Aspergillus fumigatus biofilm formation on different bone substitutes used in maxillary sinus augmentation: an in vitro analysis

BACKGROUND: Fungus ball (FB) typically affects healthy adults, and Aspergillus fumigatus is the most frequent etiologic agent: iatrogenic factors represent an important issue in FB pathogenesis. Moreover, a recent study suggested a significant association between the use of anorganic bovine bone as sinus grafting material and subsequent development of FB. The aim of the present investigation is to evaluate in vitro eventual differences in the ability of Aspergillus fumigatus to colonize different bone grafting materials and grow on them as biofilm. FINDINGS: Five different bone substitutes (demineralized bone matrix, anorganic bovine bone, f-tricalcium phosphate, synthetic nano-hydroxyapatite, and synthetic hydroxyapatite), commonly used in sinus floor augmentation procedures, were inoculated with conidia suspensions of A. fumigatus and incubated at 37\u2009\ub0C for 4 and 8\u2009h, in standardized conditions. Biofilm bound to the different materials underwent quantitative and qualitative analysis by confocal and scanning electron microscopy. A. fumigatus proved to be able to adhere and form biofilm on all the tested bone substitutes. The surface plot representation of the samples displayed some differences in the density of the superficial layer, due to the physical characteristics of the biomaterials. Nevertheless, Kruskal-Wallis test showed no significant differences in biomass amount among the five bone substitutes (p\u2009=\u20090.236 and p\u2009=\u20090.55 after 4 and 8\u2009h adhesion, respectively). CONCLUSIONS: All the bone substitutes normally used in sinus floor augmentation represent a favorable substrate for fungal growth, due to their physical and chemical characteristics. During sinus floor elevation procedures, Schneiderian membrane integrity should be maintained in order to avoid the exposure of the grafting material at the respiratory environment, with potential risks of fungal colonization

Biofilms Developed on\ua0Dental Implant Titanium Surfaces with Different Roughness: Comparison Between In Vitro and In Vivo Studies

Microbial biofilms developed on dental implants play a major role in perimplantitis\u2019 pathogenesis. Many studies have indicated that surface roughness is the main feature favoring biofilm development in vitro, but its actual influence in vivo has still to be confirmed. In this study, the amount of biofilm formed on differently treated titanium surfaces, showing distinct roughness, has been examined both in vivo and in vitro by Confocal Laser Scanning Microscopy. In vitro studies availed of biofilm developed by Pseudomonas aeruginosa or by salivary bacteria from volunteer donors. In vivo biofilm production was obtained by exposing titanium discs to the oral cavity of healthy volunteers. In vitro experiments showed that P. aeruginosa and, to a lesser extent, salivary bacteria produce more biomass and develop thicker biofilms on laser-treated and sandblasted titanium surfaces with respect to machined ones. In vivo experiments confirmed that bacterial colonization starts on sites of surface unevenness, but failed to disclose biomass differences among biofilms formed on surfaces with different roughness. Our study revealed that biofilm developed in vitro is more easily influenced by surface features than biofilm formed by complex communities in the mouth, where the cooperation of a variety of bacterial species and the presence of a wide range of nutrients and conditions allow bacteria to optimize substrate colonization. Therefore, quantitative differences observed in vitro among surfaces with different characteristics may not be predictive of different colonization rates in vivo

Influence of finish line on the marginal seal of nanohybrid composite crowns after periodontal scaling: a microleakage study

Aim. The aim of the present microleakage study was to assess the sealing ability of nanohybrid composite crowns with different finish lines exposed to simulated mechanical periodontal treatment (SMPT). Methods. After sample size calculation (\u3b1=0.05; \u3b2=0.20; \u3b4=1.0; \u3c3=0.8), sixty extracted mandibular molars were divided into four groups (N.=15): G1, 90\ub0 shoulder; G2, beveled 90\ub0 shoulder; G3, 90\ub0 shoulder and SMPT; G4, beveled 90\ub0 shoulder and SMPT. Tooth preparations were carried out by means of diamond burs and Arkansas stones. The buildup of crowns was performed with a nanohybrid composite on master casts obtained after polyether impressions and crowns were cemented with self-adhesive cement. Groups G3 and G4 were subjected to the equivalent of five years of semestral mechanical periodontal scaling with Gracey curettes (2-mm long strokes, 5 N). Samples were immersed into a methylene blue supersaturated solution for 10 minutes. Microleakage was measured by stereomicroscopic observation of multiple sections of the samples and leakage data underwent statistical analysis with non-parametric tests. Results. Marginal microleakage was 1.53\ub11.27% and 17.60\ub112.72% of the length of the adhesive interface in G1 and G2, respectively. SMPT reduced dye penetration (P<0.001) with G3 not leaking at all and G4 leaking along the 5.58\ub11.84% of the adhesive interface. The bevel preparation significantly worsened the marginal seal both in control and treated crowns (P<0.001). Conclusion. Microleakage of nano hybrid composite crowns increased by adding a bevel to a 90\ub0 shoulder preparation and diminished after SMPT

Multicenter comparative multimodality surveillance of women at genetic-familial high risk for breast cancer (HIBCRIT Study): Interim results

PURPOSE: To prospectively compare clinical breast examination (CBE), mammography, ultrasonography (US), and contrast material-enhanced magnetic resonance (MR) imaging for screening women at genetic-familial high risk for breast cancer and report interim results, with pathologic findings as standard. MATERIALS AND METHODS: Institutional review board of each center approved the research; informed written consent was obtained. CBE, mammography, US, and MR imaging were performed for yearly screening of BRCA1 or BRCA2 mutation carriers, first-degree relatives of BRCA1 or BRCA2 mutation carriers, or women enrolled because of a strong family history of breast or ovarian cancer (three or more events in first- or second-degree relatives in either maternal or paternal line; these included breast cancer in women younger than 60 years, ovarian cancer at any age, and male breast cancer at any age). RESULTS: Two hundred seventy-eight women (mean age, 46 years +/- 12 [standard deviation]) were enrolled. Breast cancer was found in 11 of 278 women at first round and seven of 99 at second round (14 invasive, four intraductal; eight were <or=10 mm in diameter). Detection rate per year was 4.8% (18 of 377) overall; 4.3% (11 of 258) in BRCA1 or BRCA2 mutation carriers and first-degree relatives of BRCA1 or BRCA2 mutation carriers versus 5.9% (seven of 119) in women enrolled because of strong family history; and 5.3% (nine of 169) in women with previous personal breast and/or ovarian cancer versus 4.3% (nine of 208) in those without. In six (33%) of 18 patients, cancer was detected only with MR imaging. Sensitivity was as follows: CBE, 50% (95% confidence interval [CI]: 29%, 71%); mammography, 59% (95% CI: 36%, 78%); US, 65% (95% CI: 41%, 83%); and MR imaging, 94% (95% CI: 82%, 99%). Positive predictive value was as follows: CBE, 82% (95% CI: 52%, 95%); mammography, 77% (95% CI: 50%, 92%); US, 65% (95% CI: 41%, 83%); and MR imaging, 63% (95% CI: 43%, 79%). CONCLUSION: Addition of MR imaging to the screening regimen for high-risk women may enable detection of otherwise unsuspected breast cancers