Wear Part 2- Lecture 1 Part 2 Flashcards
What are the issues associated with lack of posterior support?
Increased severity of wear
Increased progression rate of wear
Occlusal collapse
Functional and aesthetic issues
Why do patients with tooth wear have a lack of posterior support?
Denture intolerance/refusal
-> less likely to wear dentures if no immediate aesthetic issue
Supervised neglect- removing posteriors and not replacing with dentures intentionally
Why may you want to avoid complete dentures in bruxism patients?
- Bruxism habit does not stop
- More likely to fracture
- More ridge resorption
- More pain and ulceration due to forces on mucosa
How can rehabilitation of a dentition be achieved?
Through fixed pros, indirect restorations and removable pros
-> slight increase in OVD often necessary
What removable prosthodontics is used in tooth wear cases?
Overdentures
Transitional dentures
Metal base dentures
Simplifying small saddles
What are overdentures?
Any removable prosthesis that rests on one or more remaining natural teeth/roots of natural teeth (and/or dental implants)
What are the advantages of overdentures?
- Cutting teeth down can even up occlusion and improve aesthetics
- Support- tooth and mucosal
- Tooth wear management esp if 2/3 of crown height loss (composite build ups will likely fail)
- Preservation of ridge form- for implants at later stage
- Proprioception- keeping roots keeps PDL (better sensation of food and chewing)
- Denture retention- roots gives better undercuts
- Precision attachments- keep simple to keep repair simple
- Avoids extractions if patient undergoing radiotherapy/MRONJ
- Psychological benefits
- Eases transition to edentulism
What are the disadvantages of overdentures?
- Fail in poor OH
- Increased caries and Periodontal problems
- Denture fracture- less material as they are thinner
- Discomfort/infection around roots- would need to be extracted in these situations (further complicated by medical condition)
- Carious root extraction can be more traumatic esp. if sub alveolar
How is prep for overdentures carried out?
- Cut roots down to gum level
- Put protective coating on teeth
What can be done to make over dentures fit better around roots?
Sectional reline
How should you approach planning for overdentures?
Decide on good and bad points of dentition
-> Keep robust roots- get rid of hopeless teeth
How is care for overdentures maximised?
Good oral hygiene
Fluoride toothpaste application to roots
Regular examinations & radiographs
-> Keep eye on bone loss, PA areas, RCTs
Denture hygiene
What is the purpose of transitional dentures?
Tests if patient with lack of posterior support can cope with dentures AND increased OVD
-> Allows space for restorations to be placed to increased OVD (dentures should increase OVD to the non-worn level)
What can be done to give some anterior tooth contact and keep occlusion balanced in transitional denture?
Add some tooth coloured acrylic to go over surface of worn anteriors
What is done once it is determined that the patient can cope with dentures and increased OVD?
Get rid of hopeless teeth
Place crowns/composite build ups with rest seats and undercuts at new OVD (unworn level)
Fit definitive dentures at same OVD
What can be done for bruxist patients with cobalt chrome dentures where the teeth keep fracturing off from saddles?
Extend metal onto the biting surfaces of the denture as a backing to strengthen it
What must be done before making the chrome complete with metal backings?
A tooth trial to confirm tooth position
What can be added to complete dentures to prevent bruxism patients from fracturing them?
CoCr bar in lower
CoCr backing and palate in upper
-> again tooth trial required before casting chrome
What is the issue with the chrome palate in complete dentures?
CoCr gives inadequate peripheral seal so most posterior part of the denture is made of acrylic
-> acrylic post dam
What is an overlay denture and its purpose?
Fits over teeth and gives them CoCr biting surface in order to protect teeth below and discourage wear of anteriors (if on posteriors)
- trial required before casting
What are the issues with small anterior saddles in bruxism?
Force of bruxist will cause small weak saddle to break off
-> aim to remove this
How can small saddles be simplified?
- Cantilever bridges can be used to fill these small saddle spaces
- Difficult with adhesive bridges- lateral or protrusive forces on pontic can cause debonding in bruxists
When does conforming to the current occlusion work best?
Stable occlusion with sufficient index teeth -> Ensure your prosthesis/restoration does not alter the occlusion
When does changing or rehabilitating an occlusion work best?
- In cases due to occlusal collapse there is no stable occlusion or sufficient index teeth
- Difficult to record occlusion- OVD needs to be decided on (generally we think about where teeth would’ve been before wear)
- In tooth wear the OVD will often need to be increased
What can help you decide where the OVD should be?
Look for any teeth/restorations that occlude at the old OVD still
What can be done if conforming but teeth are edge to edge?
Keep OVD the same but attempt to change to class 1 relationship with restorations
What are the issues with using many crowns to rehabilitate a dentition?
Destructive preparation
Risk of pulpal issues
Risk of caries around margins
What 2 interocclusal records should be taken when rehabilitating?
One at current OVD
One at planned increase in OVD
What are the steps that can be helpful in planning when conforming and changing?
Impressions & facebow
-> Mounted articulated casts on semi-adjustable articulator + or – surveying
High quality Interocclusal record – with & without increasing the OVD
Diagnostic wax up(s)
-> Stents – mock-up – temporaries (if indirect); for build-ups; aids consent
Temporary (transitional) dentures
Clinical photographs- before and afters
Radiographs
How are casts mounted?
Using Alminax and face-bow recording at OVD
-> diagnostic wax up can then be done
What is the Dahl technique?
Disclude posterior teeth by propping anteriors up canine to canine
-> Extrusion occurs and occlusion re-establishes itself
What should be done when carrying out a diagnostic wax up?
- Use as much of buccal surface as possible- enamel is better for retention of composite build ups (if increasing OVD- consider if palatal surfaces can be used for this too)
- Build up itself is best guess at how teeth would’ve looked pre-wear
What are diagnostic wax ups used for?
Wax-up is duplicated in stone
- Gives working cast to make stents- vacuum formed retainer (some people use silicone- which you can light cure through)
- We can put over initial cast to see how much teeth are being built up
- We can use stent and fill with protemp to give patient an idea what it will look like
What is it important that the patient knows before undergoing occlusal rehabilitation treatment for tooth wear?
Likely to be multiple long appointments for build ups
-> more if dentures required
Who can you seek advice from when treating tooth wear if the case is complex?
- Principle/trainer
- Restorative specialist
