title: Correlation of clinical performance with 'in vitro tests' of restorative dental materials that use polymer-based matrices.
abstract: OBJECTIVE
  Review correlations of in vivo clinical performance with in vitro laboratory tests of restorative dental materials involving polymer-based matrices. Identify those factors interfering with the process.
  
  
  METHODS
  An evidence-based dentistry approach was used to identify clinical trials, critical reviews, and meta-analyses involving correlations. Factors impacting meaningful correlations were reviewed. The limited bona fide correlations were reviewed.
  
  
  RESULTS
  In vitro tests include physical, chemical, mechanical, and biological properties. Clinical research measurements routinely include 10-15 categories of clinical observations of performance such as color match, caries resistance, marginal integrity, surface texture, and others, but do not correspond well with laboratory properties. Clinical trials of restorative dental materials represent a small fraction of the total research in this arena (typically <10% of dental materials research over many years). Trials are generally short-term (2-5 years) and are designed primarily to test product "safety and efficacy." A large number of risk factors (operator, design, material, intraoral location, patient) affect clinical outcomes and are not simulated well in laboratories. Little long-term information exists for clinical performance other than on composite wear. Very few meaningful correlations of laboratory tests and clinical results are demonstrated.
  
  
  CONCLUSIONS
  New studies should be focused on recovering restorations from service and characterizing them with the same tests as normally conducted in the laboratory. Many more long-term clinical trials that involve 10-20 years of observations are needed. Those trials should include planned restoration recovery to assess changes in laboratory properties of interest.
authors.affiliation: Cariology, Restorative Sciences, and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1078, United States. sbayne@umich.edu
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Bayne
mesh_terms: D002986:Clinical Trials as Topic; D001840:Dental Bonding; D003763:Dental Leakage; D003764:Dental Materials / Q000737:chemistry / Q000592:standards; D018865:Dental Research / Q000379:methods; D019232:Dental Restoration Failure; D019554:Dental Restoration Wear; D003793:Dental Restoration, Permanent / Q000592:standards; D003799:Dental Stress Analysis / Q000379:methods* / Q000592:standards; D055094:Evidence-Based Dentistry; D006801:Humans; D008422:Materials Testing / Q000379:methods* / Q000592:standards; D055595:Mechanical Phenomena; D015201:Meta-Analysis as Topic; D017063:Outcome Assessment, Health Care; D011108:Polymers / Q000737:chemistry*; D012107:Research Design / Q000592:standards; D012196:Review Literature as Topic; D013329:Structure-Activity Relationship
chemical_list: D003764:Dental Materials; D011108:Polymers