Obturation

gutta percha
obturation technique
monoblock concept

1. OBTURATION

2. Definition: The method used to fill and seal a cleaned and shaped root canal using a root canal sealer and core filling material; sealers are frequently used as the sole  obturating  material in deciduous teeth; there are a variety of techniques used to  obturate  the canal space Glossary of Endodontic Terms.

3. Features of an ideal root canal obturation Three-dimensional obturation close to CDJ. Radiographically , filling should be seen 0.5-0.75 mm from radiographic apex. Minimal use of a root canal sealer which is confined to root canal .

4. Characteristics of an ideal root canal filling material 1 . Easily introduced in the canal. 2. Seal canal laterally and apically. 3. Dimensionally stable after being inserted. 4. Impervious to moisture. 5. Bacteriostatic or at least should not encourage bacterial growth . 6. Radiopaque. 7. Non staining to tooth structure. 8. Non irritating. 9. Sterile/easily sterilized. 10. Removed easily from canal if required.

5. Materials used for obturation • Plastics: Gutta-percha, resilon • Solids or metal cores: Silver points, Gold, stainless steel, titanium • Cements and pastes: – Hydron – MTA – Calcium phosphate – Gutta flow

6. Gutta percha Gutta-percha is derived from two words. “GETAH” - meaning gum “PERTJA” - name of the tree 1843 : Sir Jose d Almeida – First introduced gutta-percha to Royal Asiatic society of England In Dentistry : Edwin Truman – Introduced gutta-percha as temporary filling material . 1867 : Bowman – First to use gutta-percha as root canal filling material

7. Gutta-percha cones

8. Gutta percha 1887 : SS White company – First company to start the commercial manufacture of gutta-percha points. Sources Gutta-percha is a dried coagulated extract which is derived from Brazillian trees ( Palaquium ) . These trees belong to Sapotaceae family . In India, these are found in Assam and Western Ghats .

9. Composition of commercially available gutta-percha ( Given by Friedman, et al)

10. Different forms of gutta-percha Alpha form • Pliable and tacky at 56°-64°. • Available in form of bars or pellets. • Used in thermo-plasticized obturation technique. Beta form • Rigid and solid 42°-44°. • Used for manufacturing gutta-percha points and sticks. Amorphous form • Exists in molten stage.

11. Phases of Gutta-percha These phases are inter-convertible . • α - runny, tacky and sticky (lower viscosity) • β - solid, compactable and elongatable (higher viscosity ) • γ - unstable form

12. Aging of gutta-percha It causes brittleness because of the oxidation process. Storage under artificial light also speeds up their deterioration. This brittle gutta-percha can be rejuvenated by a technique described by Sorien and Oliet . In this, gutta-percha is immersed in hot water (55°C ) for one or two seconds and then immediately immersed in cold water for few seconds.

13. Brittle gutta-percha point breaks on bending

14. Disinfection of gutta-percha Gutta-percha cannot be heat sterilized. For disinfection of gutta-percha points, they should be immersed in 5.25 percent NaOCl for one minute. Then , gutta-percha should be rinsed in hydrogen peroxide or ethyl alcohol. The aim of rinsing is to remove crystallized NaOCl before obturation, as these crystallized particles impair the obturation.

15. Sterilization of gutta-percha by immersing them in 5.25 percent sodium hypochlorite for one minute

16. Current Available Forms of Gutta-percha Gutta-percha points: Standard cones are of same size and shape as that of ISO endodontic instruments. Auxiliary points: Non-standardized cones; perceive form of root canal.

17. Current Available Forms of Gutta-percha Greater taper gutta-percha points: Available in 4 percent,6 percent, 80 percent and 10 percent taper Precoated core carrier gutta-percha : In these stainless steel, titanium or plastic carriers are precoated with alpha phase gutta-percha for use in canal. e.g. thermafil

18. Current Available Forms of Gutta-percha Syringe systems: They use low viscosity gutta-percha. e.g. successful and alpha seal. Gutta flow: In this gutta-percha powder is incorporated into resin based sealer .

19. Current Available Forms of Gutta-percha Gutta-percha sealers like chloropercha and eucopercha :- In these gutta-percha is dissolved in chloroform/eucalyptol to be used in the canal . Medicated gutta-percha: calcium hydroxide, iodoform or chlorhexidine diacetate containing gutta-percha points . Gutta-percha pellets/bars: They are used in thermoplastisized gutta-percha obturation e.g. obtura system.

20. Advantages of gutta-percha • Compactiblity : adaptation to canal walls • Inertness: makes it non-reactive material • Dimensionally stable • Tissue tolerance • Radiopacity: easily recognizable on radiograph (Fig. 18.12) • Plasticity: becomes plastic when heated • Dissolve in some solvents like chloroform, eucalyptus oil , etc . This property makes it more versatile as canal filling material .

21. Disadvantages of gutta-percha • Lack of rigidity: Bending of gutta-percha is seen when lateral pressure is applied. So, difficult to use in smaller canals • Easily displaced by pressure • Lacks adhesive quality.

22. Classification of obturation techniques 1. Use of cold gutta-percha • Lateral compaction technique 2. Use of chemically softened gutta-percha • Chloroform • Halothane • Eucalyptol

23. Classification of obturation techniques 3 . Use of heat softened gutta-percha • Vertical compaction technique • System B continuous wave condensation technique • Lateral/vertical compaction • Sectional compaction technique • McSpadden compaction of gutta-percha

24. Classification of obturation techniques • Thermoplasticized gutta-percha technique including – Obtura II – Ultrasonic plasticizing – Ultrafil system • Solid core obturation technique including – Thermafil system – Silver point obturation

25. Armamentarium for obturation • Primary and accessory gutta-percha points. • Spreaders and pluggers for compaction of gutta-percha • Absorbent paper points for drying the prepared root canal before applying sealer.

26. Armamentarium for obturation • Lentulospirals for placing sealer • Scissors for cutting gutta-percha • Endo gauge for measuring size of gutta-percha • Endo block for measuring gutta-percha points • Endo organizer for arranging gutta-percha and accessory points of various sizes. • Heating device like spirit lamp or butane gas torch • Heating instrument like ball burnisher , spoon excavator, etc.

27. Lateral compaction technique

28. Vertical compaction technique Vertical compaction of warm gutta-percha method of filling the root canal was introduced by Schilder with an objective of filling all the portals of exit with maximum amount of guttapercha and minimum amount of sealer. This is also known as Schilder’s technique of obturation.

29. Advantage of Vertical Compaction Technique Excellent sealing of canal apically, laterally and obturation of lateral as well as accessory canals. Disadvantages of this Technique • Increased risk of vertical root fracture. • Overfilling of canals with gutta-percha or sealer from apex . • Time consuming.

30. Sectional method of obturation In this technique, small pieces of gutta-percha cones are used to fill the sections of the canal. It is also known as Chicago technique because it was widely promoted by Coolidge , Lundquist , Blayney, all from Chicago .

31. Techniques

32. Advantages • It seals the canals apically and laterally. • In case of post and core cases, only apical section of canal is filled. Disadvantages • Time consuming. • If canal gets overfilled, difficult to remove sections of guttapercha .

33. ROOT CANAL SEALERS The purpose of sealing root canals is to prevent periapical exudates from diffusing into the unfilled part of the canal, to avoid reentry and colonization of bacteria and to check residual bacteria from reaching the periapical tissues. Therefore , to accomplish a fluid tight seal, a root canal sealer is needed.

34. Requirements of an ideal root canal sealer • Should be tacky when mixed to provide good adhesion between it and the canal wall when set. • Should create hermetic seal. • Should be radiopaque. • Powder particles size should be very fine, for easy mixing with liquid . • Should not shrink upon setting.

35. Requirements of an ideal root canal sealer • Should not stain tooth structure. • Should be bacteriostatic. • Should set slowly. • Should be insoluble in tissue fluids . • Should be non-irritating to periradicular tissue. • Should be soluble in a common solvent. • Should not provide immune response in periradicular tissue. • Should not be mutagenic or carcinogenic.

36. Functions of root canal sealers • As antimicrobial agent • Fill the discrepancies between the materials and dentin walls • As binding agent • As lubricant • Give radiopacity • As canal obturating material

37. Classification of obturation sealers Classification of sealer according to Grossman • Zinc oxide resin cements • Calcium hydroxide cements • Paraformaldehyde cements • Pastes

38. A ccording Cohen (ADA and ANSI) Type I: Material’s intended to be used with core material. Class I: Includes materials in the form of powder and liquid that set through a non polymerizing process. Class II: Includes materials in the form of two pastes that set through a non polymerizing process. Class III: Includes polymers and resin systems that set through polymerization.

39. A ccording Cohen (ADA and ANSI) Type II Intended for use with or without core material or sealer. Class I: Powder and liquid-non polymerizing Class II: Paste and paste-non polymerizing Class III: Metal amalgams Class IV: Polymer and resin systems-polymerization

40. A ccording to Composition 1 . Eugenol group may be divided into subgroups namely: a . Silver containing cements: • Kerr sealer ( Rickert , 1931) • Procosol radiopaque silver cement (Grossman, 1936) b . Silver free cements: • Procosol nonstaining cement (Grossman, 1958) • Grossman’s sealer (Grossman, 1974) • Tubliseal (Kerr, 1961) • Wach’s paste ( Wach )

41. Zinc Oxide Eugenol Sealers / Kerr Root Canal Sealer / Rickert’s Formula Composition : Powder Zinc oxide 34-41.2 percent Precipitated silver 25-30.0 percent Oleo resins 30-16 percent Thymol iodide 11-12 percent Liquid Oil of cloves 78-80 percent Canada balsam 20-22 percent

42. Advantages Zinc Oxide Eugenol Sealers 1 . Excellent lubricating properties. 2 . It allows a working time of more than 30 minutes, when mixed in 1:1 ratio. 3 . Germicidal action and biocompatibility. 4 . Greater bulk than any sealer and thus makes it ideal for condensation techniques to fill voids, auxilliary canals and irregularities present lateral to gutta-percha cones.

43. Disadvantage Zinc Oxide Eugenol Sealers The major disadvantage is that the presence of silver makes the sealer extremely staining if any of the material enters the dentinal tubuli . So sealers must be removed carefully from the pulp chamber with xylol .

44. Manipulation Zinc Oxide Eugenol Sealers Powder is contained in a pellet and the liquid in a bottle. One drop of liquid is added to one pellet of powder and mixed with a heavy spatula until relative homogenicity is obtained. Kerr pulp canal sealer completely sets and is inert within 15-30 minutes, thus reduces the inflammatory responses.

45. Grossman’s sealer Composition Powder Zinc oxide (reagent) - 40 parts Staybelite resin - 30 parts Bismuth Subcarbonate -15 parts Barium Sulfate - 15 parts Sodiumborate - 1 part Liquid Eugenol

46. Properties of Grossman’s sealer 1 . It has plasticity and slow setting time due to the presence of sodiumborate anhydrate. 2 . It has good sealing potential. 3 . Zinc eugenolate is decomposed by water through continuous loss of eugenol, which makes zinc oxide eugenol a weak unstable compound.

47. Disadvantage of Grossman’s sealer Resin has coarse particle size, so the material is spatulated vigorously during mixing. If it is not done, a piece of resin may lodge on the canal walls.

48. Setting Time of Grossman’s sealer Cement hardens approximately in 2 hours at 37°C. The setting time is influenced by: 1 . Quality of the ZnO and pH of the resin used. 2 . Technique used in mixing the cement. 3 . Amount of humidity in the temperature. 4 . Temperature and dryness of the mixing slab and spatula .

49. A ccording to Composition Non-eugenol: These sealers do not contain eugenol and consist of wide variety of chemicals. Examples : • Diaket • AH-26 • Chloropercha and Eucapercha • Nogenol • Hydron • Endofil • Glass ionomer • Polycarboxylate • Calcium Phosphate cement

50. AH-26 This is an epoxy resin recommended by Shroeder in 1957. Epoxy resin based sealers are characterized by the reactive epoxide ring and are polymerized by the breaking this ring. Feldman and Nyborg gave the following composition.

51. Composition of AH-26 Powder Bismuth oxide 60 percent Hexamethylene tetramine 25 percent Silver powder 10 percent Titanium oxide 5 percent Liquid Bisphenol diglycidyl ether

52. Properties of AH-26 1 . Good adhesive property. 2. Good flow 3. Antibacterial 4. Contracts slightly while hardening 5. Low toxicity and well tolerated by periapical tissue. 6. The addition of a hardener, hexamethylene tetramine , makes the cured resin inert chemically and biologically.

53. AH-26 AH 26 consists of a yellow powder and viscous resin liquid and mixed to a thick creamy consistency. The setting time is 36 to 48 hours at body temperature and 5-7 days at room temperature . AH 26 produces greater adhesion to dentin especially when smear layer is removed. Smear layer removal exposes the dentinal tubules creating an irritating surface thus enhancing adhesion.

54. AH Plus AH Plus is an Epoxide-Amine resin pulp canal sealer, developed from its predecessor AH26 because of color and shade stability, this is the material of choice where aesthetic demands are high.

55. Composition of AH Plus AH Plus Paste A Epoxy Resins Calcium tungstate Zirconium oxide Silica Iron oxide

56. Composition of AH Plus AH Plus Paste B Adamantianeamine N, N-Dibenzyl-5-Oxanonane-diamine-1, 9, TCD-diamine Calcium tungstate Zirconium oxide Silica Silicone oil

57. Dosage and Mixing Mix equal volume units (1:1) of Paste A and Paste B on a glass slab or mixing pad using a metal spatula. Mix to a homogeneous consistency .

58. Difference between AH 26 and AH plus

59. A ccording to Composition Medicated: These include the group of root canal sealers which have therapeutic properties. These materials are usually used without core materials. Examples : • Diaket -A • N2 • Endomethasone • SPAD • Iodoform paste • Riebler’s paste • Mynol cement • Ca(OH)2 paste

60. Calcium Hydroxide Sealer Calcium hydroxide has been used in endodontics as a root canal filling material, intra canal medicaments or as a sealer in combination with solid core materials. The pure calcium hydroxide powder can be used alone or it

61. Calcium hydroxide sealers can: • Induce mineralization • Induce apical closure via cementogenesis • Inhibit root resorption subsequent to trauma • Inhibit osteoclast activity via an alkaline pH • Seal or prevent leakage as good as or better than ZOE sealers • Less toxic than ZOE sealers

62. Seal Apex It is a non eugenol calcium hydroxide polymeric resin root canal sealer. Advantage It has good therapeutic effect and biocompatible. The extruded material resorbs in 4-5 months . Disadvantages • Poor cohesive strength • Takes long time to set (three weeks) • Absorbs water and expands on setting.

63. Composition of Seal Apex Base Calcium hydroxide 25 percent Zinc oxide 6.5 percent Calcium oxide Butyl benzene Fumed silica (silicon dioxide )

64. Composition of Seal Apex Catalyst Barium sulfate 18.6 percent Titanium dioxide 5.1 percent Zinc stearate 1.0 percent Isobutyl salicylate Disalicylate Trisalicylate Bismuth trioxide

65. The Monoblock Concept The monoblock concept means the creation of a solid, bonded, continuous material from one dentin wall of the canal to the other. One added benefit of the monoblock is that research has shown that it strengthens the root by approximately 20%

66. Classification of Monoblock concept Primary : In this obturation is completely done with core material , for example, use of MTA for obturation in cases of apexification. Secondary: In this bond is there between etched dentin of canal wall impregnated with resin tags which are attached to resin cement that is bonded to core layer, e.g. resilon based system .

67. Classification of Monoblock concept Tertiary : In this conventional gutta-percha surface is coated with resin which bond with the sealer, which further bond to canal walls, e.g. Endo Rez and Activ GP system.

68. Failure of obturation Overfilling is complete obturation of root canal system with excess material extruding beyond apical foramen. Overextension is extrusion of filling material beyond apical foramen but the canal may not have been filled completely.