Tooth Wear Flashcards
Define “tooth surface loss”
the loss of tooth substance as a result of:
- caries
- trauma
- developmental problems
- tooth wear
what are possible causes of non-carious tooth surface loss?
- trauma
- developmental problems
- tooth wear
define “physiological tooth wear”
normal tooth wear associated with normal function of the dentition
define “pathological tooth wear”
- the remaining tooth structure or pulpal health can be compromised
- tooth wear occurring at a rate faster than physiological tooth wear
- wear that can cause the patient to experience a masticatory defecit
What are the 4 subcategories of tooth wear?
- attrition
- erosion
- abfraction
- abrasion
define “attrition”
the physiological wearing away of tooth tissue as a result of tooth to tooth contact
define “abrasion”
the physical wear of tooth substance through an abnormal mechanical process, independent of the occlusion
define “erosion”
the loss of tooth surface by a chemical process that does not involve bacterial action
define “abfraction”
the loss of hard tissue from eccentric occlusal forces, leading to compressive and tensile stresses at the cervical fulcrum of the tooth
On which tooth surfaces are attritive lesions found and why?
the occlusal and incisal surfaces of the teeth
- the wear facets occur where there is tooth to tooth contact
what is almost always the case of attrition?
a parafunctional habit, specifically bruxism
define “bruxism”
the grinding and clenching of teeth outwith normal function
What is an important distinction between erosive wear and attritive wear you can identify on the teeth?
any restorations will wear at the same rate as the tooth tissue in attrition, however erosion will mean that the restorations will sit proud of the eroded tooth surface
what are the most common areas to experience abrasive wear and why?
the labial/buccal cervical region of the crown
- this is because abrasion is usually caused by brushing too hard in these areas
What do abrasive lesions appear like and why?
they form V shaped notches in the tooth tissue with a sharp edge at the enamel as dentine is worn away preferentially (softer)
Apart from toothbrushing, what are other cases of abrasion?
- occupational links (nails in teeth, electrical wire stripping, sewing needles)
- pipe smoking
- dietary habits (chewing seeds and cracking hard foods)
- e cigarettes
- nail biting
what is the most common form of pathological tooth wear?
erosive wear
how does erosive wear appear in the early and late stages?
early = loss of tooth surface detail, smooth and flat tooth surface
late = bilateral concave lesions without the chalky appearance that is a result of bacterial acids. Exposed dentine worn faster than enamel leading to cupping of the tooth surface
Why may the incisal edges appear “dark” in erosive wear of anterior teeth?
the tooth structure is thinner, and therefore more translucent, which causes the darkness of the back of the mouth to be seen through the incisal edges
what are the 2 theories of how abfraction is thought to occur?
- it is the basic cause of all non-carious cervical lesions
- there is a multifactorial aetiology which is a combination of occlusal stress, abrasion and erosion
Describe the mechanics of how abfraction occurs
- biomechanical forces applied to the teeth cause flexure of the enamel at its weakest point
- this is the fulcrum area, at the cervical margin. as the tooth bends, more force it concentrated here
- this causes disruption of the ordered crystalline structure of the enamel and dentine, caused by cyclic fatigue
- the tooth will bend slightly when forced are applied and this will increase as the tooth weakens, causing tissue to wear away and break off
what 4 things must you do when assessing wear cases?
- recognise a problem is present
- grade the severity of the wear
- diagnose the likely cause or causes of the wear
- monitor the progression of the disease over time
what medical issues may be contributing to tooth wear in some patients?
- medications with a low pH
- medications that cause dry mouth
- eating disorders
- alcoholism
- heartburn
- GORD
- hiatus hernia
- rumination
- pregnancy (transient problem - morning sickness, heartburn and reflux)
what features of a persons past dental history are relevant to wear cases and why?
- what their previous attendance was like (regular attendance is key for engagement in often complex treatment of wear cases)
- dental phobia (again patient attendance and commitment)
- patient cooperation is key
- previous experience of treatment (can be quite complex to undergo)
- oral hygiene habits (is toothbrushing contributing to wear, do they have poor OH)
what social history factors are importatnt to assess in wear cases?
- Lifestyle factors- Stressful lifestyle more likely to have parafunctional habits
- Occupational details- Some occupations more prone than others to parafunction and bad habits causing wear- Taxi drivers, electrician, joiners, seamstress
- Alcohol consumption- Straight gin is the only non acidic alcohol
- Dietary analysis
- Habits and hobbies -Weight lifting and grinding
- Sports - Runners gels
What may you find in an E/O exam of a patient who has wear?
- TMJ issues (trismus from muscle spasm, crepitus, pain)
- MoM (hypertrophic and sensetive in parafunctional cases)
- trismus (deviation of the jaw and limited opening <4cm)
- swelling/asymmetry (parotid or muscular hypertrophy)
- overclosure (reduced tooth height)
- low lip and smile line as loss of crown height
What must be assessed in the I/O exam in a patient who exhibits signs of tooth wear?
The Occlusion
- FWS should be assessed
- Record the OVD and RFH (these are often normal as the wear happens really slowly and there is dento-alveolar compensation)
- Has there been dento-alveolar compensation
- Record the overbite and overjet
- Are there stable contacts in centric relation
- what are the tooth contacts like in excursive movement (can you re-establish canine guidance)
Soft tissue
- are they dry
- any signs of buccal keratosis or lingual sculpting
Oral Hygiene
BPE
dental charting
What should you record in regards to the presentation of tooth wear in the mouth?
- location (anterior, posterior, generalised)
- severity (enamel only, into dentine, pulp compromised)
- wear indice score (BEWE)
What do the BEWE scores range from?
0-3
BEWE score 0
no erosive wear
BEWE score 1
initial loss of surface texture
BEWE score 2
distinct defect with hard tissue loss on <50% of the tooth surface
BEWE score 3
hard tissue loss of more than 50% of the surface area of the tooth
What would equate to no risk from the BEWE scores?
less than or equal to 2
What would equate to low risk from the BEWE scores?
between 3 and 8
What would equate to medium risk from the BEWE scores?
between 9 and 13
What would equate to high risk from the BEWE scores?
14 and over
How is BEWE calculated for the whole mouth?
score each sextant and then add the scores all together
what are the 3 types of generalised tooth wear?
- wear with loss of OVD
- wear without loss of OVD but with space available
- wear without loss of OVD but with no/limited space abailable
what immediate treatment options are there for patients who present with wear and they are in pain?
- Sensitivity
- Desensitising agents
- Fluoride toothpastes
- Bonding agents (GIC) covering exposed dentine through wear
- Pulp extirpation
- If wear has compromised the pulpal health
- Can occur at a rate faster than tertiary dentine can form
- Smooth sharp edges
* Prevents trauma to the tongue and cheeks - Extraction
* Any non restorable, painful or non-functional teeth - TMJ pain
- Important in attrition
- Acute symptoms need to be controlled before pain gets worse
what can be used to take a baseline recording of a patients wear to monitor it over time?
- wear indices
- models
- clinical photographs
why is it key to monitor wear cases?
- to determine if wear is active/progressing or historic
- to monitor the rate of progression of the wear
- to monitor the effects of preventive regimes and patient complience
how can abrasion be prevented?
- Remove the foreign object or substance that is involved in causing the abrasive wear
- Change their toothpaste
- Change brushing habits
- Change habits (nail biting, wire stripping, piercing biting)
- simple RMGIC restorations in to the wear facets
- They can be placed with little to no tooth preparation
- The patient can then wear through the restoration rather than damaging their tooth
- Simple and effective measure for this type of cavity
- Evidence shows that RMGIC is the best first choice of filling for abrasion cavities, it appears to have the best survival rate
- Composite may look better but its higher modulus of elasticity means that its retention can be compromised
what restorative material is reccomended when restoring wear facets caused by abrasion and why?
RMGIC as it has a lower modulus of elasticity than composite so is more likely to bend and flex into to the cavity like tooth tissue to prevent abfraction
How can attrition be prevented?
- Parafunction is generally centrally mediated in response to life stressors
- Therefore, it can often be treated with:
- CBT
- Hypnosis
- Treatment Methods for Parafunctional Habits
- Splints are the most common treatment for parafunctional habits
- They work by being softer than teeth
- They can wear away in preference to the tooth substance, without causing damage to the opposing teeth
- May be used as a habit breaker
When are hard splints recommended for attrition cases?
- long term prevention and management cases
- More robust
- Can be used over a longer period as they don’t wear down as fast
when are soft splints reccomended when treating attritive wear cases?
when looking for where the heavy contacts are and where wear is concentrated
- Can be used as a diagnostic tool
- The splint will wear rapidly and show wear facets where the patient has been grinding the most
describe how a michigan splint works
- Is a type of hard splint
- Provides the ideal occlusion with even centric
- Has canine rise which helps to provide disocclusion in eccentric mandibular movements (canine guidance) (so all teeth disocclude when go into lateral excursion apart from canines)
In what wear cases should splints never be used and why?
erosive wear cases as the acids will get under the splint and remain in contact with the teeth causing erosive wear to occur much faster
What might you reccomend OR give to a patient who is experiencing erosion?
- Fluorides
- Pronamel toothpaste
- Mouthwashes
- Duraphat
- Desensitising Agents
- Not really prevention, more symptomatic relief
- F varnish
- Duraphat toothpaste
- Desensitising toothpastes
- Dietary Management
- Often the key to prevention of erosion
- Very important if the cause is a diet high in extrinsic acids
- Bad Habits
- Swirling drinks around the mouth
- Drinking from cans
- Rumination
- Eating a lot of fruit in a day
- Vegan diets are more acidic
- Sports drinks and gels
- Medical Management
- Control of gastric acids (GORD, reflux, hiatus hernia, pregnancy – beware PPI rebound)
- Xerostomia
- Anorexia and bulimia
how can abfraction theoretically be prevented?
- Assess the occlusion on teeth with abfraction lesions
- Consider occlusal equilibriation
- Dealing with occlusal contacts if they are heavy
- Fill cavities with a low modulus material
- RMGIC
- Flowable composite
What are the goals of active management of wear?
- preservation of whatever remaining tooth structure there is
- a pragmatic improvement of aesthetics
- a functioning occlusion
- a stable occlusion
what simple restorative work can be done for patients with wear?
- Covering exposed dentine
- Filling cupped defects
- Early stage, often temporary
what 5 factors does restorative treatment of maxillary anterior tooth wear depends on?
- the pattern of the anterior maxillary tooth wear
- inter-occlusal space
- space required for the restorations being placed
- quality and quantity of remaining tooth structure, particularly enamel
- the aesthetic demands of the patient
What are the classes of maxillary anterior tooth wear?
- Tooth wear limited to the palatal surfaces only
- Tooth wear involving the palatal and incisal edges with reduced clinical crown height
- tooth wear limited to the labial surfaces (unusual, might be from holding drinks under the lip or brushing too hard)
How is maxillary anterior wear treated in cases where there is adequate inter-incisal space?
- if the teeth wear rapidly there may be no time for alveolar compensation
- this can form an anterior open bite and increased overjet
- in these cases, there can be available space for restorations with no change to the OVD
- very rare but the easiest to treat
What is dento-alveolar compensation and why does it occur?
the growth of the alveolar bone in cases of wear to increase height and reduce inter-incisal/occlusal space to maintain masticatory function
What are the 5 factors which influence the active management of maxillary anterior tooth wear?
- The pattern of anterior maxillary tooth wear
- Inter-occlusal space
- Space required for the restorations being planned
- Quality and quantity of remaining tooth structure, particularly enamel
- The aesthetic demands of the patient
How is maxillary anterior tooth wear with inadequate inter-incisal space managed?
using the Dahl technique
- build up incisor teeth to prop open bite posteriorly
- 6 months time
- posteriors over erupt and anterior teeth intrude to create space for restorations
why are traditional fixed prosthodontics not always suitable in localised anterior maxillary tooth wear cases?
Traditional fixed prosthetic devices would theoretically provide space for traditional restorations, however:
- little tooth tissue is present to restore
- there would be poor retention of crowns due to short axial walls
- there is a good chance of pulpal damage upon preparation due to short clinical crowns
- new materials offer a better and more conservative approach nowadays
what are the 5 methods of creating space to restore worn teeth?
- increase the OVD using posterior restorations to build up teeth
- occlusal re-registration from ICP to RCP
- surgical crown lengthening (more creating tooth that space)
- conventional orthodontics
- the Dahl Technique
what are the benefits of the Dahl Technique?
- Relatively simple (compared to conventional crowns)
- Conservative of tooth substance
- Reversible
- Repairable
- Can be performed in a single visit
When would be the cutoff for success of the Dahl technique be and why?
if there is no movement of the teeth after 6 months or the patient is experiencing a lot of pain and discomfort then it is not going to work
what is the success rate of the Dahl technique?
90%
what factors would make a patient not suitable for the Dahl technique?
- Active periodontal disease
- Don’t want to overload the anterior teeth
- TMJ problems
- Post orthodontics
- Teeth will move again
- Bisphosphonate therapy
- Low turnover of bone
- Dental implants are present
- Existing conventional bridges
what 5 factors would be indicative that active managent of wear is needed?
- aesthetic concerns
- symptoms of pain or discomfort
- unstable oclcusion
- functional difficulties
- excessively fast rate of tooth loss
what are contra-indications for active management of maxillary anterior wear cases?
- short roots
- reduced periodontal support due to periodontal disease (overload teeth with the Dahl technique)
- a lack of remaining enamel - not a strict CI but makes restorations much more likely to fail
what is the “ring of confidence” in reference to?
a ring of enamel surorunding the entire tooth in wear cases which allows for better bonding and retention of composite build up restorations
what 5 factors influence how worn teeth can be restored?
- the pattern of tooth loss
- inter-occlusal space
- space requirements for the restorations to be used
- the quality and quantity of the remaining hard tissue, especially the remaining enamel
- the aesthetic demands of the patient
What simple treatment may be enough to prevent further progression of localised posterior tooth wear?
canine build up to restore canine guidance and posterior disclusion in excursive movements of the mandible
what information should you give to a wear patient before commencing treatment to ensure they have informed consent?
- Your front teeth will receive tooth coloured fillings to cover the exposed and worn surface to;
- Stop them wearing more
- Restore their aesthetics
- Restore their function
- Help any sensitivity
- This procedure will be carried out without the need for local anaesthetics
- We are not taking away any tooth tissue
- Any anaesthetic changes to the teeth will be an improvement to the teeth
- Your bite will feel strange for a few days and you may find chewing feels odd
- Only the front teeth will touch together but this is what we want
- Your back teeth will come back together over 3-6 months
- You will have to adjust to the new occlusion
- Over a week or so you will become accustomed to the new bite
- Initially you may need to cut food up much smaller and have a soft diet
- The change in the shape of the teeth may cause a lisp for a few days but this will improve
- Your teeth may be slightly tender to bite on but this will improve for a few days
- You may find you bite your lips or your tongue sometimes but this will improve as the occlusion adjusts
- If you have any crowns/bridges/partial dentures at the back of the mouth these will need to be changed or replaced
- They wont move the way we want the other teeth to
- Longevity of these restorations are good but there is a small potential for some restorations to de-bond or fall off
- But they can be easily replaced without damaging the tooth
- These restorations will require maintenance
- The margins of them require occasional polishing
- There may be some chipping
what are the 3 categories of generalised tooth wear?
- Excessive wear with loss of OVD
- Excessive wear without loss of OVD but with available space
- Excessive wear without loss of OVD but no space available
what specialist treatments may be done for patients with generalised tooth wear without loss of OVD and no space available?
- crown lengthening surgery
- overdentures
- orthodontics
What may be done for patients who have generalised tooth wear and limited space before definative restorations are placed?
- can involve re-organisation of the occlusion
- a splint should be considered as an increase in the occlusal face height is required
- most patients can tolerate this increase however
- the anterior and posterior teeth are restored at this new height
- if possible this should involve minimal preparation adhesive restorations
