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)