Biomedical subjects

Valerie V Woo

Publications and source records attributed to Valerie V Woo.

3 recordsLinked to original sources

PubMed2004

Dentoalveolar reconstructive procedures as a risk factor for implant failure.

PURPOSE: Dentoalveolar reconstructive procedures (DRPs) are commonly used to enhance deficient implant recipient sites. It is unclear, however, if these procedures are independent risk factors for implant failure. The specific aim of this study was to assess the use of DRPs as a risk factor for implant failure. MATERIALS AND METHODS: To address the research aim, we used a retrospective cohort study design and a study sample derived from the population of patients who had one or more implants inserted between May 1992 and July 2000. The main predictor variable was the use of DRPs, such as external or internal sinus lifts, onlay bone grafting, or guided-tissue regeneration with autogenous bone grafts or autogenous bone graft substitutes, to enhance the recipient sites before implant insertion. The major outcome variable was implant failure. Appropriate descriptive, bivariate, and multivariate statistics were computed. RESULTS: The study sample was composed of 677 patients who had 677 implants randomly selected (1 implant per patient) for analysis. The overall 1- and 5-year implant survival rates were 95.2% and 90.2%, respectively. Bivariate analyses revealed 4 factors statistically or nearly statistically associated with implant failure: current tobacco use, implant length, implant staging, and type of prosthesis (P <.15). In the multivariate model, patients with DRPs did not have a statistically significant increased risk for implant failure (odds ratio = 1.4, P =.3). CONCLUSIONS: The results of this study suggest that the use of DRPs to reconstruct deficient implant recipient sites was not an independent risk factor for implant failure in either the unadjusted or adjusted analyses.

Adolescent↗

PubMedDate not supplied

Complications of dental implants: identification, frequency, and associated risk factors.

PURPOSE: This study sought to identify the types, frequencies, and risk factors associated with complications following placement of dental implants. It was hypothesized that one or more factors could be identified that are associated with an increased risk for complications and may be modified by the clinician to enhance outcome. MATERIALS AND METHODS: A retrospective cohort study design was used that included patients who received Bicon implants (Bicon, Boston, MA) between 1992 and 2000. Predictor variables were grouped into demographic, medical history, implant-specific, anatomic, prosthetic, and reconstructive categories. Complications were grouped into inflammatory, prosthetic, operative, and major or minor categories. Cox proportional hazards regression models were developed to identify risk factors for complications. RESULTS: The sample was composed of 677 patients. The overall frequency of implant complications was 13.9% (10.2% inflammatory, 2.7% prosthetic, 1.0% operative), of which 53% were minor. The multivariate Cox model revealed that smoking, use of 1-stage implants, and reconstructive procedures were statistically associated with an increased risk for overall complications (P < or = .05). The median duration of follow-up was 13.1 months (range 0 to 85.6 months). DISCUSSION: A lower frequency of complications was found compared to mean frequencies calculated from past reports. Investigations examining the influence of smoking and reconstructive procedures on implant complications are recommended. CONCLUSION: Of the 3 factors associated with an increased risk for complications, tobacco use and implant staging may be modified by the clinician to enhance outcome.

Adolescent↗

PubMedDate not supplied

Maxillary sinus augmentation as a risk factor for implant failure.

PURPOSE: The investigators sought to determine whether maxillary sinus augmentation (MSA) was an independent risk factor for implant failure. MATERIALS AND METHODS: Using a retrospective cohort study design, the investigators enrolled a sample composed of subjects having 1 or more implants placed in the posterior maxilla. The primary predictor variable was MSA status at the time of implant placement (MSA present or absent). MSA consisted of a lateral window (external) or an osteotome (internal) procedure. The outcome variable was implant failure defined as implant removal. Demographic, health status, anatomic, implant-specific, abutment-specific, prosthetic, and perioperative variables were also examined. Overall implant survival was estimated using Kaplan-Meier analysis. Risk factors for implant failure were identified using Cox proportional hazard regression models. RESULTS: The sample consisted of 318 patients and 762 posterior maxillary implants. The mean duration of follow-up was 22.50 +/- 19.06 months. The 5-year survival rates for implants in the ungrafted and grafted posterior maxilla were 88.0% and 87.9%, respectively (P = .08). After adjustment for covariates, MSA status was not an independent risk factor for implant failure (P = .9). Tobacco use (P < .001), implants replacing molars (P < .001), and 1-stage implants (P < .001) were statistically associated with an increased risk for implant failure. DISCUSSION: MSA status was not associated with implant failure risk. This finding may be subject to selection bias, as successful MSA was requisite prior to implant placement. CONCLUSION: MSA status was not associated with an increased risk for implant failure. Of the 3 factors associated with an increased risk for failure, tobacco use and implant staging may be modified by the clinician to enhance outcome.

Dental Implants↗