hard tooth tissue reduction
TRANSCRIPT
HARD TOOTH TISSUE
REDUCTION
Prepared by:Dr. Rea Corpuz
(1) Attrition
(2) Abrasion
(3) Erosion
(4) Abfraction
Hard Tooth Tissue Reduction
loss of tooth structure
caused by tooth-to-tooth contact during occlusion + mastication
comes from Latin verb attritum
action of rubbing against another surface
Attrition
some degree of attrition is physiologic
process becomes noticeable with age
pathologic
begins to affect esthetic appearance + function
Attrition
following factors can accelerate tooth destruction
poor- quality or absent enamel
• fluorosis• environmental or hereditary enamel hypoplasia• premature contacts (edge-to-edge occlusion)
Attrition
• intraoral abrasives• erosion• grinding habits
Attrition
occur both in deciduous + permanent dentition
most frequently
incisal + occlusal surface
lingual surface of anterior maxillary teeth
labial surface of anterior mandibular teeth
Attrition
Clinically:
Large Flat Smooth Shiny Wear Facet
Attrition
Attrition
pathologic wearing away of tooth structure
restoration secondary to mechanical action of an external agent
Abrasion
comes from the Latin verb abrasum
to scrape off implies wear or partial removal through mechanical process
Abrasion
Etiology
toothbrushing
• combines abrasive toothpaste• heavy pressure• horizontal tooth brushing stroke
Abrasion
Etiology
pencils toothpicks pipe stems bobby pins (hair grips) chewing tobacco cracking nuts biting fingernails
Abrasion
Clinically:
(tooth brush abrasion) horizontal cervical notches on buccal surface of exposed radicular cementum + dentin
sharply defined margins
hard smooth surface
Abrasion
Clinically:
(thread biting or use of pipes or bobby pins) rounded or V-shaped notches in incisal edges of anterior teeth
Abrasion
Clinically:
degree of lost is greatest on prominent teeth• cuspids• bicuspids• teeth adjacent to edentulous area
ocassionaly more advanced on the side of arch opposite dominant hand
Abrasion
loss of tooth structure caused by non bacterial chemical process
comes from Latin verb erosum
to corrode gradual destruction of surface by chemical or electrolytic process
Erosion
Acidic source:
foods or drinks involuntary regurgitation voluntary regurgitation (eg bulimia)
Erosion
Clinically
facial + palatal surfaces of maxillary anterior teeth
facial + occlusal surfaces of mandibular posterior teeth
(maxillary anteriors) shallow spoon-shaped depressions in cervical portion of crown
Erosion
Clinically
(posterior teeth) extensive loss of occlusal surface
Erosion
loss of tooth structure from occlusal stresses
create repeated tooth flexure with failure of enamel + dentin at a location away from point of loading
Abfraction
derived from Latin words ab + fractio
away + breaking
dentin is able to withstand greater tensile stress than enamel
Abfraction
when occlusal forces are applied eccentrically to a tooth
tensile stress is concentrated at cervical fulcrum
leads to flexure
produce disruption in chemical bonds of enamel crystals in cervical areas
Abfraction
once damaged, the cracked enamel can be lost or more easily removed by erosion or abrasion
Abfraction
Clinically
wedge-shaped defects limited to cervical area of teeth
deep, narrow + V-shaped
Abfraction
Clinically
occasionally lesions are subgingival
• site typically protected from abrasion + erosion
Abfraction
Clinically
predominantly affects
• bicuspids facial • molars surfaces
greater prevalence in those with brusixim
Abfraction
References:References:
BooksBooks
Neville, et al: Oral and Maxillofacial PathologyNeville, et al: Oral and Maxillofacial Pathology 33rdrd Edition Edition
• (pages 61-65)(pages 61-65)