title: Opalescence and fluorescence properties of indirect and direct resin materials.
abstract: OBJECTIVE
  To measure the opalescence and fluorescence properties of indirect and direct resin materials before and after polymerization, and to determine the influence of the material and shade group combination on these properties.
  
  
  METHODS
  BelleGlass NG (BG, indirect resin) and Estelite Sigma (ES, direct resin), each composed in 3 shade groups (EN, OD and TL for BG; BS, AS and OP for ES) out of a total of 16 shades were investigated. Resin material was packed into a mold (the BEC condition) and polymerized with a light-polymerization unit (CWL). Secondary polymerization (CIC) was performed for BG. Color was measured in the BEC, CWL, and CIC conditions, and the opalescence parameter (OP) and fluorescence parameter (FL) were calculated.
  
  
  RESULTS
  For the OP, the mean for BG material was 24.3 before polymerization, which changed to 19.9 after polymerization (CIC). In the case of ES, the mean OP before polymerization was 25.6, which changed to 12.4 after polymerization (CWL). For the FL, the mean FL for BG was 2.5 before polymerization, which changed to 0.7 after polymerization. In the case of ES, the mean FL before polymerization was 1.2, which did not change after polymerization. Material and shade group combination influenced the OP and FL values (p<0.05).
  
  
  CONCLUSIONS
  The opalescence and fluorescence properties of resin materials varied depending on the material, shade group, and polymerization. Clinically, these properties should be considered when neighboring teeth are restored with different types of material.
authors.affiliation: Department of Dental Biomaterials Science, Dental Research Institute and BK21 Program, School of Dentistry, Seoul National University, Seoul, Korea.
authors.forename: Sang-Hoon
authors.initials: SH
authors.lastname: Song
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Ahn
authors.forename: Yong-Keun
authors.initials: YK
authors.lastname: Lee
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D017609:Barium Compounds / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D005453:Fluorescence; D005898:Glass / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D053758:Nanoparticles / Q000737:chemistry; D055095:Optics and Photonics; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D000538:Aluminum Silicates; D017609:Barium Compounds; D001896:Boron Compounds; D003188:Composite Resins; D003764:Dental Materials; C507124:Estelite sigma; D008689:Methacrylates; D011108:Polymers; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D017640:Silicates; C110370:belleGlass; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D012822:Silicon Dioxide; D015040:Zirconium; C028541:zirconium oxide