BackgroundSleep has also been cherished by society as a basic human need with a crucial importance for human health. People spend around one third of their lives sleeping. Nowadays, it has never been harder to achieve a restful sleep. When sleep is better understand, that will lessen the drawbacks of the different sleep disorders. Healthy sleep is important for maintaining physical and mental health in adult individuals. Sleep deprivation poses a significant risk for the individual and leads to psychological conditions, such as depression and anxiety. Several sleep disorders are known to the science. If breathing during sleep is not regular, a case of obstructive sleep apnea (OSA) may have been diagnosed. The World Sleep Day is traditionally celebrated in March, on the Friday before the Spring vernal equinox of each year. It is a global awareness and internationally recognized event, organized annually since 2008 by the World Sleep Day Committee of the World Sleep Society. Organizers aim to raise awareness of the problems with proper sleep, sleep disorders and aspects connected to it -medical, social, educational and others. Methods Scientific databases -PubMed, SCOPUS and MEDLINE were used to search for the information targeted. The following keywords -World Sleep Day, history, events, prophylaxis, sleep disorders were used. Information from the official websites of the societies involved in celebrating World Sleep Day was included as well. The aim of the following article is to study the history of the event from its foundation till today, aiming to stress out its usefulness. Results and discussionWorld Sleep Days has been internationally celebrated since 2008 for 15 years now. Since 2016, Bulgaria actively participates in all events organized by the World Sleep Society -Scientific symposiums, prophylactic check-ups for obstructive sleep apnea, elective disciplines in the teaching of students are organized. Importance is put on informing society about the dangers of undiagnosed and untreated sleep disorders, especially sleep apnea. Sleep medicine and Dental Sleep medicine are not recognized as medical specialties in the Republic of Bulgaria. ConclusionsProblems of sleep are extremely common in our days. The situation is continuously being worsened due to the hyperconnectivity people experience with the glowing computer and mobile phone screens. It is admirable that specialists in the field and society try to raise awareness and combat the poor sleep quality consequences. Only by doing the abovementioned, alleviation of the undesirable outcomes of irregular sleep can be reached. Legislative measures should be taken in order to certify Sleep medicine and Dental sleep medicine as medical specialties in the Republic of Bulgaria.

BackgroundBiomaterials are defined as substances intended to replace a part of the body or its function in a secure, safe and economical way, while being physiologically and aesthetically acceptable. Biomaterials can be bioinert or regenerative. Biocompatibility refers to the ability of a material to elicit a specific biological response after administration in a living organism. Measuring the biocompatibility of materials used in dentistry is not an easily achievable task. Methods Scientific databases -PubMed, Scopus and Medline, as well as monographs, textbooks on the topic, websites were used to search for the data required. The following keywords were used: biomaterials, biocompatibility, dental medicine, medicine, toxicity. The aim of the following article is to summarize the main conclusions authors in the field have reached to when discussing biocompatibility and tolerance of material and products used in medicine and dental medicine. Results and discussionIn depth results and discussion are presented in the section. Materials used in medicine and dental medicine encompass a wide range of compounds, with different chemical and physical structures. Therefore, profound knowledge is needed to be able to treat the patients and keep them safe as much as possible from possible adverse biological reactions. ConclusionsMedical and dental specialists should pay special attention to the content of the materials they implement in their treatment plans on a daily basis. Being profoundly informed on the general diseases, medications usage and allergic status of their patients can prevent adverse complications. Although medicine explores and studies in depth possible biological reactions, still they may occur.