1. Tooth wear: aetiology, prevention, clinical implication
Libyan International Medical University
2nd Year nd Semester
D Caroline Piske de A. Mohamed
D.caroline Mohamed

2. Objectives: • Definitions of tooth wear • Epidemiology of tooth wear
• Aetiological factors
D.caroline Mohamed

3. 1.Definitions of tooth wear
Non carious destruction of teeth tissues.
Tooth wear is usually due to a combination of processes, abrasion, attrition, and erosion.
It is unusual for wear to be solely attributed to one of these. Rather, tooth wear is due to all three processes with perhaps one of these predominating.
Tooth wear:
Attrition
Abrasion
Erosion-Corrosion
Demastication
Abfraction
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4. a) Attrition-definition
Loss by wear of surface tooth or restoration caused by tooth to tootth contact during oclusion, mastigation or parafunction.
Microwear detail: parallel striations within the facet border.
Shiny facets
Bruxism
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5. Attrition Destruction accelerated by: Poor quality or absent enamel
Premature contacts, edge to edge oclusion
Intraoral abrasives, erosion or grinding / clenching habits
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6. Grinding, clenching habits
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7. Attrition / clinical appearence
Matching wear on occluding surfaces
Shiny facets on amalgam contacts
Enamel and dentine wear at the same time
Possible fracture of cusps or restorations
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8. b) Abrasion-definition
Loss of tooth structure secondary to the action of an external agent. Most commom source is toothbrushing.
Method of brushing
Toothpaste abrasives
Habits
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9. Most abrasion is located in the cervical area of teeth and associated with tooth brushing. Incorrect or over-vigorous brushing with an abrasive toothpaste is usually the prime aetiological factor.
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10. The orientation of the toothbrush influenced the wear of the teeth
The orientation of the toothbrush influenced the wear of the teeth. Horizontal brushing was suggested as causing 2 to 3 times as much wear compared with vertical brushing.
Some studies suggest that toothpaste has more relevance to abrasion than does the toothbrush itself.
Abrasion can occur as a result of overzealous toothbrushing, improper use of dental floss and toothpick, or detrimental oral habits such as chewing tabacco, biting on hard objects such as pens, pencils/ opening hair pins with teeth, and biting finger nails.
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11. It is not just the abrasive content of the toothpaste that is important; the abrasive type, particle size and surface, and the chemical effects of the other constituents will also affect the amount of abrasion. For example, most of the hydrated silica-based toothpastes have good cleaning values with a low to moderate dentine abrasivity.
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12. Occupational abrasion.
Tailors, seamstresses ( server thread with their teeth)
Shoemakers and upholsters ( hold nails between their teeth)
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13. Occupational abrasion.
Glassblowers and musicians (play wind instruments)
The increasing use of musical instruments since childhood, can lead to clinical conditions for which medical professionals oral health should pay particular attention in order to prevent and minimize consequences of such use. The development of pathology associated with the use of musical instruments can provide temporary or permanent limitations, justifying the importance of including valid form of the condition of the oral structures in the activities of occupational health.
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14. c) Erosion—Corrosion definition
Progressive lost of hard dental tissue by chemical or electrochemical process not involving bacteria action.
Dissolution of mineralized tooth structure occurs upon contact with acids that are introduced into the oral cavity from intrinsic or extrinsec sources.
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15. Erosion Erosion has a mutifactorial etiology. A susceptible tooth
The mineralisation of the dental hard tissues (presence of fluorapatite rather than hydroxyapatite
affects the acid solubility).
Time
Salivary flow rates and buffering capacity at
different sites also influence erosion.
Where there is abundant saliva such as in the lower incisor region, there tends to be little erosion.
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16. Multi-factorial aetiology of dental erosion: the overlapping factors may all be required to some extent to produce severe erosion shown as the red area in the centre.
L. Shaw,and A. J. Smith,2 Dental erosion — the problem and some practical solutions BRITISH DENTAL JOURNAL, VOLUME 186, NO. 3, FEBRUARY
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17. Clinical appearence
Lost of detailed surface microanatomy ( glazed and rounded)
Cupping or Cratering: It is one of the most obvious characteristics of erosive and abrasive attrition. 
Cupping happens on the cusp tips of molars and premolars  and incisal edges of incisors and canines. 
Cupping on molars has less to do with bruxing than with erosion caused by acids, while cupping on anterior teeth is more likely due to bruxing in older patients.
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18. Increased incisal translucency Wear on non occluding surfaces
“Raised amalgam or composite restorations”
Clean, non tarnished appearance of amalgam restorations
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19. Loss of surface characteristics of enamel in young children
Hypersensitivity
Pulp exposure in deciduous teeth.
Preservation of enamel “cuff” in gengival crevice is common
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20. Sources
Intrinsic sources
Extrinsinc sources
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21. Erosion-corrosion Associated with: Nervous system disorders.
Intrinsic sources: gastroesophageal acid reflux, regurgitation or vomiting.
Associated with:
Nervous system disorders.
Eating disorders such as: Anorexia and
Bulimia nervosa
Gastrointestinal disorders such as peptic
ulcers or gastritis
Alcohol abuse –gastrites associated
Pregnancy
Diabetes or others medical conditions
Drug side effects
Acid mouthwashes may be implicated
Erosion associated with alcoholism is caused by frequent vomiting.44,45 Other causes of vomiting that may cause erosion include gastrointestinal disorders such as peptic ulcers or gastritis, pregnancy, drug side effects, diabetes or nervous system disorders.
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22. Intrinsic sources of acid
Intrinsic sources of acid are essentially gastric contents, which enter the mouth as a result of reflux and vomiting. There are also some occasional case reports of rumination—deliberately bringing food back into the mouth to re-chew—which has led to extensive erosion.
Gastric reflux is much commoner than was once thought. Relatively, recent research has shown that, in the developed world, 7% of the adult population have gastrooesophageal reflux on a daily basis and more than 30% every few days.
D.caroline Mohamed

23. Principal causes of gastro-oesophageal reflux
Increased gastric pressure
Obesity
Ascites
Increased gastric volume
after heavy meals
Obstruction
Spasm
Sphincter incompetence
Hiatus hernia
Diet
Drugs, e.g. diazepam
Neuromuscular, e.g. cerebral palsy
Oesophagitis
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24. General associated symptoms are heartburn, retro-sternal discomfort and dysphagia.
People with neurological impairments such as cerebral palsy also have significantly higher levels of reflux.
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25. Vomiting, either spontaneous or self induced, may be associated with a variety of medical problems.
This phenomenon must continue over a long period to cause significant erosion, and again, there is a range in susceptibility.
Current research shows an increasing prevalence of such conditions as bulimia and anorexia nervosa, both of which may be associated with self-induced vomiting.
D.caroline Mohamed

26. Recognizing Bulimia Wear patterns on the teeth
Loss of tooth structure is progressively worse toward the anterior teeth. 
This is because of the way the tongue is held in the mouth when the patient vomits. The vomitus is projected especially toward the palatal surfaces of the maxillary incisors with progressively less damage as you proceed posteriorly.
As the palatal surfaces of the maxillary incisors erode, the incisal edges become more and more thin and translucent, eventually producing a knife-edge which is easily crazed and chipped. 
Note the image above.  Nearly all of the palatal enamel has been dissolved by the acidic stomach contents which have been projected against the incisors. 
Note especially in the image above that the loss of tooth structure is fairly even beginning at the free gingival margin. 
Chronic, excessive vomiting has long been recognized as causing erosion of the teeth. The patient with an eating disorder such as anorexia nervosa or bulimia is the classic example.  Although erosion caused by vomiting typically affects the palatal surfaces of the maxillary teeth, it is also common for individuals with eating disorders to consume large amounts of acidic beverages and fresh fruits. This results in another source of acid exposure, primarily affecting the labial surfaces of the teeth. In addition, treatment for bulimia may include use of antidepressants or other psychoactive medications that may cause salivary hypofunction. Therefore, the cause of erosion cannot be reliably determined from its location.44
D.caroline Mohamed

27. Principal causes of vomiting
Psychosomatic Stress-induced psychogenic vomiting
Eating disorders
Bulimia nervosa
Anorexia nervosa
Metabolic and endocrine
Uraemia
Diabetes
Gastro-intestinal disorders
Peptic ulcer
gastritis
Obstruction
Nervous system disorders
Cerebral palsy
Drug induced
Primary, eg. cytotoxics
Secondary to gastric irritation e.g. aspirin, non steroidal anti-inflammatory drugs
Drug-induced xerostomia over a period of time may also influence erosion
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28. Extrinsic sources of acid
There are many sources of acid from outside the body, which may affect the dental tissues.
Dietary practices ,‘nibbling’ and ‘snacking’.
Increase in soft drink consumption (children and adults)
Soft drink consumption and dental erosion are corelated, particularly, the bed-time consumption of fruit-based drinks.
Acidic foods, high consumption of fruit, pickles, and sauces and the use of acid mouthwashes.
D.caroline Mohamed

29. D.caroline Mohamed

30. Lifestyle influences
Sports drinks are not only acidic, but also contain a considerable amount of simple sugars.
Both competitive swimmers and cyclists have been reported as having higher levels of dental erosion.
The dry mouth combined with dehydration from vigorous exercise and excessive consumption of low pH drinks has also been linked to dental erosion.
D.caroline Mohamed

31. Soda Swishing
Soda swishing is the habit of retaining each mouthful of soda in the mouth for a few seconds and swishing it around between the teeth before swallowing. 
All sodas, including diet soda contain three acids:  Phosphoric acid, Citric acid and Carbonic acid.
Mandibular molars are much more heavily affected than maxillary molars because gravity keeps the soda in contact with them.
Over the years, the posterior teeth become more worn than anterior teeth due to tongue position while swishing. 
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32. Fruit mulling is the habit of "chewing" fruit pulp for prolonged periods before swallowing it. This habit causes loss of tooth structure due to a combination of erosion from the acidity of the fruit itself, as well as a modified form of abrasion from the constant rubbing together of the teeth over the fruit pulp during the mulling process. 
D.caroline Mohamed

33. Erosion clinical differences
Erosion due to gastric regurgitation:
Palatal surface of maxillary anteriors mostly affected and occlusal of posterior teeth
Erosion due to acidic drinks:
-Facial surface of maxillary anteriors mostly affected. Appears as shallow spoon shaped depressions in cervical portion of the crown and occlusal of posterior teeth.
D.caroline Mohamed

34. Occupational tooth erosion
Competitive swimming, (exposes the dentition to repeated contact with acids)
Can occur during exposure to industrial gases that contain hydrochloric or sulfuric acid, as well as acids used in plating and galvanizing and in the manufacture of batteries, ammunitions and soft drinks.
Professional wine tasters.
 Exposures to high concentrations (reportedly up to 16 mg/m3) cause dental erosion.Chromic, hydrochloric, sulfuric and nitric acids have been identified as erosion-causing acid vapors. They are released into the work environment during industrial electrolytic processes.3, 27,28 However current work safety standards make this type of erosion very rare. Dental erosion has been reported in swimmers who work out regularly in pools with excessive acidity as well as individuals who are occupational winetasters.29,30Etching of teeth may occur after a few weeks exposure, progressing to erosion after a few months exposure. Less common sources of extrinsic erosive acids are related to occupational and recreational exposure.
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35. Drugs recreational exposure.
Recreative drug abuse can be dangerous even for trrth. Meth mouth is caused by several factors tooth enamel is dissolved by the harsh chemicals of the drug. The blood vessels contined in healthy gums and teeth shrink increasing the rate of decay. The production of saliva diminishes allowing harmfull acids to further damage the mouth, cravings for sugary foods increase with meth use, oral hygiene is typically neglected while high and heavy tooth- griding is an additional side effect of the drug.
D.caroline Mohamed

36. D.caroline Mohamed

37. d) Demastication is a term used for wearing away of tooth substance during mastication. This could be specifically applied to the type of wear shown by the ancient Egyptians, and would depend on the abrasivity of the food consumed.
D.caroline Mohamed

38. Tooth wear in noncivilized communities
‘The total absence of cervical abrasion in the Yanomamis leads us to believe that this phenomenon, so common in men of our civilization, is caused by tooth brushing. The Yanomamis had no brushing habits.’
‘… it was evident that caries incidence was significantly lower than in present day civilized men. Neither water nor enamel mineralization were analyzed. Apart from those two factors we believe that physiological occlusal abrasion (eliminating sulci and fissures) produced by the intense masticatory activity, with its self cleaning and anti-plaque effects, has appreciably influenced caries incidence.”
D.caroline Mohamed

39. PEREIRA et all. Teeth of yanomamy peoplePERIODONTAL DISEASE, OCCLUSION, ATTRITION AND OTHER DENTAL CHARACTERISTICS IN PRIMITIVE BRAZILIAN MEN
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40. e) Abfraction Definition
Loss of tooth surface at the cervical areas of teeth caused by tensile and compressive forces during tooth flexure.
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41. The theory of abfraction suggests that the cervical buccal lesions were caused by the biomechanical "bending" of the teeth due to severe bruxing forces. 
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42. Note the pattern of cervical tooth wear seen in the images below. 
Was this caused by the process of abfraction, or is this toothbrush abrasion? 
Toothbrush abrasion
Abfraction
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43. Aetiology of tooth wear
• Abrasion: usually due to incorrect or over-vigorous brushing,
but there are many unusual habits that are occasionally implicated.
•Attrition: parafunctional activities, such as bruxism, are probably the most significant factors in the development of pathological tooth wear in contact areas.
•Erosion: always multifactorial but one specific aetiological factor usually predominates:
Intrinsic acid sources
• Gastro-oesophageal reflux
• Vomiting; spontaneous or self-induced
Extrinsic acid sources
• Dietary, drinks etc.
• Lifestyle influences
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44. Indices
The many published clinical indices suggest that it has been difficult to devise an ideal index for use in all clinical circumstances.
The Tooth Wear Index of Smith and Knight (1984) is a qualitative clinical index and has probably achieved the greatest general acceptance. It is intended for both epidemiological studies and individual patients for long-term monitoring of tooth wear.
Poor reproducibility of diagnosis of tooth wear in large surveys with many examiners indicate that the results of studies should be interpreted with caution.
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45. 2 Epidemiology of tooth wear
Tooth wear has long been a recognized phenomenon in adults and ascribed to the triumvirate of attrition, abrasion and erosion.
Pathological tooth wear has been seen in antiquity but the problems are becoming even more evident in society now, with an ageing population who are retaining their natural teeth for significantly longer.
There has been a gradual realization in recent years that our younger population may also be increasingly affected.
This is with increasing dental erosion, rather than attrition and abrasion, although these factors also contribute.
D.caroline Mohamed

46. Epidemiology of tooth wear
Very different types of tooth tissue loss are observed in the older adult population than in children. It is, therefore, essential to consider them separately but to regard tooth wear as a continuum throughout life with very different etiological factors at the ends of the age spectrum.
D.caroline Mohamed

47. Prevalence of tooth wear and erosion in the deciduous teeth
Researches indicate high variety in tooth wear prevalence between pre-scholars in different countries.
The primary dentition is more susceptible than the permanent because of higher acid solubility and reduced thickness of the enamel.
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48. Prevalence in children
The United Kingdom Child Dental Health Survey of 1993
randomly selected a sample of 17,061 children aged from 5 to
15 years which had their oral health condition examined.
It was found that 50 per cent of children aged 5 and 6 years
had evidence of tooth wear, largely attributed to erosion,
with almost 25 per cent having dentine involvement.
Over half of palatal surfaces of primary upper incisors
showed erosion in this age group.
At eleven years of age, 2 per cent of children were found
to have erosion in their permanent teeth.
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49. Prevalence of tooth wear and erosion in Adolescents
The 15-year-olds sampled in the National Children’s Dental Health Survey [Chadwick et al., 2006] showed an increase in Tooth Surface Loss into dentine or pulp on palatal surfaces from 2% in 1993 to 5 % in 2003 (3% in this study).
 The fissure sealant in this 14-year-old boy stands �raised� from surrounding eroded occlusal enamel.
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50. The Erosion in year-olds on Isle of Man , Milosevic et all, 1987 concluded that drinking fizzy drinks more than once a day was associated with erosion.
Mean DMFT scores were not statistically different for children with smooth surface/occlusally exposed dentine.
Multiple regression analysis showed age, gender and toothbrushing to be significant predictors of erosion.
toothbrush abrasion can affect labial surfaces, but this is unlikely to happen in teeth which are not already affected by erosion [Hooper et al., 2003]
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51. Prevalence of tooth wear and erosion in Adults
Subjects aged between years % had facial erosive lesions into dentine and 29.9 % had occlusal teethwear into dentin.
In the year group, 13.2 % had facial erosive lesions into dentine and 42.6 % had occlusal involving dentine. Lussiet al
These studies suggest that the incidence of dental erosion ranges from 5 to 50% in various populations and age groups.
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52. The consistent finding from very different published studies is that tooth wear increases with age, and a certain amount is considered to be a normal ‘physiologic’ ageing process.
An attempt has been made to determine ‘threshold’ levels, which are regarded as acceptable levels of wear for a given age.
More recent studies using the Tooth Wear Index (TWI) of Smith and Knight have indicated that young adults are showing accelerated wear, which may pose a problem for the future.
D.caroline Mohamed

53. Risk factors for erosion-corrosion
FREQUENCY
Citrus fruit intake
> Than twice daily
Sports drink intake
Weekly or more often
Soft drinks consumed
4-6 or more per weeek
Bruxism habit
Whole saliva unstimulated flow rate ( 0.1 ml/min
Excessive attrition
Apple vinegar intake
Eating disorder
Vomiting
Symmtoms or history of gastroesophageal reflux disease
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54. Questions……………..
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55. 6.References
CM Maya. A textbook of Public Health Dentistry, first edition. Jaypee Brothers Medical Publishers.
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56. Activity
Bring next class an 1 page research about recreative Drugs and oral helth
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57. Highly recommended Erosion—diagnosis and risk factors
Managment of dental erosion.
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58. Thank you!!!
D.caroline Mohamed