Key factor in denture stability?
Size and shape resiudal ridge
What is neutral zone?
Potential space for lips and cheek on buccal/ tonuge on lingual side –> space where forces between tongue and cheek/lips are equal
Keys to managing neutral zone?
Lower incisior/premolar should not be set inside ridge
Lower premolar not outside ridge
Molars shouldn’t be lingually inclided - tongue lift denture
How to identify relation of tooth on denture to case?
Candulor static pointer
Used at try in stage - shine light onto occlusal surface, remove denture and assess on model
Issue with tooth position in class III?
Anterior teeth can be retroclinced = edge-edge bite
May have bilateral cross-bite so lower molars sit on ridge
What happens in neutral zone encroached?
Musculature forces cause instability / denture to lift
Can record neutral zone?
Use heat cured base for lower registration block
Carry out normal registration so rims in contact as CR and correct OFH
Remove most wax anterior region - apply alignate adhesive
Replace missing wax w/ alignate
Place in mouth - occlude teeth and make ‘oo’ ‘ee’ sound to record
What does pre-centric mean?
Prior to first tooth-tooth contact during mandibular closure in CR
Aim pre-central check record?
Correct occlusal discrepancy so RCP=ICP
What intra-oral technique can be used for pre-centric check?
Place bite reg paste/wax bilateral on mandibular posterior teeth - mandible closed and stop prior first tooth contact
Most reliable way to do pre-centric check?
Gothic arch tracing - reduce operator error
What is BULL rule used for?
To get balanced occlusion in lateral excursion
Ideal tooth movement during lateral excursion?
Group function working side
Balancing contact non-working side
How to use BULL rule?
When adjusting working side ONLY ADJUST BUCCAL UPPER AND LINGUAL OF LOWER
Issues w/ full denture opposing natural teeth?
Increased risk of dislodgement during function
May be fibrous ridge
Most complex challenges when providing denture against natural teeth?
Complete lower denture against upper teeth
What impression take if fibrous ridge?
Mucostatic recording of fibrous ridge - use combination tray (space created)
What tray request if fibrous ridge?
Perforated spaced tray - allows material to flow reducing compression
How communicate technician fibrous ridge?
Use indelible pencil on primary imp
What impression material use for fibrous ridge?
ZoE
Can use light body silicone if very fibrous
