The impact of dental amalgam on the development of Parkinson’s disease (PD) is still uncertain, although a positive association between dental amalgam and PD has been found in a few case-control studies. The patients with amalgam fillings restored between 2000 and 2008 were identified by using the National Health Insurance Research Database (NHIRD) in Taiwan. The same number of patients who had no new amalgam filling restored was matched by sex, age, and treatment date. Both cohorts were followed up from the treatment date until the date of diagnosis of PD, death, or the end of the year 2008. The individuals who received amalgam fillings had a significantly higher risk of PD afterward (adjusted hazard ratio [HR]=1.583, 95% confidence interval [CI]=1.122–2.234, p=0.0089) than those who did not. In the individuals who received amalgam fillings, being diagnosed with diabetes or hyperlipidemia demonstrated a significantly lower HR of PD occurrence than in the patients without diabetes or hyperlipidemia (HR=0.449, 95% CI=0.254–0.794, p=0.0059; HR=0.445, 95% CI=0.260–0.763, p=0.0032) after adjusting for comorbidities and Charlson-Deyo Comorbidity Index (CCI) scores. Meanwhile, hypertension increased the hazard risk of PD (HR=1.645, 95% CI=1.098–2.464, p=0.0159). The patients exposed to dental amalgam fillings were 1.583 times more likely to have PD afterward compared to their non-exposed counterparts after adjusting for comorbidities and CCI scores.

Background/purpose Denture stomatitis is a pathological condition affecting the mucosa underneath ill-fitting dentures, and Candida albicans is considered its main etiologic factor. Tissue conditioners are temporary lining materials often applied to dentures to treat inflamed tissues. However, tissue conditioners do not exert antifungal activity, and the soft surface texture harbors C. albicans easily. The aim of this study was to examine the antifungal activity of tissue conditioners modified with chitosan (CS) or a quaternized chitosan (QCS), which was synthesized by grafting 2-[(acryloyloxy)ethyl] trimethyl ammonium chloride onto CS. Materials and methods Tissue conditioners containing varying weight percentages of CS or QCS were prepared as experimental discs 10 mm in diameter and 1 mm in thickness. Samples were co-cultured with C. albicans and the number of colony forming units was recorded. Other evaluations included cell toxicity and tensile bond strength to the resin denture base. Results It was found significantly fewer fungal colonies in tissue conditioners modified with CS or QCS, and none when the weight percentage of QCS exceeded 5%. CS and QCS did not affect the viability of human gingival epithelium cells or fibroblasts, and tensile bond strength did not differ between control and modified tissue conditioners. Conclusion This study provides a foundation for the development of QCS as a novel and safe antifungal agent applied to tissue conditioners in clinical practice.

The present investigation describes a new eco-friendly, low cost material-based approach for sensor device fabrication. In this study, sericin capped zinc oxide nanorod (ZNR)-based H 2 gas sensors and UV photodetectors were fabricated by incorporating silk-sericin with ZnO. The proposed sensors have higher sensitivity to H 2 and greater photoresponsivity. The sericin capped ZNRs were fabricated from a degummed waste sericin solution using an inexpensive hydrothermal method. The sericin capped ZNRs show excellent H 2 gas response (17.8%) and photoresponse with a fast response time under UV illumination due to sericin coating on the surface of the ZnO. Sericin is a water-soluble protein with strong polar groups as side chains, such as carboxyl, amino, and hydroxyl groups, which can easily interact with zinc particles through electrostatic interactions, resulting in the unique and improved ZnO sensor behavior. This interaction was characterized by various analytical techniques and compared with as-grown ZNR. The gas sensing property and UV photoresponse were evaluated for both as-grown ZNRs and sericin capped ZNRs as functions of the H 2 concentration and time, respectively. Under 365 nm UV illumination, the sericin capped ZNR possesses an ultrahigh photoresponse of 408.4, which is 40 times better than that of the as-prepared ZnO devices (10.3). Moreover, the sensing response for the sericin capped ZNRs shows a complete recovery to the original level after evacuation of the H 2 and UV illumination in each cycle, indicating complete desorption and decomposition of the main adsorbed moieties. The sericin capped ZNR presented in this work shows enhanced, sustained, and reversible H 2 gas sensing and fast switching speed in the UV region and can be employed for the development of inorganic−organic novel materials utilizing the biomass from industrial waste.