This document discusses non-carious lesions of the teeth. It describes various types of tooth wear including erosion, attrition, abrasion, and abfraction. Erosion can be caused by regurgitation of gastric acids, dietary acids from foods and drinks, or industrial acids. Attrition results from tooth-to-tooth contact during grinding or bruxism. Abrasion is caused by external abrasive agents like toothbrushes or pipes. Abfraction involves microstructural loss of tooth structure in areas of stress concentration. The document outlines factors that contribute to each type of wear and their presentations in the oral cavity. It emphasizes that tooth wear often results from combinations of these mechanisms.

1. NON-CARIOUSNON-CARIOUS
LESIONS.LESIONS.
Dr. Javeria Ali Khan
Lecturer
Department of Operative Dentistry.

2.  Wear: Damage to a solid surface,
generally involving progressive loss of
material, due to relative motion
between the surface and a contacting
substance or substances.
 Tooth wear: Surface loss of dental hard
tissue other then by caries or trauma
and is a natural consequences of
ageing.

3. TYPES OF TOOTH WEAR.
 Erosion (Corrosion).
 Attrition.
 Abrasion.
 Abfraction.

4. EROSION.
 Definition: It is defined as the loss of dental
hard tissue as a result of chemical process
not involving bacteria.
 Types of tooth erosion:
1- Regurgitation erosion.
2- Dietary erosion.
3- Industrial erosion.

5. REGURGITATION EROSION.
Definition:
 The erosive distruction of teeth caused by
frequent exposure of gastric acid to teeth.
Sites:
 Palatal surface of maxillary anterior teeth.
 Occlusal and buccal surfaces of mandibular
teeth.

6. REGURGITATION EROSION.
Etiology:
 1- Digestive disorders including hiatus
hernia and chronic indigestion.
 2- Anorexia and bulimia nervosa (Perimolysis,
evident on maxillary palatal surfaces).
 3- Morning sickness associated with
pregnancy.
 4- Voluntary regurgitation.

7. ORAL MANIFESTATIONS.ORAL MANIFESTATIONS.
 Tooth enamel erosion: teeth are bathed in gastric acid duringTooth enamel erosion: teeth are bathed in gastric acid during
vomiting leading to decalcificationvomiting leading to decalcification
 Tooth sensitivity to temperaturesTooth sensitivity to temperatures
 Parotid gland (sialadenosis) or submandibular glandParotid gland (sialadenosis) or submandibular gland
enlargement: can be disfiguringenlargement: can be disfiguring
 Erythema of the oral mucosaErythema of the oral mucosa
 Soreness in mouthSoreness in mouth
 CheilosisCheilosis

10. DIETARY EROSION.
Definition:
 “It is the loss of dental hard tissue by
intake of acidic foods and drinks.”
Site:
 Labial surface of maxillary teeth.

11. THE DRINKS WE SHOULD
TAKE OR NOT ?

13. DIETARY EROSION.
Etiology:
 Citrus fruits and fruit juices (contains
citric acid).
 Pickles and food containing vinegar
(contains acetic acid).
 Carbonated and energy drinks
(contains carbonic acid).

14. ETIOLOGY.
 Alcohol.
 Salad dressings.
 Effervesecent vitamin C tablets.
 Acidic candies.
 Herbal tea.

15. DIETARY TOOTH EROSION.

16. HOW DOES SALIVA HELP IN
PROTECTING AGAINST
EROSION?
 Dilutes and clears potentially erosive
agents from the mouth.
 Buffers dietary acids.
 Formation of Pellicle which protects the
enamel from demineralization by dietary
acids.
 Provide calcium and phosphate which
is necessary for remineralization.

17. WHAT ADVICE SHOULD WE
GIVE TO THE PATIENTS ?
 Diminish consumption of acid foods and
beverages.
 Finish meal using neutral food rather
then acid foods.
 Drink acid beverages quickly or through
a straw do not swish around.
 Rinse using water after acid
consumtion.

18. HOW CAN DENTAL
EROSION BE PREVENTED ?
 Use soft or medium type of tooth brush.
 Low abrasive fluoride containing
toothpaste.
 No tooth brushing immediately before
and after taking acidic food.
 Regular visits to dentist.

19. INDUSTRIAL EROSION.
Definition:
 “ It is the dissolution of dental hard tissue due to
industrial processes which produces acid fumes and
droplets.”
Sites:
 Labial surface of maxillary anterior teeth and may
also cause pitting.

20. INDUSTRIAL EROSION.
Effected indivisuals:
 Battery manufacturers.
 Wine tasters.
 Chemical and pharmaceutical company
workers.
 Soft drink manufacturers.
 Dyers.
 Tin factory workers ( tartaric acid).

21. RADIOGRAPH SHOWING
ERODED TEETH.

22. ATTRITION.
Definition:
 It is the physical wear of one tooth
against other or tooth against
restoration or prosthesis.
Sites:
 Incisal and occlusal surface of teeth.

23. ETIOLOGY OF ATTRITION.
 Bruxism.
 Associated with snuff chewing.
 Associated with bettel nut and pan
chewing.
 Associated with hypertensive patients.
 Associated with poor prosthesis and
poor restorations.

25. ATTRITION DUE TO
BRUXISM.

26. ABRASION.
Definition:
 It is the physical wear of dental hard
tissues from external agents.
Site:
 Neck of labial surface of anterior teeth.
 Neck of buccal surface of posterior
teeth.

27. ETIOLOGY OF ABRASION.
 Hard tooth brushes or excessive use of other
cleaning aids.
 Abrasive tooth pastes and tooth powders
(smokers tooth powder).
 Habits such as thread biting and pipe
smoking (can cause notches in the incisal
edges).
 Snuff chewing.
 Pan and bettel nut eating.

28. TOOTH BRUSH ABRASION.

29. ABFRACTION.
Definition:
 It is the microstructural loss of tooth
substance in areas of stress
concentration.
Site:
 Cervical region of teeth.

30. ABFRACTION ETIOLOGY.
 These lesions appear to result from
occlusal loading forces, frequently have
a crescent form along the cervical line
where the enamel is brittle and fragile.

31. ABFRACTION.

32. CONSEQUENCES OF
PATHOLOGICAL TOOTH
WEAR.
 Exposure of dentine on buccal and
lingual surfaces.
 Notched cervical surfaces.
 Exposure of dentine on incisal and
occlusal surfaces resulting in loss of
dentine producing a cupped
appearance.

33.  Restoration project above the tooth surface
as they do not erode.
 Exposure of reparative dentine or pulp.
 Causing sensitivity.
 Pulpitis and then later on loss of vitality.
 Inability to contact between incisal and
occlusal surfaces during mandibular
movements.
 Reduction in length of teeth.

35. COMBINED MECHANISM OF
TOOTH WEAR.
1- Attrition- abfraction.
 Attrition- abfraction is the joint action of
stress and friction when teeth are in
tooth-to-tooth contact, as in bruxism or
repetitive clenching

36. 2- Abrasion-abfraction.
 Abrasion-abfraction is the loss of tooth substance
caused by friction from an external material on an
area in which stress concentration due to loading
forces may cause tooth substance to break away.
Such a synergistic tooth-destructive effect may be
observed cervically when toothbrushing abrasion
exacerbates abfraction to produce wedge-shaped
lesions. The critical roles of both toothbrushing
abrasion and occlusal loading of an anatomically
vulnerable zone may be one reason why such lesions
are limited almost exclusively to the buccal and labial
cervical areas of teeth

37. 3- Erosion-abfraction:
 Corrosion-abfraction is the loss of tooth
substance due to the synergistic action of a
chemical corrodent on areas of stress
concentration. This physicochemical
mechanism may occur as a result of either
sustained or cyclic loading and leads to static
stress corrosion or cyclic stress corrosion.

38.  Static stress corrosion:
 Static stress corrosion is the loss of tooth
structure owing to the action of a corrodent on
an area of sustained stress. This may occur
during clenching. Static stress corrosion may
be observed as demineralization that occurs
around orthodontic appliances in the
presence of a corrodent.

39. CORROSION ABFRACTION.

40.  Cyclic (fatigue) stress corrosion.
 Cyclic stress corrosion is the loss of tooth structure
due to the action of a corrodent in an area of
concentrated stress during cyclic loading. This
combination of mechanisms could occur during
mastication, as seen among patients who engage in
fruit mulling as dentinal invaginations, but is seen
most strikingly among patients who brux in the
presence of endogenous (for example, GERD) or
exogenous (carbonated soft drinks) corrodents. In
such situations, tooth substance may be lost rapidly
and extensively.

41.  Attrition-corrosion:
 Attrition-corrosion is the loss of tooth
substance due to the action of a corrodent in
areas in which tooth-to-tooth wear occurs.
This process may lead to a loss of vertical
dimension, especially in patients with GERD
or gastric regurgitation. An occlusal or incisal
pattern of wear develops.

42.  Abrasion-corrosion.
 Abrasion-corrosion is the synergistic activity of
corrosion and friction from an external material. This
could occur from the frictional effects of a toothbrush
on the superficially softened surface of a tooth that
has been demineralized by a corrosive agent. Teeth
that are out of occlusion could be affected by this
mechanism and develop cervical lesions, since they
frequently extrude, thus exposing the vulnerable
dentin. Similarly, gingival recession may expose the
cementum and dentin to this odontolytic process.

43.  Biocorrosion (caries)-abfraction:
 Biocorrosion (caries)-abfraction is the pathological
loss of tooth structure associated with the caries
process, where an area is micromechanically and
physicochemically breaking away due to stress
concentration. A common site for this synergistic
activity is the cervical area of the tooth, where it may
be manifested as root or radicular caries. The
combined mechanisms of static stress corrosion and
cyclic (fatigue) stress corrosion can account for the
rapid odontolytic progression of these types of
carious lesions.

44. BIOCORROSION
ABFRACTION.