Pulp Anatomy

Question 1

what are the three areas of the pulp cavity?

Answer 1

• pulp chamber: which is the most occlusal/incisal portion of the pulp cavity
• pulp horns: which are projections of the pulp chamber (usually one per sizable cusp)
• root canals: portions of the pulp that extends into the roots

Question 2

what connects the pulp chamber to the root canals?

Answer 2

canal orifices

Question 3

what connects the root canal to the outside of the tooth?

Answer 3

apical foramen

Question 4

how many canal types can a single rooted tooth have?

Answer 4

4 types (type I, II, III, and IV)

Question 5

what are type I anatomic roots

Answer 5

one canal extends from the pulp chamber to the apex

Question 6

what are type II anatomic roots

Answer 6

two separate canals leave the pulp chamber but they join short of the apex to form one canal apically and one foramen

Question 7

what are type III anatomic roots

Answer 7

two separate canals exit the chamber and continue to two separate apical foramina

Question 8

what are type IV anatomic roots

Answer 8

one canal leaves the chamber then splits to form two canals and two apical foramina

Question 9

what are accessory canals?

Answer 9

smaller canals that exit alongside the main root canal and cause complications

Question 10

how many roots and canals are anterior teeth more likely to have? what is the exception?

Answer 10

one root, one canal

mandibular anterior teeth may have 2 canals (one facial, one lingual) and the most likely tooth for this to happen is mandibular canine

Question 11

mature vs young incisors pulp chamber/ pulp horn

Answer 11

mature incisors from the facial or lingual view have 2 pulp horns possibly 3, peg laterals have only 1 pulp horn

young incisors may have 3 pulp horns following configuration of the mamelons

canines usually only have one pulp horn

Question 12

how many pulp chambers/ pulp horns are there in premolars

Answer 12

generally premolars have ONE pulp horn PER sizable CUSP

• 2 cusp premolar has 2 pulp horns
• 3 cusp mandibular seconds have 3 pulp horns
• mandibular 1st premolars with a functionless lingual cusp may have only ONE pulp horn

Question 13

what is the length of the pulp horns in premolars?

Answer 13

pulp horn lengths tend to mirror the height of the cusps

ex: lingual pulp horn is shorter than buccal pulp horn

Question 14

how many root canals do the premolars have ?

Answer 14

maxillary 1st: 2 roots 2 canals (buccal and lingual) ***even single rooted still have 2 canals

maxillary 2nd: 1 root 1 canal **sometimes 2 canals

mandibular 1st and 2nd: 1 root 1 canal **sometimes have roots that bifurcate towards the apex

Question 15

pulp chambers and pulp horns of the maxillary molars?

Answer 15

• pulp chamber is broader buccolingually than mesiodistally
• mirrors the shape of the tooth

Question 16

pulp chambers and pulp horns of the mandibular molars?

Answer 16

• pulp chamber is broader mesiodistally than buccolingually
• mirrors the shape of the tooth

Question 17

how many pulp chambers and pulp horns do molars have?

Answer 17

• One pulp horn per functional cusp

-4 cusp type has 4 pulp horns
**cusp of carabelli is not functional

• 3 cusp types of maxillary molars have 3 pulp horns
• mandibular first molar has 5 cusps so 5 pulp horns

Question 18

root canals and orifices of maxillary molars

Answer 18

• 1st and 2nd maxillary molars have
  3 roots (palatal, MB, DB) and
  4 canals (2MB, 1P, 1DB)
• 4 orifices in the chamber floor

***palatal canal is the largest canal and most easily accessible

Question 19

root canals and orifices of mandibular molars

Answer 19

• 2 roots (M and D)
• 3 canals ( 2M and 1 D)
• 3 orifices in the chamber floor

Question 20

how many root canals does a third molar have?

Answer 20

maxillary usually have 3 root canals
mandibular usually have 2 root canals

Question 21

what are some changes in the pulp cavity as the tooth ages???

Answer 21

• primary teeth have thinner enamel and dentin and the pulp cavities are larger and closer to the occlusal/incisal surface
• as the tooth ages the odontoblasts line pulp chamber and deposit secondary dentin
• diameter of root canal decreases

***necrotic teeth (nerve and blood supply has been lost)
- pulp canal stays the same bc there is no vital odontoblasts to deposit secondary dentin

Question 22

what is a pulp cap (bandages)? and what are the two types?

Answer 22

calcium hydroxide stimulates the formation of secondary dentin

• indirect pulp cap: when calcium hydroxide is applied to thin layer of remaining dentin that covers pulp chamber
• direct pulp cap: calcium hydroxide is placed over a small pulpal exposure

Question 23

what is reversible pulpitis?

Answer 23

mild inflammation in which pulp tissue remains healthy and can be saved

Question 24

what is irreversible pulpitis and what are some findings?

Answer 24

inflammation of the pulp that will not heal without the removal of pulp tissue (root canal therapy)

hot/cold/sweet sensitivity, spontaneous pain, and or prolonged response to cold when tested with endo ice

Question 25

what is periapical disease?

Answer 25

pulp has become infected and infection spread to the alveolar bone via the apex

Question 26

what are the specifics of the maxillary central incisors?

Answer 26

• cervical outline is a triangular shape
• one canal
• no prominent root depressions

Question 27

what are the specifics of the maxillary lateral incisors?

Answer 27

• cervical outline is egg shaped
• one canal
• shallow mesial depression

Question 28

what are the specifics of the mandibular central and lateral incisors?

Answer 28

• cervical outline is ovoid (wider F-L than M-D)
• one canal is most common
• slight mesial and distal root depressions

Question 29

what are the specifics of the maxillary canines?

Answer 29

• cervical outline is ovoid (wider F-L than M-D)
• one canal
• root depression on M and D

Question 30

what are the specifics of the mandibular canines?

Answer 30

• cervical outline is ovoid (wider F-L than M-D)
• one canal (sometimes 2 canals: 1F and 1L)
• root depressions on M and D (distal deeper)

Question 31

what are the specifics of the maxillary 1st premolar?

Answer 31

• 2 roots 2 canals
• furcation in apical half
• mesial crown and root cavitation in cervical

Question 32

what are the specifics of the maxillary 2nd premolar?

Answer 32

• cervical crown outline is ovoid (wider B-L)
• usually 1 root 1 canal
• root depressions on mesial and distal (distal deeper)

Question 33

what are the specifics of the mandibular 1st premolar?

Answer 33

• cervical outline is ovoid (wider B-L)
• one canal
• root depressions on M and D (distal deeper)

Question 34

what are the specifics of the mandibular 2nd premolar?

Answer 34

• cervical outline is ovoid (wider B-L)
• usually one canal
• root depression common on the distal

Question 35

what are the specifics of the mandibular 1st and 2nd molars?

Answer 35

• 2 roots (M D)
• 3 canals (MB ML D)
• M root is wider B-L
• M root has M and D depressions

** first molars have shorter root trunks and more divergent roots; moving posteriorly trunk becomes longer, roots less divergent

Question 36

what are the specifics of the maxillary 1st and 2nd molars?

Answer 36

• 3 roots ( MB DB P)
• 4 canals ( P MB1 MB2 DB)
• MB root is wider B-L than DB and has depressions
• furcation access in mid facial, mesial and distal

** first molars have shorter root trunks and more divergent roots; moving posteriorly trunk becomes longer, roots less divergent