The coronal seal of an endodontically treated tooth is essential for the long-term success of the treatment. Microorganisms from the oral cavity can reinfect the root canal system through gaps in the temporary or permanent restoration. Several studies have shown that within a few weeks of leaving the access cavity open, bacteria from the saliva can travel down the entire length of the root canal. Placement of an adequate permanent restoration is critical to prevent reinfection of the root canal system and promote healing of the periapical tissues. The technical quality of the coronal restoration has a greater impact on apical periodontal health than the quality of the root canal filling.

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 .

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• Endodontics: Principles and Practice By Mahmoud Torabinejad, Richard E. Walton