title: Evaluation of the light energy transmission and bottom/top rate in silorane and methacrylate-based composites with different photoactivation protocols.
abstract: OBJECTIVE
  This study investigated the influence of different composite resin organic matrix (methacrylate - Filtek Z350 XT and silorane - Filtek P90) on light energy transmission through the composite and bottom/top rate.
  
  
  METHODS
  A light-emitting diode (New Blue Phase), light-curing unit was used with different photoactivation protocols (high-continuous mode - HCM, 1400 mW/cm2 for 20 seconds; low-continuous mode - LCM , 700 mW/cm2 for 40 seconds; and soft-start mode - SSM, 140 mW/cm2 for 5s followed by 39 seconds for 700 mW/cm2). Twenty specimens were prepared for each composite. The light energy transmission through the composite was calculated (n=10). The bottom/top rate of the same specimen was calculated (n=10). The data were compared by Tukey's test in different tests (light energy transmission through the composite and bottom/top rate).
  
  
  RESULTS
  The light energy transmission through the Filtek Z350 XT composite (HCM - 576 mW/cm2, LCM - 238 mW/cm2, SSM - 232 mW/cm2) did not show statistical difference when compared with Filtek P90 composite (HCM - 572 mW/cm2, LCM - 233 mW/cm2, SSM - 230 mW/cm2). The bottom/top rate of the Filtek Z350 XT composite (HCM - 88.98%, LCM - 90.94%, SSM - 89.92%) was statistically higher than that of the Filtek P90 composite (HCM-77.29%, LCM-77.51%, SSM- 77.79%).
  
  
  CONCLUSIONS
  Light energy transmission through the composite was not influenced by the use of different dental composite restoratives. However, the bottom/top rate of the composites was influenced by the use of different dental composite restoratives.
  
  
  CONCLUSIONS
  Insufficiently polymerized composite resin may present a large number of problems. For this reason, dental composite resins should have the similar deep surface polymerization as the top surface in dental restorations.
authors.affiliation: Department of Restorative Dentistry, University of North Parana, PR, Brazil. rdguiraldo@gmail.com
authors.forename: Ricardo Danil
authors.initials: RD
authors.lastname: Guiraldo
authors.forename: Simonides
authors.initials: S
authors.lastname: Consani
authors.forename: Rafael Leonardo Xediek
authors.initials: RL
authors.lastname: Consani
authors.forename: Maysa Penteado de Camargo
authors.initials: MP
authors.lastname: Bataglia
authors.forename: Ana Paula Piovezan
authors.initials: AP
authors.lastname: Fugolin
authors.forename: Sandrine Bittencourt
authors.initials: SB
authors.lastname: Berger
authors.forename: Murilo Baena
authors.initials: MB
authors.lastname: Lopes
authors.forename: Sandra Kiss
authors.initials: SK
authors.lastname: Moura
authors.forename: Mario Alexandre Coelho
authors.initials: MA
authors.lastname: Sinhoreti
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects; D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects*; D055117:Curing Lights, Dental; D006244:Hardness; D006801:Humans; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000528:radiation effects*; D055668:Photochemical Processes; D011092:Polyethylene Glycols / Q000737:chemistry / Q000528:radiation effects; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000737:chemistry / Q000528:radiation effects; D011140:Polyurethanes / Q000737:chemistry / Q000528:radiation effects; D011829:Radiation Dosage; D017655:Silicon Compounds / Q000737:chemistry; D062047:Silorane Resins; D012833:Siloxanes / Q000737:chemistry / Q000528:radiation effects*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D017554:Carbon Compounds, Inorganic; D003188:Composite Resins; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D017655:Silicon Compounds; D062047:Silorane Resins; D012833:Siloxanes; C544925:filtek P90; C533204:filtek Z350; C421283:poly(ethylene glycol)-dimethacrylate; C555513:silorane composite resin; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C022088:silicon carbide