title: Curing depth of (polyacid-modified) composite resins determined by scraping and a penetrometer.
abstract: OBJECTIVE
  The present study aimed to compare the curing depth of polyacid-modified composite resins (PAM-C) and some representative composite resins as a function of shade and post-cure using a scraping method and a penetrometer.
  
  
  METHODS
  The curing depth of the PAM-C Hytac, F2000, Glasiosite, Dyract, Dyract AP, and Compoglass F and of the composite resins Durafill VS and Z100 were determined for shade A2 and A4 using a scraping method based on ISO 4049:2000 and a digital penetrometer. Samples were light-cured (800 mW/cm2 at 40 s) in bulk in split stainless steel molds. Immediately after light-curing or after a 24 h post-cure, the height of the cylinder of cured material was measured and taken as the curing depth.
  
  
  RESULTS
  For both test methods, the curing depth was independent of post-cure (P > or = 0.05) but differed significantly among materials and shade (P<0.001). Moreover, there was a significant interaction between the latter (P<0.001). Regression analysis generally demonstrated that there was no significant systematic or proportional difference between the test methods. The curing depths of the PAM-C F2000 and Glasiosite were comparable to that of the hybrid composite Z100, but greater than the curing depth of the microfilled composite Durafill VS. The PAM-C Dyract AP, Dyract, Compoglass F and Hytac had a curing depth smaller than that of the microfilled composite.
  
  
  CONCLUSIONS
  The scraping method based on ISO 4049:2000 and a digital penetrometer give comparable curing depths for PAM-C. The curing depth greatly varies among the materials and can be considerably smaller than that of a microfilled composite resin. Shade A2 results in significantly greater values for the curing depth compared to shade A4, the effect depending quantitatively on the formulation of the material.
authors.affiliation: Department of Paediatric Dentistry, PAECAMED, Ghent University, Gent, Belgium.
authors.forename: Nikolaos S
authors.initials: NS
authors.lastname: Koupis
authors.forename: Chris W J
authors.initials: CW
authors.lastname: Vercruysse
authors.forename: Luc A M
authors.initials: LA
authors.lastname: Marks
authors.forename: Luc C
authors.initials: LC
authors.lastname: Martens
authors.forename: Ronald M H
authors.initials: RM
authors.lastname: Verbeeck
mesh_terms: D003116:Color; D020770:Compomers / Q000528:radiation effects*; D003188:Composite Resins / Q000528:radiation effects; D006245:Hardness Tests; D008027:Light; D008422:Materials Testing; D044367:Phase Transition
chemical_list: D020770:Compomers; D003188:Composite Resins