Analysis of risk factors for cluster behavior of dental implant failures.
BACKGROUND
Some studies indicated that implant failures are commonly concentrated in few patients.


OBJECTIVE
To identify and analyze cluster behavior of dental implant failures among subjects of a retrospective study.


METHODS
This retrospective study included patients receiving at least three implants only. Patients presenting at least three implant failures were classified as presenting a cluster behavior. Univariate and multivariate logistic regression models and generalized estimating equations analysis evaluated the effect of explanatory variables on the cluster behavior.


RESULTS
There were 1406 patients with three or more implants (8337 implants, 592 failures). Sixty-seven (4.77%) patients presented cluster behavior, with 56.8% of all implant failures. The intake of antidepressants and bruxism were identified as potential negative factors exerting a statistically significant influence on a cluster behavior at the patient-level. The negative factors at the implant-level were turned implants, short implants, poor bone quality, age of the patient, the intake of medicaments to reduce the acid gastric production, smoking, and bruxism.


CONCLUSIONS
A cluster pattern among patients with implant failure is highly probable. Factors of interest as predictors for implant failures could be a number of systemic and local factors, although a direct causal relationship cannot be ascertained.
Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
Bruno Ramos
BR
Chrcanovic
Clinic for Prosthodontics, Centre of Dental Specialist Care, Malmö, Sweden.
Jenö
J
Kisch
Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.|Department of Biomaterials, Göteborg University, Göteborg, Sweden.
Tomas
T
Albrektsson
Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
Ann
A
Wennerberg
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000009:adverse effects; D002012:Bruxism / Q000150:complications; D015921:Dental Implants / Q000009:adverse effects*; D019232:Dental Restoration Failure / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
D000928:Antidepressive Agents; D015921:Dental Implants
cluster phenomenon; dental implant; implant failure; logistic models; multivariate analysis; risk factors