Microhardness of different resin cement shades inside the root canal.
OBJECTIVE
To compare microhardness along the root canal post space of two resin cements in different shades and a dual-cure resin core material.


METHODS
Root canals of 21 bovine incisors were prepared for post space. Translucent posts (X∘Post, Dentsply DeTrey) were luted using one the following resin luting agent: Calibra (Dentsply DeTrey) in Translucent, Medium and Opaque shades, RelyX Unicem (3M ESPE) in Translucent, A2 and A3 shades and the dual-cure resin core material Core∘X flow. All materials were applied according to manufacturers' instructions and were all photopolymerized (Bluephase LED unit, Ivoclar Vivadent, 40s). After 24 hours, roots were transversally cut into 9 slices 1 mm thick from the coronal to apical extremes, three corresponding to each root third. Then, VHNs were recorded (100gf, 30 s) on the resin luting materials along the adhesive interface in all sections. Data were analyzed by two-way ANOVA and SNK tests (α=0.05).


RESULTS
A significant influence on microhardness of resin luting material in their respective shades (p<0.0001), root third (p<0.0001) and interactions between them was detected (p<0.0001). RelyX Unicem cement showed the highest microhardness values and Calibra the lowest, regardless of the shade selected. All resin luting materials tested exhibited a significantly higher microhardness in the cervical third.


CONCLUSIONS
Microhardness of resin luting agents tested inside the canal is dependent on material brand and resin cement shade seems to be a less relevant factor. Microhardness decreased along the root canal, regardless of the shade selected.
Department of Stomatology, Rey Juan Carlos University, Avda. de Atenas s/n, 28922 Alcorcón, Madrid, Spain.
Valeria
V
Vignolo
Maria-Victoria
MV
Fuentes
Miguel-Angel
MA
Garrido
Jesús
J
Rodríguez
Laura
L
Ceballos
D000818:Animals; D002417:Cattle; D003786:Dental Pulp Cavity; D006245:Hardness Tests; D066298:In Vitro Techniques; D008422:Materials Testing; D019279:Resin Cements
D019279:Resin Cements