Ultrastructural study of tissues surrounding replanted teeth and dental implants.
OBJECTIVE
The aim of this study was to describe the ultrastructure of the dentogingival border at replanted teeth and implants.


METHODS
Wistar rats (8 weeks old) were divided into groups for replantation and implantation experiments. In the former, the upper right first molars were extracted and then immediately replanted. In the latter, pure titanium implants were used. All tissues were fixed, demineralized and embedded in epoxy resin for ultrastructural observations.


RESULTS
One week after replantation, the junctional epithelium was lost, and the oral sulcular epithelium covered the enamel surface. The amount of the epithelium increased in 2 weeks, and resembled the junctional epithelium, and the internal basal lamina and hemidesmosomes were formed in 4 weeks. One week after implantation, peri-implant epithelium was formed, and in 2 and 4 weeks, this epithelium with aggregated connective tissue cells were observed. In 8 weeks, the peri-implant epithelium receded, and aligned special cells with surrounding elongated fibroblasts and bundles of collagen fibers appeared to seal the implant interface.


CONCLUSIONS
In replantation of the tooth, the internal basal lamina remained at the surface of the enamel of the replanted tooth, which is likely to be related to regeneration of the junctional epithelium and the attachment apparatus at the epithelium-tooth interface. Following implantation, a layer of cells with characteristics of connective tissue cells, but no junctional epithelium and attachment apparatus, was formed to seal the site of the implant.
Shioya
Kazuhiro
K
Department of Ultrastructural Science, Tokyo Dental College, Mihama-ku, Chiba City 261-8502, Japan.
Sawada
Takashi
T
Miake
Yasuo
Y
Inoue
Sadayuki
S
Yanagisawa
Takaaki
T
D000539:Alveolar Process / Q000648:ultrastructure*; D000818:Animals; D015921:Dental Implants; D004846:Epithelial Attachment / Q000648:ultrastructure; D008297:Male; D016348:Osseointegration / Q000502:physiology; D010521:Periosteum / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000502:physiology*; D014090:Tooth Replantation
D015921:Dental Implants