Effect of antioxidant on orthodontic bracket bond strength after vital bleaching

The objective of this study is to compare the neutralization effect of various antioxidant agents on the bond strength of composite resins on stainless steel and ceramic brackets immediately bonded to previously bleached teeth. Materials and Methods: One hundred and sixty human maxillary premolars were used for the study. Teeth were divided into four groups (n = 40): Group 1 (control), Group 2 (bleached), Group 3 (sodium ascorbate), and Group 4 (tocopherol acetate). Each group was divided into two subgroups, one was bonded with stainless steel and other with ceramic brackets using 3M Transbond XT. Universal testing machine was used to determine the shear bond strength (SBS). Results: Among the metal brackets, Group 1A had the highest SBS (12.18 + 1.41 MPa) and Group 2A had the least SBS (6.18 + 1.49 MPa). Weibull analysis indicated that bond strength for a 90% probability of failure was highest for Group 1A (13.99 MPa) and lowest for Group 2A (8.49 MPa). For ceramic brackets, Group 1B had the highest SBS (13.80 + 1.69 MPa) and Group 2B had the least SBS (8.05 + 1.85 MPa). Weibull analysis indicated that bond strength for a 90% probability of failure was highest for Group 1B (14.61 MPa) and lowest for Group 2B (8.85MPa). Conclusion: The in vitro study showed that bleaching reduced the SBS significantly, and this could be effectively reversed by the application of antioxidants in both metal and ceramic brackets.

Ergonomic risk factors and their association with musculoskeletal disorders among Indian dentist: A preliminary study using Rapid Upper Limb Assessment.

Context: Ergonomics is the scientific study of people and their work. The manufacturers typically do not design to accommodate the dimensions of the individual user. Work‑related musculoskeletal disorders (MSDs) have emerged as major health problem among workers in both industrialized and industrially developing countries. Rapid Upper Limb Assessment (RULA) was developed to investigate the exposure of the individual workers to risk factors associated with work‑related upper limb disorders. Aims: The assessment of the posture using RULA, which is quick reliable tool to determine the posture, has not been done in the Indian dentist population, indicating the need for the same. Settings and Design: A total of 104 subjects were included from New Delhi/NCR. Subjects and Methods: The procedure was explained, and the questionnaire was distributed and assessment was done using RULA. The MSDs can be recorded using the standard Nordic questionnaire. Statistical Analysis Used: The data were collected from 104 subjects out of the 192 evaluated and was statistically analyzed using SPSS software. Results: The study sample included 70 male and 34 female dentists. The posture of the subjects and the MSDs are not associated with a significant difference as according to Pearson’s Chi‑square test (0.231). Conclusions: RULA can be used as a screening tool for postural risks following a short training session regardless of the assessor’s experience in postural risk assessments.

Awareness among Indian dentist regarding the role of physical activity in prevention of work related musculoskeletal disorders.

Background: The prevalence of work-related musculoskeletal complaints in dentists is high and the past two decades have witnessed a sharp rise in the incidence of various disorders. The prevalence of musculoskeletal pain ranges between 64% and 93%. The most effected regions have been back and neck. Various studies have been done to record stress levels and health-related behaviors of dentists in other countries but limited data is available among the Indian dentists. Materials and Methods: Therefore a questionnaire survey was carried out among 102 Indian dentists belonging to different fields having at least one musculoskeletal disorder in last 6 months. Results: The total sample consists of 80 males and 22 females. Out of the 102 over 97 of dentists had sought medical advice for these disorders during the previous 06 months and 74 of them also consulted the physiotherapist for exercises and ergonomic advice. The number of sessions taken for regular physical exercises was minimum 6 till 44 the most. The percentage of improvement in symptoms varied between 20% and 80%. Conclusions: A significant direct correlation between the number of sessions taken for physical activity and the self-perceived improvement in the symptoms was found using the Pearson correlation test. The work-related musculoskeletal disorders among dentists not only decrease their efficiency but also is a major concern among them. Self-awareness and benefits of regular exercise is the need of the hour.