is wear a pathological process?
no it occurs whenever surfaces move together in contact or with an intervening slurry
it is pathological when it occurs to a greater extent.. even excessive wear does not always cause problems
wear can be either?
mechanical or chemical
diagnostic sign of surface to surface wear =
surfaces fit together when teeth move into lateral excursions
worsens when teeth rub against one another under pressure as in bruxism
mastication is ________ a surface to surface process
NOT
what is slurry wear?
occurs when there is an intervening abrasive slurry between the moving tooth surfaces
dx: tooth surfaces do not fit together during excursive movements
what is corrosive wear?
effects of non bacterial
acid induced tooth loss
not a wear process in its own right
the sources of acid are extrinsic and intrinsic
there may be no signs of erosion because the process may just potentiate the other wear processes
patterns of mechanical wear (4)
anterior tooth wear greater than posterior tooth wear
progressively greater wear on anterior teeth
wear on facial surfaces of cuspids and premolars
wear in variable locations primarily occlusal and incisal surfaces
causes of anterior tooth wear greater than posterior tooth wear
inadequate posterior support, traumatic anterior occlusion
causes of progressively greater wear on anterior teeth?
bruxism
causes of wear on facial surfaces of cuspids and premolars?
excessive tooth brushing
causes of wear in variable locations primarily occlusal and incisal surfaces?
parafunction, job requirements, habitual behvaiors
patterns of chemical wear?
anterior surface loss greater than posterior surface loss
posterior surface loss greater than anterior surface loss
variable locations (medications with acidic pH, ecstasy, cocaine, xerostomia, occupational hazards)
causes of anterior surface loss greater than posterior surface loss
chronic vomiting - lingual of max anterior teeth
GERD
alcoholism
citrus fruit- sucking
how does anterior surface loss greater than posterior surface loss appear?
chamfer like defects on max anterior lingual surfaces, max posterior palatal surfaces
islands of restorative material
cuppingof enamel
causes of posterior surface loss greater than anterior surface loss
dietary - acidic foods and drinks
soda swishing
can see cupping and crating of occlusal surfaces
greatest loss seen where with posterior surface loss greater than anterior surface loss?
mandibular 2nd premolars and 1st molars
if posterior surface loss greater than anterior surface loss as a result of chemical wear shows even cupping/ cratering on occlusal of max and mand posterior teeth what is suspected?
fruit mulling
extreme wear is usually caused by a combination of etiologic factors or just one?
combination
gradual tooth wear is compensated by what?
passive continuous eruption of the dentition
accelerated tooth wear may outpace passive eruption leading to what?
loss of vertical dimension
how to restore patients with excessive wear with loss of VD?
provisional restorations for 2-3 months to confirm stable, healthy occlusion and esthetically pleasing dentition
final restorations are placed at the end of the provisional period
how to restore patients with excessive wear without loss of VD but with restorative space?
continuous eruption has maintained VD
placing these patients in CR often allows for equilibration and/or restoration of posterior teeth coupled with select enameloplasty of opposing dentitions
crown lengthening can yield sufficient tooth wall lengths for
how to restore patients with excessive wear without loss of VD but with limited restorative space
minimal posterior wear and excessive gradual anterior wear
needs multidisciplinary approach to tx
increasing VD should be avoided if possible and limited to restorative needs only
relapse and intrusion of teeth in patients with FMA angle < 20 degrees