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BACKGROUND: SARS-CoV-2 (COVID-19) is considered a highly infectious and life threatening disease. OBJECTIVE: The present paper aims to evaluate various aspects of preventive measures and clinical management of the scheduled visits for orthodontic patients to the dental clinics during the outbreak of COVID-19, and to assess how orthodontists dealt with this challenge. METHODS: Orthodontists in private and public clinics were invited to fill a questionnaire that addressed infection control protocols and concerns about clinical management of patients in the clinics during the pandemic. Frequncies and percentages of the responses were obtained and compared using Chi-square tests. RESULTS: About 77% of those working in private clinics, and 63% of those working in private and governmental clinics performed room disinfection following each patient. In case of patients needing urgent management and have active infection, 56% of the participants provided care under high infection control measures; on the contrary, 64% provided symptomatic intervention including orthodontic wax, analgesics and sometimes mouthwash. CONCLUSION: The COVID-19 pandemic has had a negative impact on the orthodontic treatments. All pre-cautionary measures have to be made available in the clinic in order to minimize the spread of viral infection with continuous dental health care training.

Objectives. The present study was intended to investigate the effect of different concentrations of chitosan nanoparticles mixed with an orthodontic primer on the shear bond strength and bond failure of stainless steel brackets bonded to dental enamel. Methods. Four concentrations of chitosan nanoparticles (0%, 1%, 5%, and 10%) were prepared and mixed with Transbond™ XT primer. Forty-eight extracted maxillary first premolars were bonded under a standardized procedure with stainless steel orthodontic brackets utilizing those different concentrations (12 teeth per each group). After the bonding procedure, the specimens were stored in deionized water (37°C for 24 hr) and then thermocycling 5,000 times before shear bond testing, which was performed using a universal testing device. Bond failure sites were examined under a stereomicroscope. Scanning electron microscopy and X-ray diffraction were also performed to verify and evaluate the phase of the nanopowder. Results. The data were statistically analyzed using one-way analysis of variance) and Kruskal–Wallis H tests, and the findings revealed statistically nonsignificant group differences regarding the shear bond strength and adhesive remnant index ( p > 0.05 ). Conclusions. Primers containing varying concentrations of chitosan nanoparticles demonstrated acceptable shear bonding strength and adhesive remnant index.

Aim:The current study was aimed to determine the relationship between the orthodontic force applied by monobloc and the salivary level of alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) enzymes, considering the time factor after insertion of the appliance and whether there is a correlation between these enzymes. Materials and methods:A sample of 28 growing patients requiring orthodontic treatment with myofunctional appliance (Monoblock) was taken for the current study with an age range 9 to 12 years,all patients had Angle's class II division 1 malocclusion with no or mild crowding, the sample was selected using simple random sampling. Only 16 subjects (10 males and 6 females) were included who follow certain inclusion criteria. Unstimulated saliva was collected from the patients before monoblock insertion, then 1 hour after insertion, followed by 14 days and 28 days. Salivary levels of ALP and LDH were measured using a spectrophotometer and compared with the base line. Results:The results revealed that ALP and LDH levels increased with increasing time after monoblock insertion, and there was the statistically insignificant difference after 1-hour post-insertion for ALP enzyme level, but highly significant after 14 and 28 days. While for LDH level,there was the statistically significant difference after 1-hour post-insertion, but highly significant difference after 14 and 28 days post-insertion. In this regard to the relation between salivary ALP and LDH enzymes levels at different time intervals, showed that there were no significant correlations between the enzymes using Pearson's correlation test. Conclusion:The ALP and LDH salivary enzymes activity is affected by mechanical forces generated by monobloc activator and these enzymes activities can also be increased during the rapid growth phase of childhood such as late infancy and early puberty where the age of subjects was selected in the current study. Clinical significance:The determination of ALP and LDH salivary enzymes activities during the skeletal maturity is crucial for the success of myofunctional monobloc treatment; therefore, saliva can be used as a noninvasive diagnostic tool for determination of chemical biomarkers for detection of bone remodeling process during myofunctional monoblock treatment