Preventive Medicine Research Institute

Endodontic sealers play a vital role in providing 3-dimensional (3D) filling of complex root canal system (RCS). This study intended to compare the physical properties of a Polyurethane Expandable Sealer (PES), AH Plus and EndoSequence. Three properties including setting time, radiopacity and flow (rheology) were evaluated based on ISO 6876 standard. For evaluation of each of these physical properties, five samples from experimental groups: AH Plus, EndoSequence, PES (controlled expansion) and PES (high expansion) were used (n = 5). Data were analysed by one-way ANOVA and Post Hoc Tukey tests (a = 0.05). EndoSequence showed the longest setting time (P < 0.000); AH Plus showed that highest radiopacity (P < 0.000); and PES (high expansion) showed the highest flow (diameter and surface area) (P < 0.000). EndoSequence and PES (controlled expansion) showed promising and comparable physical properties to the AH Plus sealer in terms of flow, setting time and radiopacity.

The aim of the study was to assess the efficiency of a complex of molecular genetic techniques: PCR, RAPD, and MLST using MALDI-TOF mass-spectrometry to study the characteristics of hospital strains.Materials and Methods.We identified 23 strains of K. рneumoniae isolated in a pediatric hospital using MALDI-TOF massspectrometer Autoflex and MALDI Biotyper software (Bruker Daltonics, Germany).Antibiotic sensitivity was analyzed by means of an automatic bacteriological analyzer Phoenix-100 (Becton Dickinson, USA) using chromogenic culture media (HiMedia, India).The search for resistance determinants and molecular typing were performed using PCR, RAPD, and MLST.Results.All the strains were identified as K. pneumoniae ssp.pneumoniae.According to antibiotic sensitivity, three groups were distinguished: group 1 (n=15) -sensitive strains (wt); group 2 (n=7) -potential carbapenemase-producers; group 3 (n=1) -extendedspectrum beta-lactamase producers.No resistance determinants were found in groups 1 and 2; beta-lactamases bla SHV and bla CTX-M were revealed in group 3 strain.We identified RAPD-type of the strain, a capsule type (K-23), it belonging to the sequence type 17.Strains with this sequence type are rarely isolated in Russia, however, they are known in Europe, USA, and Asian countries, they being associated with lethal human pathologies and a high epidemic potential.Conclusion.The use of a complex of current techniques to study the phenotypic and genotypic properties of microorganisms enabled to isolate and characterize a hospital strain K. pneumoniae, which is antibiotic-resistant due to the presence of beta-lactamases: bla CTX-M-15 and bla SHV-11 , and it being dangerous in terms of resistance determinants transmission.

The identification of root caries and calculus on tooth roots is of increasing importance with our aging population. Exposed root surfaces are often impacted by erosion, abrasion, calculus and staining which can make the identification and management of caries challenging. Identification of dental calculus on root surfaces and verification of its removal is also important for patient education and to decrease susceptibility to caries and periodontal disease. The objective of this study was to determine how the contrast of root caries lesions and dental calculus varies with wavelength in the visible to near-infrared. The contrast of suspected root caries lesions and dental calculus on 30 extracted teeth was measured using cross-polarization reflectance measurements at wavelengths from 400 to 2350 nm. Significantly higher (P < 0.05) lesion contrast was measured at wavelengths greater than 1460 nm. Stains interfered significantly at wavelengths less than 850 nm yielding non-diagnostic contrast for root caries lesions. We postulate that the high absorption of water at longer wavelengths reduced the light scattering from the surrounding and underlying normal dentin, thus increasing the lesion contrast. This study indicates that wavelengths beyond 1400 nm are advantageous for imaging calculus and caries lesions on root surfaces due to the high contrast and lack of interference from stain.

This study investigated the cost-effectiveness between double and single Fecal Immunochemical Test(s) (FIT) in a mass CRC screening. A two-stage sequential screening was conducted. FIT was used as a primary screening test and recommended twice by an interval of one week at the first screening stage. We defined the first-time FIT as FIT1 and the second-time FIT as FIT2. If either FIT1 or FIT2 was positive (+), then a colonoscopy was recommended at the second stage. Costs were recorded and analyzed. A total of 24,419 participants completed either FIT1 or FIT2. The detection rate of advanced neoplasm was 19.2% among both FIT1+ and FIT2+, especially high among men with age ≥55 (27.4%). About 15.4% CRC, 18.9% advanced neoplasm, and 29.9% adenoma missed by FIT1 were detected by FIT2 alone. Average cost was $2,935 for double FITs and $2,121 for FIT1 to detect each CRC and $901 for double FITs and $680 for FIT1 to detect each advanced neoplasm. Double FITs are overall more cost-effective, having significantly higher positive and detection rates with an acceptable higher cost, than single FIT. Double FITs should be encouraged for the first screening in a mass CRC screening, especially in economically and medically underserved populations/areas/countries.

Electromechanical coupling, a phenomenon present in collagenous materials, may influence cell-extracellular matrix interactions. Here, electromechanical coupling has been investigated via piezoresponse force microscopy in transparent and opaque membranes consisting of helical-like arrays of aligned type I collagen fibrils self-assembled from acidic solution. Using atomic force microscopy, the transparent membrane was determined to contain fibrils having an average diameter of 76 ± 14 nm, whereas the opaque membrane comprised fibrils with an average diameter of 391 ± 99 nm. As the acidity of the membranes must be neutralized before they can serve as cell culture substrates, the structure and piezoelectric properties of the membranes were measured under ambient conditions before and after the neutralization process. A crimp structure (1.59 ± 0.37 µm in width) perpendicular to the fibril alignment became apparent in the transparent membrane when the pH was adjusted from acidic (pH = 2.5) to neutral (pH = 7) conditions. In addition, a 1.35-fold increase was observed in the amplitude of the shear piezoelectricity of the transparent membrane. The structure and piezoelectric properties of the opaque membrane were not significantly affected by the neutralization process. The results highlight the presence of an additional translational order in the transparent membrane in the direction perpendicular to the fibril alignment. The piezoelectric response of both membrane types was found to be an order of magnitude lower than that of collagen fibrils in rat tail tendon. This reduced response is attributed to less-ordered molecular assembly than is present in D-periodic collagen fibrils, as evidenced by the absence of D-periodicity in the membranes.

Nova Southeastern University College of Dental Medicine (NSU-CDM) has developed a program to educate its Advanced Education in General Dentistry (AEGD) residents to provide oral health services to survivors of domestic violence. NSU-CDM worked in collaboration with three community-based sites in Florida's Dade and Broward counties that provide residential and outpatient services to women survivors of domestic violence. The educational program includes didactic instruction and clinical rotations utilizing portable dental equipment assembled at the community-based sites. The central element of the program was the establishment of a partnership between NSU-CDM and local community-based organizations that serve women who have experienced domestic violence. This collaboration enabled the school to involve a range of key stakeholders in program development and implementation and to successfully establish dental clinics at two shelter sites. In total, NSU-CDM provided dental care to over 250 women, and twenty AEGD residents completed both the didactic and clinical rotations of the domestic violence education program. Elements identified as being essential to successful collaborations between oral health clinics and shelter settings are described.

Is red meat bad for you? In a word, yes. In this issue, Pan et al1 describe the outcomes from more than 37 000 men from the Harvard Health Professionals Follow-Up Study and more than 83 000 women from the Harvard Nurses Health Study who were followed up for almost 3 million person-years.