1. Obturation & the Importance of
Coronal Seal
Al-Waleed F. Abushanan, BDS
RIYADH COLLEGES
OF DENTISTRYAND PHARMACY
1

2. • The obturation phase of root canal treatment
receives a great deal of attention. Historically,
obturation has been accorded the role of the most
critical step and the cause of most treatment
failures.

3. • Preventing the reinfection by acting as a barrier.
• Sealing any surviving bacterial cells and their
irritants.
• Stopping influx of periapical tissue fluids .

5. • Failure to eliminate these etiological factors and to
prevent further irritation via continued
contamination of the root canal system are the
prime causes of failure of nonsurgical and surgical
root canal treatment.

6. • When the root filling is radiograpically acceptable,
the likelihood of leakage is still rather high.

10. • Preoperative factors
• Intraoperative factors
• Postoperative factors

11. • Apical periodontitis
• Lesion size
• Pulpal status
• Symptoms
• Age, gender, tooth location, health
• Periodontal condition

12. S Friedman

14. • Apical extent of canal instrumentation and
• Filling
• Apical enlargement
• Treatment sessions
• Material and techniques
• Complications

15. Sjogren et al.
Underfilled(>2 mm)
68% Success
0-2 mm from apex
94% Success
Overfilled
76% Success

19. • Restoration

21. • The success of endodontic therapy is commonly
thought of in terms of an adequate apical seal
• However, the coronal seal achieved by the
restoration may be considered as important for the
ultimate success of endodontic treatment.

22. • Strindberg, in 1956, considered that the most
common cause of failure was leakage of tissue fluids
apically around inadequate root fillings.
• Ingle in 1965 found that of 104 failed cases, 66 were
associated with a poor apical seal.

23. • During the mechanical preparation of the post space
it is possible that the root filling may be twisted or
vibrated , with disruption of the seal.

24. • It is generally accepted that the success rate of the
treatment is positively correlated with the criteria
for good technical quality of the root filling .

25. • Even in a good root filling performed under optimal
condition, the coronal leakage will be consistent and
extensive if the access cavity is left unfilled and thus
exposed to fluids.

26. Obturated root canals can be recontaminated by micro
organisms in a number of ways:
• Delay in placing a coronal restoration . Temporary
materials will dissolve slowly after in time in the
presence of saliva and the seal may break down . A
temporary restoration of inadequate thickness will
eventually leak restoration. down.

27. • Fracture of the coronal restoration and /or the tooth
• Preparation of post space when the remaining apical
section of the root filling is of inadequate density
and / or length.

28. • Dyes (Swanson et al, Madison et al)
• Radioactive isotopes (Marshall et al)
• Bacteria (Mortensen et al, Goldman et al,Torabinejadet al)
• Fluid filtration method (Derksen et al)

29. • Swanson & Madison, did an in vitro study where
they showed that after only 3 days exposure to
artificial saliva there was extensive coronal leakage
of a tracer dye through apparently sound root filling.

30. • Torabinejad et al, found that 50% of single rooted
teeth of gutta percha and a sealer cement , were
contaminated with bacteria along the whole length
of the root after 19 days or 42 days, depending upon
the contaminating organism.

31. • Khayat et al, have shown that root canals obturated with
gutta percha and Roth sealer , using either lateral
condensation or vertical condensation were
contaminated apically with bacteria from saliva exposed
to the coronal part of the root canal only . All canals
were contaminated within 30 days of exposure.

32. A good root filling
or
a good coronal restoration ?!

36. • The technical quality of the coronal restoration was
significantly more important than the technical
quality of the endodontic treatment for apical
periodontal health.

40. • Sealer
• Core material
• Filling Technique
• Restoration

43. • A successful endodontic treatment never ends with
a well rounded quality obturation, but needs more
attention on the coronal part after it.
• Critical to long term endodontic success is the
placement of a well designed restoration that
prevents microleakage, promotes periodontal
health and harmonious occlusion while being
esthetically acceptable .

44. • Dow PR, INGLE Isotope determination of root canal failure. Oral Surgery. Oral Medicine and Oral Pathology S. (1955) 110'0-4.
• MADLSON S. SWANSON K. CHILES SA An evaluation of coronal microleakage in endodonticaily treated teeth. Part II. Sealer Types.
Journal of Endodontics (1987) 13. 109-12.
• Swansom K, MADISON S An evaluation of corona] microleakage in endodontically treated teeth. Part I. Time periods. Journal of
Endodontics (1987) 13. 56-9.
• Sjögren U, Hägglund B, Sundqvist G, Wing K. Factors affecting the long-term results of endodontic treatment. J Endod (1990) 16:
498–504.
• Torabinejad M. IJNG B, KETTERING JD In vitro bacterial penetration of coronally unsealed endodontically treated teeth. Journal of
Endodontics (1990) 16. 566-9.
• TROPE M. CHOW E, NISSAN R In vitro endotoxin penetration of coronally unsealed endodontically treated teeth, journal of Dental
Research. (1993) 188.Abs(676).
• Khayat A, Lee SJ, Torabinejad M. Human saliva penetration of coronally unsealed obturated root canals. J Endod. 1993 Sep;19(9):458-
61.
• H. A. RAY, & M. TROPE Periapical status of endodontically treated teeth in relation to thetechnical quality of the root filling and the
coronal restoration International Endodontic Journal (1995) 28. 12-18
• Friedman S. Treatment outcome and prognosis of endodontic therapy. Essential endodontology: Prevention and treatment of apical
periodontitis. Oxford Blackwell Science, (1998).
• Tronstad L, Asbjørnsen K, Døving L, Pedersen I, Eriksen HM., Influence of coronal restorations on the periapical health of
endodontically treated teeth. Endod Dent Traumatol (2000); 16: 218–221.
• Endodontics: Principles and Practice By Mahmoud Torabinejad, Richard E. Walton