title: Implant Treatment in the Predoctoral Clinic: A Retrospective Database Study of 1091 Patients.
abstract: OBJECTIVE
  This retrospective study was conducted at the Marquette University School of Dentistry to (1) characterize the implant patient population in a predoctoral clinic, (2) describe the implants inserted, and (3) provide information on implant failures.
  
  
  METHODS
  The study cohort included 1091 patients who received 1918 dental implants between 2004 and 2012, and had their implants restored by a crown or a fixed dental prosthesis. Data were collected from patient records, entered in a database, and summarized in tables and figures. Contingency tables were prepared and analyzed by a chi-squared test. The cumulative survival probability of implants was described using a Kaplan-Meier survival curve. Univariate and multivariate frailty Cox regression models for clustered observations were computed to identify factors associated with implant failure.
  
  
  RESULTS
  Mean patient age (±1 SD) at implantation was 59.7 ± 15.3 years; 53.9% of patients were females, 73.5% were Caucasians. Noble Biocare was the most frequently used implant brand (65.0%). Most implants had a regular-size diameter (59.3%). More implants were inserted in posterior (79.0%) than in anterior jaw regions. Mandibular posterior was the most frequently restored site (43%); 87.8% of implants were restored using single implant crowns. The overall implant-based cumulative survival rate was 96.4%. The patient-based implant survival rate was 94.6%. Implant failure risk was greater among patients than within patients (p < 0.05). Age (>65 years; hazard ratio [HR] = 3.2, p = 0.02), implant staging (two-stage; HR = 4.0, p < 0.001), and implant diameter (wide; HR = 0.4, p = 0.04) were statistically associated with implant failure.
  
  
  CONCLUSIONS
  Treatment with dental implants in a supervised predoctoral clinic environment resulted in survival rates similar to published results obtained in private practice or research clinics. Older age and implant staging increased failure risk, while the selection of a wide implant diameter was associated with a lower failure risk.
authors.affiliation: Department of General Dental Science, Marquette University School of Dentistry, Milwaukee, WI.
authors.forename: Soni
authors.initials: S
authors.lastname: Prasad
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Florida College of Dentistry, Gainesville, FL.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hambrook
authors.affiliation: Access Community Health Centers, Dodgeville, WI.
authors.forename: Eric
authors.initials: E
authors.lastname: Reigle
authors.affiliation: Department of Mathematics, Statistics, and Computer Science, Marquette University School of Dentistry, Milwaukee, WI.
authors.forename: Katherine
authors.initials: K
authors.lastname: Sherman
authors.affiliation: Department of Mathematics, Statistics, and Computer Science, Marquette University School of Dentistry, Milwaukee, WI.
authors.forename: Naveen
authors.initials: N
authors.lastname: Bansal
authors.affiliation: Division of Periodontology, Ohio State University College of Dentistry, Columbus, OH.
authors.forename: Arthur
authors.initials: A
authors.lastname: Hefti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016208:Databases, Factual; D015921:Dental Implants; D019232:Dental Restoration Failure / Q000706:statistics & numerical data*; D004499:Education, Dental, Graduate; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D015921:Dental Implants
keywords: Cox regression; Kaplan-Meier; Predoctoral education; failure analysis; frailty model; hazard ratio; implants; multivariate analysis; patient age; survival analysis; univariate analysis