Impedance methodology: A new way to characterize the setting reaction of dental cements.
OBJECTIVE
Impedance spectroscopy is a non-destructive, quantitative method, commonly used nowadays for industrial research on cement and concrete. The aim of this study is to investigate the interest of impedance spectroscopy in the characterization of setting process of dental cements.


METHODS
Two types of dental cements are used in this experiment: a new Calcium Silicate cement Biodentine™ (Septodont, Saint Maur-des Fossés, France) and a glass ionomer cement resin modified or not (Fuji II(®) LC Improved Capsules and Fuji IX(®) GP Fast set Capsules, GC Corp., Tokyo, Japan). The conductivity of the dental cements was determined by impedance spectroscopy measurements carried out on dental cement samples immersed in a 0.1M potassium chloride solution (KCl) in a "like-permeation" cell connected to a potentiostat and a Frequency Response Analyzer. The temperature of the solution is 37°C. From the moment of mixing of powder and liquid, the experiments lasted 2 weeks.


RESULTS
The results obtained for each material are relevant of the setting process. For GIC, impedance values are stabilized after 5 days while at least 14 days are necessary for the calcium silicate based cement.


CONCLUSIONS
In accordance with the literature regarding studies of cements and concrete, impedance spectroscopy can characterize ion mobility, porosity and hardening process of dental hydrogel materials.
Villat
Cyril
C
Laboratoire Génie des Procédés Matériaux, Ecole Centrale Paris, Châtenay-Malabry, France.
Tran
Xuan-Vinh
XV
Tran
V X
VX
Pradelle-Plasse
Nelly
N
Ponthiaux
Pierre
P
Wenger
François
F
Grosgogeat
Brigitte
B
Colon
Pierre
P
D017610:Calcium Compounds; D058266:Dielectric Spectroscopy; D017097:Electric Impedance; D005899:Glass Ionomer Cements / Q000138:chemical synthesis* / Q000737:chemistry; D006244:Hardness; D020100:Hydrogels / Q000737:chemistry; D007474:Ion Exchange; D007700:Kinetics; D016062:Porosity; D012823:Silicate Cement / Q000138:chemical synthesis* / Q000737:chemistry; D017640:Silicates
D017610:Calcium Compounds; D005899:Glass Ionomer Cements; D020100:Hydrogels; D017640:Silicates; D012823:Silicate Cement; C031293:calcium silicate