endo

1. Treatment choices for negative
outcomes with non-surgical root
canal treatment: non-surgical
retreatment vs. surgical retreatment
vs. implants
STEVEN A. COHN
Endodontic Topics 2005

2. • The primary reason for a negative outcome
with endodontic treatment is the persistence
of bacteria within the intricacies of the root
canal system.
• Failure may also be attributed to the
persistence of bacteria in the periapical
tissues, foreign body reactions to overfilled
root canals, and the presence of cysts.

3. • 5 levels of evidence
– Prospective randomized-controlled trials (RCT)
considered the highest level of evidence (LOE 1).
• No papers dealing with non-surgical retreatment
and surgical revision that reach the highest LOE.
• The primary consideration is the patient’s values
and expectations.

4. Non-surgical retreatment
• The incidence of periapical lesions following
root canal procedures surveyed in many
countries is 20–60%.

5. Non-surgical retreatment
• Apical periodontitis
– apical periodontitis is the most important variable
influencing a positive outcome with non-surgical
retreatment.
– Hepworth&Friedman: the retreatment of teeth
without periapical lesions has a positive outcome of
95%, but in their study and others, this declines to 56–
84% in the presence of a periapical lesion.
– The true negative outcome rate may be only 10–16%.

6. Non-surgical retreatment
• Role of primary endodontic treatment
– Sjøgren found that 94% of periapical lesions
healed when the root filling was within 2mm of
the apex, a significant difference when compared
with overfilled canals (76%) and those more than
2mm short of the apex (68%).

7. Non-surgical retreatment
• Bacterial and technical considerations
– Farzanehet found that a positive outcome was most
influenced by the presence of a preoperative
perforation.
– Other negative factors were the quality of the root
filling, the lack of a final restoration, and preoperative
apical periodontitis. The overall success (or
‘healed’)rate was 81.
– 93% when asymptomatic and functional teeth were
included.

8. Reference set of radiographs with corresponding line drawings and their associated PAI score

9. • Occlusion
– The role of the occlusion following endodontic
treatment requires further investigation

10. • Restoration
– The quality of the restoration affects the outcome
because of the possibility of leakage.
– Teeth not crowned following endodontic
treatment were lost at 6 times the rate of those
teeth that did receive crowns.

11. Outcome of periradicular surgery
• Surgical retreatment
– Positive outcomes for surgical retreatment in
excess of 90% can be achieved with careful case
selection and a skilled and experienced operator

12. Outcome of periradicular surgery
• Lesion size and characteristics
– No clear consensus that small (less 5 mm) lesions
heal more favorably than larger lesions
• Tooth location
– be less important than the access to it and the
anatomy of the roots in determining a successful
outcome

13. Outcome of periradicular surgery
• Preoperative symptoms
– Symptoms do not appear to affect the outcome of
surgery
• Age and gender
– Neither the age nor the sex of the patient appears
to influence the outcome of surgery

14. Outcome of periradicular surgery
• Quality of the root filling
– Non-surgical retreatment of the root canals before
surgery improves the prognosis for surgery
– Short root fillings had a better outcome then roots
filled to the apex or overfilled

15. Outcome of periradicular surgery
• Repeat surgery
– A repeat of surgery is associated with a worse
outcome than surgery performed the first time
• Resection
– Resection of 3mm is considered sufficient to eliminate
apical pathology
• Root-end filling and materials
– IRM and MTA no significant diff.

16. Outcome of periradicular surgery
• Operator skill
– The complete healing rate in the endodontic unit
was approximately double that of the oral surgery
department.

17. Intentional replantation
• Intentional replantation is a viable alternative
to tooth extraction in selected cases.

18. Transplantation
– Endodontic treatment is indicated for teeth with
closed apices, usually within a month after
transplantation. The prognosis for both closed and
open apices is considered favorable

19. Endodontics or implants?
• Implant studies - when the criteria of EBD are
applied, there are no papers that reach the
highest level of evidence.

20. • Ruskin state that an immediate implant has a
more predictable outcome than an
endodontically treated tooth as a basis for
restorative dentistry.
– “The best candidate for endodontic treatment is a
single rooted tooth with an intact crown that has
become devitalized due to trauma, and that also
fulfills an esthetic need.”

21. Endodontics and implants: ‘success’
vs. ‘survival’
– concept of ‘survival’ is applied to implant studies
– 1.5 million teeth from an insurance company
database. The treatments were provided both by
general dentists and endodontists, and a 97%
retention rate followed up for 8 years was
reported
– the high success rates for implants may not be
duplicated at the general practitioner level

22. Indications for an implant
• Root resection?
– Langer reported a 38% failure rate of 100 molar
teeth that had undergone a root resection
– Blömlof reported on a 10-year follow-up of root-
resected molars compared with root-filled single
rooted teeth. The survival rate was similar.

23. CDA Journal , vol 36 , 2008

24. • The preliminary electronic and manual
searches identifed 5,346 endodontic and
4,361 dental implant studies.
– Inclusion criterias:
• At least 25 cases with a minimum two-year follow-up
(endodontics - from obturation time; implant - from
placement); with treatment units described as being
single individual, implant-supported restorations,
and/or endodontically treated teeth
– Exlusion criterias:
• did not define criteria for success/survival outcomes, if
they reported on treatments no longer used in practice,
or if the patients were described as having moderate or
severe periodontal disease

25. • Following full-text review, 24 endodontic, and
46 implant studies were included

27. Implant success

28. Endodontic success

29. Implant survival

30. Endodontic survival

31. Retrospective cross sectional
comparison of initial nonsurgical
endodontic treatment and
single-tooth implants.
Doyle SL, Hodges JS, Pesun IJ, Law AS,
Bowles WR.
J Endod. 2006 Sep;32(9):822-7.

32. Endodontics vs implant
• Compared 196 implant restorations and 196
matched initial nonsurgical root canal
treatment (NSRCT) teeth in patients for four
possible outcomes - success, survival, survival
with subsequent treatment intervention and
failure

33. Endodontics vs implant
0
20
40
60
80
100
Prosent
Endo Impl
Success Survival Repair Failure
Doyle SL, Hodges JS, Pesun IJ, Law AS, Bowles WR. Retrospective cross sectional comparison of initial nonsurgical
endodontic treatment and single-tooth implants. J Endod. 2006 Sep;32(9):822-7. NSRCT outcomes were affected by
periradicular periodontitis (p = 0.001), post placement (p = 0.013), and overfilling (p = 0.003).

34. Endodontics vs implant
Estimated fraction not failing at each recall time