Authors: Bystrom A, Happonen RP, Sjogren U, Sundqvist G.
Title: Healing of periapical lesions of pulpless teeth after endodontic treatment with controlled asepsis.
Journal: Endod Dent Traumatol
Date: Apr 1987
Citation: 3(2):58-63
Category: Success and Failure
Evidence-based Ranking: 2
Purpose/Objectives: To evaluate possible reasons for root canal failure based on method of treatment and causative organisms.

Materials & Methods: 79 single rooted, necrotic teeth with periapical radiolucencies were included. Teeth were treated in by three different methods. Group 1 (11 teeth) were instrumented and irrigated with sterile saline. After 4 visits 7 teeth continued to show bacteria present and were dressed with CaOH until sterile then obturated. Group 2 (42 teeth) were instrumented and irrigated with NaOCl or NaOCl and EDTA. 32 teeth were determined sterile and filled while 10 were treated with CaOH then filled. Group 3 (26 teeth) were instrumented and irrigated with NaOCl and dressed with CaOH between appointments. Once no bacteria were detected the teeth were filled. All teeth were obturated with lateral condensation and chloroform dip for the master cone. Evaluations were then conducted clinically and radiographically at 6 and 12 months then once a year thereafter. Healing was considered complete once the PDL was <0.5mm.

Results: At 2 years, of the 79 lesions, 67 healed completely and 7 had decreased lesions but healing was incomplete. 3 cases treated by surgery showed scar tissue with almost no inflammation. 1 case was treated surgically within 6 months because of continued fistula. The 4 remaining cases were treated surgically 2 of which had A. israelii and A. propionica isolated from the biopsy.

Author’s Conclusion: Only 5 of the 79 would not have healed without surgery (6.0%). If a case shows continued reduction in size of lesion it should not be judged a failure. Possible reasons for RCT failure include – failure to eliminate causative organisms, bacteria persisting in dentinal tubules, and bacteria persisting in the periapical region.

Validity of Conclusion: Valid but not well presented

Reviewer’s Comments: This study seems to be trying to use teeth and treatments from another study to present other findings. The results and conclusions are not correlated with the study protocols at all.