Remineralization across the resin-dentin interface: in vivo evaluation with nanoindentation measurements, EDS, and SEM.
OBJECTIVE
The purpose of this study was to evaluate the in vivo remineralization of the possible non-resin infiltrated hybridoid layer between the hybrid layer and the subjacent dentin substrate using nanoindentation, energy dispersive x-ray spectroscopy microanalyses (EDS), and scanning electron microscopy (SEM) technologies.


METHODS
Twenty Class V cavities were placed in healthy adult monkey teeth. Each cavity was total etched with 37% phosphoric acid for 60 seconds, rinsed, and air dispersed, and SA-Primer was applied to the collagen layer. Cavities were divided into two groups: In group 1, Protect Liner (low-viscosity resin) and Clearfil AP-X (resin composite) were placed per manufacturer's directions, and no bonding agent was placed on the acid-etched interface. In group 2, Clearfil Photobond (bonding agent) was applied, and Protect Liner and Clearfil AP-X were placed as in group 1. Teeth were observed at 7 days (control) and 6 months by nanoindentation, EDS, and SEM.


RESULTS
Six-month data showed an increased nanohardness in areas 5 pm adjacent to the demineralized or partially demineralized dentin interface. Following treatment with a conventional adhesive system on the acid-etched interface (group 2), there were increased nanohardness and calcium EDS measurements in the substrate just below the resin-dentin impregnated layer.


CONCLUSIONS
Our 6-month in vivo nanoindentation and EDS data demonstrate that the non-resin infiltrated zone becomes remineralized following adhesive resin treatment.
Akimoto
N
N
Department of Operative Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Japan. akimoto-n@tsurumi-u.ac.jp
Yokoyama
G
G
Ohmori
K
K
Suzuki
S
S
Kohno
A
A
Cox
C F
CF
D000134:Acid Etching, Dental; D000704:Analysis of Variance; D000818:Animals; D002118:Calcium / Q000032:analysis; D016009:Chi-Square Distribution; D001840:Dental Bonding; D003804:Dentin / Q000737:chemistry / Q000502:physiology*; D003806:Dentin Permeability; D004577:Electron Probe Microanalysis; D006244:Hardness; D008253:Macaca mulatta; D008689:Methacrylates; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements; D013499:Surface Properties; D014089:Tooth Remineralization
C112828:Clearfil AP-X; D008689:Methacrylates; C409388:Protect Liner F; D019279:Resin Cements; D002118:Calcium