Basic Concepts in Cleaning and Shaping of Root Canals

Basic Concepts in Cleaning and Shaping of Root Canals

1. SHAPING OF ROOT CANALS PART 1 Dr. LUBNA MOHAMMAD

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4. Biomechanical preparation—Use of rotary and/or hand instruments to expose, clean, enlarge and shape the pulp canal space, usually in conjunction with irrigants . Root canal preparation serves two main objectives: mechanical and chemical elimination of intracanal tissue and pathogens, aided by antimicrobial substances and by optimized root canal fillings Success of RCT depends on how well the canals are shaped and cleaned 5

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8. a nd ensures patency 9

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14. K files Achieved with files or reamers Apical foramen has been cleared of any debris in its path 15

15. 16 “THE LOOK”

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19. 20 The optimal preparation size of the apical foramen remains a subject of uncertainty To clean and predictably seal the foramen, the size of the file used at the end of the cleaning and shaping should be at least a No.20 or 25

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22. In order to fully understand the current techniques for canal preparation, it would be beneficial to look briefly at previous methods, and the associated problems which led to further development . Interestingly, in 1933 a paper was published in the dental literature recommending the use of maggots to consume and remove the necrotic tissue in the root canal, replacing them every 3 days. It soon became apparent that more objective and controllable techniques were required! 23

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24. Canals shaped with standardized technique end up wider than the instrument size would suggest This method was satisfactory in straight canals, but was quite unsuitable for curved canals . As the instrument sizes increase, they become less flexible and led to iatrogenic errors in curved root canals . Common problems encountered were ledging , zipping, elbow formation, perforation and loss of working length owing to compaction of dentin debris Adequate compaction of GP in such a small taper (0.02) is difficult or impossible. 25

25. 26 Clem and Weine , Schilder , Martin, Walton, Mullaney : 1969 -1979

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34. 35 described superior debridement with serial preparation compared to standardized shapes.

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89. 90 The zipped area retains tissue and dentin debris and obturation cannot seal the resulting shape. Instrumentation of the apical foramen can convert a round apical foramen into a teardrop shape or zip.

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92. Ingle’s Endodontics : 6 th edition - John I. Ingle Ingle’s Endodontics : 5 th edition - John I. Ingle Pathways of Pulp: 10 th edition – Stephen Cohen Endodontics : Principles and practice: 4 th edition - Mahmoud Torabinejad Endodontic Practice: 12 th edition – Grossman Textbook of Endodontics – Anil Kohli Textbook of Endodontics : 3 rd edition– Nisha Gargh Textbook of Endodontics - Mithra N Hedge Glossary of Endodontic terms 8 th Edition – American Association of Endodontics British dental journal volume 197 no. 10 november 27; 2004 Preparation of the Root Canal System :Dr . Crumpton Mechanical preparation of root canals : shaping goals, techniques and means Mechanical preparation of root canals , Michael Hulsmann , Ove A. Peters & Paul M.H. Dummer . Endodontic Topics 2005, 10, 30–76 93

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