steven a. cohn

Treatment choices for negative outcomes with non-surgical root

canal treatment: non-surgical retreatment vs. surgical retreatment

vs. implantsSTEVEN A. COHN

Endodontic Topics 2005

• 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.

• 5 levels of evidence– Prospective randomized-controlled trials (RCT)

considered the highest level of evidence (LOE 1).

• No papers dealing with non-surgical retreatmentand surgical revision that reach the highest LOE.

• The primary consideration is the patient’s values

and expectations.

Non-surgical retreatment

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

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%.

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%).

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.

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

• Occlusion– The role of the occlusion following endodontic

treatment requires further investigation

• 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.

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

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

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

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

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.

Outcome of periradicular surgery

• Operator skill– The complete healing rate in the endodontic unit

was approximately double that of the oral surgery department.

Intentional replantation

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

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

Endodontics or implants?

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

• 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.”

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

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.

CDA Journal , vol 36 , 2008

• 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

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

Implant success

Endodontic success

Implant survival

Endodontic survival

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.

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

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).

Endodontics vs implant

Estimated fraction not failing at each recall time