4 - Wear Flashcards
What is defined as tooth surface loss?
- caries
- trauma
- developmental problems
- tooth wear
What is physiological tooth wear?
- normal process that increases with age
- estimated normal tooth wear is 20-38um a year
What is pathological tooth wear?
- remaining tooth structure and pulpal health is compromised
- tooth wear that is in excess of what wold be expected for the age of the patient
What are the different types of tooth wear?
- attrition
- abrasion
- erosion
- abfraction
Define attrition.
Physiological wearing away of tooth structure as a result of a tooth to tooth contact
Describe how attrition presents.
- lesions are on the occlusal and incisal surfaces
- early appearance as a polished facet on cusp or slight flattening of incisal edge
- progression leads to reduction in cusp height and flattening of occlsual incisal planes
- anterior crown height is reduced
- restorations wear at the same rate as tooth tissue
- wide lateral excursion
What causes attrition?
Parafunction and bruxism
Define abrasion.
Physical wear of tooth substance through abnormal mechanical process independent of occlusion. It involves a foreign object or substance repeatedly contacting the tooth.
Describe how abrasion presents.
- site and pattern of tooth loss is related to abrasive element
- most common area is labial/buccal and cervical
- v shaped or rounded lesions
- sharp margin at enamel where dentine is worn away preferentially
What causes abrasion?
- tooth brushing
- habits including holding items between the teeth (pins, pipe, fishing line, thread)
- cracking nuts with the teeth
What impact does vaping have on abrasion?
- holding the vape between the teeth can cause abrasion
- the vape liquid is acidic so speeds up the process
Define erosion.
Loss of tooth surface by a chemical process that does not involved bacterial action.
What is the most common type of tooth wear?
Erosion
Describe how erosion presents.
- early stages the outer enamel surface detail is lost
- bilateral concave lesions that are shiny (unlikely chalky carious lesions)
- as progresses, dentine is exposed and is preferentially eroded leading to cupping of occlusal surfaces and incisal edges of anteriors, base of lesion does not contact opposing arch
- restorations do not dissolve
- no staining
What causes erosion?
- acidic drinks (also - alcohol)
- eating disorders
- medications (low pH or xerostomia)
- GORD
- rumination
- pregnancy
Define abfraction.
Loss of hard tissue from eccentric occlusal forces leading to compressive and tensile stresses at the cervical fulcrum areas of the tooth
Describe the forces behind abfraction.
- biomechanical loading forces which result in flexure and failure of enamel at a location away from the loading
- disruption in the crystalline structure of the enamel by cyclic failure
- cracks can cause tooth structure to chip away
Describe how abfraction presents.
- v shaped lesions at cervical margin where the tooth is under tension
- sharp margin at ADJ
Describe the patient demographic would experiences abfraction.
- only seen in patient who have a clean mouth
- abfraction occurs in combination with abrasion
- abrasion begins lesion which is made worse but the cyclic forces
What is involved in the assessment of tooth wear?
- accurate diagnosis is essential
- recognise risk factors eg diet
- grade the severity
- monitor progress of disease
- provide preventative measures
Do patients with tooth wear typically report pain?
Uncommon unless rapidly progressing or pulpally involved
What functional difficulties are reported by patients with tooth wear?
- typically that teeth are sharp (biting lips/cheeks)
- masticatory efficiency
How does PDH impact tooth wear treatment planning?
- wear treatment requires multiple visits so compliance is important
- OHI and education vital
What should you assess in the EO exam?
- TMJ for restriction of movement, clicking, crepitus
- hypertrophy of musculature
- opening for restriction/deviation
- overclosure
- lip line
- smile line
What should assess about the patient’s occlusion?
- freeway space
- OVD and RVD
- any dento-alveolar compensation?
- overbite and overjet
- stable tooth contacts in occlusion
- excursive movements
What is dento-alveolar compensation?
Teeth continue to erupt to maintain occlusion with opposing arch (more common in upper)
What should you assess in the IO exam?
- xerostomia (more susceptible to erosion)
- buccal keratosis or lingual scalloping (parafunction)
- OH
- perio assessment and charting
What should you assess when looking at the tooth wear?
- location
- localised vs generalised
- severity
What is the most common distribution of tooth wear?
Localised anterior
What causes localised posterior toothwear?
Associated with rumination
What are the different wear indices?
- BEWE
- Smith and Knight
What are the scores of the BEWE index?
0 - no erosive wear
1 - initial loss of surface texture
2 - distinct defect (hard tissue loss < 50% of surface)
3 - hard tissue loss > 50% of surface
What does BEWE stand for?
Basic erosive wear examination
How does the BEWE function?
Cumulative score of all sextants decides treatment and risk level
What is the score for no risk level with the BEWE index?
Less than or equal to 2
What is the score for a low risk level with the BEWE index?
3 - 8
What is the score for a medium risk level with the BEWE index?
9 - 13
What is the score for a high risk level with the BEWE index?
14+
What special tests can be utilised when planning wear treatment?
- sensibility testing
- radiographs
- articulated study models
- photos
- diagnostic wax up
- dietary analysis
What should you assess on radiographs?
- associated apical pathology
- if 1/3 crown lost, assess proximity to pulp
