[Show abstract][Hide abstract] ABSTRACT: To evaluate the performance of 5-mm-long implants.
A retrospective cohort study was conducted between January 2008 and December 2009. The sample was composed of patients who had received at least one 5-mm-wide, hydroxyapatite-coated Bicon implant. The outcome variable was implant failure. Descriptive statistics and univariate and multivariate Cox proportional hazards regression models, adjusted for multiple implants in the same patient, were utilized to identify predictors of dental implant failure.
Two hundred ninety-one subjects who received 410 locking-taper implants were followed for an average of 20 months. Of these, 211 were ultrashort implants (57 were 5 x 5.0 mm and 154 were 5 x 6.0 mm) and 199 were short implants (5 x 8.0 mm). Three hundred twenty-two implants (93.4%) were restored with single crowns. There was a higher proportion of ultrashort single-tooth implants (94.6%) as compared to short single-tooth implants (92.2%). Nine implants failed, for a cumulative survival rate of 97.5%. Of the failed implants, five were ultrashort (all 5 x 6.0 mm) and four were short. No failures were documented for 5- x 5.0-mm ultrashort implants. There was no statistically significant difference (P = .68) in the Kaplan-Meier survival rates of ultrashort implants (97.6%) and short implants (95.2%). After adjusting for other covariates in a multivariate model, implant length was not associated with implant failure (P = .49).
The survival of ultrashort (5- and 6-mm) implants was comparable to that of short (8-mm) implants.
The International journal of oral & maxillofacial implants 05/2012; 27(3):644-54. · 1.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To identify factors associated with crestal bone gain around single-tooth implants.
A retrospective cohort study was conducted. More than 90 different local and systemic factors were documented. Descriptive statistics and univariate and multivariate mixed-effects regression models, adjusted for multiple implants in the same patient, were used to identify predictors of crestal bone gain after insertion of definitive restorations.
Eighty-one subjects who received 326 Bicon implants were followed for an average of 70.7 months. Eighty-one implants in 46 patients showed varying degrees of apparent bone gain over time. Variables associated with peri-implant bone gain in the first multivariate model were: type of opposing structure, tooth (P = .02); type of restoration, crown cemented on a prefabricated titanium abutment with a spherical base (P = .006); hydroxyapatite coating (P = .0005); implant size 5 x 8 mm (P = .02); and daily intake of nonsteroidal anti-inflammatory drugs (NSAIDs) (P =.04). NSAIDs remained significantly correlated to crestal bone gain in the second multivariate analysis; an implant was significantly more likely to gain bone if the patient was taking NSAIDs daily (P = .02), but this effect was specific to hydroxyapatite-coated implants (P = .01).
Daily doses of NSAIDs were correlated with a significant increase in crestal bone levels around single-tooth hydroxyapatite-coated implants following crown insertion.
The International journal of oral & maxillofacial implants 09/2011; 26(5):1063-78. · 1.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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).
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.
Journal of Oral and Maxillofacial Surgery 07/2004; 62(7):773-80. DOI:10.1016/j.joms.2003.12.017 · 1.43 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Given the predictability of dental implant success, the attention of the scientific community is moving from descriptions of implant success toward a more detailed analysis of factors associated with implant failure. The purposes of this study were (1) to estimate the 1- and 5-year survival of Bicon dental implants and (2) to identify risk factors associated with implant failure in an objective, statistically valid manner. To address the research purposes, we used a retrospective cohort study design and a study sample composed of patients who had one or more implants placed. The predictor variables were grouped into the following categories: demographic, health status, anatomic, implant fixture-specific, prosthetic, perioperative, and ancillary variables. The major outcome variable of interest was implant failure defined as implant removal. Overall implant survival was estimated using the Kaplan-Meier analysis. Risk factors for implant failure were identified using the Cox proportional hazard regression models. The study sample was composed of 677 patients who had 677 implants randomly selected for analysis. The overall 1- and 5-year survival of the Bicon implant system was 95.2% and 90.2%, respectively. After adjusting for other covariates in a multivariate model, both tobacco use (P = .0004) and single-stage implant placement (P = .01) were statistically associated with an increased risk for failure. The results of these analyses suggest that the overall survival of the Bicon dental implant is comparable with other current implant systems. In addition, after controlling for covariates, we identified 2 exposures associated with implant survival, tobacco use and implant staging. Of interest, both of these exposures are under the clinician's control.