Post-surface conditioning improves interfacial adhesion in post/core restorations.
OBJECTIVE
To verify the influence of different etching procedures of the post-surface on microtensile bond strength values between fiber posts and composite core materials.


METHODS
60 DT Light Posts were divided into 10 subgroups using five different chemical surface treatments and two composite materials to build-up the abutment. Chemical surface treatments including etching with potassium permanganate; treatment with 10% hydrogen peroxide; treatment with 21% sodium ethoxide; etching with potassium permanganate and 10 vol.% HCl; silanization (control group) were performed on the post's surface. The build-up was performed using (A) Core Paste XP (Dent Mat) and (B) Unifil Flow (GC). Two samples of each group were randomly selected to investigate the morphologic aspect of the post/core interface with a scanning electron microscope (SEM). The remaining specimens were cut so as to obtain microtensile sticks that were loaded in tension at a cross-head speed of 1mm/min until failure. The statistical analysis was performed using two-way ANOVA and the Tukey's test for post-hoc comparisons (alpha=0.05).


RESULTS
SEM examination showed an interpenetrating adhesion network between the treated fiber post-surface and the composite material in all the groups tested. The results achieved with potassium permanganate had a significant influence on microtensile interfacial bond strength values with both the tested materials. Post-superficial treatments enhanced the bond strength particularly of Core Paste XP.


CONCLUSIONS
Etching procedures showed a similar effect on the post-surface and enhanced the adhesion of composite core build-ups as a result of micromechanical and chemical retention.
Monticelli
Francesca
F
Department of Restorative Dentistry and Dental Materials, University of Siena, Policlinico Le Scotte, Viale Bracci, 53100 Siena, Italy. francescamonticelli@supereva.it
Toledano
Manuel
M
Tay
Franklin R
FR
Cury
Alvaro H
AH
Goracci
Cecilia
C
Ferrari
Marco
M
D003188:Composite Resins; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods*; D003799:Dental Stress Analysis; D004853:Epoxy Resins; D005898:Glass; D008855:Microscopy, Electron, Scanning; D011176:Post and Core Technique; D012821:Silanes; D013499:Surface Properties; D013718:Tensile Strength
D003188:Composite Resins; C074317:Core Paste composite resin; D004853:Epoxy Resins; D012821:Silanes; C510179:UniFil Flow; C009753:fiberglass