Authors: Rud J, Andreasen JO, Jensen JE.
Title: A follow-up study of 1,000 cases treated by endodontic surgery.
Journal: Int J Oral Surg
Date: Jan 1972
Citation: 1(4):215-28
Category: Endodontic Surgery
Evidence-based Ranking: 2
Purpose/Objectives: Radiographic criteria were used to determine the results of endodontic surgery from 1-15 years post-operatively. Also, the influence of increasing observation time on the mode of healing was analyzed, and an attempt to estimate the minimum observation period needed to ascertain radiographically a success or failure.

Materials & Methods: 1000 teeth in 798 patients were re-examined 1 year after endodontic surgery. In 763 an orthograde filling was made, in 237 a retrograde amalgam was placed. 1 radiograph was used to assess healing – the naked eye and a magnifying glass were used by all three authors to classify healing as Complete, Incomplete (scar tissue), Uncertain, or Unsatisfactory (failures).

Definitions: Complete healing – reform a PDL space, lamina dura followed, root fill tolerated, bone cavity filled-in with some bone; Incomplete (scar tissue) – rarefaction exists though decreasing in size, some bone formation may be present with some lamina dura visible; Uncertain – some degree of bone regeneration so the rarefaction has decreased, but it is more than twice the size of the normal PDL space, may or may not see a lamina dura; Unsatisfactory (failure) – rarefaction is the same as pre-op or enlarged.

Results: The results are presented in tables. The group with Complete healing after 1 year was 66%. After a follow-up beyond that year, the Complete healing increased to 81%. The failure group increased from 2 to 4%. The Incomplete healing group decreased from 15 to 9%, and the Uncertain group from 17 to 6%. With longer observation time the Incomplete and Uncertain groups diminished, while the Complete and Unsatisfactory increased. Teeth with retrograde amalgam fillings showed 4 times as many failures as occurred in teeth with orthograde GP fillings.

Author’s Conclusion: Complete and Unsatisfactory healing groups remain within the groups and increase with time. Incomplete and Uncertain groups are unstable and change to become either success or failures. Standard follow-ups should be made after 1 year because most changes take place within 1 year. Few cases shifted after four years of observation. If healing is Complete, the condition is regarded as satisfactory, and no further follow-up is required. If the healing is Unsatisfactory after 1 year re-operation or extraction should be considered. If the healing is Uncertain the patient should be controlled until complete healing is established. If this does not happen after 4 years, re- operation or extraction is warranted. If the healing is Incomplete, the patients should be followed. If inflammation occurs, re-operation or extraction should be performed.