Degree of conversion of Filtek Silorane Adhesive System and Clearfil SE Bond within the hybrid and adhesive layer: an in situ Raman analysis.
OBJECTIVE
To examine the degree of conversion (DC) of the adhesive interfaces created by Filtek Silorane Adhesive and Clearfil SE Bond using micro-Raman spectroscopy.


METHODS
The adhesives were applied on human dentin in accordance with manufacturer's instructions. Specimens were cut to expose the bonded interfaces to the micro-Raman beam (Ranishaw InVia; laser wl 785 nm). Raman spectra were collected along the dentin/self-etching primer/adhesive interface at 1 microm intervals. The relative intensities of bands associated with mineral (P-O functional group at 960 cm(-1)) and adhesive (C-C-O group at 605 cm(-1)) components within the bonded interface were used to detect monomer penetration into the dentin matrix and to calculate the degree of conversion (C=C at 1640 cm(-1) as reaction peak, C-C-O at 605 cm(-1) as reference peak). Data were statistically analyzed with two-way ANOVA.


RESULTS
DC of Filtek Silorane Adhesive was 69+/-7% in the adhesive layer, increasing (p<0.05) to 93+/-5% in the primer and 92+/-9% in the hybrid layer. Clearfil SE Bond showed a DC of 83+/-3% in the hybrid and 85+/-3% in the adhesive layer. Thus, Filtek Silorane Adhesive showed a higher DC than Clearfil SE Bond in the hybrid layer (p<0.05), but a lower DC in the adhesive (p<0.05).


CONCLUSIONS
As high DC is a fundamental pre-requisite for the stability of the bond over time, this study supports the hypothesis that optimal stability of Filtek Silorane Adhesive can be obtained. However, further research is needed to investigate the mechanical properties of the hybrid layer created by Filtek Silorane Adhesive and its long-term stability.
Navarra
Chiara O
CO
Department of Biomedicine, University of Trieste, Trieste, Italy.
Cadenaro
Milena
M
Armstrong
Steven R
SR
Jessop
Julie
J
Antoniolli
Francesca
F
Sergo
Valter
V
Di Lenarda
Roberto
R
Breschi
Lorenzo
L
D003799:Dental Stress Analysis; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000528:radiation effects; D006244:Hardness; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008963:Molar; D044367:Phase Transition; D019279:Resin Cements / Q000528:radiation effects; D062047:Silorane Resins; D013059:Spectrum Analysis, Raman
C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; D019279:Resin Cements; D062047:Silorane Resins