Introduction: After debonding, white spot may appear on the area below the bracket, which is the early clinical sign of carious lesion. There is increased caries risk underneath and adjacent to orthodontic bands and brackets, which call for maximum use of caries preventive procedures using various fluoride application methods. Objective: The aim of the study was to evaluate alterations in the mechanical properties (modulus of elasticity and yield strength) in loading and unloading phases for different orthodontic archwires (nickel-titanium [NiTi] and copper-nickel-titanium [CuNiTi]) when exposed routinely to fluoride prophylactic agents for a predetermined period of time. Methods: Preformed rectangular NiTi and CuNiTi wires were immersed in fluoride solution and artificial saliva (control) for 90 minutes at 37ºC. After immersion, specimens were tested using a 3-point bend test on a universal testing machine. Results: There is a significant reduction in the unloading yield strength when the NiTi and CuNiTi wires were exposed to APF gel. Conclusion: The result suggests that use of topical fluoride agents affect the mechanical properties of the wires, leading to increase in treatment duration. Fluoride prophylactic agents must be used with caution in patients undergoing orthodontic treatment. Injudicious use of these agents may cause corrosive effects on the orthodontic wire surfaces, with alteration in their mechanical properties.

BACKGROUND Since the World Health Organization declared coronavirus disease 2019 (Covid-19) a pandemic, it has become a major challenge to public health all around the world. The situation is physically as well as mentally challenging for dental practitioners, teaching faculty, and dental students. We wanted to determine the stress among dental students due to the lockdown. This will aid us in determining the amendments to be made to help students manage the stress in such a critical situation the world is facing. METHODS This is a cross-sectional quantitative study done using a voluntarily filled online questionnaire. The survey was conducted on undergraduate dental students of School of Dental Sciences, Karad. Third and final year students were included in the study as they are more into clinical practice. Out of 163 students, 118 students responded to the questionnaire. RESULTS 93 % of the total respondents reported that the period of lockdown will have an impact on the mental wellbeing of the students. Stress due to loss of academic year, patients missing appointments, dentist’s being at high risk was found to be 97 %, 75 %, 89.8 % respectively. CONCLUSIONS A significant number of dental students had disturbed mental wellbeing during the period of lockdown. Supporting the mental health of all health care workers must be a critical part of the public health response, and special efforts should be directed to vulnerable sectors. KEY WORDS Mental Status, Students, Covid-19, Epidemic

Background: WHO declared COVID-19 as a worldwide pandemic, As a measure to control the spread of the disease, national emergencies and lockdowns have been declared in many countries. Dental appointments were suspended considering risk of transmission sand orthodontic patients have been stranded with only emergency services been provided to them, unlike the scheduled appointments. This can affect the total duration of the treatment and can affect the mental attitude and tend to increase the apprehensive behaviour amongst patients undergoing orthodontic treatment. Aim: The aim of this study is to assess the impact and attitude of COVID-19 lockdown among patients undergoing active orthodontic treatment. Materials and Methods : A self-designed questionnaire consisting of 10 questions, was widely circulated among the orthodontic patients using communication media such as Whatsapp, messaging apps and via mails. Only 208 subjects returned the questionnaire that constituted the final study sample. Participation in the study was voluntary and identification information was not collected from the study subjects. Results: The study revealed that the majority of female patients were apprehensive, stressed and anxious owing to increased treatment duration, discomfort during the lockdown period, financial worries and treatment outcomes due to their missed follow-ups during the period of lockdown. The overall future outlook post lockdown showed anxiety amongst orthodontic patients. Conclusion: Proper communication with patients is a must to reassure their concerns over treatment like concerns, anxiety, fear and disturbed mental well-being.