Assessment of internalization and viability of Porphyromonas gingivalis in KB epithelial cells by confocal microscopy.

Porphyromonas gingivalis (P. gingivalis) is considered to be one of the main periodontal pathogens. The goal of this work was to confirm the ability of P. gingivalis to invade host cells. We detected P. gingivalis inside KB cells by confocal microscopy and analyzed the various aspects of the adherence and internalization process. Lysates of P. gingivalis-infected KB cells were also examined using anaerobic growth techniques. The results showed the viability and ability to replicate, inside the host cells, of the internalized pathogen. The production of vesicles was also tracked for the first time. Confocal microscopy revealed P. gingivalis in a perinuclear position.

Expression of the alpha-subunit of CR4 (CD11c) by peripheral blood and crevicular fluid neutrophils.

This work determined the levels of expression of CD11c by neutrophils (PMNs) collected from subjects with various periodontal conditions. The percentages of CD11c-positive crevicular fluid PMNs were significantly lower than those of peripheral blood PMNs, but the levels of CD11c expression were similar in PB-PMNs and CF-PMNs (P<0.001). On the other hand, no significant difference could be found between the groups, either for the percentages of CD11c-positive cells or for the CD11c expression levels.

Ex vivo studies of polymorphonuclear neutrophils from patients with early-onset periodontitis (III). CR3 and LFA-1 expression by peripheral blood and gingival crevicular polymorphonuclear neutrophils.

In this study, we assessed the LFA-1 (CD18/CD11a) and CR3 (CD18/CD11b) expression on peripheral polymorphonuclear leukocytes (PB-PMN) and crevicular fluid polymorphonuclear leukocytes (CF-PMN), by subjects with a healthy periodontium (n = 7), gingivitis (n = 8), early-onset periodontitis (n = 17) and adult periodontitis (n = 8). Using flow cytometry analysis, the %s of CD18, CD11a and CD11b positive cells and the absolute numbers of fluorescent molecules were determined. No significant difference could be found among the 4 groups, for these 2 kinds of parameters, in PB-PMN or CF-PMN. However, a great difference could be noted between the results obtained from PB-PMN and those obtained from CF-PMN. The %s of positive CF-PMN were significantly lower than those of PB-PMN for the 3 sub-units (p < 0.001). The levels of CD18 and CD11b expressed by CF-PMN were higher than those expressed by PB-PMN and the difference was significant for CD11b (p < 0.001). On the contrary, the level of CD11a expressed on CF-PMN was significantly lower than that expressed by PB-PMN (p < 0.001). Hence, our current results show that early-onset periodontitis PMN can be quite normal and this fact is not surprising insofar as, in our study, these cells were perfectly functional and all the subjects were in good health. We concluded that the analysis of the leukocyte adhesion receptors expression on PB-PMN does not appear useful for helping to establish a differential diagnosis between the different forms of periodontitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of a new toothbrush concept with regard to bacterial elimination. Imprint study using scanning electron microscopy.

The efficacy of a new toothbrush filament layout concept (Topix, Peridental, France) was compared to that of a standard vertical-tuft toothbrush. Bacterial and exogenous deposit elimination were used as parameters of efficacy. 30 dental surgery students took part in the study. Plaque index scores were calculated according to a pre-defined protocol. Imprints of the 6 anterior teeth were taken before and after brushing with the 2 types of brushes, without toothpaste or rinsing. Imprints were examined by scanning electron microscopy (SEM). 12 h after brushing, imprint examination revealed bacterial flora polymorphism and the amount of dental plaque accumulated at the cervical third zone of teeth. Automated quantification in this zone of exogenous bodies showed that after brushing with vertical-tuft and cross-tuft brushes, there remained 1.26 mm2 and 0.83 mm2 of dental plaque, squamae, and blood residues, respectively. The plaque index values correlated to scanning electron microscopic observations. There was no significant difference in terms of efficacy between the cross-tuft and vertical-tuft toothbrushes.

[Post-eruptive formation of the root apex. A scanning electron microscopic study]. / L'apexogénèse post-éruptive. Etude au microscope électronique à balayage.

During the course of root formation, histologic examination show many pictures; however, the last stage of root formation is not well documented. In this paper, we describe cellular and extracellular components of immature teeth with incompletely formed roots. The odontoblast cells were observed with reticular fibers. The cementoblasts and epithelial cells covered the cementoid tissue. The results are discussed.

Gingival biopsy in diagnosis of inborn storage diseases: a case of aspartylglycosaminuria.

The case described is that of a 9-yr-old girl presenting with aspartylglycosaminuria. Diagnosis of this lysosomal storage disease was guided by histologic study of gingival specimen sampled in the course of dental care. Transmitted electron microscopy (TEM) revealed many vesicles and cellular inclusions, altered collagenic formations, associated with abnormal extracellular matrix. Gingival biopsy is easily performed, is noniatrogenic, leaves nor scar, and could be properly used to help diagnose metabolic diseases in children.

[Behaviour of gingival elastic constituents in periodontal disease]. / Comportement des formations élastiques gingivales dans la maladie parodontale.

Disorganization of gingival elastic constituents, including oxytalan fibers, elaunin fibers, and mature elastic fibers, is a feature of periodontal disease. In early stages where inflammation is moderate, this disorganization involves only oxytalan fibers. As the disease progresses, fragmentation and lamination of elaunin fibers and mature elastic fibers is seen. In cyclosporin A-induced gingival hyperplasia, there is a substantial increase in the amount of elastic fibers as compared with healthy gingiva. In gingival fragments from edentulous elderly individuals the elastic constituents form dense granules.

[Prevalence of juvenile periodontitis in Ille-et-Vilaine. Study of an orthodontic population]. / Prévalence de parodontites juvéniles en Ille-et-Vilaine. Etude d'une population orthodontique.

The incidence of Juvenile Periodontitis was studied in 1600 patients residing in Ille et Vilaine, France. The diagnosis was established by the use of panoramic radiography on orthodontic patients. Among this population of patients only 3 cases of Juvenile Periodontitis were found. This incidence of 0.187% is similar to that found in other industrialized countries.

Controlled trial of the action of a toothpaste containing nicomethanol hydrofluoride in the treatment of dentine hypersensitivity.

A double-blind clinical trial was performed on 76 patients with dentine hypersensitivity. For four weeks the patients used either a toothpaste containing nicomethanol hydrofluoride or one containing potassium nitrate and sodium monofluorophosphate. After one, two and four weeks the pain responses of the teeth to three types of stimuli were assessed. In normal conditions of oral hygiene, the nicomethanol hydrofluoride toothpaste was found at least as effective as the potassium nitrate/sodium monofluorophosphate preparation.