title: Color stability of experimental composites containing different photoinitiators.
abstract: OBJECTIVE
  To evaluate the color stability (ΔE) of experimental composites containing different photoinitiators when submitted to accelerated artificial ageing (AAA).
  
  
  METHODS
  Thirty test specimens were made in a Teflon matrix (8mm×2mm), using an experimental composite (n=10) with the same monomer composition and particle size, but varying photoinitiator used: Group CQ (0.4% Camphorquinone), Group PPD (0.4% 1-Phenyl-1,2 Propanodione) and Group CQ+PPD (0.2% CQ+0.2% PPD). The samples were light activated (QTH - Ultralux - Dabi Atlante - 40s) and polished before performing the initial color readouts (EasyShade - Vita). Next, they were submitted to AAA for 300h, after which final color readouts were made.
  
  
  RESULTS
  The results (1-way ANOVA - Tukey - p<0.05) demonstrated that all the groups presented color alteration above the clinically acceptable level (ΔE≥3.3), however, with no statistically significant difference among them (p>0.05). Analysis of Δb demonstrated increase in the values of this coordinate, indicating yellowing in all groups.
  
  
  CONCLUSIONS
  It was concluded that the type of photoinitiator, which presented a tendency towards yellowing, did not interfere in the color stability of composites submitted to AAA.
  
  
  CONCLUSIONS
  Alternative photoinitiators have been extensively studied since Camphorquinone presents a yellowish color, which compromises the aesthetic performance of composites, especially the lighter-shade ones.
authors.affiliation: Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Francisca Daniele Jardilino
authors.initials: FD
authors.lastname: Silami
authors.forename: Fabrício Mariano
authors.initials: FM
authors.lastname: Mundim
authors.forename: Lucas da Fonseca Roberti
authors.initials: Lda F
authors.lastname: Garcia
authors.forename: Mário Alexandre Coelho
authors.initials: MA
authors.lastname: Sinhoreti
authors.forename: Fernanda de Carvalho Panzeri
authors.initials: Fde C
authors.lastname: Pires-de-Souza
mesh_terms: D000465:Algorithms; D000538:Aluminum Silicates / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002164:Camphor / Q000031:analogs & derivatives / Q000737:chemistry; D047188:Chalcones; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental / Q000145:classification; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing / Q000379:methods; D055115:Light-Curing of Dental Adhesives / Q000295:instrumentation; D008689:Methacrylates / Q000737:chemistry; D010316:Particle Size; D058567:Photoinitiators, Dental / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013227:Steam; D013696:Temperature; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D000538:Aluminum Silicates; D047188:Chalcones; D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D058567:Photoinitiators, Dental; D011109:Polymethacrylic Acids; D011140:Polyurethanes; D013227:Steam; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; C049037:aluminosilicate; C041979:2,2-bis-(4-(2-methacryloxyethoxy)phenyl)propane; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D002164:Camphor; D012822:Silicon Dioxide; C049840:2-(dimethylamino)ethyl methacrylate; C553149:camphorquinone; C100349:1-phenyl-1,2-propanedione
keywords: Accelerated artificial ageing; Color stability; Composite; Photoinitiator