A novel accelerator for improving the handling properties of dental filling materials.
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.
Hsieh
Sung-Chih
SC
School of Dentistry, Taipei Medical University, Taipei, Taiwan, ROC.
Teng
Nai-Chia
NC
Lin
Yu-Chen
YC
Lee
Pei-Ying
PY
Ji
Dian-Yu
DY
Chen
Chien-Chung
CC
Ke
En-Sheng
ES
Lee
Sheng-Yang
SY
Yang
Jen-Chang
JC
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
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