Background: The pandemic caused by novel coronavirus (SARS-CoV-2) in Wuhan, China, in December 2019 is a highly infectious disease. The World Health Organization (WHO) has declared the outbreak of Corona Virus Diseases (COVID 19) as a global public health emergency. Currently, research on novel coronaviruses is still in the primary stage. Aims and Objective: The aim of this study is to assess knowledge and awareness on the usage of mouth masks among dental fraternity during this pandemic COVID-19. Materials and Methods: A total of 507 dentists from the Andhra Pradesh (India) region completed a questionnaire-based survey on knowledge, awareness, and infection control measures, such as usage of mouth masks during the pandemic COVID -19. The questionnaire was tailored from the guidance and the information provided for healthcare workers issued by the US Centres for Disease Control and Prevention (CDC). A suitable sampling method was used for the collection of data, and the distribution of responses was presented as percentages. Explanatory statistics were performed for all groups based on the percentage of correct responses. Results: A total of 530 participated in the survey, out of which 507 dentists completely answered the survey, and the response rate was 95.6%. Among the respondents, general practitioners and postgraduates accounted for 58.8% and 41.2%, respectively. There was a statistically significant difference for all the questions solicited among the respondents. General or private practitioners seem to be more aware than postgraduates, as they have answered correctly (>65%) for almost all the questions. Conclusion: The inputs from the study help us to throw some light and fill up space where required. There is a specific and strong need to implement periodic educational programmes and training sessions on infection control practices for COVID-19 among dentists in particular.

BackgroundTo obtain prolonged clinical success with composite restorations, better bonding of resin to the tooth substrate is crucial. AimThe study was aimed to evaluate the microtensile bond strength (µTBS) of bulk-fill composite resin restorations when bonded to a cavity previously restored with amalgam, comparing with that of freshly prepared dentin. Materials and methodMesio-occlusal cavity preparations were done on 80 extracted human mandibular molars with a buccolingual width of 4 mm and a 1.5 mm axial depth by placing the gingival seat 0.5 mm coronal to the cementoenamel junction (CEJ) and were restored with fine-grain amalgam alloy. After thermocycling, the amalgam restorations were removed. Disto-occlusal cavities with similar dimensions of mesial cavities were prepared, and both the proximal surfaces were filled with bulk-fill composite using either etch-and-rinse or self-etch adhesives. Following thermomechanical cyclic loading, all the teeth were sectioned for µTBS testing. Bond strength data expressed in megapascals (MPa) were subjected to statistical analyses using analysis of variance (ANOVA) and Tukey's multiple post-hoc tests.

Introduction: Polymerisation shrinkage stresses developed during curing of adhesive resin cements may cause debonding at the margins of cavity leading to microgap formation with secondary caries and consequently restorative failure. Thus, a restoration should have good marginal integrity and wear resistance to obtain high success with clinical longevity. Aim: To compare the influence of thermo-mechanical stresses on marginal quality and wear of class II Mesio-Occluso-Distal (MOD) restorations filled with Solare Sculpt or Cention N. Materials and Methods: An in vitro study was conducted at GITAM Dental College and Hospital, Visakhapatnam on 80 human extracted mandibular molars by preparing mesio-occlusal-distal class two cavities that restored either with Solare Sculpt or Cention N resin composites. Baseline evaluations were recorded for marginal gaps (in μm) through Scanning Electron Microscope (SEM), and the weights of the samples were recorded by an electronic balancing instrument to measure the amount of wear (in grams). Following thermo-mechanical cyclic loading, all the restored teeth were evaluated again to record the same parameters. The statistical analysis was done using Statistical Package for the Social Sciences (SPSS) programme for windows version 22.0 (IBM, NY) software. An independent t-test for intergroup comparison and a dependent t-test for intragroup comparisons were done to analyse the tested parameters with the significance level established at (p≤0.05). Results: In intergroup comparison, no difference in marginal adaptation was observed before thermo-mechanical loading between two materials with a p-value of 0.3625, but after therm-omechanical loading Cention N exhibited significantly superior marginal adaptation with a p-value of 0.0374. Both the materials have shown a significant difference in the marginal adaptation after thermo-mechanical loading in the intragroup comparison with Cention N (0.0002) and Solare sculpt (0.0001) p-values. The wear rate was not different statistically between the materials with a p-value of 0.7144 before thermo-mechanical loading and 0.2285 after thermo-mechanical loading. Conclusion: Marginal adaptation of Cention N was superior to Solare Sculpt, whereas both the materials exhibited a similar wear rate.