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In this in-vitro study, the effectiveness of experimental pure nano-hydroxyapatite (nHAP) and 1%, 2%, and 3% F¯ doped nano-HAp on dentine tubule occlusion was investigated. And also, the cytotoxicity of materials used in the experiment was evaluated. Nano-HAp types were synthesized by the precipitation method. Forty dentin specimens were randomly divided into five groups of; 1-no treatment (control), 2-specimens treated with 10% pure nano-HAp and 3, 4, 5 specimens treated with 1%, 2%, and 3% F doped 10% nano-HAp, respectively. To evaluate the effectiveness of the materials used; pH, FTIR, and scanning electron microscopy evaluations were performed before and after degredation in simulated body fluid. To determine cytotoxicity of the materials, MTT assay was performed. Statistical evaluations were performed with F and t tests. All of the nano-HAp materials used in this study built up an effective covering layer on the dentin surfaces even with plugs in tubules. It was found that this layer had also a resistance to degradation. None of the evaluated nano-HAp types were have toxicity. Fluoride doping showed a positive effect on physical and chemical stability until a critical value of 1% F . The all evaluated nano-HAp types may be effectively used in dentin hypersensitivity treatment. The formed nano-HAp layers were seem to resistant to hydrolic deletion. The pure and 1% F doped nano-HAp showed the highest biocompatibility thus it was assessed that pure and 1% F doped materials may be used as an active ingredient in dentin hypersensitivity agents.

The aim of this study was to determine the temperature increase in the pulp chamber and possible thermal effects on molecular structure of primary teeth during the irradiation with Er,Cr:YSGG laser. Primary central incisors were divided into three groups (n = 20). Labial surfaces in each group were irradiated by Er,Cr:YSGG laser within different power and frequencies as following groups:

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Medical stents are tubes made of a metal or plastic wire mesh. They are inserted into a hollow structure of a body part to keep an anatomic vessel or passageway open. Stents placed in the body can cause toxic effects by releasing metal ions into the body, and can also cause harmful effects on the body by creating corrosion products. In this study, the decomposition rate and release of corrosion products in artificial body fluid (PBS) of a stent sample with a nitinol structure produced for medical purposes were examined. If any metal decomposes in the body, it can endanger human life and can damage the body via heavy metal residues and toxic radical products that accumulate over long periods in the body. An in vitro degradation test was performed according to the standard 10993-13 and metal release values were found after short periods (one month) for nitinol. In the present study, the release values and possible toxic effects of nickel and titanium within the body with long-term intra-body use were examined. By calculating the mass loss caused by degradation, its relationship to heavy metal release inside the body and the possible side effects on human health of heavy metal residues were evaluated. Low metal ion release values of heavy metals resulting from degradation were determined by the ICP-OES device. Physical changes (diameter) in the surface of stent parts were also measured to compare and evaluate with the degradation rates.