The barrier between the keratinized mucosa and the dental implant

Abstract

The present study was performed in order to examine the composition of the connective tissue that forms an attachment to a dental implant. 6 beagle dogs were used. All mandibular premolars were extracted. After 3 months of healing, 6 fixtures--3 in each side of the mandible--(Astra Tech Implants, Dental System TiO blast; Astra Tech AB, Mölndal, Sweden) were installed. After another 3 months of healing, abutment (Uni-abutment 45; Astra Tech AB, Mölndal, Sweden) connection was performed and a plaque control program was initiated. The animals were sacrificed and perfused with a fixative through the carotid arteries. Each implant site, including the implant and the soft and hard peri-implant tissues, was dissected, decalcified in EDTA and further processed using a "fracture technique". The specimens were subsequently embedded in EPON, cut with the microtome set at 3 microm and the sections stained in PAS and toluidine blue. From the EPON-embedded blocks, ultra-thin sections were cut and electron micrographs were prepared. The detailed histologic and morphometrical examinations were restricted to a 200 microm wide zone of connective tissue interposed between the apical border of the junctional epithelium and the bone tissue. In the analysis, this zone was further subdivided into 2 different units; (i) one central, 40 microm wide unit (zone A) located immediately next to the implant surface, and (ii) one lateral, 160 microm wide unit (zone B) that was continuous with the central unit. The implant surface apical of the junctional epithelium and coronal of the bone crest appeared to be in direct contact with a connective tissue. Zone A of this connective tissue was characterized by its (i) absence of blood vessels and (ii) abundance of fibroblasts which were interposed between thin collagen fibers. The more lateral zone B contained comparatively fewer fibroblasts, but more collagen fibers and blood vessels. There are reasons to assume that the fibroblast rich barrier tissue next to the titanium surface plays a rôle in the maintenance of a proper seal between the oral environment and the peri-implant bone.

Effects of cleaning methods for custom abutment surfaces on gene expression of human gingival fibroblasts

“…32% of the HGFs of all components. They concluded that HGFs help maintain the seal between soft tissue and implant abutments (9).…”

Implant Insertion Methods and Periimplant Tissues – Experimental Study

“…In a beagle dog study of crystal sapphire implants that were placed in one-stage procedure Fartash et al (Fartash et al, 1990) observed discrete inflammatory infiltrate in periimplant soft tissue, while Chavrier et al (Chavrier et al, 1994, as cited in Weber & Cochran, 1998 observed inflammatory cells in approximately half the biopsies in their study on experimental dogs. Buser et al (Buser at al., 1990) detected the presence of periimplant epithelial attachment in one-stage implants in experimental dogs, while Abrahmsson et al (Abrahamsson et al, 1996(Abrahamsson et al, , 1999 in their similar experimental studies reported that surgical method had not influence on the formation and structure of periimplant soft tissue. Weber et al comparing non-submerged and submerged implants in beagle dogs, found significant differences between implant types.…”

“…Numerous reports have compared the submerged and non-submerged implant types in animal models (Ericsson et al, 1996;Weber et al, 1996;Abrahamsson et al, 1996Abrahamsson et al, , 1999Levy et al, 1996;Fiorellini et al, 1999;Moon et al, 1999;Berglundh et al, 2007). The amount of scientific work was focused on the achieving and maintaining a healthy relationship of dental implants to the surrounding hard and soft tissues over extended periods.…”

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

“…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.…”