title: A novel accelerator for improving the handling properties of dental filling materials.
abstract: BACKGROUND
  Mineral trioxide aggregate (MTA) fulfills many of the ideal properties of a root end filling material and repair material for furcal perforation. However, its low cohesive property often makes it difficult to handle. To improve the handling properties of MTA root canal filling materials, MTA-like cement was made, and calcium lactate gluconate (CLG) aqueous solution was used to shorten the setting time and enhance the paste viscosity.
  
  
  METHODS
  CLG solution was prepared by mixing lactic acid, glucono delta lactone, and calcium oxide by wet process. The crystalline property of the CLG powder was characterized by x-ray diffraction. The MTA-like cements were prepared by mixing Portland cement/bismuth oxide/gypsum (75/20/5); ProRoot white MTA (Dentsply Tulsa Dental, Tulsa, OK) was used as a control group. The influence of various liquid phases on initial setting time, handling properties, and pH value were investigated by a Vicat needle, questionnaire of operational hand feel, and pH meter, respectively.
  
  
  RESULTS
  By using 23.1 wt% CLG solutions as a liquid phase, the setting time of white MTA was significantly decreased from 155.5 +/- 5.0 to 12.3 +/- 2.5 minutes. The pH values for hydrated white MTA with deionized water and 23.1 wt% CLG solutions were 12.29 +/- 0.02 and 11.81 +/- 0.04 at 72 hours.
  
  
  CONCLUSIONS
  The results suggest that the addition of amorphous CLG-based liquid phase provides improvement in sealing ability as well as clinical manageability of dental filling materials.
authors.affiliation: School of Dentistry, Taipei Medical University, Taipei, Taiwan, ROC.
authors.forename: Sung-Chih
authors.initials: SC
authors.lastname: Hsieh
authors.forename: Nai-Chia
authors.initials: NC
authors.lastname: Teng
authors.forename: Yu-Chen
authors.initials: YC
authors.lastname: Lin
authors.forename: Pei-Ying
authors.initials: PY
authors.lastname: Lee
authors.forename: Dian-Yu
authors.initials: DY
authors.lastname: Ji
authors.forename: Chien-Chung
authors.initials: CC
authors.lastname: Chen
authors.forename: En-Sheng
authors.initials: ES
authors.lastname: Ke
authors.forename: Sheng-Yang
authors.initials: SY
authors.lastname: Lee
authors.forename: Jen-Chang
authors.initials: JC
authors.lastname: Yang
mesh_terms: D017607:Aluminum Compounds / Q000138:chemical synthesis*; D017610:Calcium Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002125:Calcium Gluconate / Q000737:chemistry; D004338:Drug Combinations; D004339:Drug Compounding; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000737:chemistry; D010087:Oxides / Q000138:chemical synthesis*; D012387:Root Canal Filling Materials / Q000138:chemical synthesis*; D017640:Silicates / Q000138:chemical synthesis*; D013997:Time Factors; D014867:Water
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D007773:Lactates; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D014867:Water; C110051:calcium lactate; D002125:Calcium Gluconate