start-ver=1.4
cd-journal=joma
no-vol=33
cd-vols=
no-issue=3
article-no=
start-page=e124
end-page=e135
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2017
dt-pub=201703
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Sandblasting may damage the surface of composite CAD-CAM blocks
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　OBJECTIVE:　
CAD-CAM blocks to fabricate semi-direct and indirect restorations are available in different sorts of ceramics as well as composite. In order to bond restorations prepared out of composite blocks into tooth cavities, it is recommended to gently sandblast the surface prior to the application of a primer/adhesive. Today, the effect of sandblasting composite block surfaces has not thoroughly been investigated. In this study, the ultra-structure of composite CAD-CAM blocks was investigated with special attention to the effect of sandblasting on the surface topography and of silanization on the bonding performance.
　METHODS:　
Five different composite CAD-CAM blocks were involved. We correlatively investigated their structural and chemical composition using X-ray diffraction (XRD), energy dispersion spectroscopy (EDS), scanning electron microscopy (SEM) and (scanning) transmission electron microscopy ((S)TEM). The effect of sandblasting was also imaged in cross-section and at the interface with composite cement. Finally, we measured the shear bond strength to the sandblasted block surface with and without silanization.
　RESULTS:　
All composite blocks revealed a different ultra-structure. Sandblasting increased surface roughness and resulted in an irregular surface with some filler exposure. Sandblasting also damaged the surface. When the sandblasted composite blocks were silanized, superior bonding receptiveness in terms of higher bond strength was achieved except for Shofu Block HC.
　SIGNIFICANCE:　
Sandblasting followed by silanization improved the bond strength to composite CAD-CAM blocks. However, sandblasting may also damage the composite CAD-CAM block surface. For the composite CAD-CAM block Shofu Block HC, the damage was so severe that silanization did not improve bond strength.
en-copyright=
kn-copyright=

en-aut-name=YoshiharaKumiko
en-aut-sei=Yoshihara
en-aut-mei=Kumiko
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=NagaokaNoriyuki
en-aut-sei=Nagaoka
en-aut-mei=Noriyuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=MaruoYukinori
en-aut-sei=Maruo
en-aut-mei=Yukinori
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=NishigawaGoro
en-aut-sei=Nishigawa
en-aut-mei=Goro
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

en-aut-name=IrieMasao
en-aut-sei=Irie
en-aut-mei=Masao
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=5
ORCID=

en-aut-name=YoshidaYasuhiro
en-aut-sei=Yoshida
en-aut-mei=Yasuhiro
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=6
ORCID=

en-aut-name=MeerbeekfBart Van
en-aut-sei=Meerbeekf
en-aut-mei=Bart Van
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=7
ORCID=

affil-num=1
en-affil=Centrer for Innovative Clinical Medicine, Okayama University Hospital
kn-affil=

affil-num=2
en-affil=Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School
kn-affil=

affil-num=3
en-affil= Department of Occlusion and Removable Prosthodontics, Okayama University Hospital
kn-affil=

affil-num=4
en-affil= Department of Occlusion and Removable Prosthodontics, Okayama University Hospital
kn-affil=

affil-num=5
en-affil=Department of Biomaterials, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
kn-affil=

affil-num=6
en-affil= Department of Biomaterials and Bioengineering, Graduate School of Dental Medicine, Hokkaido University
kn-affil=

affil-num=7
en-affil= KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & University Hospitals
kn-affil=
en-keyword=CAD–CAM
kn-keyword=CAD–CAM
en-keyword=bond strength
kn-keyword=bond strength
en-keyword=composite
kn-keyword=composite
en-keyword=sandblast
kn-keyword=sandblast
en-keyword=silane coupling agent
kn-keyword=silane coupling agent
END