Regeneration of nerve fibres in the peri‐implant epithelium incident to implantation in the rat maxilla as demonstrated by immunocytochemistry for protein gene product 9.5 (PGP9.5) and calcitonin gene‐related peptide (CGRP)

Abstract

The response of nerve fibres in the peri-implant epithelium to titanium implantation was investigated with an experimental model using rat maxilla and immunohistochemical techniques. The latter employed antibodies to protein gene product 9.5 (PGP9.5), and to calcitonin gene-related peptide (CGRP). In control rats without an implantation, a dense innervation of PGP9.5- and CGRP-positive nerve fibres was recognized throughout the junctional epithelium, as has been previously reported. A titanium-implantation induced a remarkable inflammatory reaction, as well as the destruction of covering epithelial cells. By 3-5 days post-implantation, inflammatory reaction showed a tendency to disappear, and the peri-implant epithelium showed proliferation and down-growth along the implant. At this stage, no nerve fibres were found around the peri-implant epithelium. At 10 days, a few nerve fibres reached the basal cell layers of the peri-implant epithelium, and entered it 15 days after implantation when the peri-implant epithelial cells showed morphological features roughly resembling those of normal junctional epithelial cells. At the complete osseointegration stage (days 20-30), the PGP9.5- and CGRP-positive nerve fibres, thin and beaded in appearance, were found distributed in the peri-implant epithelium. After 20 days, the numerical density of the intraepithelial nerves in the peri-implant epithelium appeared the same as, or less than, that in the normal junctional epithelium. These findings indicate that the peri-implant epithelium shows the same innervation as that in normal junctional epithelium, and that the intraepithelial nerve fibres in the peri-implant epithelium might have diverse functions, which have been suggested in the literature.

Distribution of substance P and neurokinin-1 receptors in the peri-implant epithelium around titanium dental implants in rats

“…With regard to the innervation of the PIE, S-100-immunoreactive nerve fibers are more densely distributed within the implant-facing epithelium of the peri-implant mucosa than in the outer epithelium (Arvidson et al 1996). A recent study has reported that nerve regeneration in the PIE involves protein gene product 9.5 (PGP9.5) and calcitonin gene-related peptide (CGRP), suggesting that the nerve distribution in the PIE is similar to that in the JE (Fujii et al 2003). However, no information is available regarding the distribution of substance-P-containing nerve fibers or the cellular localization of NK1 receptors in the PIE and the subepithelial connective tissue.…”

Proposal for a new site to insertion of dental implants for osseointegration test: Research methodology

“…[13,14] In this manuscript, we attempted to reproduce the same technique, but some issues hampered our efforts at this particular method. Among them were the extraction of the upper first molar and the possible loss of implants during animal feeding.…”

“…The literature describes implants placed in the region of the upper first molars, [13,14] but that technique requires great precision and produces little material (i.e., bone tissue) to analyze. Given the above evidence, the objective of this study is to present a methodology for osseointegration in rat mandibles.…”

Biological Sealing and Defense Mechanisms in Peri-Implant Mucosa of Dental Implants

“…The sensory nerve fibers contain the neuropeptides, calcitonin gene-related peptide (Byers et al, 1987;Nagata et al, 1992Nagata et al, , 1994 and substance P (Nagata et al, , 1994Tanaka et al, 1996;Kido et al, 1999), and terminate close to endothelial cells, neutrophils, and junctional epithelial cells Tanaka et al, 1996). The peri-implant mucosa is also supplied with sensory nerves containing calcitonin generelated peptide (Fujii et al, 2003) and substance P (Yamaza et al, 2009) (Figure 7a). The innervation of the PIE is denser than in other parts of the epithelium (peri-implant sulcular epithelium and oral epithelium) (Figure 7b).…”

“…Histological analysis of in vivo models, including animal and human subjects, is one of the gold standard methods for investigating the mechanisms at the implant-soft tissue interface. However data on periimplant tissue from human subjects are scarce because of the limited collecting opportunities and ethical issues (Piattelli et al, 1993(Piattelli et al, , 1997a(Piattelli et al, , 1997bArvidson et al, 1996;Corpe et al, 1999;Baschong et al, 2001), animal models have therefore been widely used (Albrektsson et al, 1985;Buser et al, 1992;Berglundh et al, 1994;Berglundh & Lindhe, 1996;Weber et al, 1996;Abrahamsson et al, 1998, Fujii et al, 1998, 2003Kawahara et al, 1998;Moon et al, 1999;Hermann et al, 2000Hermann et al, , 2001. Peri-implant tissue contains both hard (bone) and soft (mucosa) tissues, which presents a challenge in terms of the histochemical examination of the intact implant-soft tissue interface.…”