Toothwear Flashcards
What is the difference between physiological and pathological toothwear?
Physiological toothwear is normal wear associated with function.
- roughly 20-38 microns per annum.
Pathological toothwear occurs if the remaining tooth structure or pulpal health is compormosed or the rate of toothwear is in excess of what would be expected for that age.
What is attrition?
Physiological wearing away of tooth structure as a result of tooth to tooth contact.
What intra-oral signs would suggest attritional wear?
Polished facet on a crisp of slight flattening of an incisal edge
Reduction in cusp height and flattening of occlusal inclined planes
Shortening of clinical crown and canine teeth
Restorations show the same wear as the tooth- both become flat.
Almost always related to a parafunctional habit.
What is abrasion?
Physical wear of a tooth substance through an abnormal mechanical process that is not related to the occlusion.
It involves a foreign object or substance repeatedly contacting the tooth.
- Toothbrush
- Tongue stud
- Interdental brushes
- oral self harm
- chewing pens
How does abrasion present intra-orally?
V-shaped or rounded indents at the cervical margin of teeth.
Usually labial/buccal area, cervical on canines and premolar teeth.
Sharp margin at enamel edge where dentine is worn away preferentially.
Can manifest as notching on the incisal edge.
Usually caused by a toothbrush.
What is erosion?
Physiological loss of tooth substance by a chemical process that doe snot involve bacterial action
- most commonly from acid in the diet or systemic acid reflux.
Can be extrinsic or intrinsic.
How does erosion present intra-orally?
Early stages- enamel surface is affected, loss of surface detail and surfaces become flat and smooth.
- typically bilateral, concave lesions without chalky appearance of bacterial acid calcification.
Later lesions- dentine becomes exposed, cupping of occlusal surfaces of the molars and incisal edges of anteriors.
- restorations aren’t affected- they will usually stand high of the occlusal surface.
Increased translucency of incisal edges.
Loss of staining- acid is stripping it away.
Base of lesion not in contact with opposing tooth.
Altered taste
Halitosis
Caries
Sensitivity
If someone presented with palatal erosion on their upper incisors, what would you think?
Probably more of a systemic cause- alcoholics, bullimics, GORD, acid reflux.
What is abfraction?
Loss of hard tissue from eccentric occlusal forces leading to compressive and tensile stresses at the cervical fulcrum area of the tooth.
Likely to be multifactorial.
How does abfraction present?
V-shaped tooth loss where the tooth is under tension- classically sharp rim at the ACJ.
What aspects of patient history will tell you about the possible aetiology of their toothwear?
Find out the chief complaint- is it aesthetics, functional difficulties, pain?
Detailed medical history
- GORD
- Hiatus Hernia
- Medication that has a low pH
- Eating disorders
- Alcoholism
- Heartburn
- Rumination
- Pregnancy
Past dental history
- Previous attendance
- Previous treatment history
- Oral hygiene habits- important to determine this if abrasive lesions are present.
- Frequency, intensity, duration and the of toothpaste.
Social history
- Lifestyle stresses- bruxism
- Occupational details
- Alcohol consumption
- Dietary analysis
- Habits
What aspects should be examined?
Full E/O examination- muscular hypertrophy, TMJ tenderness, limited mouth opening, clicking/crepitus noises, parotid hypertrophy, lip Line, smile line, overclosure.
Occlusion- OVD, RVD, freeway space, overbite, overjet, stable contacts in centric occlusion, guidance.
Examine the soft tissues- linea alba, tongue scalloping, wear signs on the teeth.
Location and severity of the toothwear.
What wear indices might you use to monitor toothwear?
Smith and Knight
- 0- no loss of enamel characteristics
- 1- Loss of surface enamel characteristics
- 2- buccal, lingual and occlusal loss of enamel, exposing dentine for less than 1/3 of the surface. Incisal loss of enamel and minimal dentine exposure.
- 3- Buccal, lingual and occlusal surface loss for more than 1/3 of dentine. Incisal loss of enamel, substantial dentine exposure.
- 4- Buccal, lingual and occlusal complete loss of enamel, pulpal exposure or exposure of secondary dentine.
BEWE-
- 0- no erosive wear
- 1- Initial loss of surface texture
- 2- Distinct defect hard tissue loss less than 50% of surface
3- hard tissue loss greater than 50% of surface area.
Cumulative BEWE score determines risk level and treatment need.
What special investigations might you want to do?
Diet diary
Sensibility tests
6PPC
Articulated study models
Diagnostic wax up
Clinical photographs
Radiographs
In terms of treatment planning for wear cases, what is the first thing you should do?
Determine a diagnosis and causative factor.
Then plan a preventative regime.
- Important to have a scheme to be able to monitor the wear as well.
What prevention can be done or abrasion?
Change habits- stop biting nails, alter tooth brushing habits, change toothpaste.
GIC, RMGIC or composite restorations cervically so the patient wears through the material and not the tooth structure.
- RMGIC recommended.
What prevention can be done for attrition?
Generally related to a parafunctional habit.
Hypnosis
CBT
Splint- Upper Michigan splint provides an ideal occlusion with even centric stops- has canine rise which provides discussion in eccentric mandibular movements.
Soft splints can be used as a diagnostic device.
What prevention can be done for erosion?
Fluorides
Dietary management
Referral to GP for further investigation
Use a straw when drinking something acidic
Sports drinks/gels
Eating lots of acidic fruit
Gaviscon, Omeprazole
What prevention can be done for abfraction?
Fill cavities with RMGIC or flowable composite.
Consider occlusal equilibration.
What are the goals of active management of toothwear?
Preservation of remaining tooth tissue
Improvement to aesthetics
A functioning occlusion
Stability
What factors determine decisions on treatment for maxillary anterior tooth wear?
Pattern of anterior maxillary tooth wear
Inter-occlusal space
Space required for the restorations being planned
Quality and quantity of tooth structure left
Aesthetic demands of the patient
What categories are there that describe patterns of maxillary incisal wear?
Toothwear limited to palatal surfaces only
Toothwear involving the palatal and incisal edges with reduced clinical crown height
Toothwear limited to labial surfaces
Under what circumstances might there be enough inter-incisal space to provide restorations?
AOB
Overjet
Teeth wear rapidly and there has been no time for alveolar compensation
In most toothwear cases, what happens to maintain masticatory efficiency?
Dentoalveolar compensation
- to combat the fact that tooth structure is being lost, there will be dento-alveolar bone growth to maintain masticatory efficiency.
This is a good thing but it leaves no space for restorations to be placed.
How could you make space for restorations?
Increase the OVD- multiple posterior extra-coronal restorations.
Occlusal reorganisation from ICP to RCP
Surgical crown lengthening
Elective RCT and post crowns
Conventional orthodontics.
Dahl technique
What is the Dahl technique?
Method for gaining space in cases of localised toothwear.
originally a removable CoCr anterior bite plane but can also use composite on the palatal aspects of the anterior teeth.
Results in posterior disclusion and increase in OVD by 2-3mm.
- Anteriors intrude
- Posteriors erupt
Results in space between upper and lower anteriors allowing restoration with no need for occlusal reduction.
What are the advantages of the Dahl technique?
Conservative of tooth substance
Reversible
Repairable
Performed in a single visit
Relatively simple
What cohorts of patients are not suitable for the Dahl technique?
Active periodontal disease
TMJ problems
Previous ortho treatment
Bisphosphonates
Dental implants present
Existing conventional bridges
If you’re thinking of restoring maxillary anterior wear with composite, what would you look for to influence your decision?
Quality and quantity of enamel that is left- look for the ring of confidence.
- circumferential enamel gives better prognosis for retention
Short roots
Reduce periodontal support due to periodontal disease- perio drifting can occur.
What is the aim in treating localised posterior tooth wear?
If erosive wear, the teeth can be built up in composite to the same dimensions.
You want to cause posterior disclussion during lateral excursions of the mandible- build up the canines.
- this will save the posterior teeth from future damage.
Normally there is canine wear which has caused group function to occur and led to posterior wear.
- by building the canine back up you are is-occluding the posterior teeth and regain canine guidance.
You are increasing the OVD by 2mm roughly.
How might you choose to build up teeth?
Free hand
Alginate impression- get the lab to pour the casts and then do a diagnostic wav up, putty matrix impression of this- use this as a stent.
Same as above but get the lab to make a vacuum formed splint to use as a stent.
Describe the process for how to make a putty matrix stent or a vacuum formed stent.
Impressions in alginate of the arch you are restoring.
Diagnostic wax up- start with the canines to create guidance and then do the incisors.
Take an alginate impression of the diagnostic wax up- pour the casts in 100% dental stone.
Take a putty impression of this or make the vacuum formed stent from this.
Describe th procedure for how you would build up an incisor tooth using a putty wax stent.
Apply LA is required
Apply rubber dam
place cellulose strips medially and distally to the tooth and through the stent
Etch the enamel for 10 seconds and then dentine for a further 10 seconds and wash off.
Apply stent
Bond applied to the incisal surface of the tooth and light cured for 20 secs
Place composite to recreate the palatal and incisal surfaces
Place wedges to ensure interdental contour and fill mesial, distal and labial.
Remove excess with high speed diamond bur and smooth with so flex disc in a mandrel.
Check occlusion.
Always do canines first to achieve canine guidance.
How would you explain to patients the idea of composite build ups?
Tooth coloured filling material will be used to cover the exposed and worn down tooth surface on your front teeth.
- prevent the teeth from wearing down any more.
No LA required
Bite will feel strange for a few days- only the front teeth will touch but your teeth will gradually come back together over 3-6 months.
Over the course of 1 week- you will get used to the new bite and be able to eat comfortably again.
May lisp
Front teeth may feel a bit tender to bite on for the first few days
May bite your lips and tongue initially
If you have crowns/bridges or partial dentures at the back of the mouth, these are likely to need to be replaced.
Composite can chip, debond and stain over time- this will come at a cost to you.
What 3 categories of generalised toothwear are there?
Excessive tooth wear with loss of OVD
Excessive toothwear without loss of OVD but with available space
Excessive toothwear with loss of OVD and no space available.
What is excessive toothwear with loss of OVD?
Toothwear that has happened very quickly, where there has not been time to allow for dentoalveolar compensation.
What should be considered for treatment planning of a patient with excessive toothwear with loss of OVD?
Splint- to assess the patient’s tolerance of the new face height or can provide an over denture for this purpose.
Ideally half of the OVD increase should be maxillary and half mandibular- even distribution.
Dentures may be required to provide posterior support at the new OVD.
What approach may be involved for excessive generalised toothwear with or without available space?
Re-organised approach
How would you increase the OVD in this case?
Splints/overdentures
Crown lengthening surgery
Elective endodontics
Orthodontics
What is crown lengthening surgery?
Used to increase the amount of coronal tooth substance.
May result in black triangles between the teeth where the interdental papilla are further down.
Can lad to unfavourable crown:root ratio- increased chance of tooth mobility.
Often post op sensitivity
Any subsequent crown preparation will be further down the root.
If you aren’t doing any active treatment, what must you do?
Record that you have recognised the toothwear
Explain to the patient
Monitor- Bewe, clinical photographs, study models
Preventative advice- must record this in the notes
What must you say to the patient to gain consent?
Explain diagnosis
Explain treatment options and the one you recommend
Pros and cons of all treatment options
They must understand their role in the treatment
Consequences of non-compliance
What modifying factors exist for attrition?
Lack of posterior support- anterior teeth are taking all the load
Bruxism
Stress and anxiety
Occlusion- deep overbite or edge to edge occlusion
Restorations- particularly if natural teeth are opposed by porcelain.
Erosion and abrasion in combination will make attrition worse
What are the common features of a bruxist?
Repeated failure of restorations
Multiple cracks around restorations
Multiple cusp fracture
Fractures in virgin teeth
Generalised attritive wear
Progressive- keeps getting worse
May also have muscle hypertrophy, TMJ pain, MOM tenderness, limited mouth opening.
Linea alba
Tongue scalloping
Evidence of lip biting
What are the extrinsic and intrinsic sources of erosion?
Extrinsic- carbonated drinks, high fruit diet, sports drinks, acidic sweets, pickles, drugs, alcoholic acidic drinks.
Intrinsic- GORD, eating disorders, Hiatus Hernia, Heartburn.
Modifying factors- lifestyle, amount and frequency, level of control.
What might you want to classify the toothwear as?
Progressive or non-progressive
Physiological or pathological
Localised or generalised
What preventative advice would you give someone with toothwear?
Toothbrushing advice
High fluoride toothpaste
Alcohol free mouthwash
CPP-ACP mousse
Diet advice- drink through a straw, reduce frequency, have it at meal times, dilute if possible.
- try drink more water.
- reduce sugary snacks and replace with appropriate.
Chew sugar free chewing gum to stimulate saliva
Why might someone have a lack of posterior support?
Lost teeth and didn’t want a denture
Lost teeth and couldn’t cope with a denture- denture intolerance
Supervised neglect
Why should you avoid complete dentures in bruxism patients?
The bruxism isn’t going to go away just because you have removed all their natural teeth.
There will be ulceration and pain on the mucosa where the denture is rubbing.
What is an overdenture?
Premovable prosthesis that rests on one or more remaining natural teeth, roots and/or dental implants.
What are the advantages of over dentures?
Restore function and aesthetics
Provide tooth support and mucosal support fo saddles
Toothwear management
preserve ridge form
Proprioception
Good in MRONJ patients
Psychological benefits- patient feels like they still have natural teeth
Useful in elderly patients
Eases transition to edentulism
Can be used to increase the OVD and provide posterior support.
What are the disadvantages of over dentures?
Need good oral health
Increased caries/periodontal problems
Denture fracture
Discomfort/infection
Potentially more traumatic extractions if caries becomes subgingival on roots.
What is required for the care of over dentures?
Denture hygiene
Oral hygiene
Fluoride varnish application to roots
Regular examinations and radiographs
What is a transitional denture?
Can increase the OVD in cases where poor posterior support to create space for restorations.
- patient wears the denture for a period of time, determine if they can cope with it at the increased OVD and then if they do then you can provide restorations at this new OVD.
- i.e. build the restorations or definitive denture up to the same OVD as the transitional denture.
What can be added to dentures to make them more resistant in bruxists?
CoCr backing- bring the metal up onto the occlusal surfaces of the teeth- more resistant to fracture than acrylic.
- can be done on anterior and posterior teeth.
Metal palate with acrylic post dam in a complete denture
Overlay denture with metal on the occlusal surface.
What are the advantages and disadvantages of using chrome backing?
Advantages- more resistant to fracture than acrylic.
Disadvantages- technically demanding and you need a wax trial before the framework. The technician needs to know exactly where the teeth are going on the framework.
How do you know how much to increase the OVD by?
Think about where the teeth would have been before they were worn down and use this as a guide to how much you need to increase the OVD.
What Pre-op investigations would you want to go prior to embarking on a toothwear case?
Clinical photographs
Sensibility tests
Measure OVD, RVD and freeway space
Mounted study casts on a semi-adjustable articulator with a face bow
Diagnostic wax ups- then impression of this to make a stent from.
Stents made for composite restorations
Radiographs
High quality interocclusal record - of the current OVD and then the OVD you wish to make the restorations to.
Why is tooth preparation difficult in toothwear?
Lack of occlusal-gingival height
Lack of occlusal space
Severely compromised teeth
What modifications can be made in toothwear cases to create retention and resistance in small teeth?
Metal on biting surfaces- metal is more ductile than porcelain so you want to use this in bruxists if you can.
- can still make the buccal aspect in porcelain but have the occlusal and plate in metal.
Grooves in the preparation of the tooth and can also incorporate this into a post- parallel them with the POI.
- Must radiographically assess the tooth first to determine where the pulp is.
Ensure adequate ferrule
Make preps more parallel- increases retention.
- this will compromise aesthetics because the metal ceramic will be made thinner, so the crown will look more opaque.
Metal backing of anterior crowns
Metal margins of a crown- means you don’t need to take as much tooth tissue away in this area.
Surgical crown lengthening surgery- will increase SA for bonding crown to and more area for prep.
Electrosurgery of the gingivae- remove some of the gingivae.
What is dental demolition?
Demolition of restorations.
This is common in toothwear because restorations fail- heavily restored, exposed to repeated failure, so less tooth substance left to work with.
What factors should you consider in dental demolition?
Risks vs benefits
Be honest with the patient about the risk of failure and that restorations are likely to require to be replaced.
Can you achieve health and aesthetic objectives?
Adequate dental health risk assessment
Valid consent
Before removing a restoration, what must you do?
Make the patient aware that you aren’t sure what you will find underneath the restoration, it may not be restorable once it comes off- may need to be extracted.
Take pre-op impressions for a temp denture if required.
How would you dismantle a crown?
Vertical cut on the buccal side
Instrument into the cut and twist the crown off.
- superfloss under the bridge to protect the airway, high volume aspiration, dental dam.
May have to cut into the occlusal or palatal surface.
Assess the margins, caries, status of core once it is off- is it restorable?
If it is porcelain- diamond cutting bur
If it is metal- gold cutting bur
In problems cases, what could you use to dismantle a restoration?
Sliding hammers with matrices
Use enamel chisel
What factors would you consider when thinking about removing a post?
How easy is it going to be to remove the post?
- How long is the post?
- How much root dentine will be left?
- How much coronal dentine will be left?
- How long is the root?
- PA pathology
- Bone loss- mobile teeth are more difficult to remove posts
- Taper of the post
Risk of fracture to the tooth
What can be used to remove a post?
Extraction forceps
Post bur
What is a failing dentition?
Dentition where deteriorating teeth, restorations or oral health or a combination of issues means a loss of adequate basic oral functions such as mastication and acceptable aesthetics is inevitable if untreated.
What prevention should be done in the failing dentition?
Individualised OHI
Individualised diet advice
Fluoride regime
Habit advice- smoking, alcohol, nail biting
Assess response to this advice before embarking on advanced treatment
Describe the protocol for giving patients bad news.
SPIKES
Set up the interview- mental and physical preparation
Perception- assess what the patient knows about the medical situation
Invitation- ask how much they want to know
Knowledge- give the medical facts
Emotion- respond to patients emotions
Strategy and summary- negotiate a concrete follow up step
