Toothwear 1 Flashcards
physiological tooth wear
normal physiological process that increases with increasing age
approx 20-38um per annum
pathological tooth wear
tooth wear occurs if remaining tooth structure or pulpal health is compromised or the rate is in excess of what it should be at that age
can also be pathological if pt experiences a masticatory or aesthetic deficit
4 main causes of tooth wear
- attrition
- abrasion
- erosion
- abfraction
attrition
physiological wearing away of tooth structure as a result of tooth to tooth contact
signs of attrition
- found on occlusal & incisal contacting surfaces
- early appearance is a polished facet on a cusp or slight flattening of an incisal edge
- progression leads to reduction in cusp height & flattening of occlusal inclined planes
- can be shortening of clinical crown of incisor & canine teeth; more common anteriorly than posteriorly
causes of attrition
almost always related to a parafunctional habit i.e. bruxism
flat facets are present
restorations show the same wear in this case as tooth structure
abrasion
physical wear of tooth substance through an abnormal mechanical process independent of occlusion; it involved a foreign object or substance repeatedly contacting the tooth
causes of abrasion
site & pattern related to abrasive element i.e. buccal / labial surfaces most common & related to toothbrushing, cervical on canine and premolar teeth
usually V shaped or rounded lesions
sharp margin at enamel edge where dentine is worn away preferentially
can manifest as notching of incisal edges
related to habit/lifestyle/occupation i.e. biting nails, electrical wire stripping, fishing line, thread, pipe smoking
erosion
loss of tooth surface by a chemical process that does not involved bacterial action
it is the most common cause of pathological tooth wear and is increasing in prevalence
causes of erosion
chronic exposure of dental hard tissues to acidic substances which can be extrinsic or intrinsic
process of erosion
early stages enamel surface is affected with loss of surface detail, surfaces become flat & smooth
typically bilateral concave lesions without chalky appearance of bacterial acid decalcification
later dentine becomes exposed
preferantial wear of dentine leads to ‘cupping’ (dip in cusp tip) of occlusal surfaces of molars & incisal edges of anteriors
exact position & severity is dependent on source, type & frequency of acid exposure
restorations & erosion
restorations are not affected as the tooth dissolves around the restoration so this is good to tell the difference between erosion & attrition
appearance of erosion
increased translucency of incisal edges (can appear dark)
base of lesion not in contact with opposing tooth
amalgam & composite restorations stand proud of the tooth
no tooth staining present
maxillary & palatal are the most likely sites
abfraction
loss of hard tissue from eccentric occlusal forces leading to compressive & tensile stresses at the cervical fulcrum areas of the tooth
happens in bridges
causes of abfraction
pathological loss of tooth substance at cervical margin
caused by biomechanical loading forces
forces result in flexure & failure of enamel / dentine at a location away from the loading
disruption of the ordered crystalline structure of enamel and dentine by cyclic fatigue
this theory is based on engineering principles which demonstrates stress concentrations in these areas of the tooth during loading
identifying abfraction
v shaped tooth loss where the tooth is under tension
classically sharp rim at the ACJ
cervical wear
- probably multifactorial; overzealous tooth brushing
- lesions mainly in premolars & molars on buccal surface almost never lingually
- good OH & this wear pattern go together
- restorations in this area wear at same rate as tooth structure
epidemiology of tooth wear
increases with increasing age
common type in older pt is physiological
increase in prevalence of all ages in last 10+ yrs
increase not uniform
greater relative increase amongst young adults & children and this tooth wear is considered pathological
key questions to ask tooth wear case
- is there aesthetic impairment
- are there functional difficulties i.e. masticatory efficiency, biting of tongue or lips
- pain; relatively uncommon unless it is rapidly progressing / pulpal involvement
medical conditions that can influence tooth wear
particularly erosion
medication with low pH, medication that dries the mouth, eating disorders, alcoholism, heartburn, GORD, hiatus hernia, rumination, pregnancy, pt not always aware of reflux
upon EO exam of pt
- examine TMJ for restriction of movement, clicking, crepitus
- examine musculature for hypertrophy
- examine mouth opening for restriction (<4cm) and deviation during movement
- parotid hypertrophy
- overclosure
- lip line & smile line
examining pt occlusion
FWS should be assessed
record OVD & resting face height
has there been dento alveolar compensation
record OB / OJ
are there stable contacts in centric relation
what are tooth contacts like in excursive movements
tooth wear index
0 - no loss of enamel surface characteristics
1 - loss of surface enamel characteristics
2 - buccal, lingual, occlusal loss of enamel exposing dentine for < 1/3 of surface, incisal loss of enamel, minimal dentine exposure
3 - buccal, lingual, occlusal loss of enamel exposing dentine for > 1/3 of surface, incisal loss of enamel, substantial dentine exposure
4 - buccal, lingual & occlusal complete loss of enamel, pulpal exposure or exposure of 2ndary dentine, incisal pulp exposure or exposure of 2ndary dentine
BEWE
basic erosive wear examination
basically a BPE for erosive wear, recorded in sextants
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
risk level:
none = <2
low = 3-8
medium = 9-13
high = 14+
special tests used in tooth wear
sensibility testing
radiographs
articulated study models
intra oral photos
salivary analysis
diagnostic wax up
dietary analysis
