title: An overview of characteristics of registered studies on dental implants.
abstract: OBJECTIVE
  Clinical trials serve as the empirical basis for clinical decision making. The objective of the current study is to provide an overview of clinical trials examining dental implant outcomes.
  
  
  METHODS
  All registered studies on Dental Implants were selected for analysis. The clinicaltrials.gov<http://clinicaltrials.gov/> website was used to query the characteristics of registered studies. The search term used was dental implants.
  
  
  RESULTS
  As of the study conduct date (01/01/2014), a total of 205 studies on dental implants were registered. These included 168 interventional and 37 observational studies. Results were available for only 14 studies. All observational studies and 98.8% of interventional studies included both male and female subjects. Close to 60% of studies had sample sizes between 1 and 50. NIH was listed as funding source in only 5 interventional studies and 3 observational studies. 80% of interventional studies were randomized. However, double masking was reported in only 15% of interventional studies with majority being open labeled.
  
  
  CONCLUSIONS
  ClinicalTrials.gov registry was created with the intention of increasing the transparency of conducted or ongoing clinical studies and to minimize publication bias commonly seen with industry-sponsored studies. Results of the current study showed that a predominating number of registered studies are funded by industry and other sources, very few registered studies have made their results public, and the ClinicalTrials.gov registry does not provide sufficient information on the quality of study design and thus precluding the public and researchers to judge on the quality of registered studies and publication bias.
authors.affiliation: Department of Periodontics, College of Dentistry, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Praveenkumar
authors.initials: P
authors.lastname: Gajendrareddy
authors.affiliation: Department of Periodontics, College of Dentistry, The University of Iowa, Iowa City, IA, USA.
authors.forename: Satheesh
authors.initials: S
authors.lastname: Elangovan
authors.affiliation: Texas A and M University, College Station, TX, USA.
authors.forename: Sankeerth
authors.initials: S
authors.lastname: Rampa
authors.affiliation: Department of Oral Pathology, Radiology and Medicine, College of Dentistry, The University of Iowa, Iowa City, IA, USA.
authors.forename: Veeratrishul
authors.initials: V
authors.lastname: Allareddy
authors.affiliation: Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, USA.
authors.forename: Min Kyeong
authors.initials: MK
authors.lastname: Lee
authors.affiliation: Office of Global Health, Harvard School of Dental Medicine, Boston, MA, USA.
authors.forename: Romesh P
authors.initials: RP
authors.lastname: Nalliah
authors.affiliation: Department of Orthodontics, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA. Electronic address: Veerasathpurush-Allareddy@uiowa.edu.
authors.forename: Veerasathpurush
authors.initials: V
authors.lastname: Allareddy
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D002986:Clinical Trials as Topic / Q000145:classification / Q000592:standards*; D015921:Dental Implants; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D009316:National Institutes of Health (U.S.); D064887:Observational Studies as Topic; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic / Q000592:standards; D012042:Registries; D012107:Research Design / Q000592:standards; D012109:Research Support as Topic; D018401:Sample Size; D016037:Single-Blind Method; D016896:Treatment Outcome; D014481:United States
chemical_list: D015921:Dental Implants