title: Conversion and temperature rise of remineralizing composites reinforced with inert fillers.
abstract: OBJECTIVE
  Remineralizing experimental composites based on amorphous calcium phosphate (ACP) were investigated. The impact of curing time (20 and 40s), curing depth (1, 2, 3 and 4mm) and addition of inert fillers (barium glass and silica) on the conversion and temperature rise during curing were examined.
  
  
  METHODS
  Five ACP-composites and two control composites were prepared based on the light-curable EBPADMA-TEGDMA-HEMA resin. For temperature measurements, a commercial composite was used as an additional control. Conversion was assessed using FT-Raman spectroscopy by comparing the relative change of the band at 1640 cm(-1) before and after polymerization. The temperature rise during curing was recorded in real-time using a T-type thermocouple.
  
  
  RESULTS
  At 1mm depth, the ACP-composites attained significantly higher conversion (77.8-87.3%) than the control composites based on the same resin (60.5-66.3%). The addition of inert fillers resulted in approximately 5% lower conversion at clinically relevant depths (up to 2mm) for the curing time of 40s. Conversion decline through depths depended on the added inert fillers. Conversion values higher than 80% of the maximum conversion were observed for all of the ACP-composites at depths up to 3mm, when cured for 40s. Significantly higher total temperature rise for the ACP-composites (11.5-13.1 °C) was measured compared to the control composites (8.6-10.8 °C) and the commercial control (8.7 °C).
  
  
  CONCLUSIONS
  The admixture of inert fillers represents a promising strategy for further development of ACP-composites, as it reduced the temperature rise while negligibly impairing the conversion.
  
  
  CONCLUSIONS
  High conversions of ACP-composites are favorable in terms of mechanical properties and biocompatibility. However, high conversions were accompanied with high temperature rise, which might present a pulpal hazard.
authors.affiliation: Private Dental Practice, Zagreb, Croatia. Electronic address: mpar@inet.hr.
authors.forename: Matej
authors.initials: M
authors.lastname: Par
authors.affiliation: Department of Physics and Biophysics, School of Medicine, University of Zagreb, Salata 3b, Zagreb, Croatia. Electronic address: ozren@mef.hr.
authors.forename: Ozren
authors.initials: O
authors.lastname: Gamulin
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, Zagreb, Croatia. Electronic address: marovic@sfzg.hr.
authors.forename: Danijela
authors.initials: D
authors.lastname: Marovic
authors.affiliation: Institute of Physics, Bijenicka cesta 46, Zagreb, Croatia. Electronic address: hrvoje@ifs.hr.
authors.forename: Hrvoje
authors.initials: H
authors.lastname: Skenderovic
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, Zagreb, Croatia. Electronic address: eklaric@sfzg.hr.
authors.forename: Eva
authors.initials: E
authors.lastname: Klaric
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, Zagreb, Croatia. Electronic address: tarle@sfzg.hr.
authors.forename: Zrinka
authors.initials: Z
authors.lastname: Tarle
mesh_terms: D017609:Barium Compounds / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental; D003764:Dental Materials / Q000737:chemistry*; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D015040:Zirconium / Q000737:chemistry
chemical_list: D017609:Barium Compounds; D002130:Calcium Phosphates; D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D011109:Polymethacrylic Acids; C519480:amorphous calcium phosphate; C102738:barium glass filler; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C074277:ethoxylated bis-phenol A dimethacrylate; D012822:Silicon Dioxide; D015040:Zirconium; C028541:zirconium oxide
keywords: Amorphous calcium phosphate; Conversion; Raman spectroscopy; Remineralizing composite; Resin composite; Temperature