Acquired diseases of teeth, Dental materials and Dental radiography in small animals

1. Acquired diseases of teeth, Dental materials
and
Dental radiography in small animals
Prepared by
Ganga Prasad Yadav
MVSc
Vet. Surgery and Radiology

2. Dental Caries
oCaused by oral bacteria that live
on teeth in the form of plaque and
calculus (tartar).
oDark brown or black in color.
oDiagnosis
- clinical exam
- x-ray
oTreatment :-
Restorative
Extraction

3. Dental Calculus

4. Enamel Hypoplasia
• Deficiency in thickness of enamel:-
1) Circumscribed Area
2) Pitted Hypoplasia
• Etiology:-
• High Fever, Infection & Nutritional
Deficiency. Epitheliotropic Virus—
Morbilli Virus and trauma.
• Metabolic disturbance –during enamel
development.
• Treatment
- crown restoration
- composite restoration
- dentin bonding
- fluoride treatment

5. Endodontic disease
• Damaged to dental pulp
also k/a pulpitis.
• It may be caused by :-
Fractures
Trauma
Iatrogenic factors such as
overheating of teeth
during cleaning process.

6. Pathogenesis
Normally the pulp is
protected by
impervious enamel
Developmental
anomalie of enamel,
caries, trauma to the
tooth (fracture)--
Exposure of pulp
Infection of pulp-
pulpitis and pulp
necrosis
Release of
inflammatory
mediators in the
periradicular
tissues
Granuloma, cyst or
abcess development

7. Clinical findings and lesions
 Discolored tooth
 Haemorrhage from pulp
into the dentin
 Initially pulp appear as red
dot and then black after
necrosis
 Abscess of the root tips
that can result in facial or
jaw swelling (large
carnassials (chewing)
teeth)
 On radiograph periapical
lucency seen around the
root tip

8. Treatment
• One option is root canal therapy.
▫ This involves removal of the diseased
pulpal tissue
▫ The clean and disinfected root canal is
then filled with an inert material to
prevent future bacterial contamination.
▫ Tooth-coloured restorations are then
placed to seal the crown against further
infection.
▫ metal crown may be indicated following
root canal treatment, depending on the
extent of crown that is missing and the
function of the dog.

9. Tooth Fracture
• Traumatic tooth injuries may cause fracture of
enamal, dentine and cement and damage to
periodontium.
• May involve root and crown of the affected tooth.
• May be classified on the basis of pulp exposed:
 Uncomplicated fractures: when pulp is not
exposed.
 Complicated fractures: when pulp is exposed.

10. AVDC Dental Fracture Classification
• Enamel infarction: an incomplete fracture (crack) of the
enamel without loss of tooth structure.
• Enamel fracture: A fracture with loss of crown substance
confined to enamel .
• Uncomplicated crown fracture: A fracture of the crown
that does not expose the pulp .
• Complicated crown fracture: A fracture of the crown that
exposes the pulp.

11. Enamel infraction (EI)
An incomplete fracture (crack) of the enamel without
loss of tooth substance.

12. Enamel fracture (EF)
• A fracture with loss of crown substance confined
to the enamel.

13. Uncomplicated crown fracture (UCF)
• A fracture of the crown that does not expose the
pulp.

14. Complicated crown fracture (CCF)
• A fracture of the crown that exposes the pulp.

15. Uncomplicated crown-root fracture (UCRF)
• A fracture of the crown and root that does not
expose the pulp.

16. Complicated crown-root fracture (CCRF)
• A fracture of the crown and root that exposes the
pulp.

17. Root fracture (RF)
• A fracture involving the root.

18. Etiology and Pathophysiology
• Traumatic incidents like blunt blows, road traffic
accidents, chewing on hard objects.
• Untreated pulp exposure invariably leads to pulpitis and
eventually pulpal necrosis.
• Pulpitis and pulpal necrosis may also occur with
uncomplicated fractures , particularly if the fracture line
is close to the pulp chamber , which exposes a large
number of dentinal tubules and allow communication
between pulp and external environment.

19. Differential diagnosis & Diagnostics
• Crown Fracture: teeth attrition, abnormal tooth
formation.
• Root Fracture: Luxation
• Radiographs are mandatory for diagnosis.
• Transillumination to help detrmine tooth vitality:
shine a bright light through tooth (otoscope light), a
vital tooth should transilluminate well.

20. Therapeutics
• Drugs:
Appropriate antimicrobial and pain management
therapy.
• A broad spectrum bactericidal antibiotic drugs for 5-7
days may be indicated when long standing infection
is present.
• Mouth wash

21. • Uncomplicated crown fracture: Remove sharp edges
with bur and seal the exposed dentine tubules with a
suitable liner, dentinal bonding agent or restorative
material.
• Complicated crown fracture: All require endodontic
therapy if the tooth is to be maintained; Extraction is
preferable to no treatment at all

22. Pulpitis
• Inflammation of the pulp in response to stimuli ; most
commonly used in reference to the tooth discoloured
by blunt trauma
• Reversible : Inflammatory changes of the pulp with
potential resolution
• Irreversible : Significant inflammatory changes with
the end result of pulpal death and necrosis

23. Treatment
• Teeth with irreversible pulpitis or pulp necrosis
require either Endodontic therapy (root canal therapy
) or Extraction
• Except in very young patients, one of these options
are indicated for every tooth in which a fracture has
exposed pulp cavity
• Root canal treatment for the patients is much more
comfortable than extraction and allows continued
function.

24. Carnassial tooth abscess

25. Root tip abscess

26. Pulp necrosis

27. Tooth resorption
• Seen in dogs and cats.
• Type 1 : Roots are not replaced
by bone dense tissue.
• Type 2 : Roots are replaced by
bone.
• Type I teeth show focal loss of
tooth structure and adjacent
alveolar bone, with the
remaining root structure being
radiographically distinct from
the bone.

28. • Type II lesions, the roots
and the alveolar bone
taken on a similar
radiographic appearance
and cannot be easy
distinguished from one
another.

29. Staging of tooth resorption
• There are 5 different stages of tooth resorption.
• Stage 1 : Lesions only affects the cementum.

30. Stage 2 : Involves dentin but not the pulp

31. Stage 3 : Lesions involving the pulp

32. Stage 4a : Destroyed significant amount of crown and
weakening of crown which laces it at the risk of
fractures
Stage 4 a – crown and root are equally affected

33. Stage 4 b – crown is more severely affected
than root

34. Stage 4 c : Root is more severely affected
then crown

35. Stage 5 : Destruction of entire crown of tooth

36. Periodontal Disease

37. Tooth Luxation

38. Swelling and neoplasia
• Swellings
• Eruption cysts

39. Dentigerous cyst
Retained PM1

40. Tumors
• Tumors include : fibromas ( benign )
• Malignant ones include :
• Calcifying epithelial odontogenic tumor.
• Complex odontoma.
• Squamous cell carcinoma.
• Fibrosarcoma.

41. Fig: Calcifying epithelial odontogenic tumor

42. Gemination

43. Microdontia

44. Dental Materials
Characteristics
• Biocompatible
• Mechanically stable and durable
• Resistant to corrosion
• Esthetic
• Easy to manipulate
• Adheres to tissues
• Tasteless and odorless
• Cost effective

45. Four groups of materials are used:
• Metals: silver, gold, platinum
• Ceramics
• Polymers: silicone, Vinyl acrylic, polysulphide
• Composites

47. Classification
• Preventive dental materials
- Pits and Fissure sealing
- Liners, Bases, Cement etc.
• Restorative dental materials
- Synthetic components used
- to repair or replace tooth structures
- amalgam, metal ceramics, cement bases

48. Auxiliary dental materials
- process of fabricating dental
prosthetics and appliances
- impression material, gypsum
cast, dental waxes.

50. Dental Radiography
• Dental Radiography is a vital diagnostic tool in
veterinary practice.
• Required general anesthesia for radiography.
Indication:
To reach a diagnosis
To plan optimal treatment
To perform certain procedures
To assess the outcome of treatment performed

51. • Intraoral radiographic techniques are generally used.
• Film is placed inside the mouth and X-ray beam is
directed from outside through the tooth and adjacent
structures onto the film.
• Extraoral radiographic techniques are less commonly
used or if not available intraoral radiographic
techniques.

52. Equipment for conventional intra-oral
radiography
• X - ray machine
• X - ray film
• Processing facilities
• Mounts or envelops for film storage

53. • Traditional x- ray machines can be used for
dental radiography but it requires considerable
effort in positioning the patient and hence
patient must be moved several times to reorient
the head.
Film focal distance 16 inches.
Time of 0.1 sec.
100mA ( for a total technique of 10 MaS ).
65-90 kV , depending on the size of the patient.

54. Dental Machine
• Advantages are:-
Dental radiographic unit can
be angled, which minimizes
patient positioning.
More radiographs can be taken
as machine is easy to use.
Has preset mA and kV and is
well collimated .
Place the x ray machine in the
close proximity where dental
procedures are performed.
 Greater the number of
radiographs, greater the
amount of diagnostic
information.

55. Types of Dental machine
Mounted on the wall
Advantage :- has small foot prints
Disadvantage :- cannot be moved from room to
room
Stand mounted units
Advantage :- can be moved from room to room
Disadvantage :- takes more space
Handheld units :- less powerful than stand mounted
units

56. Mounted on wall Stand mounted unit

57. Handheld unit

58. Intra oral film
• Contains series of layers i.e.,
 A plastic coating covers the
external portion.
 Layer of paper
 Radiographic film
 Layer of paper
 Layer of lead
 Layer of paper
• Some manufacturers have
combined lead and paper layers

59. Film size Use in dog Use in cat
0 mandible
- Premolars and molars
2
- (DF-58)
-- also k/a periapical
film
Pre molars and molars
Upper canines in
smaller dogs
Upper incisors
Lower incisors +/-
Lower canines
Upper canines
4
- (DF-50)
-- also k/a occlusal
film
Upper incisor
Lower incisor +/- lower
canines
Upper canines in
medium to larger dogs
Nasal films
Nasal films

60. Developing films
1. Developing done in the solution placed in small jar or plastic
bottles
2. Use hemostat to grasp the films.
3. developer.
4. Rinser
5. Fixer
6. Finally rinse it in the flowing water.

61. Digital radiography
• Two basic components
1. dental x-ray machine: control unit, tube
head, collimator and timer.
2. digital x-ray system
• use either wired sensor or phosphor
screen.

62. Digital Sensor and Digital image
• Digital Sensor:
- easy to use
- various sizes
- no processing
required.
- digital images can
be taken as much
as required.

63. Phosphor plate radiograph
• A thin film
• Easy to use
• Reusable
• Different sizes: 0 to 6.

64. Full mouth radiographs
• A set of x-rays that include all the teeth in mouth.
• In cats, minimum 8 views are taken but 10 views are
recommended.
• In dogs, minimum 12 views required.

65. Positioning for dental radiographs
• Correct positioning requires :-
Tube
angulation
Tube position
Film position

66. Tube Angulation
• Two basic positioning techniques are used in
veterinary dental radiology.
Parallel
technique
Bisecting angle
technique

67. Radiographic techniques
Radiographic technique Teeth to be radiographed
Intraoral bisecting technique Maxillary and mandibular incisors and
canines
Intraoral Parallel Mandibular premolars and molars
Extraoral parallel or intraoral bisecting
angle
Maxillary premolars and molars

68. Parallel technique
• Used for imaging of lower molars and pre-
molars and nasal cavity.

70. Bisecting angle technique
• Beam of x-ray will be
perpendicular to the
imaginary bisecting angle
line between tooth and
film.

72. • If the beam is angled too vertically,
perpendicular to film (i.e., too acute or vertical),
the image is foreshortened.
• If angle beam perpendicular to tooth is too flat
or horizontal), the image will be elongated.

73. Tube position
• Centre the beam on the gingival margin so that
both crown and root structures are visible.
• “Cone cut’’ --- condition when beam centered
over crown and root usually cuts of the film.
Cone cut dental radiograph

74. Film position
• Place the white side of
the film packet towards
the X-ray beam.
• Place the film where
image will be projected.
• Parallel technique ---
easy to visualize.

75. STANDARD VIEWS
FOR DOGS AND
CATS

76. Radiography of maxillary teeth
• Sternal recumbancy
• Technique used :
Bisecting angle
technique.
• Open mouth and place
size 4 film between
crowns of canines and
parallel to hard palate.

78. Positioning of film for maxillary canine and
incisor teeth

80. Maxillary canine
• Lateral view –
Bisecting angle
technique.
• Open mouth and
place # 4 film
between crowns of
canines and hard
palate.

81. Rostral maxilla P1 – P3
• Bisecting angle
technique is used.
• Open the mouth and
place the film ( #1 or
#2 ) diagonally across
the hard palate.

83. Caudal maxillary P4 – M2
• Bisecting angle technique.
• Open the mouth and place the film ( #2 or #4 )
diagonally across the hard palate.

84. • Place the animal in dorsal recumbancy

85. Mandibular incisors and canine teeth
• Technique used :
Bisecting angle
technique.
• Open the mouth and
place a #4 size film
between the crowns of
canine tooth and the
tongue.
• Both canine tooth should
be touching the film.

91. Rostral mandible P1 – P4
• Bisecting angle technique.
• Open the mouth and place #1 or #2 size of film
diagonally across the symphysis area and the floor of
the mouth.
• Draw a bisecting angle and direct beam perpendicular
to it.
• In large dogs it may not be possible to fit all premolar
teeth on one film and it may be necessary to obtain an
radiograph centred on P4.

92. CAUDAL MANDIBULAR P4 – M3
• Parallel technique is used.
• Open the mouth and place #2 or #4 film
intra-orally behind desired teeth so that film
is parallel to the teeth.
• Centre the beam perpendicular to the film.

93. Interpreting of dental radiograph
• Evaluate the image quality.
• Examine the whole radiograph from left to right.
• Teeth : check for
1. Changes in contour and density of dentine.
2. Changes in bone level around teeth.
3. Changes in pulp chamber or periodontal space.
4. Change in bone density around teeth and lamina Dura .
• Jaw : look for
1. Site : location, extent, solitary, multifocal or generalised.
2. Size and shape : measure and describe.
3. Symmetry : examine the contralateral side.
4. Border : sclerosis, resorption, lack of continuity.
5. Contents : lucent or opaque.
6. Association with other structures : Teeth displaced or resorbing.
• Attempt diagnosis or further tests.

97. Thank You