Subgingival strains of Candida albicans in relation to geographical origin and occurrence of periodontal pathogenic bacteria.

Clonal diversity of subgingival yeast strains was determined in relation to geographical location and coexistence of selected periodontal pathogenic bacteria. A total of 60 dental patients from Finland, the United States and Turkey each contributed five Candida albicans isolates. C. albicans isolates were serotyped using slide agglutination and genotyped using polymerase chain reaction (PCR) amplification and a random sequence primer. In general, each study subject yielded C. albicans isolates belonging to the same serotype and genotype. C. albicans serotype A occurred more frequently in subjects from Finland and Turkey than in subjects from the United States. A total of 27 PCR-based C. albicans genotypes were identified. One C. albicans genotype occurred with particularly high frequency in subjects from Turkey and another genotype in subjects from the United States. Relationships were identified between C. albicans serotypes and genotypes. Further studies are needed to determine environmental factors of importance for subgingival colonization and persistence of C. albicans.

Topography of periodontally involved human root surfaces after different chemical treatment modalities: an in vitro scanning electron microscopic study.

The significance of chemical and conservative treatments of cemental tissue proximal to periodontal pockets has been pointed out in recent years. This in vitro scanning electron microscopy (SEM) study aimed to investigate the surface effects of topical applications of 0.1% cetylpyridinium chloride (CPC) and 2% sodium lauryl sulfate (SLS) and polishing on the periodontally involved root surfaces of human teeth. Ten single-rooted teeth from 8 patients with advanced adult periodontitis were included. Following extraction, any calculus was removed with extreme care to preserve as much cementum as possible. Eighty root specimens were prepared. Fresh solutions of CPC and SLS were applied for 1, 3 and 5 minutes each to 10 segments of root cementum. A total of 20 segments formed the polished (P) and control (C) groups, respectively. The results showed that the surfaces treated with CPC or SLS differed considerably from polished and control specimens. Depending on time, the surface coating was partly or wholly removed, leaving a nodular cementum structure, uncovering a fibrillar collagen substrate and the openings of dentinal tubules. Scarce debris was present on both control and polished surfaces, whereas bacteria were observed only on the control specimens. In view of these results, further definitive in vitro and in vivo research must be done to determine the advantages of chemical treatment and its effect on periodontal regeneration.

Bacterial adhesion of Actinobacillus actinomycetemcomitans serotypes to titanium implants: SEM evaluation. A preliminary report.

BACKGROUND: In this study, the adherence ability of Actinobacillus actinomycetemcomitans serotypes to titanium implant surfaces was evaluated to demonstrate if any selective adherence occurs according to the serotypes of the microorganism. METHODS: The study material included 3 reference strains of A. actinomycetemcomitans serotypes a, b, and c (ATCC 29523, ATCC 43718, ATCC 33384) and 2 clinical isolates of A. actinomycetemcomitans serotypes d and e (IDH 781, IDH 1705), together with commercially available titanium blade implants. For each strain, bacterial suspensions with identical concentrations (5 x 10(7) cells/ml) were prepared and 0.5 ml of each was added on to the implant surfaces, which had been precoated with glycine-bovine serum albumin (BSA). After incubation at 37 degrees C for 60 minutes in 5% CO2 in air, the implants with attached bacteria were prepared for scanning electron microscopic (SEM) observations. Bacterial adhesion was quantified on the textured body surfaces of the implants, and results were statistically analyzed with analysis of variance followed by Duncan's test. The surface ultrastructure of the bacterial cells was also evaluated descriptively. RESULTS: The tested strains adhered to implant surfaces in different quantities. Serotype a (ATCC 29523) showed the highest adherence affinity (statistically significant, P <0.01). When compared with each other, serotypes b, c, and d (ATCC 43718, ATCC 33384, and IDH 781) attached equally well, whereas serotype e (IDH 1705) had a statistically significant low adherence capability. CONCLUSIONS: It is suggested that in vitro A. actinomycetemcomitans adhesion to implant surfaces is strain dependent.

Histological assessment of root cementum at periodontally healthy and diseased human teeth.

This study aimed to investigate and compare the lipid and polysaccharide content of the cemental surfaces of healthy and periodontally-involved teeth. Thirty periodontally-involved single-rooted teeth from fifteen patients with localized juvenile, adult and rapidly progressive periodontitis were included in the experimental group and 5 healthy teeth were assessed in the control group. Frozen serial sections were obtained and stained with hematoxylin-eosin for morphological assessment. Oil-Red-O and Alcian Blue-Periodic Acid Schiff stains were used to evaluate the presence of lipids, neutral and acidic polysaccharides using light microscopy. It was found that with hematoxylin-eosin staining in the experimental group, both the involved and uninvolved cementum surfaces of teeth, which belong to all periodontitis groups, showed generally irregular surfaces that contain some resorption areas. Alcian Blue-Periodic Acid Schiff positive staining was observed only superficially and at the areas associated with microbial dental plaque. However, Oil-Red-O staining was positive only superficially at 5 teeth that belonged to localized juvenile and rapidly progressive periodontitis groups. Apparent lipopolysaccharide staining into cementum was not seen in any of the diseased teeth. The results presented here suggest that endotoxin was only localized in superficial layers and associated with only microbial colonization.