Objectives: This study identified clinical factors related to noncompletion
of root canal therapy (RCT) among patients in a dental health maintenance
organization (HMO) based in Portland, OR. Methods: A secondary analysis of
a case-control study was conducted using data from 303 individuals enrolled
continuously in the HMO from January 1, 1987, through December 31, 1994, w
ho received endodontic access on a permanent nonwisdom tooth in 1987 or 198
8. Person- and tooth-level characteristics were evaluated to compare patien
ts whose accessed tooth was obturated by December 31, 1994, with patients w
hose accessed tooth was not obturated by that date. Written and electronic
records were reviewed to ascertain study variables, and multivariate logist
ic regression models were developed to describe differences between the two
groups. Results: Incomplete RCT was more common among patients who were sy
mptomatic prior to access and had more missing first molars at access. It a
lso was more common among teeth that were decayed, had more pockets greater
than or equal to5 mm, and had fewer decayed or filled surfaces at access.
Conclusions: Because patients with greater evidence of past and current ora
l disease were less likely to have completed RCT, they may require addition
al counseling about the importance of carrying through with prescribed trea
tment.