Resin infiltrates performed better in regaining the baseline microhardness and penetrating deep into the porous white spot lesions, when compared to colloidal silica infiltrates.

Context:The initial bond strength and potential durability of an adhesive restoration are significantly affected by regional variations in dentin composition.Aim:The aim of this study is to evaluate the influence of dentin location and thermomechanical cyclic loading on microtensile bond strength of bulk-fill composite resin to coronal dentin.Materials and Methods:Disto-occlusal cavity preparations were done on 60 extracted human mandibular molars with pulpal floor depth of 1.5 and 3.5 mm for superficial and deep dentin and 1.5 mm axial wall depth and are restored with bulk-fill restorative composite. Bond strength evaluation was done using universal testing machine, and mode of bond failure was observed under scanning electron microscope.Statistical Analysis:Statistical analyses were done using ANOVA and Tukey's multiple post hoc test. For comparison of failure mode, Mann–Whitney U-test was used.Results:Superficial dentin has shown higher bond strength compared to deep dentin and gingival wall dentin (P = 0.001). The bond strength values decreased with the thermomechanical cycling (P = 0.001). Deep dentin and gingival dentin have exhibited more of adhesive failures.Conclusion:Bond strength of bulk-fill composite was negatively influenced by the depth of dentin and thermomechanical loading.

BackgroundTo evaluate the incidence of dentinal microcracks formation after root canal shaping procedures with HyFlex EDM and Vortex Blue rotary systems comparing with that of hand instrumentation using micro-computed tomography.Material and MethodsMandibular first molar teeth (n=60) having 50 to 200mesial root curvature were scanned using high resolution micro-CT imaging before root canal preparation to identify the presence of dentinal defects. Post-instrumentation cross-sectional images were taken and increased number and type of root defects were assessed and recorded. The data was statistically analysed by using chi-square test and McNemar’s test at a significance level of 5%.ResultsHyFlex EDM has shown greater increase in post instrumentation dentinal defects. Both rotary systems exhibited increased dentinal defects formation at coronal, middle regions which is statistically significant (P=0.042) when compared to apical region.ConclusionsHyFlex EDM has shown greater increase in post instrumentation dentinal defects followed by Vortex Blue rotary system and hand instrumentation resulted minimal defects. Key words:Craze lines, dentinal microcracks, micro–computed tomography, nickel-titanium files, root canal preparation.

Pneumonia triggered by novel corona virus (SARS-CoV-2) in Wuhan, China, in December 2019 is an extremely contagious disease. The WHO has stated the outbreak of COVID-19 (corona virus) as a pandemic issue. Corona virus cases started increasing day by day in India, also from the time the first case was diagnosed on January 30, 2020. In this regard, there are so many colleges and universities across India which cancelled or rescheduled their academic activities such as conferences, workshops, and other academic and sports activities. Because the universities and colleges should protect and take care of their students and faculty in this regard. In this brief communication, I would like to give an idea on the potential impact of the dangerous COVID-19 outbreak on the education system and mental health of students and staff.

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.