COVID-19 vaccine effectiveness among healthcare workers: a hospital-based cohort study.

OBJECTIVES: Healthcare workers (HCWs) were the first to be prioritised for COVID-19 vaccination. This study aims to estimate the COVID-19 vaccine effectiveness (VE) against SARS-CoV-2 symptomatic infection among HCWs in Portuguese hospitals. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: We analysed data from HCWs (all professional categories) from three central hospitals: one in the Lisbon and Tagus Valley region and two in the central region of mainland Portugal, between December 2020 and March 2022. VE against symptomatic SARS-CoV-2 infection was estimated as one minus the confounder adjusted HRs by Cox models considering age group, sex, self-reported chronic disease and occupational exposure to patients diagnosed with COVID-19 as adjustment variables. RESULTS: During the 15 months of follow-up, the 3034 HCWs contributed a total of 3054 person-years at risk, and 581 SARS-CoV-2 events occurred. Most participants were already vaccinated with a booster dose (n=2653, 87%), some are vaccinated with only the primary scheme (n=369, 12.6%) and a few remained unvaccinated (n=12, 0.4%) at the end of the study period. VE against symptomatic infection was 63.6% (95% CI 22.6% to 82.9%) for HCWs vaccinated with two doses and 55.9% (95% CI -1.3% to 80.8%) for HCWs vaccinated with one booster dose. Point estimate VE was higher for individuals with two doses taken between 14 days and 98 days (VE=71.9%; 95% CI 32.3% to 88.3%). CONCLUSION: This cohort study found a high COVID-19 VE against symptomatic SARS-CoV-2 infection in Portuguese HCWs after vaccination with one booster dose, even after Omicron variant occurrence. The small sample size, the high vaccine coverage, the very low number of unvaccinated individuals and the few events observed during the study period contributed to the low precision of the estimates.

Prevalence of Dentinal Defects after Root Canal Preparations in Molars with Reciproc and WaveOne Systems

Objective: To evaluate the prevalence of dentin defects, including partial and complete cracks and fractures, after root canal preparation in molars with Reciproc and WaveOne reciprocating instruments. Material and Methods: Fifty mandibular first and second molars with mature apices were selected to endodontic in vitro instrumentation. Ten teeth were unprepared and served as the control, and the remaining forty teeth were divided into two groups, being twenty corresponding to each reciprocating system. Reciproc and WaveOne systems were used in a reciprocating working motion, under the same conditions, to prepare the two mesial canals. Roots were then sectioned 2, 4 and 6 mm from the apex, and the cut surface was observed under a microscope using 20-fold magnification and checked for the presence of fractures and incomplete cracks. Results: none of the evaluated groups presented fractures, and the control group showed no incomplete cracks. Overall evaluation showed statistical differences between these two groups and the control group (p=0.017) for the prevalence of incomplete cracks, but no significant differences were obtained between Reciproc and WaveOne groups (p>0.05). Reciproc group presented more incomplete cracks on 4-mm sections compared with the control group on the same section (p=0.0326). Conclusion: Root canal preparation with both reciprocating instruments resulted in incomplete cracks, but not fractures. At the level of 4 mm from the apex of the canals, the Reciproc system produced significantly more incomplete cracks. Considering both systems, WaveOne utilization resulted in lesser structural alterations on dentin considering the middle portion of the roots.

Influência do Polimento Superficial na Retenção de Placa Bacteriana em Restaurações Estéticas / Influence of Superficial Polishing on Bacterial Plaque Retention in Aesthetic Restorations

Objetivo: Objetivou-se avaliar a influência do procedimentode acabamento e polimento superficial na retenção de placabacteriana em restaurações de resina composta. Material eMétodos: Participaram 20 pacientes, que apresentaram 40superfícies restauradas em várias classificações decavidades, limites cervicais e tipos de dentes. O acabamentoe polimento foi realizado com discos de lixa (TDV), pontassiliconadas (Optmize - TDV) e tiras de lixa (Tiras de LixaTM -3M); na verificação da retenção de placa utilizou-se o Índicede Retenção e Extensão de Placa em Restaurações – IRPR,aplicado antes do polimento e após 7 e 14 dias. Resultados:Os resultados revelaram que antes do polimento a maioriadas superfícies apresentou retenção de placa nos níveismais elevados do IRPR, já após o polimento, houve reduçãoe até ausência de retenção de placa, evidenciada pelos grausmais baixos do IRPR. Conclusão: Concluiu-se que o osmateriais de polimento e a técnica utilizada foram eficazesna diminuição da retenção de placa bacteriana sobre assuperfícies restauradas e que o IRPR se mostrou um métodoeficaz em demonstrar a retenção de placa em restauraçõesestéticas.

Objective: The aim of this study was to evaluate the influenceof superficial finishing and polishing procedures on bacterialplaque retention of composite resin restorations. Materialand Methods: Twenty patients participated in the studypresenting forty restored surfaces in various classificationsof cavities, cervical edges and types of teeth. The finishingand polishing procedures were performed with polishingdiscs (TDV), silicone points (Optimize – TDV) and stripspolishing (3M). To verify plaque retention was used IndexRetention and Extension Plaque in Restoration – IRPR, appliedbefore polishing and after 7 and 14 days. Results: The resultsshowed that, before polishing, most of surfaces presentedplaque retention on highest levels of IRPR, and after polishingthere was reduction and also absence of plaque retention,demonstrated by the lowest levels of IRPR. Conclusion: Itwas concluded that the polishing materials and the techniqueused were effective in reducing bacterial plaque retentionover restored surfaces, and that IRPR is an efficient methodto demonstrate the plaque retention on esthetic restoration.

Influência da Presença do Cálcio em Agentes Clareadores e sua Relação com a Microdureza do Esmalte Dental Humano / Influence of the Presence of Calcium in Bleaching Agents and their Relation to the Microhardness of Human Enamel

Este trabalho analisou a microdureza do esmalteexposto ao agente clareador peróxido de hidrogênio a 35%,contendo ou não cálcio em sua composição, a fim de verificarse a adição deste elemento influencia na alteração damicrodureza. Material e Métodos: A amostra foi constituídapor dez terceiros molares humanos hígidos, dos quais seobteve três fragmentos, de modo que cada fragmento obtidode um mesmo dente fizesse parte de um grupo diferente. Ogrupo B foi composto por dez corpos de prova, clareadoscom peróxido de hidrogênio a 35% contendo cálcio; o grupoM, composto por dez corpos de prova, clareados comperóxido de hidrogênio a 35% sem cálcio e o grupo C(controle), composto por dez corpos de prova imersos emsaliva artificial. A microdureza foi avaliada antes doclareamento e após três sessões, com intervalo de sete diasentre elas. Resultados: No Grupo B houve um aumento de5,47% na microdureza, considerada significativa, atribuída àpresença do cálcio no clareador. O Grupo M apresentou umaredução de 2,59% e o grupo C de 0,64%, não sendoconsideradas significantes. Conclusão: Concluiu-se que apresença do cálcio no gel clareador aumenta a microdurezado esmalte clareado, proporcionando uma remineralizaçãodeste substrato...

This study examined the microhardness of toothenamel exposed to the bleaching agent hydrogen peroxide35%, with or without calcium in its composition in order toascertain whether the addition of this substance influencesthe change in microhardness. Material and methods: Thesamples were composed of ten intact human third molars, ofwhich three fragments were obtained, so that each fragmentfrom the same tooth was part of a different group. Group Bconsisted of ten samples, bleached with hydrogen peroxide35% containing calcium. Group M consisted of ten samples,bleached with hydrogen peroxide at 35% without calcium,and group C (control) consisted of ten samples immersed inartificial saliva. The microhardness was evaluated beforethe treatment and after three sessions with an interval ofseven days between them. Results: In Group B there wasan increase of 5.47% in microhardness, consideredsignificant, assigned to the presence of calcium in thebleaching agent. There was a reduction of 2.59% and 0.64%in groups M and C respectively, both considered nonsignificant.Conclusion: It was concluded that the presenceof calcium in the whitening gel increases the microhardnessof the bleached enamel, providing a remineralization of thissubstrate...

Solução estética através da interação do clareamento endógeno e restauração em resina composta / Aesthetic solution through the interaction of endogenous bleachingand composite resin restoration

Os autores relatam um caso de clareamento não vital associado à restauração em resina composta para o restabelecimento estético. Paciente do sexo feminino, 31 anos, sofreu trauma aos 15 anos e relatava escurecimento do elemento 11 desde os 20 anos. O referido elemento apresentava coloração C4 e os elementos 11 e 21 sofreram perda de esmalte na borda incisal devido ao trauma já relatado que provocou a necrose do elemento 11, levando-o a um tratamento endodôntico quando a mesma tinha 28 anos. Realizou-se o clareamento não vital do elemento 11 utilizando uma associação da técnica mediata e imediata, onde se fez três aplicações do curativo de demora (técnica mediata) e duas aplicações em consultório do agente clareador (técnica imediata). Após a neutralização realizou-se a restauração definitiva da câmara pulpar e partiu-se para a restauração estética dos elementos 11 e 21. Com a finalização do caso obteve-se um excelente resultado estético através de um procedimento conservador que além de melhorar a alteração cromática, repôs o tecido dental perdido no trauma.

The authors report a case of non-vital bleaching associated with a composite resin restoration for the aesthetic reestablishment. Female patient, 31 years, suffered trauma with 15 years old and reported darkening of the element 11 when she was 20. In that element was verified color C4 and elements 11 and 21 suffered loss of enamel on the incisal edge due to the trauma which has been reported by causing necrosis of element 11, leading him to a root canal treatment when the patient was 28. It was done a non-vital bleaching at the element 11 using a combination of mediate and immediate technique, where was made three applications of the temporary endodontic dressing (mediate technique) and two applications of whitening agent (immediate technique). After neutralization, the final restoration of the pulp chamber and the esthetic restoration of the elements 11 and 21 were made. With the conclusion of the case it was obtained an excellent cosmetic result with a conservative procedure the improved chromatic changes and replaced the dental tissue lost to trauma.