牙体牙髓病学：Root Canal Obturation

1、,Root Canal Obturation,commercial post,sinus,post unfilled canal open apices periapical pathosis,permanent filling casting post crown,vitapex,preoperation,root canal therapy,root canal preparation intracanal medicaments root canal obturation,root canal preparation instruments：hand rotary techniques：

2、 standard step back step down,intracanal medicament? one-visit? multi-visit?,The success rates of endodontic treatment: 53%94% Intimate relationship between the success rate and canal infection: success Engstrom (1964) Sjogren (1997),purpose of the root canal preparation -free-infection in the canal

3、 system vital pulp(noninfected canals) -preparation obturation infected canals - preparation medicament obturation,Impaction for the postoperative pain (Martin Trope 1991) one-visit muti-visit No apical lecions 0% 0% Apical lesions 3.4% 3.7% retreatment 13.6% 4.08%,Methods of root canal dressing med

4、icine electrolysis microwave laser,甲醛甲酚合剂（FC） 抑菌杀菌作用 刺激作用 毒性作用 潜在的抗原作用,樟脑酚（CP） 抗菌作用 镇痛作用 毒性小,丁香油酚（OC） 防腐作用 镇痛和麻醉作用 毒性小 刺激性小,木馏油 消毒作用 镇痛作用 刺激性 特殊气味,calcium hydroxide killing germs (hydrolysis effection; high PH） Decomposing the necrosis tissues Inducing fiberization of the apical lesions Inducing the

5、 formation of the hard tissues (cementum、dentin、alveolar bone),root canal obturation,objectives When Instruments Materials Methods/techniques,objectives,Prevention of periradicular pathosis Healing and recovering of the periapical pathosis,The necessary of theroot canal obturation,Bacteria in the cl

6、eaned and shaped root canal system(dentinal tubules) Free immunity of the canal system in the body Serum (seeping from the apical tissues)serves as the furnishes for the microorganisms persistent in the tubules,when to obturate the canal,The canal is cleaned and shaped to a optimum size and dryness

7、Patient has free symptoms,Instruments for the obturationhand-instruments cotton pliers spreader plugger,Spreader sharp tip,Plugger plane tip,Maillefer Thermafil,Materials used in obturation It should (be) easily introduced into a root canal seal the canal laterally as well as apically not shrink aft

8、er being inserted impervious to moisture bacteriostatic or at least not encourage bacterial growth,Materials used in obturation It should (be) radiopaque not stain tooth structure not irritate periradicular tissue easily and quickly sterilized immediately before insertion removed easily from the roo

9、t canal if necessary,Solid core material- gutta-percha from Malaysian trees（latex） commercial gutta-percha contains zine oxide-eugenol(ZOE) the heating property:warm gutta-percha bio-compatibility stability toxicity X-ray feature,commercial gutta-percha pointsISO standard .02taper,Non-ISO standard g

10、utta percha points .041.2taper,The ruler for selecting different points 20#140#,root canal cement sealers requirements and characteristics of a good root canal sealer should be tacky when mixed to provide good adhesion between it and the canal wall when set make a hermetic seal radiopaque not shrink

11、 upon setting not stain tooth structure bacteriostatic or at least not encourage bacterial growth,set slowly insoluble in tissue fluids tissue tolerant soluble in a common solvent when retreatment not provoke an immune response in periradicular tissue neither mutagenic nor carcinogenic,Different typ

12、es of the root canal sealers zine oxide-eugenol(ZOE) calcium cydroxide containing sealers resin-reinforced chelate formed sealers,zine oxide-eugenol(ZOE) widely used in clinic reasonably meets most of Grossmans requirements for sealers,Kerr Pulp Canal Sealer Powder Zinc oxide, reagent 42 parts Stayb

13、elite resin 27 parts Bismuth subcarbonate 15 parts Barium sulfate 15 parts Sodium borate, anhydrous 1 part Liquid Eugenol,calcium cydroxide containing sealers Inducing fiberization of the apical lesions Inducing the formation of the hard tissues Dycal cavita .,resin-reinforced chelate formed sealers

14、 based on resin chemistry very tacky materials contract slightly while setting has good sealing ability AHplus AH26,Methods of obturating the root canal space Over 100 years countless ways and materials have been developed to fill prepared canals Webster noted “it would seem that the dental professi

15、on has not yet decided upon a universal root canal filling material.”,Today most root canals are being filled with gutta-percha and sealers methods vary by the direction of the compaction (lateral or vertical) and/or the temperature of the gutta-percha, either cold or warm warmed gutta-percha shrink

16、s when it cools,lateral compaction of cold gutta-percha vertical compaction of warmed gutta-percha,Apical constriction at cementodentinal junction marks end of root canal From this point to anatomic apex (0.5 to 0.7 mm) tissue is periodontal,Ideal end of the preparation and obturation,Filling to the

17、 radiographic end of the root is actually overfilling,overfilling,filling short of the apex,exactly filling,Primary point size determination Selection of the master cone the primary point should be selected to match the size of the last instrument used at the apex it should not be able to be forced

18、beyond the working distance the cone should bind in the apical portion of the canal,four methods used to determine the proper fit of the primary point visual test tactile test patient response radiographic test,Visual Test measured and grasped with cotton pliers at a position within 1 mm short of th

19、e prepared length of the canal carried into the canal until the cotton pliers touch the external reference point of the tooth. tried in a wet canal If the working length of the tooth is correct and the point goes completely to position, the visual test has been passed,If the point can be pushed to t

20、he root end, it might well be pushed beyond into the tissue. Either the foramen was originally large or it has been perforated. If the point can be extended beyond the apex, the next larger size point should be tried.,If this larger point does not go into place, the original point may be used by cut

21、ting pieces off the tip. Each time the tip is cut back 1 mm, the diameter becomes larger by approximately .02 mm. By trial and error, the point is retried in the canal until it goes to the correct position.,trial and error 试尖,Tactile Test the cone should bind in the apical portion of the canal the a

22、pical 3 to 4 mm of the canal it should exhibit “tugback” or resistance to withdrawal,it should not be able to be forced beyond the working distance. if the point is loose in the canal, the next larger size point should be tried or the method of cutting segments from the tip of the initial point.,Pat

23、ient Response Patients may feel the gutta-percha penetrate the foramen (not anesthetized during the treatment or nonvital pulp),Adjustments can be made until it is completely comfortable. This is a good test when the position of the foramen does not appear to be accurately determined by the radiogra

24、ph or by tactile sensation. Pulp remnants from a short preparation will cause a sensation of much greater intensity than periapical tissue,Radiograph Test the final testthe radiograph the film must show the point extending to within 1 mm from the tip of the preparation is a better criterion of succe

25、ss than either the visual or tactile method It must fit tightly and come to a dead stop,Short! the initial point will not go completely into place,This condition may arise because the enlarging instrument was not used to its fullest extent there was a larger than standard deviation between the sizes

26、 of instruments and gutta-percha debris remains or was dislodged into the canal a ledge exists in the canal on which the point is catching,finishing,radiograph test,the trial point test,radiograph test,the trial point test,master cone,spreader,0.51.0mm,Lateral Compaction of Cold Gutta-percha,Lateral

27、 Compaction of Cold Gutta-percha steps Spreader Size Determination Primary Point Size Determination Preparation of the Initial Point Drying the Canal,Mixing and Placement of the Sealer Placement of the Master Point Multiple-Point Obturation with Lateral Compaction,Spreader Size Determination Spreade

28、rs are available to match the instruments size(ISO) to reach to within 1.0 to 2.0 mm of the true working length and to match the taper of the preparation should not penetrate the apical orifice Recommend to choose the spreader of the same apical instrument size or one size larger,Primary Point Size

29、Determination visual test tactile test patient response radiographic test,Preparation of the Initial Point scar the soft point or snipped with the scissors at the reference point,Drying the Canal absorbent paper points excess moisture or blood may affect the properties of the sealer,Mixing of the Se

30、aler ideal consistency mixture can be held for 10 seconds on an inverted spatula without dropping off mixture can stretch between the slab and spatula 2 cm before breaking,Placement of the Sealer Root canal cement/sealer may be placed in a number of ways “Pump” into the canal with a gutta-percha poi

31、nt Carry the sealer in on a file or reamer Use rotary or spiral paste fillers turned clockwise in ones fingers or very slowly in a handpiece,rotary paste fillers,master point coated with sealer about 10mm,Placement of the Master Point The premeasured primary (or master, or initial) point coated with

32、 cement Slowly moved to full working length minus 0.5-10mm,0.5-10mm,Lateral compaction, multiple-point filling procedure,A Primary point is carried fully to place, to within 1.0 mm of “apical stop. Excess in crown is severed at cervical with hot instrument B Spreader (arrow) is inserted to full dept

33、h, allowed to remain 1 full minute as gutta- percha is compacted laterally and somewhat apically C Spreader is removed by rotation and immediately replaced by first auxiliary point previously dipped in sealer,D Spreader is returned to canal to laterally compact mass of filling. Secondary vertical co

34、mpaction seals apical foramen E Spreader is again removed, followed by matching auxiliary point. Process continues until canal is totally obturated F All excess gutta-percha and sealer are removed from crown to below free gingival level.Vertical compaction completes root filling. After an intraorifi

35、ce barrier is placed, a permanent restoration with adhesives is placed in crown.,试 尖,主尖作标记,试侧压器小了,试侧压器合适,涂封闭剂,主牙胶尖就位,侧压器加压,加入更多副尖,Cross-section of middle third of root demonstrating primary and auxiliary cones Gutta-percha cones frozen in a sea of cement Apical part is less condense than middle part

36、,Disadvantage 1,Gutta-percha cones never merge into homogeneous mass,Disadvantage 2,Root fracture occurs when the wedging force is absorbed by the canal wall Premeasuring the spreader depth can reduce risk of fracture,Warm gutta percha techniques Schilder technique Obtura II technique ThermaFil tech

37、nique SimpliFil technique ,Schilder technique vertical compaction of warm gutta-percha,Schilder technique introduced by Schilder in 1967 three-dimensional obturation of the root canal system with warm gutta-percha obturated with a maximum amount of gutta-percha and a minimum amount of sealer,Vertica

38、l Compaction of Warm Gutta-percha Has proved most effective in filling the canals of severely curved roots and roots with accessory, auxiliary, or lateral canals, or with multiple foramina,Preparation before the step-by-Step procedure thoroughly cleansed and continuously tapering canal(s) 6%10% Fitt

39、ing the master Gutta-percha mone Prefitting the vertical pluggers Heat transfer instrument Root canal sealer,the key to success in this technique- a successful relationship between the radicular preparation and the master cone Using the conventional cone-shaped gutta-percha points, not the standardi

40、zed numbered points The cone must fit tightly in the apical third, have “tugback”,Fitting the Master Gutta-percha Cone,Fitting the Master Gutta-percha Cone,Prefitting the Vertical Pluggers the wider plugger- the coronal third of the canal the narrower plugger-the middle third the narrowest plugger -

41、 the apical third,Schilder Pluggers (designed by Schilder),Heat Transfer Instrument,“Touch n Heat” 5004, battery-powered (rechargeable) heat source. Heat carrier heats to glowing within seconds to plasticize gutta-percha in canal. Also used in removal of gutta-percha for postpreparation or re-treatm

42、ent .,Obtura II delivery system Panel has temperature control and digital temperature display in degrees Celsius. The pistol-grip syringe extrudes plasticized beta-phase gutta-percha through flexible needle,Root Canal Sealer,Step-by-Step Procedure of Vertical Compaction of Warm Gutta-percha,down-Pac

43、king back-Packing,Dry the canal! Best achieved by using 100% alcohol irrigated deep within the root canal system using thin, safe-tipped irrigating “needles” Dried with paper points Confirm the patency of the foramen with an instrument smaller than the last size instrument used to develop the apical

44、 preparation.,2. Fit the appropriate gutta-percha cone to the patent radiographic terminus It should visually go to full working length and exhibit tug-back Confirm the position radiographically Cut off the butt end of the cone at the incisal or occlusal reference point,3. Remove the cone and cut ba

45、ck 0.5 to 1.0 mm of the tip, reinsert, and check the length and tug-back The cones apical diameter should be the same diameter as the last apical instrument to reach the radiographic terminus of the preparation Remove the cone, dip it in alcohol, set the cone aside,4. Prefit the three pluggers to th

46、e prepared canal first the widest plugger to a 10 mm depth next, the middle plugger to a 15 mm depth finally, the narrowest plugger to within 3 to 4 mm of the terminus Record the lengths of the desired plugger depth,5. Deposit a small amount of root canal sealer in the canal. Lightly coat all of the

47、 walls 6. Coat the apical third of the gutta-percha cone with a thin film of sealer,7. Grasp the butt-end of the cone with cotton pliers and slide the cone approximately halfway down the canal,8. Using the Touch n Heat 5004 heat carrier, sear off the cone surplus in the pulp chamber down to the cerv

48、ical level,9. Using the widest vertical plugger to compact the gutta-percha in an apical direction with sustained 5-to10-second pressure,10. The second heat wave begins by introducing the heat carrier back into the gutta-percha, where it remains for 2 to 3 seconds and, when retrieved, carries with i

49、t the first selective gutta-percha removal,11. Immediately, the midsized coated plugger is submerged into the warm gutta-percha. The vertical pressure also exerts lateral pressure. This filling mass is shepherded apically in 3 to 4 mm waves created by repeated heat and compaction cycles,12. The seco

50、nd heating of the heat carrier warms the next 3 to 4 mm of gutta-percha and again an amount is removed on the end of the heat carrier,13. The narrowest plugger is immediately inserted in the canal and the surplus material along the walls is folded centrally into the apical mass so that the heat wave

51、 begins from a flat plateau. The warmed gutta-percha is then compacted vertically, and the material flows into and seals the apical portals of exit,14. The apical “down-pack” is now completed, and if a post is to be placed at this depth, no more gutta-percha need be used,15. “Backpacking” the remain

52、der of the canal completes the obturation,16. An alternative method of backpacking may be done by injecting plasticized gutta-percha from one of the syringes, such as Obtura II,17. The final act involves the thorough cleansing of the pulp chamber below the CE junction, the addition of an appropriate barrier, and the placement of a permanent restoration,Disadvantages complexity undesirable stress concentrations