Ultrastructural study of tissues surrounding replanted teeth and dental implants

Abstract

Objectives: The aim of this study was to describe the ultrastructure of the dento-gingival border at replanted teeth and implants. Material and 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. Conclusion: In replantation of the tooth the internal basal lamina remained at the 2 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 epithe lium and attachment apparatus, was formed to seal the site of the implant.

Marginal bone and soft tissue behavior following platform switching abutment connection/disconnection– a dog model study

“…Authors reported that the orientation of the fibers differs in rough and smooth surfaces: smooth surfaces revealed an orientation of fibers parallel to the implant surface, while porous-coated surfaces promoted the formation of perpendicular fibers. The presence of these fibers has been confirmed in the study of Shioya et al (Shioya et al 2009). The overall tissue was described as "an inflammation free scar tissue".…”

“…In a work on rats (Ikeda et al 2000), the presence of a basal lamina and hemidesmosomes in peri-implant junctional epithelium was confirmed although it was stated that the finding of a basal lamina was less evident than on the control tooth sites, and it was well detectable only in the lower part of junctional epithelium. Results from a more recent article by Shioya et al (Shioya et al 2009) differ greatly by the work of Ikeda et al 2000. One week after implant insertion, peri-implant epithelium was observed and 8 weeks after implant insertion, the peri-implant epithelium receded, and the implant interface appeared to be sealed by aligned special cells with surrounding elongated fibroblasts and bundles of collagen fibers.…”

Ultrastructure of Dentogingival Border of Normal and Replanted Tooth and Dental Implant

“…12. Electron micrograph of peri-implant epithelium at 8 weeks after implantation (CaTiO 3 implant) 3.5.2 Interface between dental implant and connective tissue Alternative structures of peri-implant tissues were reported (Abrahamsson et al, 2002;Berglundh et al, 2007;Moon et al, 1999;Shioya et al, 2009). A layer of aligned, epitheliallike cells emerged within peri-implant tissue, and this cell layer was unaccompanied by any structures related to attachment apparatus, including hemidesmosomes or basement membrane (Fig.…”

“…However, if avulsed teeth are immediately replanted with minimum extra-oral dry time, "favorable healing" results, with repair of damaged root surface by cementum (Andreasen, 1981;Line et al, 1974). In a recent study, tissues around replanted teeth in rat were examined morphologically and ultrastructurally in detail in order to determine whether the attachment apparatus at the dentogingival border was regenerated following replantation (Shioya et al, 2009). Rat molars, luxated and extracted with care to keep damage to the surrounding tissues to a minimum, were immediately replanted into their original sockets.…”

“…Whether the attachment apparatus is regenerated at the dento (implant)-gingival border in either case remains to be determined. In the latter half of this article, we will, therefore, describe the ultrastructure of the dentogingival border in replanted teeth and implants based upon our recent study (Shioya et al, 2009). …”