53 research outputs found

    High-efficiency tooth bleaching using non-thermal atmospheric pressure plasma with low concentration of hydrogen peroxide

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    Light-activated tooth bleaching with a high hydrogen peroxide (HP; H(2)O(2)) concentration has risks and the actual role of the light source is doubtful. The use of conventional light might result in an increase in the temperature and cause thermal damage to the health of the tooth tissue. OBJECTIVE: This study investigated the efficacy of tooth bleaching using non-thermal atmospheric pressure plasma (NAPP) with 15% carbamide peroxide (CP; CH(6)N(2)O(3)) including 5.4% HP, as compared with conventional light sources. MATERIAL AND METHODS: Forty human teeth were randomly divided into four groups: Group I (CP+NAPP), Group II (CP+plasma arc lamp; PAC), Group III (CP+diode laser), and Group IV (CP alone). Color changes (ΔE ) of the tooth and tooth surface temperatures were measured. Data were evaluated by one-way analysis of variance (ANOVA) and post-hoc Tukey's tests. RESULTS: Group I showed the highest bleaching efficacy, with a ΔE value of 1.92-, 2.61 and 2.97-fold greater than those of Groups II, III and IV, respectively (P<0.05). The tooth surface temperature was maintained around 37ºC in Group I, but it reached 43ºC in Groups II and III. CONCLUSIONS: The NAPP has a greater capability for effective tooth bleaching than conventional light sources with a low concentration of HP without causing thermal damage. Tooth bleaching using NAPP can become a major technique for in-office bleaching in the near future

    Nichtlineare Gleichungen, Minimierung und Ableitung

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    Premenstrual dysphoric disorder: evidence for a new category for DSM-5

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    Premenstrual dysphoric disorder, which affects 2%–5% of premenopausal women, was included in Appendix B of DSM-IV, “Criterion Sets and Axes Provided for Further Study.” Since then, aided by the inclusion of specific and rigorous criteria in DSM-IV, there has been an explosion of research on the epidemiology, phenomenology, pathogenesis, and treatment of the disorder. In 2009, the Mood Disorders Work Group for DSM-5 convened a group of experts to examine the literature on premenstrual dysphoric disorder and provide recommendations regarding the appropriate criteria and placement for the disorder in DSM-5. Based on thorough review and lengthy discussion, the work group proposed that the information on the diagnosis, treatment, and validation of the disorder has matured sufficiently for it to qualify as a full category in DSM-5. A move to the position of category, rather than a criterion set in need of further study, will provide greater legitimacy for the disorder and encourage the growth of evidence-based research, ultimately leading to new treatments
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