Apexogenesis & apexification

Overview of techniques with recent concepts

1. Apexogenesis & Apexification Dr.Sucheta Prabhu 3 rd year MDS

2. Open Apex Problems associated with open apex 1.Normal crown / root ratio is compromised, may cause mobility 2. Difficult to achieve apical seal

3. Causes of open apices ´ caries with pulp involvement, ´ extensive resorption of the mature apex as a result of orthodontic treatment ´ Periapical pathosis, ´ Trauma causing necrosis

4. Types of open apices 1- non-blunderbuss 2- blunderbuss Blunderbuss: The apex is funnel shaped and -typically wider than the coronal aspect of the canal. Non –blunderbuss: broad (cylinder shaped) tapered (convergent)

5. Pulp injury in teeth with developing roots Important role of Hertwig’s epithelial root sheath in continued root development after pulpal injury, every effort should be made to Maintain its viability. HERS Sensitive to trauma – increase vascularity and Cellularity Hard tissue can be formed by :  Cementoblasts -apical region  Fibroblasts of the dental follicle  Periodontal ligament that undergo differentiation after the injury to become hard tissue producing cells

6. Stages of root development ( Cvek 1972) In anatomy the apical foramen is the opening at the apex of the root of a tooth , through which the nerve and blood vessels that supply the dental pulp pass. Thus it represents the junction of the pulp & the periodontal tissue

7. Treatment  Treatment is based on the vitality of the pulp .  If the immature tooth has vital pulp, exhibiting reversible pulpitis, then physiological root end development or apexogenesis is attempted . On the other hand if irreversible pulpitis is present or pulp is necrotic, then root end closure or apexification is induced.

8. Reversible pulpitis Irreversible pulpitis/Necrotic pulp Closed apex Open apex Vital pulp therapy Pulp regeneration Root end closure Root canal therapy

9. Apexogenesis / vital pulp therapy  “ Apexogenesis is defined as treatment of a vital pulp in an immature tooth to permit continued root growth and apical closure. A vital pulp of an immature tooth may have a small exposure after trauma.” - Ingle “Physiologic root end development and formation” according to American Association of Endodontists in 1981 . Apexogenesis as endodontic treatment of partially developed permanent teeth that clinically and radiographically displays evidence of pulp necrosis. Stephen Wei (1988) The continued formation of the root in the teeth with vital root pulpal tissue .(McDonald & Avery, 2000)

10. Indications & Contraindications

11. Goals of Apexogenesis : (Weber 1984)

12. Procedure  Calcium hydroxide powder was mixed with saline to a thick consistency . The paste was carefully placed on the pulp stump surface 1 to 2 mm thick.

13. Follow up Time required  1 and 2 years depending on the degree of tooth development at the time of the procedure .  Recalled every 3 months

14. Apexification Defined as the method of inducing apical closure by the formation of osteo cementum or a similar hard tissue or the continued apical development of the root of an incompletely formed tooth in which the pulp is no longer vital. – American Association of Endodontics A method of inducing apical closure of the roots of an incompletely formed, nonvital radicular tissue just short of root end and placing a suitable biocompatible agent in the canal. (AAPD Guidelines 1998) Inducement to form a calcified apical barrier in teeth that have pulpal necrosis. (McDonald & Avery , 2000)

15. Root end closure I ntroduced by Torabinejad in 2002 . Indication – restorable immature tooth with pulp necrosis. Contraindications  All vertical and unfavorable horizontal root fractures. Very short roots  Periodontal breakdown Objectives  Induce root end closure No evidence of post treatment signs and symptoms No evidence of calcification No internal or external resorption No breakdown of periradicular supporting tissues

16. Classification Morse et al., (1983) various approaches :

17. Blunt end/rolled cone (customized cone) What? Large coronal end of gutta percha Not advisable because the apical foramen is generally wider than the root canal orifice. This prevents proper condensation of GP Weakens tooth

18. Short fill 

19. Periapical surgery Not recommended Already short roots further shortened Physically & Psychologically traumatic Removal of HERS prevents possibility of further root development Thin walls make retrograde condensation difficult resulting in an inadequate seal

20. Apical closure induction  Most widely used approach but exact mechanism unknown It has been considered that treatment of teeth with necrotic pulp the basic aim should be stimulation & preservation of the formative activity of the granulation tissue cells in apical part of the root canal This should enhance the formation of a calcified callus in the wide apical opening.

21. Drawbacks of multivisit apexification Induction of apical healing , regardless of the material used, takes at least 3–4 months and requires multiple appointments  Patient compliance with this regimen may be poor and many fail to return for scheduled visits The temporary seal may fail resulting in re-infection and prolongation or failure of treatment

22. Single visit apexification The rationale is to establish an apical stop that would enable the root canal to be filled immediately There is no attempt at root end closure. Rather an artificial apical stop is created Morse et al., (1990) defined as the nonsurgical condensation of a biocompatible material into the apical end of the root canal

23. Materials to induce Apexification in teeth with immature apices

24. Time required for apical barrier formation in apexification using calcium hydroxide

25. Procedure Primary aim is enlargement as per Torneck et al & Holland et al Ingle recommends using H file Circumferential filing

26. Drying of the canals  Often difficult because of seepage  Paper points are pre measured to working length  In continuous seepage, a pre fitted point can be left in canal until calcium hydroxide is placed

27. Techniques of calcium hydroxide placement  Webbers technique  Using amalgam carrier and endodontic pluggers .

28. Refilling procedure-Holland  First recall is at 6 weeks  Paste is diluted in canal.  Removed 1-2mm short of the original working length  Remaining powder on canal walls removed with larger size instruments.

29. Recall Procedure to detect barrier formation  Radiographic evaluation  Paper point

30. Mechanism of action of Ca (OH)2 to induce formation of a solid apical barrier

31. Cruz et al.1998., histological analysis of the apical barrier  Dense acellular cementum -like tissue . Irregular dense fibrocollagenous connective tissue irregular fragments of highly mineralized calcifications.

32. Nature and source of cells participating in Apexification process

33. Structure of apical barrier

34. Five outcomes of apexification ( W eine ) 1. No radiographic change is apparent; but if instrument is inserted, a blockage at the apex is encountered . 2. Radiographic evidence of calcified material is seen at or near the apex . 3. Apex closes without any change in canal space . 4. Apex continues to develop with closure of the canal apace . 5. No radiographic evidence of change is seen, and clinical symptom and/or development of or the increase in size of periapical lesion occurs. This would need either retreatment with CaOH2 or surgery.

35. Inherent disadvantages of calcium hydroxide apexification Variability of treatment time Unpredictability of apical closure Difficulty to patient follow up Delayed treatment

36. Studies where CaOH was used to induce apical barrier formation (ABF) and healing.

37. MTA (Mineral Trioxide Aggregate) dicalcium silicate tricalcium silicate tricalcium aluminate Gypsum bismuth powder(RO) Torabinejad and members at the Loma Linda University, California, USA pH 12.5 Inductive potential with hard tissue formation

38. Physical and Chemical Properties

39. Inductive potential

40. Sealing ability & Marginal adaptation Fischer et al.1998, using bacterial leakage model

41. Biodentine Calcium silicate based . Developed as a permananent dentin substitute Powder- tricalcium silicate and dicalcium silicate Calcium carbonate, calcium oxide, iron oxide, and zirconium oxide Liquid- calcium chloride and a water-soluble polymer

42. Han And Okji (2003) Biodentine v/s MTA  The thickness of the calcium and silica -rich layers increased over time, and was significantly larger in Biodentine compared to MTA after 30 and 90 days , concluding that dentin element uptake was greater for Biodentine than for MTA .

43. Conclusion 

44. References Grossman LI: Endodontic practice, 10 edition, Philadelphia. 1981,Lea & Febiger Endodontics , ingle & Bakland , 6th edit, Mosby pub . Textbook of pediatric dentistry 3rd edition. Marwah Pediatric dentistry in children & adolescent, 8th edit, McDonald, Avery & Dean, Elsevier pub. Camp JH, Barrett EJ, Pulver F. Pediatric endodontics . In: Cohen S,Burns RC, eds. Pathways of the pulp. 8th ed. St Louis: Mosby; 2002.pp . 797–844. Ingle: Endodontics 6th edition . A paradigm shift in endodontic management of immature teeth: Conservation of stem cells for regeneration. George T.-J. Huang. Journal of Dentistry 2008

45. References Apexification : Case report. Peter Parashos . Australian Dental Journal 1997;42:(1): 43-6 Camilleri J, Pitt Ford TR. Mineral trioxide aggregate: a review of the constituents and biological properties of the material. International Endodontic Journal, 39, 747–754, 2006 . Bhasker SN. Orbans oral histology & embryology, 11th edn . St. louis : Mosby- year book. 1991.