Biomedical subjects

G E Romanos

Publications and source records attributed to G E Romanos.

23 records · Page 2Linked to original sources

PubMed1990

[Collagen as a basic element of the periodontium: immunohistochemical aspects in the human and animal. 1. Gingiva and alveolar bone].

The connective tissue (CT) is responsible for stability and function of the whole periodontium. It consists of cells, which are embedded in the extracellular matrix. Collagen plays the main role for the function of the periodontal unit. Collagen types I, III, IV, V and VI are distributed in a different pattern in all periodontal tissues, as has been here demonstrated in the gingiva and alveolar bone. Collagen type I, as a characteristic collagen type of the hard tissues, has been demonstrated by thick collagen fibers in the alveolar bone and in the gingival connective tissue. It can be differentiated from the thinner collagen type III fibers, which are localized in the gingiva (especially under the basement membrane of the epithelium) as well as only in the bone marrow stroma. The epithelium, blood vessels and nerves contain the characteristic collagen type IV in their basement membrane Filamentous (collagen type V) and microfibrillar (collagen type VI) components demonstrate different patterns of distribution, especially around the bone cells and in contrast to the other collagen types of fibrillar networks in the gingival CT. This morphological differentiation of the extracellular matrix components of the periodontium allows conclusions in the pathological and inflammatory processes as well as in the regenerative and reparative procedures.

Alveolar Process↗

PubMed1990

[The distribution of different collagen types and laminin in the gingiva of the common marmoset (Callithrix jacchus)].

The distribution of the collagen types I, III, IV, V, VI and of the glycoprotein laminin have been examined in the healthy gingiva of the marmoset with the indirect immunofluorescence method. It has been shown that collagen type I formed thick fibrils in a wave-like pattern, while collagen type III formed thinner fibrils, especially under the epithelial basal membrane. Collagen type IV and laminin showed a strong fluorescence in the basal membrane (epithelium, vessels, nerves). Collagen type V has been demonstrated as a fine fibrillar pattern in the lamina propria and occasionally close to the basal membrane. Collagen type VI has been represented as a microfibrillar network in the connective tissue matrix with a brilliant pericellular fluorescence around vessels and nerves. The study showed the structural model of the connective tissue matrix of the marmoset gingiva and allows a later comparison between inflamed and healthy gingiva.

Animals↗

PubMedDate not supplied

Single molar replacement with a progressive thread design implant system: a retrospective clinical report.

Many clinical studies have shown that replacement of molars with only 1 implant is commonly associated with various functional complications, such as implant fracture and screw loosening. Thus, multiple implants have been recommended to withstand the high occlusal forces present in the molar region. The aim of this retrospective study was to evaluate the clinical response to the use of single implants with a progressive thread design (Ankylos) in the replacement of molar teeth. Fifty-eight implants (10 in the maxilla and 48 in the mandible) were placed in 51 patients. The implants were in situ for 29.30 +/- 16.52 months and in function for 20.60 +/- 16.64 months. All crowns were cemented to the abutments. The crown occlusion was adjusted to obtain minimal normal contacts in the centric occlusion and eccentric positions. Implants were clinically and radiographically evaluated, and clinical indices (Plaque Index, Sulcus Bleeding Index, probing pocket depth, keratinized mucosa width, Perio-test) were recorded immediately before the placement of the prosthesis and once annually. Vertical and horizontal bone loss were also examined radiographically. Two implants were lost (1 because of fracture in a patient who was a bruxer and another because of abutment fracture in the endosseous part of the implant). All clinical and radiographic parameters of most of the implants were comparable to the values found for the same type of implant in other clinical indications. The reduced incidence of failure (96.55% survival rate) found in this study with the Ankylos implant system compared to the results reported in the literature indicate that this system can be used for the replacement of molars using single-implant-supported restorations.

Alveolar Bone Loss↗

PubMedDate not supplied

Health human periodontal versus peri-implant gingival tissues: an immunohistochemical differentiation of the extracellular matrix.

Healthy human periodontal and peri-implant (ITI Bonefit) keratinized gingival tissues were studied immunohistochemically to evaluate the possible presence of structural differences in the extracellular matrix protein localization. Collagen types I, III, IV, and VII and fibronectin showed similar distribution in these tissues. Compared to the periodontal tissues, collagen type V was localized in higher amounts in the lamina propria of the peri-implant gingival tissues. Collagen type VI stained the periodontal tissues as a delicate microfibrillar network contrasting to the not well-stained peri-implant gingival tissues. The data show that structural differences between these tissues are present. The structural differences may be responsible for the defense of peri-implant keratinized gingival connective tissues to bacterial penetration, because of the high amount of the collagen type V component, which is responsible for the higher collagenase stability.

Adult↗

PubMedDate not supplied

Inflamed human periodontal versus peri-implant gingival tissues: an immunohistochemical differentiation of the extracellular matrix.

Inflamed human periodontal and peri-implant (ITI Bonefit) gingival tissues were studied immunohistochemically to evaluate the possible presence of structural differences in the extracellular matrix protein localization. Collagen types I, III, IV, V, VI, and VII and fibronectin showed a similar distribution in these tissues. Data show that morphologic structural differences between these inflamed tissues are not present. According to these findings, the connective tissue response of inflamed peri-implant as well as periodontal gingival tissues should be similar during treatment when the inflammation is localized only in the soft tissue level.

Aged↗