National medical university of LVIV department of therapeutic dentistry



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DANYLO HALYTSKY

NATIONAL MEDICAL UNIVERSITY OF LVIV

DEPARTMENT OF THERAPEUTIC DENTISTRY


METHODological GUide

for|by| practical classes

Preclinical course of Therapeutic Dentistry”



(IV semester)

for the 2-nd year students

Part II


Lviv-2012

The methodological guide worked out by: M. Hysyk, O. Ripetska, Yu. Riznyk

Edited by prof. V. Zubachyk
Accountable for an issue  first vice-rector of scientific and academicl work, professor, Corresponding Member of the Academy of Medical Sciences of Ukraine, M.R. Gzhegotskiy.

Reviewers: associate professor of department of Surgical dentistry N. Krupnik,

associate professor of department of Pediatric dentistry N. Chukhraj


Methodological guide|elaboration| for students in Therapeutic dentistry (III semester) was discussed and approved on the sitting|sitting| of the department|pulpit| of Therapeutic dentistry (record of proceedings №15, dated from 11, May, 2010) and approved on the meeting|sitting| of Methodological committee in dentistry disciplines on June 22, 2010, protocol № 3.

Computer printing: Oksana Zamoiyska

CONTENT OF THE COURSE








Page


1.

Practical lesson 33. Endodontics. Topographical anatomy of permanent teeth cavities and root canals …………………………

4


2.

Practical lesson 34. Technique of tooth cavity opening. Medications for pulp devitalization. Local anesthesia ………………………………..

26


3.

Practical lesson 35. Endodontic instruments. Classification. Types. Indications for use ………

33


4.

Practical lesson 36. Work with endodontic instruments. The use of medications for cleaning of the root canal. Methods of cleaning and widening of root canals …………………………

42


5.

Practical lesson 37. Root canal filling materials. Classification. Main demands. Partially hardening sillers. Composition. Characteristic. Indications for use ……………………………...

49


6.

Practical lesson 38. Filling of the root canals with partially hardening and hardening sealers and fillers ……………………………………….

61


7.

Practical lesson 39. Methods of fillings of the root canals. Mistakes and complications during endodontic manipulations, their reasons and ways of removal ………………………………..

67


8.

Practical lesson 40. Summary control 2 ……..

75



Practical lesson No 33
Theme: Endodontics. Topographical anatomy of permanent teeth cavities and root canals.

Short description of a theme
The endodont complex connects dentin, pulp, apical periodont, cement of the apical part of the root and a bone. The effectiveness of the root canal system treatment depends on the pulp chamber anatomy and a root canal system morphology. The pulp chamber is similar to the crown morphology.

Pic.1. The root canal systems


The 4 canal types:

  • the teeth, which have 1 root canal from orifice to apex opening

  • the teeth have 2 root canals which are connected near the root apex and have 1 apex opening

  • the teeth which have two roots, and have 2 apexes opening

  • the teeth which have 1 root canal and are divided in the root apical part on part and have 2 apex opening


Central upper incisors

On the mesiodistal cut in central incisors, the pulp chamber is broad and may have a suggestion of mesial and distal horns. On the labiolingual cut the pulp chamber tapers to a point toward the incisal edge. Often central incisors root have a bend in apical area, as usual in palatal direction.

Medium length of the tooth is 22,5 mm

The number of roots is most frequently one.

Central incisor usually has 1 canal (type I)

Lateral canals – seldom

Apical delts – often

Apical opening localization

- 0-1 mm from the root apex - 80%

- 1-2 mm from the root apex - 20%




Pic.2. Central upper incisors



Lateral upper incisor



In the neck area the canal is wider in vestibule-oral direction. On the mesiodistal cut in lateral incisors, the pulp chamber is broad and may have a suggestion of mesial and distal horns. On the labiolingual cut the pulp chamber tapers to a point toward the incisal edge. The roof of the pulp chamber is often rounded. Often lateral incisors roots have a bend in apical area, as usual in palatal direction.

Medium length of the tooth is 22 mm

The number of roots is most frequently 1 – 99,9%

Amount of canals 1 – 99,9%

Lateral canals – seldom

Apical delts – often

Apical opening localization - 0-1 mm from the root apex - 90%

- 1-2 mm from the root apex - 10%





Pic. 3. Lateral upper incisor


Upper canine

The pulp cavity is large. The incisal wall or roof of the pulp chamber is often rounded. The upper canine pulp chamber is similar to the crown. Root canal is straight. Often upper canine roots have a bend in apical area, as usual in palatal or distal direction.

Medium length of the tooth is 26,5 mm

The number of roots is most frequently 1 – 99,9%

Amount of canals 1 – 99,9%

Lateral canals – seldom

Apical delts – seldom

Apical opening localization - 0-1 mm from the root apex - 70%

- 1-2 mm from the root apex - 30%




Pic. 4. Upper canine


1-st upper premolar

On the mesiodistally at the occlusal border of roof is curved beneath the cusp similar to the curvature of the occlusal surface. Pulp chamber is prolong in vestibulooral direction. The buccal canal orifice is located just lingual to the buccal cusp tip. The lingual canal is located just lingual to the central fossa. Most of the 1-st upper premolars are concave on mesial root surface. On buccolinguale cut the pulp horns in the roof are visible beneath each cusp. The buccal horn is longer than the lingual horn. The pulp chamber often has general outline of the tooth surface, sometimes including a constriction near or apical to the cervix. The average incidence of two canals, buccal and lingual, is 90% (both Type I when two roots are present, and either a Type II or Type III with one root).

Medium length of the tooth is 20,6 mm

The number of roots 1 – 19%, 2 – 80%, 3 – 1%

Amount of canals 1 – 4%, 2 - 95%, 3 – 1%

Lateral canals – seldom

Apical delts – seldom

Apical opening localization - 0-1 mm from the root apex - 95%

- 1-2 mm from the root apex - 5%



Pic. 5. 1-st upper premolar



2-nd upper premolar

Medium length of the tooth is 21,5 mm

The number of roots 1 – 90%, 2 – 9%, 3 – 1%

Amount of canals 1 – 75%, 2 - 24%, 3 – 1%

Lateral canals – seldom

Apical delts – seldom

Apical opening localization - 0-1 mm from the root apex - 75%

- 1-2 mm from the root apex - 25%

When there is one canal, the orifice is located in the exact center of the tooth. If the orifice is located toward the buccal or the lingual, it probably means there are two canals in the root. The average incidence of two canals is about 24% (Type II or Type III) .

In 10-15% cases on 3-4 mm from root apex the basic root canal may be divided into on two canals. Often, near the apical opening two canals can be connected, but in this case most often it there are two apical openings.





Pic. 6. 2-nd upper premolar
1-st upper molar

Pulp Chamber.

There is a pulp horn well beneath each cusp in the roof of the chamber. The pulp chamber is normally deep to or some distance from the occlusal surface. One exception might be the pulp horn of the mesiolingual cusp. The pulp chamber is broader buccolingually than mesiodistally and is often constricted near the floor of the chamber. The floor of the pulp chamber is constricted apically to the cervical line; it is located in the root trunk. It has three or four openings, one for each root canal. Most frequently three are roots, but four canals; one for each in the distobuccal and palatal root: two in the mesiobuccal root. In the palatal root, the canal is larger and more easily accessible from the floor of the pulp chamber than for the other two roots, but this root and its canal often bend toward the buccal in the apical third.

The palatal orifice is located beneath the mesiolingual cusp. The distobuccal orifice is located on a line between the palatal orifice and the buccal developmental groove at a point just short of the angle formed by the buccal and distal walls of the pulp chamber. The mesiodistal orifice is located slightly mesially to and beneath the mesiobuccal cusp tip. The MB2 orifice is located 2-3 mm distal and slightly to the palatal aspect of the mesiobuccal orifice.

Medium length of the tooth is 20,8 mm

The number of roots 2 – 15%, 3 – 85%

Amount of canals 3 – 60%, 4- 40%

Lateral canals – sometimes

Apical delts – seldom



Pic. 7. 1-st upper molar


2-nd upper molar

Pulp Chamber.

There is a pulp horn well beneath each cusp in the roof of the chamber. The pulp chamber is normally deep to or some distance from the occlusal surface. One exception might be the pulp horn of the mesiolingual cusp. The pulp chamber is broader buccolingually than mesiodistally and is often constricted near the floor of the chamber. The floor of the pulp chamber is constricted apically to the cervical line; it is located in the root trunk. It has three or four openings, one for each root canal. Most frequently have there are roots, but sometimes four canals; one for each in the distobuccal and palatal root: two in the mesiobuccal root. In the palatal root, the canal is larger and more easily accessible from the floor of the pulp chamber than for the other two roots, but this root and its canal often bend toward the buccal in the apical third.

The location of the orifices in the maxillary second molar is similar to the maxillary first molar, except that they are closer together.


Medium length of the tooth is 20mm

The number of roots 1-1%, 2 – 19%, 3 – 80%

Amount of canals 1-1%, 2 – 2%, 3 – 57%, 4- 40%

Lateral canals – sometimes

Apical delts – seldom


Pic. 8. 2-nd upper molar


First lower incisor

On the mesiodistal cut in central incisors, the pulp chamber is broad and may have a suggestion of mesial and distal horns. On the labiolingual cut the pulp chamber tapers to a point toward the incisal edge.

In 60% the lower central incisor canal has - I type, 35% - II type, 5% - III type

Medium length of the tooth is 20,7 mm

The number of roots is most frequently one.

Central incisor has 1 canal (60%), 2 canals (40%)

Lateral canals – seldom

Apical delts – seldom

Apical opening localization - 0-1 mm from the root apex - 90%

- 1-2 mm from the root apex - 10%



Pic. 9. First lower incisor



Second lower incisor

On the mesiodistal cut in central incisors, the pulp chamber is broad and may have a suggestion of mesial and distal horns. On the labiolingual cut the pulp chamber tapers to a point toward the incisal edge.

Medium length of the tooth is 21,7 mm

The number of roots is most frequently one.

Central incisor has1 canal (60%), 2 canals (40%, usually Type II)

Lateral canals – seldom

Apical delts – seldom

Apical opening localization - 0-1 mm from the root apex - 90%



  • 1-2 mm from the root apex - 10%




Pic. 10. Second lower incisor
Lower canine

Tha pulp cavity is large. The incisal wall or roof of the pulp chamber is often rounded. The lower canine pulp chamber is similar to the crown. Root canal is straight. Often lower canine has a bend in apical area, as usual in distal direction

Medium length of the tooth is 25,6 mm

The number of roots - 1 (98%), 2 (2%)

The number of canals - 1 (94%), 2 (6%)

Lateral canals – seldom

Apical delts – seldom

Apical opening localization - 0-1 mm from the root apex - 95%

- 1-2 mm from the root apex - 5%


Pic. 11. Lower canine





First lower premolar

The occlusial border or roof is curved beneath the cusp similar to the curvature of the occlusal surface. On buccolingual cut the pulp horns in the roof are visible beneath each cusp. The buccal horn is longer than lingual horn. The pulp chamber often has the general outline of the tooth surface, sometimes including a constriction near or apically to the cervix. First premolar most frequently has one root and one canal. The first premolar has a Type I canal system about 70% of the time and Type IV canal system 24% of the time. The canal orifice is located just buccal to the central fossa.

Medium length of the tooth is 25,6 mm

The number of roots - 1 (98%), 2 (2%)

The number of canals - 1 (94%), 2 (6%)

Lateral canals – seldom

Apical delts – seldom

Apical opening localization - 0-1 mm from the root apex - 95%

- 1-2 mm from the root apex - 5%


Pic.12. First lower premolar














.



Second lower premolar



The occlusial border or roof is curved beneath the cusp similar to the curvature of the occlusal surface. On buccolingual cut the pulp horns in the roof are visible beneath each cusp. The buccal horn is longer than lingual horn. The pulp chamber often has the general outline of the tooth surface, sometimes including a constriction near or apically to the cervix.

The second premolar has one root canal 96% of the time and a Type IV system 2,5% of the time. The canal orifice is located just buccally to the central fossa.

Medium length of the tooth is 25,5 mm

The number of roots - 1 (100%)

The number of canals - 1 (89%), 2(10%), 3(1%)

Lateral canals – seldom

Apical delts – seldom

Apical opening localization - 0-1 mm from the root apex - 65%

- 1-2 mm from the root apex - 30%

- 2-3 mm from the root apex - 5%






Pic. 13. Second lower premolar






First lower molar

There is a pulp horn well beneath each cusp in the roof of the chamber. The pulp chamber is normally deep to or some distance from the occlusal surface. The floor of the pulp chamber is constricted apically to the cervical line; it is located in the root trunk. It has three or four openings, one for each root canal.

Most frequently there are two roots (mesial and distal), and three canals (one in the distal root and two in the mesial root). The mesial root usually has two canals: mesiobuccal and mesiolingual. A Type III canal system is present 60% of the time and Type II canal system is present 40% of the time. The mesiobuccal orifice is located slightly mesial and close to the mesiobuccal cusp tip. The mesiolingual orifice is just lingual to the mesial developmental groove of the mesial marginal ridge. It is not under the mesiolingual cusp tip, but is in a more central location.

In the distal root, the canal is larger and more easily accessible from the floor of the pulp chamber than for the other root. The distal root has two canals approximately 35% of the time. If the distal root has one canal, the orifice is larger and located just distal to the center of the crown. When two canals are present, the distolingual orifice is smaller and is located centrally just lingual to the central fossa. Usually the canal configuration is Type II system.


Medium length of the tooth is 21 mm

The number of roots 2 – 98%, 3 – 2%

Amount of canal 3 – 80%, 4- 7%, 2 -13%

Lateral canals – sometimes in furcation region

Apical delts – seldom





Pic. 14. First lower molar








Second lower molar

Pulp Chamber.

There is a pulp horn well beneath each cusp in the roof of the chamber. The pulp chamber is normally deep to or some distance from the occlusal surface. The floor of the pulp chamber is constricted apically to the cervical line; it is located in the root trunk. It has three or four openings, one for each root canal. Most frequently there are two roots (mesial and distal), and three canals (one in the distal root and two in the mesial root). In the distal root, the canal is larger and more easily accessible from the floor of the pulp chamber than for the other root.

A Type II canal system is present 38% of the time and a type III canal system is present 26% of the time. The location of the orifices for mandibular second molars is similar to that of the mandibular first molars.


Medium length of the tooth is 20 mm

The number of roots 2 – 84%, 3 – 1%, 1-15%

Amount of canals 3 – 77%, 4- 7%, 2 -13%, 1-3%

Lateral canals – sometimes in furcation region

Apical delts – seldom


Pic. 15. Second lower molar









Third molars

Maxillary and mandibular third molars are very considerable in form, having from one to seven cusps. Third molars will have as many pulp horns as cusps, and as many root canals as roots. Maxillary third molars usually have three root canals and mandibular molars usually have two.











Pic. 16. Third upper molar





Pic. 17. Third lower molar






Control questions to|by| practical lesson


  1. How many roots and canals are there in the central upper incisor?

  2. How many roots and canals are there in the lateral upper incisor?

  3. How many roots and canals are there in the upper canine?

  4. How many roots and canals are there in the 1-st upper premolar?

  5. How many roots and canals are there in the 2-nd upper incisor?

  6. How many roots and canals are there in the 1-st upper molar?

  7. How many roots and canals are there in the 2-nd upper molar?

  8. How many roots and canals are there in the 3-d upper molar?

  9. How many roots and canals have the central lower incisor?

  10. How many roots and canals are there in the lateral lower incisor?

  11. How many roots and canals are there in the lower canine?

  12. How many roots and canals are there in the 1-st lower premolar?

  13. How many roots and canals are there in the 2-nd lower premolar?

  14. How many roots and canals are there in the 1-st lower molar?

  15. How many roots and canals are there in the 2-nd lower molar?

  16. How many roots and canals are there in the 3-d lower molar?



Situation tasks and test control
1. What elements does the „tooth cavity” include?

A. pulp chamber, root canal system

B. pulp chamber, basic root canal, additional root canals, apex

C. pulp chamber, basic root canal, additional root canals, apical delta, apex

D. pulp chamber
2. What elements does the pulp-dentinal complex consist of?

A. Odontoblasts, predentin, dentin

B. Odontoblasts, predentin, dentin, vessels, nerves

C. Odontoblasts, predentin, dentin, vessels, nerves, pure cells layer, rich cells layer

D. Odontoblasts, predentin, dentin, vessels, nerves, pure cells layer, rich cells layer, central layer

3. What formations contain the epithelial cells?

A. Pulp-dentin complex

B. Pulp-periapical complex

C. Pulp


D. No one
4. What formations does the „endodont” clinical definition include?

A. Pulp-dentin complex

B. Pulp-periapical complex

C. Pulp


D. Any
5. What classes according Black classification are the most rare that cause the pulp inflammation?

A. I


B. II

C. III


D. IV

E. V
6. What elements does the root canal system consist of?

A. Basic canal

B. Second basic canal in the same root

C. Additional canals

D. Аpical deltas

E. Transversal canals
7. How often the apical opening does not coincide with the tooth root apex? Name the percentage.

A. 25%


B. 50%

C. 75%


D. 100%
8. What is the mean distance from the anatomical to the tooth root apex?

A. 0 mm


B. 0, 5 mm

C. 1 mm


D. 1, 5 mm

E. 2 mm
9. What is the time of the apex of the root maturation?

A. 0,5 year

B. 1 year

C. 2 years

D. 3 years


10. What are the age changes in tooth and tooth root canal system?

A. tooth cavity decrease, abrasion, tooth mobility

B. tooth cavity decrease, secondary dentin and cement formation (deposition), alveolar process atrophy

C. tooth cavity decrease, secondary dentin and cement formation (deposition), alveolar process atrophy, tooth mobility


11. Name the percentage of cases when 4 canals in the 1-st lower molar can be observed?

A. 5%


B. 10%

C. 20%


D. 30%
12. The cell activity is temporarily suspended in the external pulp area. What tooth tissue possesses the menace of physiological regeneration deficit?

A. Dentin

B. Cement with cells

C. Cement without cells

D. Enamel

E. Pulp


13. The examination of a patient revealed the insufficient tooth pulp development. What embryonal source was damaged?

A. Endoderm

B. epithelium of the mouth

C. Mesenchyma

E. Ectoderm
14. A healthy dental pulp responses to the damage:

A. by effective collateral blood circulation for transporting the inflammatory elements to the affected site

B. by deposition of highly mineralized and tubular restorative dentin

C. by development of the inflammatory reaction with the following partial or complete pulp necrosis



d. by formation of the reparative dentin on the pulp surface under the foci of irritation
15. Fibroblasts:

A. the smallest amount of cells in the pulp

B. the cells producing collagen fibers

C. the cells whose amount increases simultaneously with the increase of blood vessels, nerves and fibers



d. the cells which are subjected to active differentiation in the pulp
16. Capillaries are found throughout the entire pulp, but the majority of them is in:

A. pulp cusps

B. central pulp

c. subodontoblastic layer

d. in the root region
17. Root canal obliteration:

A. usually the prognosis as to the tooth saving in not comforting

B. can be removed with a drill

c. in most cases it happens in patients with pathology of development

d. it may need a complex special measures in treatment
18. The sharp root canal narrowing on the X-ray film usually means:

A. root canal obliteration

B. branching or separating of the root canal

c. artefact on the X-ray

D. dystrophic calcification



Reference literature


  1. Clincal endodontics: a textbook /Leif Tronstad.– 3rd rev. ed.– New Yourk, 2009.– 249 p.

  2. Stephen Cohen, Richard C. Burns. Pathways of the pulp. Eighth edition.– Mosby, 2002.– 1031 p.

  3. Fan B, Wu M-K, Wesselink PR. Leakage along warm gutta-percha fillings in the apical canals of curved roots. Endod Dent Traumatol 2000;16:29-33.

  4. Glosson CR, Haller RH, Brent Dove S, del Rio CE. Comparison of root canal preparations using NiTihand, NiTi engine-driven and K-flex endodontic instruments. J Endod 1995;21:146-51.

  5. Molven O, Halse A, Grung B. Surgical management of endodontic failures: indications and treatment results. Int Dent J 1991;41:33-42.

  6. Seltzer and Bender’s. Dental pulp // Quintessence Publishing, 2002.



Practical lesson No 34
Theme: Technique of tooth cavity opening. Medications for pulp devitalization. Local anesthesia.

Short description of a theme
Access cavity preparation.

Access to the pulp chamber and canal system is achieved through the use of rotary high-speed burs in a dental handpiece to bore an opening in the affected tooth, typically on the lingual surface of anterior teeth and the occlusal surface of posterior teeth. A variety of bur types can be used depending on the preference of the operator and the status of the clinical crown. Long-shanked tungsten-carbide burs and size 2, 4, or 6 round burs can be used to make the access cavity. After the pulp chamber is located with a sharp, stainless steel endodontic explorer, safe-ended diamond burs or Endo-Z (Dentsply) burs are used to unroof the chamber and refine the axial walls of the cavity preparation. En­hanced illumination and magnification with head lamps, loupes, or a surgical operating endodontic mi­croscope, with magnifications up to 26 X, can aid the clinician in locating calcified canals and identifying fractures.

Removal of roof. The first step is to locate and remove the entire roof of the pulp chamber so that its walls are continuous with the access cavity. Any pulpal remnants left in the pulp chamber will break down and cause the crown of the tooth to discolour. In addition during preparation of the canal the debris left in the pulp chamber may be pushed down the canal by instruments and cause infection. Direct line access. The shape of the access cavity should be cut so that the coronal walls do not deflect instruments during root canal preparation. Access should be in a direct line with the apical third of the root canal.

Particular care must be taken not to damage the floor of the pulp chamber. In the case the floor of the pulp chamber in the molar is flattened with a bur, the location of the canal orifices will be much more difficult. The natural floor tends to guide an instrument into the canal orifice. The floor of the pulp chamber in the mandibular molar for example has the hump in the centre of the floor which will deflect the point of an instrument.

Conserve tooth substance. The access should not be made so large that the walls of the tooth will be unnecessarily weakened. The tooth must be capable of being restored.

Cutting the access cavity may be divided into three stages -locating the pulp chamber with a bur, secondly removing the roof of the pulp chamber, and finally completing the shape of the cavity.



Stage 1. A tapered tungsten 701 friction grip bur is used to locate the pulp chamber. In anterior and premolar teeth the bur is held in the main axis of the tooth. If the preoperative radiograph shows a fine canal this stage is carried out before the rubber dam is placed so that the orientation of the tooth is not lost.

In posterior teeth the handpiece head and bur are held in front of the preoperative radiograph which has been taken with a paralleling technique. The depth and angle of penetration from the occlusal surface may be estimated.

The initial penetration in posterior teeth is directed towards the main axis of the largest canal, that is the palatal canal in the maxillary teeth and the distal canal in the mandibular teeth. The pulp chamber will be at its widest in this area.

Stage 2. A No. 6 round bur in a slow handpiece is used to remove the pulp cornua and remainder of the roof of the pulp chamber. The bur is placed in the pulp chamber and a cutting action used only on the withdrawal stroke so that the roof is lifted off the chamber.

Stage 3. The access cavity shape is completed using a non-end cutting, tapered, diamond friction grip bur. It is important to ensure that the walls of the pulp chamber are continuous with the walls of the access cavity and that the cavity is bevelled to provide resistance form for the temporary restoration.

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