Pulp cavities

Pulp Morphology
Dr.Vaishnavi

1. Pulp cavities DR.VAISHNAVI Department of Oral Pathology SRM Dental College, Ramapuram , Chennai, India

2. DENTAL PULP ORIGIN – Mesenchyme Functions: Formative: Dentin formation (during developmental period) Formation of reparative dentin, secondary dentin, reactive dentin Nutritive Sensory Defensive.

3. The dental pulp is the soft tissue component of the tooth. The crown and root portion of a tooth that contains the pulp tissues has been arbitrarily divided into the pulp chamber the root or pulp canal the outline form of the pulp chamber corresponds with the shape of the crown the outline form of the pulp canal corresponds with the shape of the roots of a tooth.

4. Various terms pulp chamber pulp cavity, coronal pulp root pulp radicular pulp, pulp canal root canal to designate that part of the crown normally filled with soft tissue to designate that part of the root normally filled with soft tissue

5. Common use: pulp cavity The pulp chamber is in the crown portion mainly The pulp canal is in the root The spaces are continuous with each other and are spoken of collectively as the pulp cavity.

6. Why should we learn about pulp cavities?? Clinical Applications It is essential that the clinician be aware of the location and size of the pulp cavities during operative procedures to prevent unnecessary encroachment on the pulp. Endodontic procedures require a thorough knowledge of the pulp cavity. Perforation during access preparation, failure to locate all the canals, or perforation of the root surface may result in the ultimate loss of the tooth. Therefore the clinician performing endodontics must know the size and location of the pulp chamber and the expected number of roots and canals.

7. SIZE OF THE PULP CAVITY The size of the pulp chamber depends on the age of the tooth and its history of trauma. The size of the pulp cavity is much larger in a young individual than in an adult Secondary dentin is formed continuously throughout the life of the tooth as a normal process, as long as the vitality of the tooth is maintained. The formation of secondary dentin is not uniform, because the odontoblasts adjacent to the floor and roof of the pulp cavity produce greater quantities of secondary dentin than do the odontoblasts located adjacent to the walls of the pulp cavity should be considered before extensive tooth reduction is accomplished, especially in a young person. Elective endodontics should be considered when extreme calcification (Irritation induced or reparative dentin) is present in a tooth scheduled for complex restorative procedures.

8. Comparison in size of the pulps of two intact lower first permanent molars at different ages. the young pulp chamber is large The older pulp is reduced in size

9. apical foramen The neurovascular bundle, which supplies the internal contents of the pulp cavity, enters through the apical foramen or foramina It is possible for any root of a tooth to have multiple apical foramina If these openings are large enough, the space that leads to the main root canal is called a supplementary or lateral canal If the root canal breaks up into multiple tiny canals, it is referred to as a delta system because of its complexity

10. Apical foramen – various stages of development

11. Pulp horns Projections or prolongations in the roof of the pulp chamber correspond to the various major cusps or lobes of the crown. The pulpal tissues that occupy these prolongations are called pulp horns The prominence of the cusps or lobes corresponds with the development of the pulp horns. If the cusps or labial lobes are prominent (as in young individuals), one should expect to find equally prominent pulp horns underlying these structures These projections become less prominent with time as a result of the formation of secondary dentin

12. Molar and bicuspid pulp cavities. Note the prominence of the pulp horns and the complexities of the pulp chambers and root canal systems.

13. MICROCOMPUTED TOMOGRAPHIC SCANS OF DENTAL ANATOMY Two accessory canals and an apical bifurcation Working length radiograph with files placed in both apical canal aspects.

14. Clinical view of tooth #3 shows a fine mesiobuccal and distobuccal canal system with additional anatomy in all three roots.

15. Vertucci’s classification

16. MORPHOLOGY OF PULP CHAMBERS AND CANALS IN DECIDUOUS TEETH The pulp chambers in deciduous teeth are relatively larger than their permanent counterparts. They have certain common features as follows: Pulp horns are closer to the outer surface. Deciduous teeth exhibit great variation in size and location. The mesial pulp horn is located higher when compared with other pulp horns There is usually a pulp horn under each cusp.

17. Pulp cavities of DECIDUOUS INCISORS AND CANINES The morphology of the pulp chambers and canals follows the outline of the tooth single root canal The chamber is larger than the permanent teeth with pointed pulp horns. The root canals are wider in the coronal aspect and taper towards the apex.

18. Pulp cavities of DECIDUOUS MOLARS Deciduous molars have four root canals in each tooth. The maxillary deciduous molars have two canals in the mesial root accounting for four in total The mandibular deciduous molars have two canals in each of the two roots. The pulp chamber is very close to the coronal surface and the furcation area. Care should be taken during restorative procedures.

19. Maxillary Central Incisor Intracoronal anatomy The pulp chamber is broader from mesial to distal direction than from the facial to palatal direction, following the external contour of the crown. (b) Two or three slender extensions of pulp tissue form pulp horns usually towards incisal edges in young teeth. (c) the chamber space has a triangular configuration with a broad base towards incisal edge and apex towards the cervical aspect.

20. Intra-radicular anatomy The coronal pulp space converges towards the neck of the tooth and continues into the root. (b) The central incisor usually contains a single root canal, rarely, it may contain more than one canal. The dimensions of the root are wider labiopalatally than in the mesiodistal direction. (c) The pulp canal is a tubular structure which is wide near the coronal region and narrows down to a circular or oval-shaped apical foramen. (d) The shape of the root canal at various levels are as follows: • Cervical: Wider in the mesiodistal dimension • Midroot : Ovoid • Apical third: Round

21. Maxillary lateral incisor Intracoronal anatomy (a) The anatomy is similar to that of a central incisor but of smaller dimensions. (b) Pulp horns may or may not be present. (c) The mesial and distal surface margins converge and narrow down towards the cervical region more when compared with the central incisor.

22. Maxillary lateral incisor 2. Intraradicular anatomy The root canal begins at the orifice in a small triangular form and ends in a circular or oval-shaped apical foramen. b) Similar to central incisor there may be more than one canal in about less than 5% of people; if there are two canals, they are placed in the labiopalatal direction. (c) The shape of the root canal at various levels is as follows: • Cervical: Wider in the labiopalatal dimension • Midroot : Ovoid in shape • Apical third: Generally round-shaped and gradually curved

23. Maxillary Canine Intracoronal Anatomy The crown is wider in dimension in the labiopalatal direction, and the pulp space follows this feature. (b) Pulpal extensions to form pulp horns are absent. (c)The large pulp space constricts to have an oval configuration, which continues into the root.

24. Maxillary canine 2. Intraradicular anatomy The maxillary canine has a single root canal (b) The canal space begins in an oval form and continues in the same way till the root apex, where it is smaller in cross-section. (c) A gentle buccal curvature of the root outline is a common occurrence at the apex, which makes the internal canal also curved near the apex. (d) The shape of the root canal at various levels are as follows: Cervical: Wider in the mesiodistal dimension Midroot : Ovoid Apical third: Round

25. Maxillary First Premolar Intracoronal anatomy The tooth has two cuspal eminences, buccal and palatal, with a hexagonal crown form.  pulp horns The buccal pulp horn is higher than the palatal pulp horn. © The pulp space in the crown of premolar is wider in the buccolingual direction and is kidney-shaped in cross-section. (d) The space does not constrict much near the cervical part as there are two separate roots and two canals.

26. Maxillary First Premolar Intraradicular anatomy The anatomy follows the external outline form of the two slender roots separately. (b) The palatal canal is relatively larger in dimension than the buccal canal. (c) There is a possibility of three canals occurring with one in the palatal root and two in the buccal root. (d) The root canals show a curvature towards the buccal aspect as they follow the root outline. (e) The shape of the root canal at various levels is as follows: • Cervical: Very wide buccolingually • Midroot : Slightly ovoid • Apical third: Round-shaped

27. Maxillary Second Premolar 1. Intracoronal anatomy It is similar to the maxillary first premolar, but smaller and more rounded than the first premolar. 2. Intraradicular anatomy The number of roots and the internal anatomy of root differ. It can have a single or up to three roots (not very common) and a single or two canals within the same root or different roots. (b) The roots are slender than the first premolar and hence the root canal space is narrower and in oval fashion. (c) The shape of the root canal at various levels is as follows: • Cervical: Very wide mesiodistal dimension • Midroot : Ovoid • Apical third: Round

28. Maxillary First Molar Intracoronal anatomy (a) The crown has a large pulp space from the buccal to the lingual direction with four cuspal prominences ( mesiobuccal , distobuccal , mesiopalatal , distopalatal ). (b) The shape of the chamber is rhomboid because of the external contour of the crown. (c) The coronal pulp space is continuous with root canal at the level of floor of the pulp chamber near the area of division of the root known as the furcation area .

29. Intraradicular anatomy There are usually three roots (palatal, mesiobuccal , distobuccal ). (b) The intraradicular pulp anatomy depends on the number of canals as a second canal in the mesiobuccal root is a common occurrence. (c) Palatal root is the largest and has a single palatal canal; more than one canal can occur in palatal root. The distobuccal root can also have more than one canal. (d) The shape of the root canal at various levels is as follows: • Cervical: Triangular • Apical third: Round

30. Maxillary second molar Intracoronal anatomy (a) It appears identical to maxillary first molar. (b) Three to four pulp horns are present. (c) rhomboid in shape 2. Intraradicular anatomy The maxillary second molar has three roots but they converge more towards each other than the maxillary first molar. This convergence causes curvature of the root canals. (b) three canals - more common (c) The shape of the root canal at various levels is as follows: • Cervical: Triangular • Apical third: Round

31. Maxillary Third Molar Large variation is seen both in the intracoronal and intraradicular anatomy because of shape, size, number of cusps and roots and the spatial orientation of roots. 2. The intracoronal anatomy depends on the number of the cusps. 3. Three roots and three canals is a common occurrence. 4. The root can exhibit curvature of different nature. 5. The intracoronal and intraradicular anatomy of maxillary third molar cannot be generalised .

32. Mandibular central Incisor Intracoronal anatomy It has a small pulp chamber with three distinct pulp horns at birth. (b)The pulp chamber is wide labiolingually . 2. Intraradicular anatomy It has a single root which is flat and narrow mesiodistally and wide labiolingually . (b) At the cementoenamel junction, the pulpal outline is oval  becomes more narrower towards the apex (c) The root is straight in 60% of the cases. Nearly 70% of the cases have one canal and one apical foramen, whereas 22% of the cases show one canal, which bifurcates into two and exits into one apical foramen. (d) The shape of the root canal at various levels is as follows: • Cervical: Wider labiolingually • Midroot : Ovoid • Apical third: Round

33. Mandibular Lateral Incisor 1. Intracoronal anatomy The Configuration of the pulp chamber is similar to central incisor but with larger dimensions. 2. Intraradicular anatomy The root of the lateral incisor is larger than but similar to the central incisor, (b) The distal curve of the root is sharper. (c) The incidence of two root canals at the apex is same as the central incisor. (d) The cross-sectional anatomy is also similar to the central incisor. (e) The shape of the root canal at various levels is as follows: • Cervical: Wider in the labiolingually direction • Midroot : Ovoid • Apical third: Round-shaped

34. Mandibular Canine Intracoronal anatomy It has a prominent pulp horn. The pulp chamber is wide labiolingually . (c) There is no distinct demarcation between the pulp chamber and the root canal. (d) The pulp chamber tapers at incisal one third of the crown and is wide at the cervical third. (e) The pulp chamber is ovoid in the cervical third of the crown.

35. Mandibular canine 2. Intraradicular anatomy The root is broad in the middle third and tapers in the apical third. The cross-section in the cervical and middle third is ovoid, whereas in the apical third, it is round. Usually the root canals are straight, but sometimes distal curvatures are present. One canal exiting in one foramen is usually seen. If two canals are present, they join before exiting the apex. Sometimes two roots and two canal are present. The shape of the root canal at various levels are as follows: • Cervical: Wider in the labiolingual direction • Midroot : Ovoid • Apical third: Round-shaped

36. Mandibular First Premolar Intracoronal anatomy The mesiodistal width of the pulp chamber is wide. (b) A prominent buccal pulp horn is present under the well-developed buccal cusp. In young tooth, a smaller lingual pulp horn is present. (c) In cross-section, the pulp chamber is ovoid, with greater diameter buccolingually . (d) If only one canal is present, then there is no distinct division between the pulp chamber and the root canal.

37. Mandibular first premolar 2. Intraradicular anatomy The tooth exhibits wide variation in the intraradicular anatomy. (b) It has a short, conical root canal. • If one canal is present, it is cone-shaped and simple in outline. Mesiodistally it is narrow and broader buccolingually and tapers towards apical third. • In cross-section, the cervical and middle thirds are ovoid, whereas the apical third is round. (d) The shape of the root canal at various levels is as follows: • Cervical: Wider in the buccolingual dimension • Midroot : Ovoid • Apical third: Round-shaped

38. Mandibular first premolar The possibilities of variation in the root canal and foramen pattern are as follows: • One canal and one foramen – 70% • One canal bifurcates into two canals, exits in two foramina –24% • Two canals exit in two foramina–1.5% • One canal bifurcates into two canals and unites in the apical third and exits in one foramen – 04% • Three canals exiting in three foramina – 0.5%

39. Mandibular Second Premolar Intracoronal anatomy (a) It is similar to the first premolar except that the lingual pulp horn is larger than the first premolar. (b) The pulp chamber is wider buccolingually . (c) The separation of the pulp chamber and the root canal can be seen. 2. Intraradicular anatomy (a) It has one root and one canal, which may be curved distally. (b) The cross-section in the cervical third is rectangular or triangular. (c) In 2.5% of cases, the single canal bifurcates into two foramina. (d) The shape of the root canal at various levels is as follows: • Cervical: Wider buccolingually • Midroot : Long ovoid • Apical third: Round-shaped

40. Mandibular First Molar Intracoronal anatomy The shape of the pulp cavity is rectangular to trapezoid. (b) It has four pulp horns, namely, mesiobuccal , mesiolingual , distobuccal and distolingual . (c) Three distinct orifices are present: mesiobuccal , mesiolingual and distal.

41. Mandibular first molar 2. Intraradicular anatomy It has two mesial and one distal canals. An additional distal canal and a third mesial canal, known as the middle mesial canal ,are common variations. (b) Access opening is usually trapezoid, with round corners, or rectangular, if a second distal canal is present. The shape of the root canal at various levels is as follows: • Cervical: Oval-shaped • Midroot : Ovoid • Apical third: Round-shaped

42. middle mesial canal

43. Mandibular Second Molar Intracoronal anatomy The tooth is smaller than the mandibular first molar. (b) Two mesial orifices are located close together. (c) The pulp horns are rather prominent . (d) The pulp chamber of the mesial root is well demarcated. (e) In cross-section, the pulp chamber is square or rectangular.

44. Mandibular Second Molar Intraradicular anatomy (a) Two canals in mesial root and one in distal root are present. (b) Canals taper from the pulp chamber to apex. (c) Mesial canals have greater curvature than the distal canal. The cross-section at the midroot level is kidney-shaped or in the shape of the number 8. (e) Mesial canals either have one foramen or exit as two or more foramina. (f) Joining of two mesial canals is most common. (g) C-shaped canals may occur in fused roots. (h) The distal root may have two canals in occasional cases. ( i ) The shape of the root canal at various levels is as follows: • Cervical: Oval-shaped • Midroot : Ovoid • Apical third: Round-shaped

45. Mandibular third molars

46. ANATOMICAL VARIATIONS IN ROOT CANALS Additional root canals: Second root canal in distal root of mand . First molar Second mesiobuccal canal in the maxillary first molar Morphological variations: Bifurcations and joining of root canals Anomalies of external morphology  affects internal anatomy for example: Taurodontism Dens evaginatus Dens invaginatus Fusion Gemination

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