RESUMO
Objective: The objective of this research is to determine whether the thermoplastic polyurethane (TPU) coated with carboxymethylcellulose chitosan has better mechanical and antibacterial action (anti-Streptococcus mutans) when utilized in intraoral simulations with synthetic saliva. Materials and Methods: The TPU sheets (n = 45) were divided into three groups. Control (n = 15) consists of as-received TPU sheets. Test 1 consists of TPU sheets coated with carboxymethyl cellulose (CMC) chitosan (CHI) (n = 15). Test 2 consists of thermoformed nano-coated TPU (n = 15). For the polyurethane sheets, CHI-CMC sheets, and thermoformed CHI-CMC sheets, scanning electron microscopy (SEM) and three-point flexural tests were conducted and assessed. The materials testing software was used to calculate the elastic modulus and tensile strength. To study the bacterial accumulation, the cut circles of the TPU aligner were placed in centrifuge tubes with 2.5 mL of bacterial suspension at a concentration of 104 or 105 CFU/mL. SEM was done to assess the presence of cell growth in all three groups. Results: According to SEM analyses of bacterial buildup, the coated TPU had minimal biofilms compared to the bare TPUs numerous biofilms. The effect of aging on coating thickness reveals that the thickness of thermoformed coated TPU films dramatically decreased over time, while the thickness of coated TPU films was maintained. When TPU is coated with CMC/CHI, the elastic modulus and tensile strength were observed to improve. Conclusion: The development of a super-hydrophilic coating by the CHI CMC coating on TPU sheets improved the coating's biocompatibility while also changing the shape of the multilayer film to prevent bacterial adhesion. The effect on the improvement in the mechanical properties diminished after the material underwent a thermoforming process. It is therefore suggested that the nanofilm be used in therapeutic applications following the thermoforming process.
RESUMO
AIM: The objective of this study was to determine the problem encountered by an orthodontist due to suspended treatment during and after lockdown COVID 19 and to assess the pandemic impact on orthodontic practices. MATERIALS AND METHODS: This was a cross-sectional web-based questionnaire survey conducted among orthodontist in India. The pilot study was conducted to estimate the sample size and final sample size is 263 participants. The predesigned and validated, self-administered, structured 10 questions related to the impact of an orthodontist and their orthodontic practices during and after COVID 19 are used. The statistical analysis was done using Statistical Package for Social Sciences SPSS (V 22.0) the frequency distribution was computed. RESULTS: The result showed that 81% orthodontist were reported that routine orthodontic treatment was disturbed due to this COVID 19 lockdown, about 79.1% reported hospital/clinic was closed due to lockdown with a duration of more than 1 month. Still, 64.6% orthodontist handling their orthodontic emergencies through telecommunication and 47.9% of orthodontist received a complaint about fixed appliance among all other appliances. Due to the current situation, 41.4% orthodontist suggested 3-6 months' period required to normalize the current situation and 66.9% agreed that there will be decline in orthodontic treatment need after COVID 19. CONCLUSION: Owing to the high virulence activity, elective procedures have been postponed and can manage a patient through virtual teleconsultation. Reassurance of the patient is needed regarding prolonged treatment duration due to this COVID 19 pandemic.
