title: Setting characteristics of a resin infiltration system for incipient caries treatment.
abstract: OBJECTIVE
  This study investigated the curing efficiency, the extent of atmospheric oxygen inhibition to the polymerization reaction and the mechanical properties of a new resin-infiltration system for caries treatment.
  
  
  METHODS
  The curing efficiency was estimated by measuring the percentage degree of cure (%DC) of thin resin films (h: 150μm, Ø: 5mm, n=3), 10min after 40s exposure to a quartz halogen bulb (750mW/cm2) light curing unit (Optilux 501, Demetron/Kerr, USA), in the absence of O2, by micro ATR-FTIR spectroscopy. The extent of O2 inhibition on resin film setting (width in μm) was assessed by transmission optical microscopy on thin films (h: 150μm, Ø: ∼7mm, n=5) placed between two transparent cover slips and exposed to air from lateral sites. For each sample the extent of inhibition was measured at 5 different locations. The mechanical properties were tested employing Instrumented Indentation Testing according to ISO 14577:2002. Resin specimens (h: 2mm, Ø: 10mm, n=5) were prepared employing cylindrical teflon moulds enclosed in transparent matrix strips and glass slides as before. The measurements were performed employing a Vickers indenter attached to a universal hardness testing machine (ZHU2.5/Z2.5 plus test Xpert software, Zwick/Roell, Ulm, Germany). The parameters tested were Martens Hardness (MH), Vickers Hardness (VHN), Indentation Elastic Modulus (EIT) and elastic to total ratio of indentation work (ηIT). For all these tests, specimens of a conventional light-curing bonding resin (HB-Heliobond, Ivoclar-Vivadent, FL) prepared as above were used as control. Student t-test was used to identify statistically significant differences between the two materials in the parameters tested (a: 0.05).
  
  
  RESULTS
  The results of the materials tested were: (a) [% DC]; IC: 57.4±1.5, HB: 59.8±2.4, (b) [Width of O2 inhibition/μm]; IC: 33.1±6.5, HB: 23.6±4.4, (c) [MH/N/mm(2)] IC; 116±16, HB: 261±35, (d) [VHN]; IC; 15.4±2.5, HB: 22.1±1.8, (e) [EIT/(GPa)]; IC; 2.3±0.4, HB: 7.5±0.5, and (g) [ηIT (%)] IC; 50.3±3.4, HB: 35.1±1.9. The IC presented no significant difference in terms of % DC, higher thickness of the inhibited layer, lower MH, VHN, EIT and greater ηIT values than HB.
  The resin-infiltrating system for incipient caries treatment demonstrated the same curing efficiency with a conventional unfilled bonding resin, but exhibited higher extent of oxygen inhibition, lower hardness, lower elastic modulus and higher plastic to elastic indentation energy.
authors: Department of Operative Dentistry, Faculty of Dentistry, National and Kapodistrian University of Athens, Thivon 2, Goudi, 11527 Athens, Greece. Electronic address: craxioti@dent.uoa.gr.
authors: C
authors: C
authors: Rahiotis
authors: Department of Biomaterials, Faculty of Dentistry, National and Kapodistrian University of Athens, Thivon 2, Goudi, 11527 Athens, Greece. Electronic address: szinelis@dent.uoa.gr.
authors: S
authors: S
authors: Zinelis
authors: Department of Biomaterials, Faculty of Dentistry, National and Kapodistrian University of Athens, Thivon 2, Goudi, 11527 Athens, Greece. Electronic address: geliad@dent.uoa.gr.
authors: G
authors: G
authors: Eliades
authors: Department of Orthodontics and Paediatric Dentistry, Centre of Dental Medicine, University of Zurich, Switzerland. Electronic address: Theodore.Eliades@zzm.uzh.ch.
authors: T
authors: T
authors: Eliades
mesh_terms: D003188:Composite Resins / Q000737:chemistry / Q000528:radiation effects; D055117:Curing Lights, Dental; D003731:Dental Caries / Q000628:therapy*; D003764:Dental Materials / Q000737:chemistry* / Q000528:radiation effects*; D003776:Dental Porcelain / Q000737:chemistry; D006244:Hardness; D055115:Light-Curing of Dental Adhesives / Q000295:instrumentation / Q000379:methods*; D055595:Mechanical Phenomena / Q000528:radiation effects
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D003776:Dental Porcelain
keywords: Caries; ICON; Infiltration; Mechanical properties; Oxygen inhibition; Resin composites