1. TOOTH WEAR

2. WHAT IS TOOTH WEAR?
 Tooth wear has been defined as loss of tooth substance
resulting from abrasion, attrition and erosion acting singly or
concurrently i.e. abfractions.
 When wear is due to more than one predominant etiological
factor, special terms have been suggested to highlight the
multiplicity of causes. For example:
 abrosion
 demastication

3. TYPES OF TOOTH WEAR
 Abrasion
Wear process involving foreign objects sliding or rubbing against
the tooth surfaces.
Attrition
Wear process of the tooth substance by tooth-to tooth contact.

4.  Abfraction
Non-carious cervical lesions caused by tensile stress generated
from occlusal loading, and micro fracture of cervical enamel rods.
 Erosion
Loss of dental hard tissues by non-bacteriogenic acid etching.

5. ABRASION
 The combination of a hard toothbrush, an abrasive toothpaste
and an intensive horizontal brushing technique is believed to
cause well-defined, V-shaped notches in the cervical regions of
one or more facial tooth surfaces, where the dentine and
cementum are less wear-resistant than coronal enamel.

6. OTHER HABITS CAUSING ABRASION INCLUDE:
 The misuse of dental floss and toothpick, and pipe-smoking.
 Thread biting
 Holding hair-grips between the teeth can lead to abrasion
defects of incisal tooth edges in seamstresses and hairdressers,
respectively.

7. ATTRITION
 Attrition resulting from tooth-to-tooth contact (two-body
wear) produces well defined wear facets on the functional
surfaces of teeth in one jaw which match corresponding lesions
on teeth in the other jaw
 Para functional habits such as bruxism and clenching were also
believed to be important factors in causing accelerated
attrition.

8. OTHER FACTORS PREDISPOSING TO ATTRITION
INCLUDE
 developmental dental defects,
 coarse diet
 natural teeth opposing coarse porcelain

9.  Attrition of incisal edges of 1/1 and pseudo-Class III incisal
malocclusion.
 Attrition of 1/ because of lack of posterior support.

10. ABFRACTION
 The concept of „stress-induced cervical lesions‟ was introduced
to explain how wedge-shaped Class V lesions can be created by
repeated compression and flexure of the teeth under occlusal
loading. Dentine is more elastic than enamel and enamel rods
can be fractured in such situations. In older adults, enamel
crazing and micro fractures are more common.

11. o The term abfraction was used to describe this „stress corrosion‟
mechanism
o The „stress corrosion‟ theory has been supported by a number
of observations:
• in vitro evidence of tensile stresses created in the cervical
region under occlusal loading
• a high incidence in bruxists
• lesions can be found on only one tooth in one segment
• lesions found in subgingival regions
• the presence of such lesions in animals.

12. EROSION
 Erosion of tooth substance may be caused by intrinsic or
extrinsic acids, and modified by changes of salivary flow and
constituents.
 Acid erosion
 Flow of Saliva

13. PATTERNS OF TOOTH WEAR IN EROSION
 Erosion can lead to old amalgam restorations becoming
outstanding
 Erosion of palatal surfaces of 321/123 in a patient with
bulimia nervosa.

14. DIAGNOSIS
 Before any intervention or restorative treatment, the nature and
duration of patient‟s chief complaints and expectations must
be ascertained.
 Apart from using a routine medical questionnaire, emphasis
may be placed on medical conditions predisposing to erosion
due to gastro-esophageal reflux or reduced salivary flow.
 Evaluation of the family and social history can reveal if the
patient is under unusual stress, which may be related to
bruxism, changes of diet and regurgitation.

15.  Clinical examination of the dentition has two primary
objectives:
• To document and record the location, appearance and degree of
tooth wear.
• To evaluate the progress of tooth wear over time.
 Clinical examination can supplemented with high-density stone
study casts, intra-oral photographs, radiographs and salivary
tests.

16. PREVENTIVE AND INITIAL MANAGEMENT
 Before any definitive restorative treatment is undertaken,
plaque-induced dental disease such as caries and periodontal
disease should be controlled.
 The long term success of rehabilitation is dependent on good
oral hygiene and regular maintenance.
 Efforts should be made to eliminate or control the etiological
factors.

17. RESTORATIVE MANAGEMENT OF TOOTH WEAR
 Tooth wear can be classified as physiological or pathological,
but no universally accepted guidelines are available to
differentiate the two entities; the same loss of tooth substance
may be regarded as physiological in an elderly person, but
pathological in young one.
 Clinical indications for restorative management:
 Biological
• Loss of tooth substance could lead to irregular tooth surfaces
which may enhance plaque retention
• Pulpal exposure
• Weakening of tooth structure

18.  Functional
• Loss of tooth substance cannot be compensated by continuous
eruption, and there is reduced masticatory efficiency because of
occlusal wear.
 Esthetic
• Loss of tooth substance is esthetically unacceptable to the patient.

19.  A systematic treatment approach should be used to manage
characteristic worn dentitions involving different tooth surfaces
and degree of severity. For practical reasons, the worn dentition
can be classified according to location:
• Localized anterior tooth wear
• Localized posterior tooth wear
• Generalized tooth wear

20.  When erosion is the primary etiological factor then the palatal
surfaces of the upper anterior teeth are most commonly involved
in tooth wear, less frequently the posterior teeth may also be
affected in a localized manner.
 Adhesive techniques with minimal tooth preparation should be
employed if only the palatal tooth surfaces are affected. It is
difficult to construct a crown on a shortened tooth without
clinical crown lengthening surgery or subgingival placement of
the crown margin.
 As a result of compensatory tooth eruption and alveolar bone
growth several methods are used to create interocclusal space
needed for the management of localized tooth wear before the
placement of the final restoration. These include:

21.  Fixed or removable anterior bite planes ( Dahl appliance)
 Tooth preparation at existing intercuspal position
 Occlusal adjustment
 In addition to these methods, provisional or permanent
restorations can be placed at increased OVD. These supra-
occluding appliances are used as “individual Dahl appliances”.
 With the Dahl appliance or individual supra-occluding
restorations placed at increased OVD, a palatal platform should
be present as an „ICP stop‟ to dissipate occlusal forces more
axially.

22. LONG TERM MANAGEMENT OF PATIENTS USING
REMOVABLE PROSTHESIS
 The use of removable prostheses can be broadly divided into
two categories:
 First, those cases where the appearance of the worn teeth is
acceptable to the patient. In these circumstances management is
directed at trying to prevent progression of the tooth surface
loss.
 Second, there are those cases where the appearance is
unacceptable. In these circumstances treatment options can be
divided broadly into:
• tooth reduction and the provision of overdentures
• treatment combining removable prostheses and adhesive
techniques
• treatment combining fixed and removable prostheses.

23. 1. MAINTENANCE ASSOCIATED WITH
ACCEPTING THE APPEARANCE
 In these cases, partial dentures are provided to ensure there is
adequate occlusal support.
 The maintenance in these cases is usually the least demanding,
because the degree of intervention necessary is limited and
simple. This will consist of regular reviews, and very often the
provision of a „soft, vacuum formed, night mouth guard‟ to
protect the remaining teeth.
 The use of a night mouth guard is inadvisable where the tooth
surface loss has an erosive component, e.g. gastric acid reflux, as
some individuals may reflux „silently‟ when supine during sleep.

24. 2. MAINTENANCE ASSOCIATED WITH
TOOTH REDUCTION AND THE PROVISION
OF OVERDENTURES
 Where the tooth surface loss is severe, often the most
appropriate treatment is to reduce the worn teeth further and
restore the missing crowns with an overdenture.
 It is also necessary to consider that there is a consequence to the
retention of overdenture abutments upon the success of the
removable prosthesis. The retention of the overdenture
abutments reduces the space for the artificial teeth and base.
This increases the likelihood of fatigue fracture, particularly in
those individuals who have a tooth clenching or grinding habit.

25. o It can be worth considering the use of porcelain teeth on the
denture, as they have a high abrasion resistance, so will resist
wear and help maintain the occlusal vertical dimension.
However, porcelain teeth may crack and, if left rough following
occlusal adjustment, will wear down natural teeth.
o In addition, attaching porcelain teeth to the denture can be
particularly difficult if there is limited space available, as the
means of mechanical retention may be ground away. An
alternative would be to replace the occlusal surfaces of
conventional resin teeth with cast gold alloy restorations.

26. 3. MAINTENANCE ASSOCIATED WITH THE
RESTORATION OF CASES WITH A
COMBINATION OF ADHESIVE TECHNIQUES
AND REMOVABLE APPLIANCES
o Where possible, it is desirable to create canine guidance using
direct or indirect composite additions, or at least anterior
group function. This can help protect remaining natural tooth
substance from further wear in lateral excursive movements and
will also help to protect restorations on the incisor teeth from
unfavorable loading.

27. 4. MAINTENANCE ASSOCIATED WITH
THE RESTORATION OF CASES WITH A
COMBINATION OF FIXED RESTORATIONS
AND REMOVABLE APPLIANCES
 A tooth surface loss case, where the vertical and horizontal jaw
relations have been restored with a combination of full veneer
crowns, a post and core-retained crown (upper left canine) and an
upper removable partial overdenture in an older patient where the
standard of oral hygiene was not ideal.

28. CONCLUSION:
 The causes of tooth surface loss are multi-factorial and hence
difficult to eradicate
 Treatments should be planned which would enable the dentist
to recover the situation with minimal inconvenience to the
patient.
 When considering possible treatment options for patients,
especially those who have exhibited tooth surface loss, they
should be made fully aware of the possibility of failure in the
future of any restorative procedure carried out.
 This is a consequence of continued wear and tear, which may
cause the failure of even the most clinically and technically
acceptable restoration.

29. Thank you