Pulpotomy and apexification
Young permanent teeth and teeth with incompletely formed apices are a real challenge to the dentist to make their survival possible in the oral cavity and this section details up the indications and contraindications, the procedures involved and their prognosis.
1. What are the indications for a vital pulp therapy?
Vital pulp therapy is indicated in teeth with incomplete apical development, primary teeth, teeth that would be difficult to be treated endodontically and teeth with pulpal inflammation confined to a small segment of the coronal pulp.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 6th Edn,516,517
2. What is Apexogenesis?
A pulpotomy procedure that is indicated in a tooth with an open apex to allow completion of apical closure, with a vital pulp is called as Apexogenesis.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 6th Edn,520
3. What is a Blunderbuss canal?
When trauma or decay causes a pulpal exposure or periapical involvement prior to the completion of root formation, an open apex results in which there is no conical taper to the canal. The canal is wider towards the apex than the cervical area. This is called a blunderbuss canal.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 6th Edn,519,520
4. What are the materials used to fill the canal in apexification?
A thick paste that contains calcium hydroxide and CMCP is placed in the canal till it reaches the apical portion, to stimulate the tissues to form a calcific barrier.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 6th Edn,525
5. What are the possible apical conditions in 6 months follow up radiograph of a patient treated by Apexification?
- No radiographic change, but an inserted instrument encounters blockage
- Radiographic evidence of calcified material at the apex.
- Closure of the apex with no change in the canal space
- Continuous apical development with canal space closure
- No radiographic evidences, persistence of symptoms and an increase in the size of the periapical lesion.
Ref: Franklin S.Weine,Endodontic therapy, Mosby , 6th Edn,525
6. Why is pulp testing not reliable in primary teeth and young permanent teeth?
The EPT or thermal tests are not reliable because of the incompletely formed apex, immature development of nerve bundle and the extent of inflammation within the pulp is not obtained. Also apprehension, fear, management problems give unreliable results.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,804
7. What is indirect pulp therapy?
It is a technique done for vital teeth, to avoid pulp exposure while treating teeth with deep carious lesions with no clinical evidence of pulpal degeneration or periapical disease.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,804
8. What is the objective of indirect pulp therapy?
The objective is to arrest the carious process by promoting dentinal sclerosis and stimulating the formation of reparative dentin with remineralisation of the carious dentin and also preserving the vitality of the pulp. The natural protective mechanisms of the pulp against caries are used by the teeth.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,804
9. What are the layers in an active caries?
- Necrotic soft dentin, not painful to stimulation and grossly infected with bacteria.
- Firm but softened dentin, painful to stimulation, containing fewer bacteria.
- Slightly discoloured, hard, sound dentin containing few bacteria and painful to stimulation.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,805
10. How does indirect pulp capping aid in reparative dentin formation?
When indirect pulp capping is done, the outer layer of carious dentin are removed and most of the bacteria are eliminated from the lesion. When the lesion is sealed, the substrate for acid production is also removed. When the carious process is arrested, the reparative mechanism starts and dentin is laid down, avoiding pulpal exposure.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,805
11. What is direct pulp capping?
It is the procedure in which a medicament or a dressing is applied to the exposed pulp, in an attempt to preserve the vitality.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,807
12. Why is pulp capping not done in teeth with canal calcifications?
Teeth with calcifications in the canal or pulp chamber are indicative of previous inflammatory responses or trauma and make the pulp less responsive to vital pulp therapy. So pulp capping is not done in such teeth.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,807
13. Exposed caries on primary teeth should not be pulp capped - WHY?
It is because, in carious pulp exposures, microorganisms and inflammation are associated which cannot be eliminated macroscopically. Also a larger area of carious exposure has more inflamed tissue and microorganisms. So pulp capping is indicated only for mechanical pulp exposures in primary teeth.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,808
14. How does location of pulp exposure affect the prognosis of pulp capping?
If the pulp is mechanically exposed on the axial wall, the pulp tissue that is coronal to the exposure site is deprived of its blood supply and necrosis occurs. So in such cases, a pulpotomy or a pulpectomy is advised.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,808
15. What is MTA?
MTA is Mineral Trioxide Aggregate which is a biocompatible pulp capping agent. It produces more dentinal bridge in a shorter period of time, with less inflammation when compared to calcium hydroxide.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,810
16. What are the contra indications for pulp capping?
- Primary teeth with carious exposures
- Permanent teeth with H/o spontaneous tooth ache
- Radiographic evidence of pulpal or periapical pathosis
- Calcified canals
- Excessive bleeding at the exposure site
- Purulent or serous exudates at the exposure site
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,810
17. How is the pulpotomy procedure described for a primary tooth?
The pulpotomy procedure in a primary tooth is described as the amputation of the affected or infected coronal portion of the dental pulp, preserving the vitality and function of all or part of the remaining radicular pulp.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,811
18. What are the evidences for the success for a pulpotomy in a primary tooth?
- Vitality for major part of the radicular pulp
- Absence of adverse signs and symptoms
- No radiographic evidence of canal calcifications or internal resorption
- No breakdown of periradicular tissue
- No harm to the succeeding tooth
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,811
19. What are the zones present in a tooth that is exposed to formocresol pulpotomy?
- A broad acidophilic zone of fixation
- A broad pale staining zone with diminished cellular and fiber definition
- A broad zone of inflammatory cells concentrated at the pale staining junction and diffusing apically into the normal pulp.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,811
20. When is formocresol pulpotomy contraindicated in a primary tooth?
- When the tooth is non restorable
- Tooth nearing exfoliation
- H/o spontaneous tooth ache
- Presence of periapical pathology
- No bleeding pulp
- Uncontrolled bleeding after pulp amputation
- Draining pulp
- Presence of sinus
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,813
21. How is hemorrhage controlled when coronal pulp is removed in pulpotomy?
Slightly moistened cotton pellets are placed against the pulp stumps at the openings of the root canals. Dry cotton pellets are not used because fibres of dry cotton may get impregnated in the clot and when removed will bleed again. Over the moist pellets, dry pellets can be placed and pressure is applied to control bleeding. The procedure is continued till bleeding stops and the site is clean.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,813
22. How to proceed when hemorrhage doesn’t stop in a pulpotomy procedure?
When the bleeding in the amputated site is not controlled within 5 minutes, the pulp is inflamed and a pulpotomy cannot be proceeded. A pulpectomy or extraction of the tooth should be done.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,813
23. What is the ideal concentration of formocresol used in pulpotomy and how is it prepared?
Formacresol is used in one- fifth concentration and is prepared as follows:
- Three parts of glycerine is mixed with one part of distilled water to make a dilute solution
- One part of formocresol is mixed with four parts of diluent to make the required concentration of formocresol
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,813
24. How is formocresol placed in the chamber for pulpotomy?
After the bleeding is controlled, one-fifth dilution of formocresol is taken in a cotton pellet that is blotted to remove the excess formocresol and placed in the tooth in direct contact with the pulp stumps failing which the fixation doesn’t occur. It is placed for 5 minutes and removed. On removal, the tissue appears brown with no hemorrhage.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,813,814
25. How is failure of formocresol pulpotomy detected?
It is detected radiographically. The first sign may be an internal resorption of the area adjacent to formocresol placement. A radioluscency may develop apically, laterally or in the bifurcation areas of the molars. Excessive destruction makes the tooth mobile and a fistula develops. Pain is usually not present.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,815
26. Why is GP contraindicated in pulpectomy of a primary tooth?
The materials used for filling the canals of a primary tooth should be absorbable when the root resorbs and should not offer any resistance to the eruption of the permanent tooth. So GP is contraindicated in primary teeth.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,819
27. Why is the root length important in a primary tooth for pulpectomy?
Root length is important because excessive pathologic resorption will affect the integrity of the root and atleast 4 mm of root is necessary for a pulpectomy procedure in a primary tooth.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,821
28. What happens when a small amount of ZnoE extends beyond the apex in a primary tooth?
The ZnoE that is pushed beyond the apical foramen in a primary tooth can be left undisturbed since ZnoE is an absorbable material that gets absorbed along with the root, when it resorbs. It does not affect the succedaneous permanent tooth also.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,823
29. What is the root filling material used in a primary tooth when there is no permanent successor?
When the permanent successor is missing, the primary tooth that is pulpally involved can be treated by pulpectomy followed by obturation with GP since the eruption of the permanent tooth is not a factor here.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,823
30. What is partial pulpotomy?
It is a procedure on young permanent molars for vital carious pulp exposures. The pulp tissue beneath the exposure site that is judged to be inflamed (1-3mm) is removed till healthy pulp is reached. The degree of inflammation should be evaluated properly before the procedure is started.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,832
31. What is Apexification?
Pulpless permanent teeth with an incompletely developed apex is treated by this procedure called apexification in which the canal is cleansed and filled with a temporary paste to stimulate the formation of calcified tissue at the apex. When there is a radiographic evidence of apical closure, the temporary paste is removed and the canal is obturated with GP.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,833
32. Why the radiographic interpretation of apical closure in apexification is is misleading?
The extent of apical closure is difficult to be determined. The IOPA x ray is a two dimensional picture of two dimensional object. As the tooth develops, the facio lingual aspect of the root canal is the last to become convergent apically. Since the IOPA shows the mesio distal plane only, the facio lingual convergence cannot be checked with a radiograph.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,835
33. What are the factors most important for a successful apexification?
Thorough debridement of the canal to remove all the necrotic pulp tissue and proper sealing of the tooth to prevent bacterial contamination are very important for a successful apexification.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,836
34. What is Apical barrier technique?
It is an alternative treatment for apexification in which the canal can be obturated immediately. Tricalcium phosphate is used as an apical barrier which is packed into the apical 2 mm of the canal and GP is condensed in the rest of the canal, in the same appointment.
Ref: Stephen Cohen,Richard C.Burns,Pathways of the pulp, Mosby, 8th Edn,838