Authors
Erakat, MS.
Chuang, SK.
Yoo, R.
Weed, M.
Dodson, TB. 

Abstract
Purpose: The purpose of this study was to estimate the 1-year survival rate of immediate vertical-load splinted locking-taper implants and to identify risk factors for implant failure. Materials and Methods: To address the research aim, the investigators implemented a retrospective cohort study design and enrolled a sample derived from the population of patients who had received immediate vertical-load splinted implants (Bicon, Boston, MA). The predictor variables were the sets of exposures associated with implant failure and classified as demographic, health status, anatomic, implant specific, prosthetic, and surgical. The primary outcome variable was implant failure, which was defined as implant removal. Descriptive, univariate, and multivariate analyses using clustered marginal approach of the Cox proportional hazards models were computed. The level of statistical significance was set at P < .05.Results: The study cohort was composed of 209 patients who received 477 implants. The overall 1-year Kaplan-Meier survival estimate was 90.3% (95% CI: 86.9%, 93.7%). In the multivariate model, implant placement in a delayed manner versus implantation the same day as extraction (hazard ratio = 3.7, P = .002), uncoated implants versus coated implants (hazard ratio = 22.1, P < .001), and an increased per-unit number of pontics involved in the temporary prosthesis (hazard ratio = 1.8, P < .001) were statistically associated with an increased risk of implant failure. Conclusions: An overall 1-year survival estimate of 90.3% (95% CI: 86.9%, 93.7%) was calculated for immediately loaded splinted implants. After controlling for other variables, 3 variables—timing of implant placement relative to extraction (delayed implant placement after tooth extraction), coating of implant (uncoated), and increased number of pontics—were associated with an increased risk for implant failure. Int J Oral Maxillofac Implants 2008;23:105–110 

Authors
Markiewicz, MR.
Chuang, SK.
Weed, M.
Dodson, TB. 

Abstract
Statement of the Problem: Conventional implant practice dictates a delay between tooth extraction and implant placement. Some investigators advocate inserting implants immediately after the tooth is extracted. Advantages of immediate over delayed implant placement following extraction include shorter treatment time, fewer visits, and a diminished time period of functional and esthetic deficiency. Offsetting the advantages of immediate implant placement may be an increased risk for implant failure.
Purpose: The purpose of this study was to answer the following clinical question: “Among implants inserted, do those placed immediately after tooth extraction, when compared to those placed at some time after tooth extraction, have a decreased likelihood of survival one-year after insertion?” A secondary purpose was to identify prognostic factors associated with one-year implant survival.
Materials and Methods: Using a retrospective cohort design, the investigators enrolled a sample of subjects having at least one implant inserted between 7/1/01-8/31/05 at the Implant Dentistry Centre, Boston, MA. The primary predictor variable was the timing of implant placement following extraction (immediate vs delayed). An immediate implant was defined as an implant inserted immediately following the extraction. A delayed implant was defined as an implant inserted at any time after the day of tooth extraction. The outcome variable was implant survival at one-year after insertion. Secondary explanatory variables were categorized as demographic, health status (e.g. ASA status, tobacco use), implant-specific (diameter, length, coating), anatomic (location), and perioperative variables (e.g. staging, dentoalveolar reconstructive procedures, antibiotic use, implant stability at stage 2). Descriptive statistics, Kaplan- Meir survival analysis, as well as univariate and multivariate Cox proportional hazards regression analyses were completed using SAS (version 9, SAS Institute Inc, Cary, NC). Level of statistical significance was set apriori at α = 0.05. 
Results: The study sample was composed of 161 patients having 963 implants inserted (412 immediate-placed vs. 551 delayed-placed). The mean duration of clinical follow-up amongst the study sample was 26.2 months. The one-year unadjusted Kaplan-Meier survival rates for immediate- and delayed-placed implants were 87.5% and 92.8%, respectively (p_0.06). Multivariate analysis revealed no statistically significant difference in overall follow-up survival time between immediate- and delayed-placed implants (p_0.4) (Hazard Ratio _ 0.7, 95%CI: 0.3, 1.6). After adjusting for potential confounders, factors significantly associated with implant survival (p_0.05) were implant length, bone quality at the implant site, coated implants, two-stage implant placement (insertion and subsequent uncovering at a future visit), and implant stability at the uncovering stage of treatment. 
Conclusions: Implant survival at one year was not statistically statistically different between implants placed immediately after tooth extraction and those placed in a delayed manner in the unadjusted or adjusted analyses. The data support the hypothesis that there is no significant difference in survival between implants immediately or delayed placed following tooth extraction. After adjusting for potential confounders, the investigators found implant staging, implant length, bone quality at the implant site, and coated implants were associated with an increased likelihood of implant survival at five years post-insertion. 
References: Casap N, Zeltser C, Wexler A, Tarazi E, Zeltser R. Immediate placement of dental implants into debrided infected dentoalveolar sockets. J Oral Maxillofac Surg. 2007 Mar; 65(3):384-92 Lindeboom JA, Tjiook Y, Kroon FH. Immediate placement of implants in periapical infected sites: a prospective randomized study in 50 patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Jun;101(6):705-10 

Authors
Marincola, M.
Di Carlo, F.
Quaranta, A.
Pecci, R.
Bedini, R. 

Authors
Urdaneta, R. 
Marincola, M 

Abstract
A technique is presented for the restoration of single-tooth, implant-supported crowns where the abutment and the crown material are chemomechanically bonded; therefore, there is no need for cement, and the implant and implant-abutment are connected with a screwless locking-taper. The clinical and laboratory procedures involved in the fabrication and insertion of the restoration are described in detail. This restoration offers the restorative dentist some advantages: excellent marginal adaptation with a cementless interface, a bacterially sealed implant-abutment connection, a crown material with a similar wear rate and hardness values of human enamel, a simple laboratory technique, and a reduced number of prosthetic components. Due to the light-cured nature of the crown material, chairside modifications can be accomplished. The major drawbacks are: studies are necessary to assess the long-term performance of the Integrated Abutment Crown™ (IAC)’s in both anterior and posterior areas of the mouth. Resin materials have higher roughness values, accumulate plaque at a higher rate, and are more likely to stain than tooth structure and all-ceramic restorations. 

Author
Daher, S. 

Author
Horowitz, R. 

Authors
Schulte, J.,
Flores, A.,
Weed, M. 

Authors
Coelho AL,
Suzuki M,
Dibart S,
DA Silva N,
Coelho PG 

Authors
Freire JN 
Silva NR 
Gil JN
Magini RS
Coelho PG  

Authors
Takahashi, Y.,
Tanaka, H.,
Sakai, K.,
Murai, A.,
Shirakura, H.,
Meguro, K.,
Tanaka, K.,
Kosugi, K.,
Wakai, C.