The Association of Periodontopathic Bacteria Levels in Saliva and Tongue Coating with Oral Malodor in Periodontitis Patients.

PURPOSE: To elucidate the association oral malodor with the levels of periodontopathic bacteria in saliva and tongue coating of periodontitis patients with oral malodor. MATERIALS AND METHODS: In 25 periodontitis patients, the organoleptic test (OLT) was performed, the levels of volatile sulfur compounds (VSCs) were measured, tongue coating (TC) score was determined, and periodontal parameters and the proportions of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Tannerella forsythia and Prevotella intermedia in the saliva and the tongue coating were evaluated. RESULTS: The proportions of T. denticola and T. forsythia in the saliva of patients with an OLT score ≥ 2 were significantly higher than those with OLT scores < 2. The proportion of P. gingivalis in the saliva significantly correlated with periodontal parameters, whereas T. denticola and T. forsythia levels in the tongue coating correlated with VSC levels. However, the five periodontopathic bacteria were found in the tongue coating at levels approximately 12 times lower than in the saliva. CONCLUSIONS: The findings suggest that the levels of T. denticola and T. forsythia in the saliva of periodontitis patients correlate with oral malodor, and that the prevalence of P. gingivalis in the saliva is related to periodontitis. Periodontopathic bacteria in the tongue coating contribute minimally to oral malodor in periodontitis patients.

Evidence of Helicobacter pylori heterogeneity in human stomachs by susceptibility testing and characterization of mutations in drug-resistant isolates.

Heterogeneity of Helicobacter pylori communities contributes to its pathogenicity and diverse clinical outcomes. We conducted drug-susceptibility tests using four antibiotics, clarithromycin (CLR), amoxicillin (AMX), metronidazole and sitafloxacin, to examine H. pylori population diversity. We also analyzed genes associated with resistance to CLR and AMX. We examined multiple isolates from 42 Japanese patients, including 28 patients in whom primary eradication with CLR and AMX had failed, and 14 treatment-naïve patients. We identified some patients with coexistence of drug resistant- and sensitive-isolates (drug-heteroR/S-patients). More than 60% of patients were drug-heteroR/S to all four drugs, indicating extensive heterogeneity. For the four drugs except AMX, the rates of drug-heteroR/S-patients were higher in treatment-naïve patients than in primary eradication-failure patients. In primary eradication-failure patients, isolates multi-resistant to all four drugs existed among other isolates. In primary eradication-failure drug-heteroR/S-patients, CLR- and AMX-resistant isolates were preferentially distributed to the corpus and antrum with different minimum inhibitory concentrations, respectively. We found two mutations in PBP1A, G591K and A480V, and analyzed these in recombinants to directly demonstrate their association with AMX resistance. Assessment of multiple isolates from different stomach regions will improve accurate assessment of H. pylori colonization status in the stomach.

Effect of surface roughness on initial responses of osteoblast-like cells on two types of zirconia.

The aim of this study was to evaluate the effect of surface roughness on the initial attachment of mouse osteoblast-like cells on ceriastabilized zirconia/alumina nanocomposite (NANOZR) and yttria-stabilized zirconia (3Y-TZP) in comparison to those on pure titanium (Ti) and alumina oxide (AO). Specimens with smooth and rough surfaces were prepared by grinding with diamond paper or by sandblasting, respectively. For four substrates examined, the number of attached cells on the rough surface specimens was significantly higher than that on the smooth surface specimens (p < 0.05). Integrin alpha(5) and beta(1) expression had a greater increase in rough surface specimens than in smooth surface specimens. Actin cytoskeleton organization was, however, similar for both smooth and rough surface specimens. NANOZR and 3Y-TZP produced good cell attachment, similar to Ti and AO. The overall results demonstrated that NANOZR and 3Y-TZP with rough surface could provide good initial cell responses, adequate for future implant usage.

Effectable application of vascular endothelial growth factor to critical sized rat calvaria defects.

OBJECTIVE: An early vascular response for angiogenesis is essential for the normal progression of bone defect healing. Vascular endothelial growth factor (VEGF) is a potent inducer of angiogenesis. The aim of this study was to evaluate the effects of a poly (L,D-lactic-co-glycolic acid) (PLGA) membrane with VEGF encapsulated into PLGA microspheres on bone regeneration at bone defects in rat calvaria. STUDY DESIGN: Microspheres of PLGA incorporating VEGF(165) (VEGF microspheres) were prepared, and critical-size bone defects were created in rat calvaria. The VEGF microspheres, PLGA microspheres, or VEGF microspheres plus PLGA membrane were applied to the defects. Bone regeneration was evaluated using image analysis based on soft radiographic and histologic examination. RESULTS: Mature thick bone regeneration was observed in selected sites at bone defects that had been applied with VEGF microspheres/PLGA membrane compared with those that had been applied with the other treatments. CONCLUSION: A combination of VEGF microspheres and a PLGA membrane effectively enhances bone regeneration.