Multifactorial risk assessment for survival of abutments of removable partial dentures based on practice-based longitudinal study

• Published in: Journal of dentistry 2013-12, Vol.41 (12), p.1175-1180
• Main Authors: Tada, Sayaka, Ikebe, Kazunori, Matsuda, Ken-ichi, Maeda, Yoshinobu
• Format: Article
• Language: English
• Subjects: Abutment; Aged; Chromium Alloys - chemistry; Cohort Studies; Community-Based Participatory Research; Confidence intervals; Dental Abutments - statistics & numerical data; Dental care; Dental Clasps; Dentistry; Denture Design; Denture, Partial, Removable - statistics & numerical data; Dentures; Design; Drug therapy; Family medical history; Female; Hospitals; Humans; Kaplan-Meier Estimate; Longitudinal Studies; Longitudinal study; Male; Medical prognosis; Middle Aged; Multifactorial risk assessment; Multivariate Analysis; Odontometry; Periodontal Pocket - classification; Prognosis; Proportional Hazards Models; Prostheses; Removable partial denture; Retrospective Studies; Risk Assessment; Root Canal Therapy - statistics & numerical data; Studies; Survival Analysis; Survival rate; Tooth Crown - anatomy & histology; Tooth Loss - prevention & control; Tooth Root - anatomy & histology; Variables
• ISSN: 0300-5712; 1879-176X
• DOI: 10.1016/j.jdent.2013.07.018

Abstract Objectives Predicting the tooth survival is such a great challenge for evidence-based dentistry. To prevent further tooth loss of partially edentulous patients, estimation of individualized risk and benefit for each residual tooth is important to the clinical decision-making. While there are several reports indicating a risk of losing the abutment teeth of RPDs, there are no existing reports exploring the cause of abutment loss by multifactorial analysis. The aim of this practice-based longitudinal study was to determine the prognostic factors affecting the survival period of RPD abutments using a multifactorial risk assessment. Methods One hundred and forty-seven patients had been previously provided with a total of 236 new RPDs at the Osaka University Dental Hospital; the 856 abutments for these RPDs were analyzed. Survival of abutment teeth was estimated using the Kaplan–Meier method. Multivariate analysis was conducted by Cox's proportional hazard modelling. Results The 5-year survival rates were 86.6% for direct abutments and 93.1% for indirect abutments, compared with 95.8% survival in non-abutment teeth. The multivariate analysis showed that abutment survival was significantly associated with crown-root ratio (hazard ratio (HR): 3.13), root canal treatment (HR: 2.93), pocket depth (HR: 2.51), type of abutments (HR: 2.19) and occlusal support (HR: 1.90). Conclusion From this practice-based longitudinal study, we concluded that RPD abutment teeth are more likely to be lost than other residual teeth. From the multifactorial risk factor assessment, several prognostic factors, such as occlusal support, crown-root ratio, root canal treatment, and pocket depth were suggested. Clinical significance These results could be used to estimate the individualized risk for the residual teeth, to predict the prognosis of RPD abutments and to facilitate an evidence-based clinical decision making.