Comparative Evaluation of Penetration Ability of Three Pit and Fissure Sealants and Their Relationship with Fissure Patterns

Statement of the Problem: Pit and fissure sealant placement is considered as an effective modality for prevention of caries on occlusal surfaces. Penetration, retention and lateral wall adaptation are the key factors in success of pit and fissure sealant restorations. Purpose: The purpose of this paper was to compare penetration ability and lateral wall adaptation of three commercially available pit and fissure sealants. Materials and Method: The present in-vitro study was done on 45 extracted sound human molars to evaluate the fissure pattern and assess the penetration ability of three commercially available sealants [Delton® FS Sealant (Dentsply DeTrey GmbH, Konstanz, Germany), Clinpro™ Sealant (3M™ ESPE™, Minnesota, USA) and GC Fuji VII Glass Ionomer Cement (GC Asia Dental Pte Ltd, Singapore)] on molars divided into 3 equal groups of 15 each, with further sectioning of each sample into 2 parts giving 30 samples per group. Following thermocycling and embedding of teeth in clear auto-polymerizing acrylic resin, sections were evaluated for fissure morphology, sealant penetration, unfilled space, lateral wall adaptation, and for presence of voids. Results: Penetrability of all the sealants studied was found to be significantly more in U-type fissure pattern (93.89%) followed by V-type (78.62%), IK-type (74.34%) and then in I-type (65.91). The depth of penetration of the GC Fuji VII Glass Ionomer sealant (85.82%) was found to be superior followed by unfilled resin sealant (Clinpro™ Sealant- 78.26%) and then by filled resin sealant (Delton® FS Sealant- 74.89%). Conclusion: U- type fissure pattern was more common than other fissure patterns and showed significantly higher penetrability of different type of sealants evaluated in the present study. GIC based sealant, due to significantly higher penetration depth than unfilled and filled sealants used in the present study, can be preferred over filled or unfilled resin sealants

Surface plasmons on ordered and bi-continuous spongy nanoporous gold

The dispersion relation and propagation of surface plasmons polaritons (SPPs) on nanoporous gold films is experimentally investigated and an increasing red shift of the SPPs is observed with rising porosity. This is caused by a less negative effective dielectric constant of the nanoporous metal films and is predicted by classical Bruggeman or specific two dimensional Maxwell-Garnett effective medium models. The dispersion relation data is supported with leakage radiation microscopy enabling the determination of the propagation length and losses of surface plasmons on these nanoporous films. These results demonstrate how the control of the nanoporosity of metal layers leads to designer plasmons in the visible and near infrared allowing the tuning of the SPP dispersion to match the requirements of certain applications

Occlusal characteristics and prevalence of associated dental anomalies in the primary dentition

Introduction: Morphological variations in primary dentition are of great concern to a pediatric dentist as it may pose clinical problems like dental caries, delayed exfoliation and also anomalies in the permanent dentition, such as impaction of successors, supernumerary teeth, permanent double teeth or aplasia of teeth. The present study was conducted to investigate the presence of dental anomalies in the primary dentition of 1000 schoolchildren in the 3–5 year-old age group in Faridabad. Materials and methods: One-thousand schoolchildren were examined using Type III examination (WHO, 1997) for primary molar relationship, occlusal characteristics, primate spaces, physiological spaces and other anomalies of teeth, including number and morphology. Results and conclusions: The prevalence of physiological spaces in maxillary and mandibular arches was 50.9% and 46.7%, respectively, whereas primate spaces were found in 61.7% of the children in the maxillary arch and 27.9% in the mandibular arch. The prevalence of unilateral anterior and posterior cross-bite was 0.1% and 0.8%, respectively, in the present study. The prevalence of hypodontia in the primary dentition was found to be 0.4% and the prevalence of fusion and gemination in the present study was 0.5%. Double teeth (fusion and gemination) and hypodontia were the most common dental anomalies found in the primary dentition in the present study

A randomized controlled clinical trial to evaluate and compare three chairside techniques of veneering stainless steel crowns

Background: With the increasing patient demands of esthetics in paediatric dentistry, pre-veneered stainless steel crowns (SSCs) have been made available commercially. However, they suffer from technique sensitivity, limited ability to crimp and associated higher costs. Aim: The present study was planned to clinically evaluate and compare the success of preformed SSCs in which esthetic modification was done using three different techniques of composite veneering. Materials and Methods: A total of 60 primary molars selected from patients between the age group of 4–9 years were randomly divided into three groups having 20 samples each: Group A (composite veneering done using the open face technique), Group B (composite veneering done after sand-blasting SSCs), and Group C (composite veneering done after preparing retentive grooves on SSCs). The patients were evaluated at 1, 3, 6, and 9 months as per evaluation criteria. Statistical Analysis: Kruskal–Wallis and ANOVA were used to compare means among three groups at different time intervals. Results: All 60 SSCs were retained at the end of the study, thereby demonstrating 100% success of SSCs. Open window technique of veneering significantly showed maximum retention of composite veneers; therefore, highest level of parental satisfaction. Overall, the most common fracture was of adhesive type seen at the metal composite interface. Conclusions: All the three techniques used provide a chairside and easy method for esthetic modification of the SSCs. The open window is the most successful of the three methods of veneering and may be clinically useful technique for dental practitioners and pediatric dentists

A Synergic Approach of Deep Learning towards Digital Additive Manufacturing: A Review

Deep learning and additive manufacturing have progressed together in the previous couple of decades. Despite being one of the most promising technologies, they have several flaws that a collaborative effort may address. However, digital manufacturing has established itself in the current industrial revolution and it has slowed down quality control and inspection due to the different defects linked with it. Industry 4.0, the most recent industrial revolution, emphasizes the integration of intelligent production systems and current information technologies. As a result, deep learning has received a lot of attention and has been shown to be quite effective at understanding image data. This review aims to provide a cutting-edge deep learning application of the AM approach and application. This article also addresses the current issues of data privacy and security and potential solutions to provide a more significant dimension to future studies

Human genetic factors associated with pneumonia risk, a cue for COVID-19 susceptibility

: Pneumonia, an acute respiratory tract infection, is one of the major causes of mortality worldwide. Depending on the site of acquisition, pneumonia can be community acquired pneumonia (CAP) or nosocomial pneumonia (NP). The risk of pneumonia, is partially driven by host genetics. CYP1A1 is a widely studied pulmonary CYP family gene primarily expressed in peripheral airway epithelium. The CYP1A1 genetic variants, included in this study, alter the gene activity and are known to contribute in lung inflammation, which may cause pneumonia pathogenesis. In this study, we performed a meta-analysis to establish the possible contribution of CYP1A1 gene, and its three variants (rs2606345, rs1048943 and rs4646903) towards the genetic etiology of pneumonia risk. Using PRISMA guidelines, we systematically reviewed and meta-analysed case-control studies, evaluating risk of pneumonia in patients carrying the risk alleles of CYP1A1 variants. Heterogeneity across the studies was evaluated using I2 statistics. Based on heterogeneity, a random-effect (using maximum likelihood) or fixed-effect (using inverse variance) model was applied to estimate the effect size. Pooled odds ratio (OR) was calculated to estimate the overall effect of the risk allele association with pneumonia susceptibility. Egger's regression test and funnel plot were used to assess publication bias. Subgroup analysis was performed based on pneumonia type (CAP and NP), population, as well as age group. A total of ten articles were identified as eligible studies, which included 3049 cases and 2249 healthy controls. The meta-analysis findings revealed CYP1A1 variants, rs2606345 [T vs G; OR = 1.12 (0.75-1.50); p = 0.02; I2 = 84.89%], and rs1048943 [G vs T; OR = 1.19 (0.76-1.61); p = 0.02; I2 = 0.00%] as risk markers whereas rs4646903 showed no statistical significance for susceptibility to pneumonia. On subgroup analysis, both the genetic variants showed significant association with CAP but not with NP. We additionally performed a spatial analysis to identify the key factors possibly explaining the variability across countries in the prevalence of the coronavirus disease 2019 (COVID-19), a viral pneumonia. We observed a significant association between the risk allele of rs2606345 and rs1048943, with a higher COVID-19 prevalence worldwide, providing us important links in understanding the variability in COVID-19 prevalence