The suppression of T-cell function by cyclosporin therapy can result in an increase of HPV infection, adding to the proliferative activity of cyclosporin in the oral mucosa.

Human dental calculi are biological calcium phosphates, which consist of an organic phase and an inorganic or mineral phase. In the latter phase, spectrochemical analyses have revealed the presence of several different magnesium and calcium phosphates. As the crystalline structure of the calculus passes through several stages during its allocation in the mouth, special attention is paid to some elements, such as zinc, that can modify the mineralization process. Several in vitro studies relating to the dental calculus mineralization process have been performed so far, but there is a lack of data obtained from biologically synthesized samples. The knowledge of the zinc distribution and incorporation in biological calcium phosphates is of great interest in providing more information about the biological process of calculus formation. In this paper we present surveys of the elemental distribution and incorporation of zinc in human dental calculus, by using a combination of different techniques: x‐ray microfluorescence using synchrotron radiation, scanning electron microscopy and x‐ray absorption spectroscopy. One‐dimensional x‐ray microfluorescence of zinc and magnesium measurement shows that there is a high accumulation of both elements in the sub‐gingival region of the calculus and a strong correlation of their spatial distribution. Experimental Ca/P molar ratios were determined by energy‐dispersive spectroscopy to identify different calcium phosphate phases, the sub‐gingival region being composed of a mixture of highly and poorly calcified phosphates and the supra‐gingival region composed mainly of carbonated hydroxyapatite. Finally, x‐ray absorption measurements were carried out at the zinc K edge on synthetic and biological samples. The Zn—O distance and coordination number of the synthetic samples and the supra‐gingival calculus show that zinc is adsorbed on these structures, whereas in the sub‐gingival samples it is allocated in a cation site. The results are indicative of the active participation of zinc in the calcification process of sub‐gingival calculus. Copyright © 2003 John Wiley & Sons, Ltd.

This work presents a study of elemental composition (major, minor and trace elements) of oral fluids such as saliva and gingival crevice fluid, and their relation with smoking. Spectrochemical analyses were accomplished by the total reflection X-ray fluorescence (TXRF) method using synchrotron radiation. Smoking habit is a well-known factor of risk that can trigger the development of periodontal diseases. The presence of certain elements and their correlation with smoking could be used to predict the development of oral affections, i.e. gingivitis. Two set of patients, smokers and non-smokers, were selected according to certain criteria to analyze saliva and gingival crevice fluid. The elemental concentrations were measured, and the differences between their mean values of both groups were determined. The results reveal significant differences in the elemental concentrations of saliva. On the other hand, the mean values of elemental concentrations in gingival crevice fluid show fewer differences between both groups. The most significant differences in concentration between smokers and non-smokers were found in saliva samples for S, K and Ca. In addition, a significant difference in the concentration of Cl in gingival crevice fluid was observed between both groups.

This work presents a study of elemental composition and preponderant structure of human dental calculus, as they mature in the mouth for a period of 1 year. The synchrotron radiation X-ray fluorescence technique using a white beam was employed as an analytical method. The set of samples were extracted from different dental elements of the same subject, who did not require any other clinical care. By means of analyzing the Ca/P molar ratio an estimation of the main crystallographic structure was attained, by simple comparison with stoichiometric values of the several crystalline structures that compose the calculus. The results showed a slowly progressive transformation of the initial crystalline structures (brushite) into more stable structures (hydroxyapatite), passing through octacalcium phosphate and whitlockite. The concentrations of mayor components (Ca and P) as a function of time followed a sigmoid curve. The analysis of trace element concentrations versus time indicated a null or small correlation of concentration values with the kinetics of the crystallization process.

Corrosion of metals in implanted biomaterials lifetime is expected to occur. Nowadays, medical implants have good biocompatibility, present proper mechanical properties, and promote tissue regeneration; nevertheless, corrosion will eventually happen. Biological fluids are rich in chemically active ions; hence, electrochemical processes appear on the surface of the metal immediately after implantation. In order to evaluate corrosion resistance of metal implants, several studies have been carried out in artificial environments, but their results have not been always directly correlated to living systems.This work presents an indirect study of corrosion of dental implants by analyzing changes of elemental concentration of metals in oral fluids. It will also contribute to the knowledge of implant corrosion in relation to its biological environment. Degradation of the implant surface releases material to the medium, which, depending on the concentrations, can represent toxic risk, organic malfunction, pain, rejection, and so on. In order to evaluate this process, the concentrations of representative metals such as Ti, Al, and V in saliva and gingival fluids were analyzed by means of total reflection of X‐rays fluorescence analysis using synchrotron radiation.The results obtained here show that Ti‐ions present a different behavior in the oral fluids, revealing higher concentrations in gingival crevice fluid than in saliva. On the other hand, V and Al have not shown significant differences from normal levels in the oral fluids. Metal release is discussed under mechanical and chemical considerations, taking into account the oral environment of the implant. Copyright © 2014 John Wiley & Sons, Ltd.