Long-term outcome of primary non-surgical root canal treatment.
OBJECTIVE
The aim of this study is to examine the survival distributions of primary root canal treatment using interval-censored data and to assess the factors affecting the outcome of primary root canal treatment, in terms of periapical healing and tooth survival.


METHODS
About one tenth of primary root canal treatment performed between January 1981 and December 1994 in a dental teaching hospital were systematically sampled for inclusion in this study. Information about the patients' personal particulars, medical history, pre-operative status, treatment details, and previous review status of the treated teeth, were obtained from dental records. Patients were recalled for examination clinically and radiographically. Treatment outcomes were categorized according to the status for periapical healing and tooth survival. The event time was interval-censored and subjected to survival analysis using the Weibull accelerated failure time model.


RESULTS
A total of 889 teeth were suitable for analysis. Survival curves of both outcome measures (periapical healing and tooth survival) declined in a non-linear fashion with time. Median survival of the treated teeth was 119 months (periapical healing) and 252 months (tooth survival). Age, tooth type, pre-operative periapical status, occlusion, type of final restoration, and condition of the tooth/restoration margin were significant factors affecting both periapical healing and tooth survival. Apical extent and homogeneity of root canal fillings had a significant impact towards periapical healing (p < 0.05), but not tooth survival.


CONCLUSIONS
The longevity of treated teeth based on tooth survival was considerably greater than that of periapical healing. Both outcome measures were affected by a number of socio-demographic, pre-, intra-, and post-operative factors.


CONCLUSIONS
Root canal-treated teeth may continue to function for a considerable period of time even though there may be radiographic periapical lesion present. Decision for extraction may be due to reasons other than a failure of the periapical tissues to heal.
Faculty of Dentistry, The University of Hong Kong, 3/F, Prince Philip Dental Hospital, 34 Hospital Road, Sai Ying Pun, Hong Kong, HKSAR, China.
A H C
AH
Lee
G S P
GS
Cheung
M C M
MC
Wong
D000328:Adult; D000367:Age Factors; D003731:Dental Caries / Q000000981:diagnostic imaging; D018772:Dental Marginal Adaptation; D003766:Dental Occlusion; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging; D003793:Dental Restoration, Permanent / Q000145:classification; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging / Q000628:therapy; D010486:Periapical Tissue / Q000000981:diagnostic imaging; D016300:Radiography, Bitewing; D019252:Radiography, Dental, Digital; D019233:Retreatment; D012189:Retrospective Studies; D012387:Root Canal Filling Materials / Q000592:standards; D012389:Root Canal Obturation / Q000592:standards; D012390:Root Canal Therapy / Q000706:statistics & numerical data*; D016019:Survival Analysis; D016388:Tooth Loss / Q000145:classification; D019553:Tooth, Nonvital / Q000000981:diagnostic imaging; D016896:Treatment Outcome; D014945:Wound Healing / Q000502:physiology
D012387:Root Canal Filling Materials