Direct adhesive pulp capping: pulpal healing and ultra-morphology of the resin-pulp interface.
OBJECTIVE
To test the hypothesis that healing of adhesively capped pulps may depend on the type of adhesive system used and its specific application approach.


METHODS
Buccal Class V cavities were prepared in 24 intact monkey teeth. After exposing the pulps, infiltration anesthesia (Xylocaine containing 1:80,000 epinephrine) was administered around the root apex. Two adhesives that make use of a different hybridization approach, Clearfil Liner Bond II (CLB-II) and Super-Bond D Liner II (SB-II) were directly applied to the exposed cavities. The pulpal response was histopathologically investigated using light microscopy at 3 and 90 days. In addition, the resin-pulp interface was characterized by transmission electron microscopy in an attempt to elucidate the underlying mechanisms of healing.


RESULTS
In the CLB-II capped pulps, little inflammation was detected at 3 days with the bonding resin intimately attached to the exposed pulpal tissue. At 90 days, a complete dentin bridge was formed in close adaptation to the resin cap. The ultra-structure of a thin intermediary layer at the bridge front resembled a so-called "reversal line". This layer typically appears during remodeling of bone to couple the newly formed to the old osseous tissue. In the SB-II capped pulps, an acute inflammation was in progress immediately beneath the bonding resin at 3 days. This tissue was resorbing the resin that had infiltrated relatively deeply into the pulp. Whereas healing of CLB-II capped pulps appeared to have been initiated promptly, healing of SB-II capped pulps was probably retarded. The formed soft-tissue hybrid layer had first to be resorbed before the formation of a dentin bridge could have been initiated. Hence, the dentin bridge was not completely finished at 90 days and no evidence of a "reversal line"-like layer could be detected. These results suggested that although both the adhesives tested appeared effective as pulp capping materials, the process and duration of healing substantially differed.
Fujitani
Morioki
M
Department of Operative Dentistry and Dental Materials, Graduate School of Biomedical Sciences, Hiroshima University, Kasumi, Hiroshima, Japan. morioki-fujitani@jcom.home.ne.jp
Shibata
Shunichi
S
Van Meerbeek
Bart
B
Yoshida
Yasuhiro
Y
Shintani
Hideaki
H
D000818:Animals; D001840:Dental Bonding; D003782:Dental Pulp / Q000187:drug effects* / Q000648:ultrastructure; D003785:Dental Pulp Capping / Q000379:methods*; D003809:Dentin, Secondary / Q000254:growth & development* / Q000378:metabolism / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000494:pharmacology*; D008251:Macaca; D008689:Methacrylates / Q000494:pharmacology; D008854:Microscopy, Electron; D019279:Resin Cements / Q000494:pharmacology*; D014945:Wound Healing / Q000187:drug effects
C084544:Clearfil Linerbond System; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C084543:Super Bond D-Liner