Perceived sources of stress in fifth year dental students--a comparative study.

INTRODUCTION: The term "stress" refers to the effect of certain external factors (physical or mental) on the individual's physical and psychological health. Stress is very high in dental medicine. It may well be generated by the process of training in dentistry. During their training dental students express high levels of stress and considerable stress-related symptoms such as physical problems, depression, obsessive-compulsive and personality disorders. The perceived stress can be dependent on socio-cultural factors. The type of personality, gender, emotional intelligence and other individual characteristics may also influence the stress effects. AIM: To determine the main sources of stress in students during their dental training and compare the level of stress fifth-year dental students experience in the Faculty of Dental Medicine, Plovdiv, Bulgaria and the Faculty of Dentistry in Montpellier, France. METHODS: We recruited in the study fifth-year students from the Faculty of Dental Medicine in Plovdiv, Bulgaria and the Faculty of Dentistry in Montpellier, France. The modified Dental Environment Stress (DES) questionnaire was used to assess the effect of the various stressors. The questionnaire survey was conducted between February and March 2008. RESULTS: The living arrangements domain indicates higher levels of stress in Bulgarian students compared to their French counterparts with significant statistical difference for all factors. In personal factors the highest levels of stress were found with respect to the reduced holidays during school year and financial problems. Exams were the highest stressor in academic work domain and for the survey as a whole. In educational environment factors the stressors with the highest significance were the interactions with patients, academic environment (for French students) and risk of cross transmitted infections (for Bulgarian students). The high stress during clinical work is related to completing the assigned clinical workload quota and the shortage of time for clinical work. CONCLUSIONS: The students from both faculties report the highest mean levels of stress are related to examinations and clinical factors. Bulgarian students experienced higher mean levels of stress compared to their French colleges. The differences in mean stress levels are associated with socio-cultural factors and variations in educational curriculums at both dental faculties.

Calcium-strontium mixed phosphate as novel injectable and radio-opaque hydraulic cement.

Sterile calcium hydrogenophosphate dihydrate (DCPD) (CaHPO(4).2H(2)O), calcium oxide and strontium carbonate powders were mixed in various liquid phases. Among these, ammonium phosphate buffer (0.75 M, pH 6.9) led to a novel strontium-containing calcium phosphate cement. At a 6/2.5/1.5 M ratio and for a liquid to powder ratio (L/P) of 0.5 mlg(-1), the initial paste was fluid and remained injectable for 12 min at 25 degrees C. It was easily obtained by mixing sterile powders and the liquid phase using the push-pull technique, avoiding complex mixing apparatus. The cement set after 15 min at 37 degrees C and was hard after 1h. The compressive strength was in the 20 MPa range, a value higher than that generally assigned to trabecular bone (5-15MPa). This strength appeared sufficient for repairing non-loading sites or reinforcing osteoporotic vertebrae (vertebroplasty). After setting, the initial mixture formed a strontium-calcium-deficient carbonate apatite. The radio-opacity of the resulting cement was three times greater than that of cortical bone because of the presence of strontium ions, a feature that complies with the requirements for vertebroplasty. Furthermore, the cement powder remained stable and retained its properties for at least 4 years.