Endodontics

Question 1

Cementum is comprised of what percentage of inorganic materials vs organic components and water?
Arnbjerg, 2014

Answer 1

65% inorganic, 35% organic materials and water

Question 2

What is the radiological density of cementum?
Arnbjerg, 2014

Answer 2

1200-1500 H

Question 3

What is the radiological density of dentin?
Arnbjerg, 2014

Answer 3

1600-1800 H

Question 4

What is the radiological density of enamel?
Arnbjerg, 2014

Answer 4

2400-2600 H

Question 5

Dentin is comprised of what percentage of inorganic materials vs organic components and water?
Arnbjerg, 2014

Answer 5

70% inorganic, 30% organic materials and water

Question 6

Enamel is comprised of what percentage of inorganic materials vs organic components and water?
Arnbjerg, 2014

Answer 6

96-98% inorganic, 2-4% organic materials and water

Question 7

According to the study by Arnbjerg in 2014, “Generalized hypercementosis in geriatric horses”, hypercementotic lesions are seen concentrated on which aspects of incisor tooth roots?

Answer 7

Axial and lingual

Question 8

Identify the pathology in these radiographs as presented by Arnbjerg in 2014.

Answer 8

Hypercementosis

Question 9

Identify the pathology indicated by the white arrows as seen in the study by Arnbjerg in 2014

Answer 9

Irregular hypercementosis

Question 10

Identify the type of resorption as described by Henry et al. in 2016

Answer 10

External replacement resorption

Question 11

Identify the type of resorption as described by Henry et al. in 2016

Answer 11

External inflammatory resorption

Question 12

In the study by Henry et al in 2016, “Radiographic evaluation in clinical practice of the types and stage of incisor tooth resorption and hypercementosis in horses,” what are the two most prevalent forms of resorption seen in equine incisors?

Answer 12

Most prevalent- External replacement resorption:
-76.9% of horses and 31.4% of teeth affected w/ a majority of the lesions being stage 2 (554/614 teeth)
-Significant association w/ increasing age but not breed or sex
-Tooth most commonly affected= third incisor
- Narrowing of PDL space w/ progressive replacement of root tissue by the surrounding alveolar bone

Second most prevalent- External inflammatory resorption:
-49.1% of horses and 17.2% of teeth w/ a majority of the lesions being stage 2 (260/336 teeth)
-Tooth most commonly affected= first incisor
-Increase in the PDL space related to an inflammatory process

Question 13

Name the 8 types of tooth resorption classified with radiographic criteria described by Andreasen and Andreasen and Peralta et al as presented by Henry et all in 2016.

Answer 13

1) external surface resorption
2) external replacement resorption
3) external inflammatory resorption
4) external cervical root surface resorption
5) internal surface resorption
6) internal replacement resorption
7) internal inflammatory resorption
8) unclassifiable

Question 14

List the 4 stages of lesions seen in tooth resorption as described in the paper by Henry et al in 2016, “Radiographic evaluation in clinical practice of the types and stage of incisor tooth resorption and hypercementosis in horses.”

Answer 14

1) loss of cementum or cementum and enamel
2) cementum and enamel with loss of dentin, not extending into the pulp cavity
3) loss of cementum, enamel, dentin; extending into the pulp cavity
4) most of the tooth has lost its integrity w/ 3 subcategories

4A) crown and root equally affected
4B) crown is more affected than root
4C) root is more affected than crown

Question 15

In the 2016 paper by Henry et al discussing the radiographic evaluation of tooth resorption and hypercementosis, what was the prevalence of tooth resorption in the study population?

Answer 15

149/169 (88.2%) of horses had radiographic evidence of tooth resorption
&
998/1953 (51.1%) of teeth evaluated had tooth resorption

Maxillary incisors statistically more likely to have resorption than mandibular incisors

Question 16

In the 2016 paper by Henry et al discussing the radiographic evaluation of tooth resorption and hypercementosis, what was the prevalence of hypercementosis in the study population?

Answer 16

35/169 (20.7%) of horses had radiographic evidence of hypercementosis

148/1953 (7.6%) of teeth

All horses w/ hypercementosis had resorption (35/35, 100%) whereas only 35/149 (23.4%) of horses w/ resorption had hypercementosis

Question 17

In the 2015 study by Smedley et al, “Equine Odontoclastic Tooth Resorption and Hypercementosis: Histopathologic Features,” what were the common histopathologic findings?

Answer 17

1. Cemental lesions: all affected incisors and canine teeth → cemental hyperplasia & lytic lesions
2. Dentinal lysis: 2/17 (12%); varied from replacement resorption in all cases to inflammatory resorption
3. Endodontic lesions: 12/15 horses (mild neutrophilic to lymphoplasmacytic inflammation (n=6), internal lysis of dentin (n=4), fibrosis (n=10), rim of atubular mineralized material (n=11))
4. Periodontal disease: at least one tooth in 15/17 horses (88%); primarily lymphoplasmacytic inflammation and fibrosis of the PDL
5. Gingival lesions: at least one tooth in 5/9 horses that had gingiva present (Mild to moderate lymphoplasmacytic and neutrophilic inflammation (n=3), mild lymphoplasmacytic inflammation (n=2), occasional downward growth of epithelium in regions of neutrophilic inflammation (n=1), mild hyperplasia (n=1))
6. Lesions in the alveolar bone: at least one tooth in 5/9 horses that had alveolar bone present; scalloped surface w/ occasional osteoclasts within resorptive pits