RESUMO
BACKGROUND: To determine an exploratory estimation of the strength of type 2 diabetes mellitus (T2DM) and hypertension diagnoses as risk indicators for missing teeth in a sample of Mexican adults. MATERIALS AND METHODS: A comparative cross-sectional study of sixty adult patients in a health center in Mexico included as dependent variable, the number of missing teeth (and having a functional dentition) and as independent variables, diagnoses for diabetes or hypertension, age, sex, maximum level of schooling, and tobacco use. Of the 60 participants, 20 were diagnosed with T2DM, 13 with hypertension, and 27 were otherwise diagnosed as healthy in their most recent medical checkup. A negative binomial regression (NBR) model was generated. RESULTS: Mean age was 50.7 ± 16.2 and 50.0% were women. Mean number of missing teeth was 4.98 ± 4.17. In the multivariate NBR model, we observed that individuals with T2DM had higher risk of more missing teeth (incidence rate ratios [IRRs] = 3.13; 95% confidence interval [CI] = 2.09-4.69), followed by those with hypertension (IRRs = 2.63; 95% CI = 1.77-3.90). In addition, participants with current tobacco use were significantly more likely to have suffered tooth loss (P < 0.05) than those who were never smokers or former smokers, just like older participants (P < 0.05). CONCLUSIONS: T2DM and hypertension are independently associated with higher experience of missing teeth in an open adult population in Mexico. Future studies with a more sophisticated epidemiological design and encompassing a more detailed landscape of chronic diseases, type and length of use of long-term medications, and patterns of dental care use are needed to better delineate these associations.
Assuntos
Diabetes Mellitus Tipo 2/etnologia , Hipertensão/etnologia , Perda de Dente/epidemiologia , Adulto , Idoso , Estudos Transversais , Assistência Odontológica , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Fatores de Risco , Fumar/epidemiologiaRESUMO
In this work, we study theoretically the elastic properties of the orthorhombic (Pnma) high-pressure phase of IV-B group oxides: titania, zirconia and hafnia. By means of the self-consistent SIESTA code, pseudopotentials, density functional theory in the LDA and GGA approximations, the total energies, hydrostatic pressures and stress tensor components are calculated. From the stress-strain relationships, in the linear regime, the elastic constants C(ij) are determined. Derived elastic constants, such as bulk, Young's and shear modulus, Poisson coefficient and brittle/ductile behavior are estimated with the polycrystalline approach, using Voigt-Reuss-Hill theories. We have found that C(11), C(22) and C(33) elastic constants of hafnia and zirconia show increased strength with respect to the experimental values of the normal phase, P 2(1)/c. A similar situation applies to titania if these constants are compared with its normal phase, rutile. However, shear elastic constants C(44), C(55) and C(66) are similar to the values found in the normal phase. This fact increases the compound anisotropy as well as its ductile behavior. The dependence of unit-cell volumes under hydrostatic pressures is also analyzed. P-V data, fitted to third-order Birch-Murnaghan equations of state, provide the bulk modulus B(0) and its pressure derivatives B'(0). In this case, LDA estimations show good agreement with respect to recent measured bulk moduli of ZrO(2) and HfO(2). Thermo-acoustic properties, e.g. the propagation speed of transverse, longitudinal elastic waves together with associated Debye temperatures, are also estimated.