Occlusion for partial dentures Flashcards
RCP how to get
Tongue on roof if their mouth and bite together
Check their ICR and RCP before - are lower anterior different
interocclusal record should be
thin
occlusion
static relationship between the incising or masticating surfaces of the maxillary or mandibular teeth or tooth analogues (dentures)
intercuspal occlusion
ICP
The complete intercuspation of the opposing teeth independent of condylar position, sometimes referred to as the best fit of the teeth regardless of the condylar position
Tooth position, irrelevant to condyle position – can change throughout life with teeth extractions and restorations
retruded contact position
RCP
Guided occlusal relationship occurring at the most retruded position of the condyles in the joint cavities.
Condylar position, fixed in life (unless a condylar fracture), can guide the person into this relationship
index teeth
definition
Contacting facets of teeth in ICP
Enough meeting to give stable occlusion
Can be used to measure the quality of natural occlusion
ICP Vs RCP
index teeth
ICP - need sufficient index teeth
RCP - insufficient index teeth
ICP Vs RCP
occlusion
ICP - stable
RCP - unstable
ICP Vs RCP
throughout life
ICP - vary
RCP - most reproducible position
ICP Vs RCP
tooth or bone relationship
ICP - depends on tooth relationship
RCP - condylar position
ICP Vs RCP
relation to each other
ICP is more anterior to RCP (sometimes)
conforming to occlusion
Works best in a stable occlusion with sufficient index teeth
Ensure your prosthesis doesn’t alter the occlusion
* E.g. partial upper denture, before fit look at occlusion, place denture and ensure unaltered occlusion by denture
Usually use ICP
changing occlusion
Often occlusion is unstable and lack of sufficient index teeth
Often use RCP
* Only reproducible position available
Usually more challenging to record occlusion
recording occlusion so can
articulated study casts
when is it simple to record occlusion
sufficient teeth and index teeth - hand articulate or obtain an inter-occlusal record (more accurate)
when is it difficult to record occlusion
insufficient teeth (record blocks needed)
3 types of interocclusal record
bite registration paste (usually silicone paste)
wax wafer (modelling wax)
modified wax wafer (alminwax)
recording occlusion steps
record blocks (wax on wax/wirestrengthener/CoCr/Shellac)
modify block
* melt wax block and cut notches in wax
record occlusion
* more wax or bite registration paste
how to modifiy survey lines
Composite
Aim to be as non-invasive as possible
More difficult if have to crown teeth – greater tooth damage
why modify survery lines
2
Can give more favourable clasping
Improves denture retention
precision attachments for dentures
Relative rarely used
Many different types
Full range at Cendres et Metaux catalogue
E.g. Ball on post and diaphragm, Tubelock
technically demanding case – difficult to repair/replace
2 part denture
Useful when gross tissue loss & different paths of insertion
E.g. advanced perio at young age resulting in tissue loss
* Make chrome at POI for chrome, ignoring anterior saddle
* 3 split pins added
* Separately make teeth – covering bony defect with large flange, works as on different POI
Split pins on cobalt-chrome denture
Acrylic slots into pins on different path of insertion
swinglock dentures
Engages bone & tissue undercuts for retention
* Bilateral free end saddles mainly
* Unilateral free end saddle sometimes
Good oral hygiene essential
* Acrylic interdentally buccally
* Lingual plate on lingual side of remaining teeth
Technically demanding
connector option for lower partial denture in pt with lingually tilted teeth
buccal bar
denture options for bruxists
4
Metal –backing to teeth
* Need to know tooth position
* Try in important
Use of cross-linked teeth as better wear resistance
* £££
Cobalt-chrome reduces fracture
* Acrylic postdam increases retention (better peripheral seal)
Metal-occlusal surfaces
6 problem solving options for dentures
Modification of survey lines
Precision attachments
Two-part denture
Swinglock denture
Connector for lingually tilted teeth
Dentures for bruxists
* Toothwear is very common
