Is immediate dentin sealing a mandatory or optional clinical step for indirect restorations?

OBJECTIVE: The use of immediate dentin sealing (IDS) following tooth preparation for indirect restorations is well-supported by laboratory studies. The inclusion of IDS as a mandatory clinical step, it must be firmly supported by evidence from randomized clinical trials (RCT). The objective of this study is to assess whether IDS should be added as a mandatory procedure in all indirect restorations, taking into consideration clinically significant outcomes for the patient, such as restoration longevity and hypersensitivity. MATERIALS AND METHODS: A bibliographic search was carried out in the PubMed. In addition, a manual search was conducted in the references of literature reviews. RESULTS: Data from four RCT were included. Two studies assessed preparations for full crowns, and two assessed preparations for partial restorations. Data from full crown preparations were subjected to a meta-analysis, revealing a reduction in hypersensitivity incidence in the IDS group 1 week after restoration cementation. With respect to hypersensitivity, IDS seems to offer advantages exclusively during the provisional phase and up to 1 week following the cementation of the final restoration. One study has shown no difference on longevity. CONCLUSION: The use of IDS should be considered as an elective clinical step during the rehabilitation with indirect restorations. CLINICAL SIGNIFICANCE: IDS is an elective clinical step that should be considered in patients and preparations with a higher risk of sensitivity between appointments.

Color variation of composite resins in relation to the Vita Classical shade guide: colorimetric analysis

Aim: The aim of this study was to verify the color variation between different composite resins and the Vita Classical Shade Guide. Methods: Two-millimeter thickness samples were made (n = 6) from eight commercial brands of composite resin (shade A2): Charisma (Kulzer), Forma (Ultradent), Harmonize (Kerr), Luna (SDI), Opallis (FGM), Oppus Bulk Fill (FGM), Vittra (FGM) and Filtek Z250 XT (3M ESPE). Specimens were stored in distilled water for 7 days and then polished. Color measurements of samples and A2 shade of the Vita Classical Shade Guide were performed using the Vita Easy Shade Advance 4.0 spectrophotometer on a black background. Color variations were calculated using the CIEDE2000 formula, considering values ≥0.81 being noticeable by the human eye and ≥1.77 being clinically unacceptable. Results were statistically analyzed with a 5% significance level. Results: Color variation (ΔE) of composite (E1 ) compared to the Vita Classical Shade Guide (E0 ) was greater than clinically acceptable for all the materials evaluated in this study. Forma (ΔE=2.08 ± sd=0.47) and Filtek Z250 XT (2.50 ± 0.20) had the smallest amount of color variation values found in the results. Harmonize (3.32 ± 0.63) presented values similar to Filtek Z250 XT, but it was worse than Forma. Vittra (3.51 ± 0.28), Charisma (3.80 ± 0.20), Opallis (4.24 ± 0.30) and Luna (5.67 ± 0.20) did not differ among each other and presented higher color variation than Forma, Filtek Z350XT and Harmonize. Oppus Bulk Fill (13.94 ± 1.12) was the composite with the greatest color variation. Conclusions: The findings in this study show that attention should be taken when using the Vita Color Shade Guide for composite shade selection

Influence of the incorporation of titanium dioxide nanofibers net on bond strength and morphology of a total etching adhesive system.

Background: The aim of this study was to evaluate the nanoleakage and microtensile bond strength (µTBS) of an ethanol based-adhesive containing Titanium dioxide (TiO2) nanofibers to dentin. Material and Methods: TiO2 nanofiber was produced by electrospinning and it was inserted in an ethanol-based adhesive in 0.5, 1.5 and 2.5% by weight. The original adhesive did not receive nanofiber. The middle dentin was exposed by diamond saw under water-cooling and dentin was polished with wet 600-grit SiC abrasive paper. Resin composite build-ups were applied incrementally to the dentin after adhesive application. After storage in distilled water (24 hours/37°C) the teeth were sectioned perpendicularly to the bonded interface and sticks were obtained. Twenty-five sticks per group were tested by µTBS with a crosshead speed of 0.5mm/minute. The average values (MPa) obtained in each substrate were subjected to one-way ANOVA (α=0,05) with the tooth being considered the experimental unit. The nanoleakage pattern was observed in ten sticks per group and analyzed by Chi-square test (α=0,05). Results: There was no difference in µTBS among the experimental groups. However, there was a statistically significant difference among 2.5 % nanofiber adhesive, 0.5 % nanofibers and control groups, (p=0,028) in relation to nanoleakage. Conclusions: TiO2 nanofibers in 2.5% of weight inserted in dental adhesive reduced the nanoleakage, but did not improve the µTBS to dentin. Key words:Dentin-bonding agents, nanoleakage, tensile bond strength.

Crown Fracture of an Unerupted Incisor in a Young Child: Case Report and Restorative Protocol.

Aim: This case report describes a protocol for restoring a crown fracture of an unerupted permanent incisor in a child. Background: Crown fractures are an important concern in pediatric dentistry due to the negative impact on oral health-related quality of life (OHRQoL) in children and adolescents resulting from functional limitations as well as consequences related to social and emotional well-being. Case description: An enamel and dentin fracture of the crown of unerupted tooth 11 due to direct trauma is being presented in a 7-year-old girl. The restorative treatment involved minimally invasive dentistry, including computer-aided design (CAD)/computer-aided manufacturing (CAM) technology and direct resin restoration. Conclusion: The treatment decision was essential for maintaining pulp vitality and continued root development, as well as ensuring esthetic and functional results. Clinical significance: Crown fracture of an unerupted incisor may occur in childhood, requiring a long-term clinical and radiographic follow-up. Predictable, positive, and reliable esthetic outcomes can be achieved using CAD/CAM technology combined with adhesive protocols. How to cite this article: Kamanski D, Tavares JG, Weber JBB, et al. Crown Fracture of an Unerupted Incisor in a Young Child: Case Report and Restorative Protocol. Int J Clin Pediatr Dent 2022;15(5):636-641.

Experiências e percepções de discentes e docentes de odontologia sobre as aulas remotas durante a pandemia de COVID-19 / Experiences and perception of dentistry students and professors regarding online classes during the COVID-19 pandemic

O presente estudo objetivoudescrever a percepção de docentes e discentes de Odontologia sobre as atividades desenvolvidas nos ambientes virtuaisde aprendizagemdurante o período de isolamento social. Professores e estudantes dequatro cursosde Odontologia foram convidados a responderaum questionário autoaplicável, contendo questões objetivas e subjetivas arespeito de suas experiências e sensações em relação às atividades.Tanto docentes quanto discentes consideram que o aprendizado nesse período foi inferior ao presencial, contudo, concordam com a manutenção das aulas virtuais durante o período da pandemia (AU).

The present study aimed to describe the perception of Dentistry professors and students regarding the activities developed in virtual environments during the period of social isolation. Through self-administered questionnaires, professors and students from four Dentistry courses were invited to answer objective and subjective questions about their experiences and sensations during the period. Both professors and students consider that the learning in this period was inferior to the face-to-face, however, they agree with the maintenance of the virtual classes during the pandemic period (AU).

Cytotoxicity assessment of Bio-C Repair Íon+: A new calcium silicate-based cement.

Background. Direct pulp capping is a method designed to preserve the exposed dental pulp. Due to good biological, physical, and mechanical properties, new versions of calcium silicate-based materials have been developed as pulp capping materials. The present study aimed to evaluate the cytotoxic effects of four calcium silicate-based pulp capping materials, of which the Bio-C Repair Íon+ is still in an experimental phase. Methods. Biodentine, MTA Repair HP, Bio-C Repair, and Bio-C Repair Íon+ cements were dispensed in a metallic matrix to produce 125-mm3 specimens, which were immersed in Dulbecco's Modified Eagle Medium (DMEM) to obtain extracts. NIH 3T3 cells were cultured and exposed to the extracts for 24 hours and seven days. Cell viability was assessed by the methyl tetrazolium test (MTT). The mean values for the experimental and control groups (without treatment) were compared by analysis of variance (ANOVA) and post hoc Tukey tests, considering a significance level of 5%. Results. All the tested materials demonstrated a reduction in cell viability (P < 0.05). According to ISO 10993-5: 2009 (E), Bio-C Repair Íon+ exhibited mild and moderate cytotoxicity in the 24- hour and 7-day analyses, respectively. Bio-C Repair and Biodentine showed mild cytotoxicity, and MTA Repair HP exhibited moderate cytotoxicity at both intervals. Conclusion. The highest cell viability was demonstrated by Biodentine, MTA, and Repair HP, in descending order. Bio-C Repair and Bio-C Repair Íon+ showed moderate cytotoxicity, similar to MTA Repair HP in the 7-day analysis.

Influência do polimento na estabilidade de cor de uma resina composta após imersão em diferentes substâncias corantes / Influence of polishing on color stability of a composite resin after immersion in different coloring substances

Objetivo: Avaliar o grau de pigmentação da resina composta imersa em água destilada, molho shoyu e vinho tinto, submetida a diferentes métodos de polimento. Método: Foram confeccionadas 90 espécimes de resina composta cor A2 esmalte (4 mm de diâmetro de topo, 3 mm de diâmetro de fundo e 2 mm de espessura), divididos igualmente em três grupos, de acordo com o tratamento superficial realizado (sem polimento, polimento com Diamond Pro e polimento com lixa). As 30 amostras de cada grupo foram divididas em três subgrupos (n=10) e imersas em diferentes soluções (água, molho shoyu e vinho tinto). A análise colorimétrica foi realizada previamente, 7 e 15 dias após a imersão das amostras nas soluções, com o auxílio de um colorímetro. Os dados foram submetidos aos testes de ANOVA/Tukey considerando um nível de significância de 5%. Resultados: Amostras imersas em água apresentaram pequena variação de cor (E=2,2), com exceção das que não receberam polimento (E=7,8). O vinho tinto apresentou significativo maior potencial de pigmentação (E=15), independente do método de polimento, enquanto o molho shoyu (E=11) demonstrou pigmentar com maior intensidade as amostras polidas com discos de lixa. Conclusões: É necessário fazer um acabamento e um polimento adequado na restauração de resina composta para que o grau de pigmentação seja o menor possível. Sobre os alimentos corantes, conclui-se que tanto o molho shoyu quanto o vinho tinto pigmentam a resina composta, porém o vinho pigmenta com uma intensidade maior(AU)

Objective: To evaluate the degree of pigmentation of composite resin immersed in distilled water, shoyu sauce and red wine, with different polishing methods. Method: 90 specimens of A2 enamel composite resin (4 mm of top diameter, 3 mm of bottom diameter and 2 mm of thickness) were made, equally divided into three groups, according to the surface treatment carried out (without polishing, polishing with Diamond Pro and polishing with sandpaper). The 30 samples from each group were divided into three subgroups (n = 10) and immersed in different solutions (water, shoyu sauce and red wine). The colorimetric analysis was performed previously, 7 and 15 days after the samples immersion in the solutions, with the aid of a colorimeter. The data were submitted to ANOVA/Tukey tests considering a significance level of 5%. Results: Samples immersed in water showed little color variation (E = 2.2), with the exception of those that did not receive polishing (E = 7.8). Red wine showed a significant higher pigmentation potential (E = 15), regardless of the polishing method, while shoyu sauce (E = 11) demonstrated to pigment the polished samples with sandpaper with greater intensity. Conclusion: It is necessary to finish and polish the composite resin properly so that the degree of pigmentation is as low as possible. Regarding coloring foods, it is concluded that both shoyu sauce and red wine pigment the composite resin, but the wine pigments with greater intensity(AU)

Effect of preheating on cytotoxicity and physicochemical properties of light-cured calcium-based cements.

The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.

O objetivo do presente estudo foi avaliar o grau de conversão, citotoxicidade, solubilidade e pH de cimentos à base de cálcio fotopolimerizáveis submetidos a pré-aquecimento. O grau de conversão foi analisado por espectroscopia no infravermelho com transformada de Fourier, a citotoxicidade pelo teste de MTT e a solubilidade através da perda de massa. Os dados foram submetidos a testes estatísticos (ANOVA/Tukey, p<0,05). Os materiais fotopolimerizáveis apresentaram baixo grau de conversão, independente do pré-aquecimento. Todos os materiais causaram redução da viabilidade celular nas análises de 24 horas e 7 dias, sendo que o Dycal (controle) apresentouse mais citotóxico e o calor apresentou efeito positivo sobre o Biocal na análise de 7 dias. O Dycal é o material mais solúvel e o calor não causou efeito na solubilidade e pH dos materiais polimerizáveis. Assim, conclui-se que os cimentos à base de cálcio fotopolimerizáveis apresentam baixo grau de conversão e são solúveis, que resulta em citotoxicidade suave e moderada.

Effect of preheating on cytotoxicity and physicochemical properties of light-cured calcium-based cements / Efeito do pré-aquecimento na citotoxicidade e propriedades físico-químicas de cimentos à base de cálcio fotopolimerizáveis

ABSTRACT The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.

RESUMO O objetivo do presente estudo foi avaliar o grau de conversão, citotoxicidade, solubilidade e pH de cimentos à base de cálcio fotopolimerizáveis submetidos a pré-aquecimento. O grau de conversão foi analisado por espectroscopia no infravermelho com transformada de Fourier, a citotoxicidade pelo teste de MTT e a solubilidade através da perda de massa. Os dados foram submetidos a testes estatísticos (ANOVA/Tukey, p<0,05). Os materiais fotopolimerizáveis apresentaram baixo grau de conversão, independente do pré-aquecimento. Todos os materiais causaram redução da viabilidade celular nas análises de 24 horas e 7 dias, sendo que o Dycal (controle) apresentouse mais citotóxico e o calor apresentou efeito positivo sobre o Biocal na análise de 7 dias. O Dycal é o material mais solúvel e o calor não causou efeito na solubilidade e pH dos materiais polimerizáveis. Assim, conclui-se que os cimentos à base de cálcio fotopolimerizáveis apresentam baixo grau de conversão e são solúveis, que resulta em citotoxicidade suave e moderada.

Effect of heat treatment on cytotoxicity and polymerization of universal adhesives.

To assess, in vitro, the influence of heat air treatment on cytotoxicity and degree of conversion (DC) of universal self-etch adhesives (Ambar Universal APS, Scotchbond Universal Adhesive, and Tetric N-Bond Universal) in an NIH/3T3 fibroblast cell culture. Samples were divided into three groups: 1) no heat treatment (control), 2) 37°C and 3) 60°C heat treatment before photopolymerization. Cytotoxicity was analyzed by MTT assay and the DC by FTIR. All adhesives heated at 60°C showed reduced cytotoxicity levels when compared with those heated at 37°C. In general, DC of Ambar Universal APS presented the highest DC than Scotchbond Universal Adhesive and Tetric N-Bond Universal, and the hot air treatment do not influence the conversion. Heat treatment at 60°C was able to reduce the cytotoxicity of universal self-etch adhesives, even, the heat treatment does not enhances the DC.

Hot air stream reduces cytotoxicity of light-cured calcium hydroxide based cements.

BACKGROUND: The light-cured calcium hydroxide based cements have incomplete polymerization and unconverted monomers can cause pulp cell damage. The aim of this study was to evaluate the influence of a warm and hot air stream on the cytotoxicity of light-cured calcium hydroxide based cements. MATERIAL AND METHODS: The materials Dycal (conventional cement), Biocal, Hidrox-Cal, and Ultra-Blend Plus (light-cured calcium hydroxide cements) were submitted to cytotoxicity analysis after polymerization, without vs. with previous heat treatment with a warm (37°C) and a hot (60°C) air stream. Following polymerization, cements were maintained in culture medium for 24 hours and 7 days, and subjected to the MTT test. Data were analyzed using analysis of variance (ANOVA) followed by post-hoc Student-Newman-Keuls (<0.05). RESULTS: The results indicated significant differences between the materials according to their composition, i.e., light-cured cements treated with a jet of warm air showed similar cytotoxicity levels to those observed for conventional cement, suggesting that they may be considered alternatives in cases requiring pulp-capping treatment. CONCLUSIONS: Application of a hot air stream reduced cytotoxicity of materials tested. Key words:Dental pulp capping, dental cements, calcium hydroxide, cell survival.

Evaluation of Tensile Bond Strength of Metallic Prefabricated Posts Cemented with Different Luting Agents

Abstract Objective: To assess the tensile bond strength of prefabricated metal posts cemented with different luting agents. Material and Methods: Fifty single-rooted endodontically treated human teeth had their crowns cut, mounted into acrylic-resin blocks and then an 8mm depth post space were prepared. Prefabricated cylindrical metal posts were cemented using different luting agents: a zinc phosphate cement (SS White), a conventional glass ionomer cement (Vidrion C), two resin-modified glass ionomer cements (Vitremer and RelyX Luting 2) and a resin cement (RelyX ARC). Samples were stored in distilled water for seven days and then submitted to a tensile bond strength test until complete dislocation of the post. One-way analysis of variance and Tukey test for pairwise multiple comparisons were used to evaluate differences between luting agents. Results: Tensile bond strength was 563.88±203.41 N for zinc phosphate cement, 336.86 ± 137.64 N for Vidrion C, 515.24 ± 239.48 N for Vitremer, 828.47±433.99 N for RelyX Luting 2 and 1262.51 ± 356.29 for RelyX ARC. The Relyx ARC presented the highest tensile bond strength regard the luting agent tested (p< 0.05). Conclusion: RelyX ARC presented the higher tensile bond strength compared to the other luting agents evaluated.

Development and evaluation of calcium hydroxide-coated, pericardium-based biomembranes for direct pulp capping.

AIM: The aim of the present study was to develop a bovine pericardium biomembrane (BPB) and to evaluate pulp response in vivo. METHODS: A double-layer bovine BPB/chitosan was manufactured, and the porous chitosan side was coated with calcium hydroxide. The microstructure of the matrices was evaluated with electron microscopy. To test pulp response, cavities were prepared on the occlusal surface of Wistar rats' mandibular left first molars and capped with matrices, followed by appropriate adhesives/composite restorations. The animals were divided into three groups: group 1, calcium hydroxide alone; group 2, BPB without calcium hydroxide; and group 3, BPB coated with calcium hydroxide. Specimens were processed and histologically evaluated at 7, 14, and 30 days, postoperatively. RESULTS: Electron microscopy showed porous chitosan surface and a cohesive calcium hydroxide layer. Histological analysis showed that groups 1 and 3 had mild odontoblast layer disorganization, but normal pulp tissue appearance at 7, 14, and 30 days. At the same time points, group 2 showed a loss of general pulp tissue, pulp necrosis, and periapical abscess in some teeth. CONCLUSION: Coated bovine pericardium-based biomembranes resulted in favorable outcomes in cases of pulp exposure after a 30-day observation period, and might protect against injuries caused by adhesive systems and composites.

Restauração de dentes tratados endodonticamente com resinas bulk-fill: revisão integrativa / Endodontically treated teeth restored with bulk-fill resins: integrative review

Objetivo: realizar uma revisão de literatura sobre o uso de resinas bulk-fill para restaurar dentes tratados endodonticamente. Materiais e método: a busca dos estudos, clínicos ou laboratoriais, foi realizada no portal PubMed, utilizando os descritores "bulk fill" e "endodontically treated". Os dados extraídos da literatura foram agrupados em um quadro, que apresenta as características metodológicas e os principais resultados de cada estudo. Resultados: Sete estudos foram incluídos na revisão. Dentre eles, cinco avaliaram a resistência à fratura dos dentes após a restauração, um avaliou a adaptação da resina ao assoalho da câmara pulpar, e um realizou um ensaio clínico com acompanhamento de três anos, comparando o uso de resina bulk-fill com resina convencional. Considerações finais: o desempenho das resinas bulk-fill mostrou-se semelhante ao das resinas convencionais nas características de resistência à fratura dos dentes (in vitro) e longevidade (in vivo). A economia de tempo clínico proporcionada pelas resinas bulk-fill pode justificar o seu emprego para a restauração de dentes tratados endodonticamente. (AU)

Objective: the aim of this study was to review the literature regarding the use of bulk-fill resin to restore endodontically treated teeth. Materials and method: the search was performed at PubMed, using the descriptors "bulk fill" AND "endodontically treated". Clinical and laboratorial studies were included. The extracted data was presented on a table showing the methodological features and results of each study. Results: seven studies evaluated the bulk-fill resin on direct restoration. Five of these seven evaluated the resistance to fracture, one assessed the resin adaptation to the floor chamber, and one was a randomized clinical trial comparing the bulkfill resin to conventional resin. Final considerations: the performance of bulk-fill resins was similar to the conventional resins when compared to the in vitro studies on tooth fracture resistance and in vivo study on longevity of restorations. The economy of clinical time may justify its use to restore endodontically treated teeth. (AU)

To Whom it may concern

We have experienced many changes in the past few years, both in our country and worldwide. We have to be bold and face changes, and never hide from them. It is essential that we adjust to an era where typing may temporarily replace human touch or human voice, or even a hug or a kiss. Indeed... However there are things that will never change or be replaced: honesty, for example. Brazil is a blessed country still struggling to meet basic needs, such as public health, education, and security. All around this huge and beloved land it is possible to hear claims for more respect to human dignity. How could this reality be transformed and how could Brazil become not only a blessed, but also a calm, peaceful and healthy country, where individuals are proud to have the national flag waving in front of their homes and to sing the national anthem? There is a single, straightforward answer to that question: we all have to become real citizens, in the full sense of the word. Our population currently reaches 200 million people, and half of them are responsible for electing politicians, who are constantly accused (at least part of them) of misappropriation of public money or resources ­ public money that comes from heavy taxes paid without appeal by those who really work hard, no matter if making little or a lot of money. This same diverted money should be allocated to improve the trinomial mentioned above: public health, education and security. And this same scarce money that comes from taxes will also support graduate scholarships in public and private universities. Please allow me to build another trinomial with other words also mentioned in this text: Honesty / Public Money / Scholarships. Facing the facts with deep sincerity, some questions suddenly arise: Is it possible to say that the blessed individuals who earn scholarships financed by scarce public resources are behaving as real citizens? Are these publicly sponsored students changing the reality around them, serving as opinion leaders and highly qualified health promoters? Can we see in these students a real commitment to dedicate the appropriate required time to make Brazil a better country? Former U.S. president John Kennedy once quoted: "Ask not what your country can do for you, ask what you can do for your country". On behalf of those who have already lived more than half of their lives, I may say that it urges that the new generation of masters and researches stop complaining and start proposing changes with the aim of shifting from the noxious standard currently in place to a new standard marked by a positive, constructive attitude. As mentioned in the title of this editorial, these reflections are offered "to whom it may concern," or to whomever the cap fits.

O papel das mídias sociais na construção do conhecimento em Odontologia / The role of social media in the construction of knowledge in Dentistry

Este artigo, de cunho teórico, discute a construção do conhecimento em Odontologia no contexto da Sociedade em Rede, aproximando essa temática ao ponto de vista de alguns autores das Ciências Sociais Contemporâneas em voga. A bibliografia especializada aponta que a sociedade vive em uma constante transformação. Prova disso é que a construção de conhecimento pedagógico em Odontologia se dá hoje com maior intensidade na internet, principalmente nas mídias sociais, do que através da busca em livros. Por essa nova forma de agregar conhecimento ser uma realidade, é de fundamental importância que pessoas qualificadas sejam vetores de transmissão desses conhecimentos, de uma forma didática e com embasamento científico. Além disso, cabe aos professores se adaptarem ao novo estilo de construção do conhecimento pedagógico, elaborando aulas mais interativas e com o auxílio de ferramentas que chamem a atenção dos seus alunos e, concomitante a isso, ofereçam-lhes informações de qualidade.

This theoretical article discusses the construction of knowledge in dentistry in the context of the Network Society, bringing this theme closer to the point of view of some contemporary Social Science writers, nowadays in vogue. The specialized bibliography indicates that the society lives in a constant transformation, proof of this is that the construction of pedagogical knowledge in dentistry occurs today with greater intensity in the internet, mainly in the social media, than through the search in books. Because this new form of knowledge aggregation is a reality, it is of fundamental importance that qualified people are vectors of transmission of this knowledge, in a didactic and scientific basis. In addition, it is up to teachers to adapt to the new style of construction of pedagogical knowledge, developing more interactive classes and with the help of tools that attract the attention of their students and, at the same time, offer them quality information.

Mesiolingual Canal Prevalence in Maxillary First Molars assessed through Different Methods.

AIM: Evaluate the prevalence of mesiolingual canal prevalence orifice in mesiobuccal roots of maxillary first molars using five methods of visualization. MATERIALS AND METHODS: About 73 first permanent maxillary molars were analyzed. Visual clinical analysis of the presence of the fourth canal was performed using a straight end-odontic exploratory probe (EXDG16®) and a K10 manual file (SybronEndo®). Dental elements that were not located on the fourth canal were analyzed with the aid of a magnifying glass (Zeiss®) with a 2.5-fold increase and those teeth in which the fourth canal was not found went through the examination with clinical surgical microscope (OPTO®) with magnification of 20 times with both the explorer and endodontic file. Next, a periapical radiography of the teeth was performed in the teeth in which the mesiolingual canal was not yet found to observe the presence or absence of the fourth canal. Afterward, the teeth in which the canal was not yet located were scanned using the microtomography equipment (SkyScan®), at 100 kV and 100 µA, with an isotropic resolution of 16 µm. RESULTS: The mesiolingual canal was located in 70 teeth (95.8%) and in only 3 teeth it was not identified. CONCLUSION: The visual method in the fourth canal search has limitations, whereas the composite magnifying glass, the clinical surgical microscopy, and the computerized microtomography are efficient methods for locating the fourth canal in the upper first molars. CLINICAL SIGNIFICANCE: The anatomical complexity of the first maxillary molars is one of the factors that leads to high failure rates in the endodontic treatments of this group of teeth. In most clinical situations, the mesiolingual canal goes unnoticed by professionals, since conventional radiographs do not always allow the visualization of all root canals. Determining an effective method for locating the mesiolingual canal is of paramount importance to the success of endodontic treatment.

Effect of heat treatment on cytotoxicity of self-adhesive resin cements: Cell viability analysis.

OBJECTIVE: The aim of the study was to assess, in vitro, the influence on cytotoxicity of heat treatment applied before photopolymerization, while mixing three self-adhesive resin cements, in an NIH/3T3 fibroblast cell culture, based on cell viability measures. METHODS: Samples were divided into three groups: (1) no heat treatment while mixing (control), (2) 37°C, and (3) 60°C heat treatment while mixing. Cements were light-cured immediately after mixing and immersed in Dulbecco's Modified Eagle Media for the extraction of possibly uncured products after 24 h and 7 days. Cultures contained 0.5 mL of NIH/3T3 fibroblasts per well at a concentration of 0.4 × 105 cells/mL and specific extracts for each sample. STATISTICAL ANALYSIS USED: Data were statistically analyzed with ANOVA and post hoc Student-Newman-Keuls (significance of 5%). RESULTS: Cement cytotoxicity increased with time, as shown by the higher values observed at 7 days. There was a slight difference in intragroup cytotoxicity levels between 24 h and 7 days. Heat treatment at 60°C was associated with a major decrease in cytotoxicity levels in all three groups, both at 24 h and at 7 days, with no differences among the cements. CONCLUSIONS: Heat treatment at 60°C should be considered as a strategy to reduce cytotoxicity of self-adhesive resin cements, as evidenced by the results observed at 24 h and 7 days of analysis.

Validation method of research instruments for Dental Radiology curriculum study / Método de validação de instrumentos de pesquisa para estudo do currículo de Radiologia Odontológica

Dental radiology is an important subject to Dental undergraduate education. Along with other disciplines, it plays a key role in diagnostics, the starting point for patient care. In this way, a specific international guideline for Dental Radiology curriculum was published in 2007. The aim of this study was to develop and validate two distinct instruments, a self-administered online survey, and an interview script, both designed for dental radiology education research. The processes for developing and validating the instruments are described, and the final documents are presented. There were several steps in the validation process of the research instruments in this study, such as translation, cultural adaptation, expert evaluation, read-aloud sessions and pilot testing. This detailed process guarantees control of the variables and helps to avoid bias in regard to the interview and the quantitative/qualitative method analysis (AU).

Effect of At-home and In-office Bleaching on Marginal Microleakage in Composite Resin Restorations using Two Adhesive Systems.

AIM: The aim of this study is to assess marginal microleakage of cervical cavities restored with composite resins and two different adhesive techniques subjected to at-home and in-office bleaching. MATERIALS AND METHODS: In this randomized, blind laboratory experiment, 60 bovine teeth recently extracted were collected and divided into six groups (n = 10 each group). The teeth received cervical cavity preparations (2 mm × 3 mm × 1 mm) with enamel margins. Two different adhesive systems were used (Single Bond 2 and Clearfil SE Bond), in addition to composite resin (Z250). Restored teeth received two different bleaching gels (Opalescence PF and Opalescence Boost). Teeth were thermo-cycled and analyzed under confocal laser scanning microscopy. RESULTS: No significant differences were observed (p > 0.05) in microleakage scores between the two groups not subjected to bleaching nor between the four groups that received bleaching treatment (p > 0.05), regardless of the gel and adhesive system employed. However, when comparing nonbleached with bleached teeth, those not subjected to bleaching showed statistically lower marginal microleakage scores (p < 0.05). Data were statistically analyzed using the Kruskal-Wallis test followed by Student-Newman-Keuls post hoc test, with significance set at 5%. CONCLUSION: Marginal microleakage in composite resin restorations is influenced by the action of bleaching agents used both at-home and in-office, regardless of the adhesive system employed (total-etch or self-etch). CLINICAL SIGNIFICANCE: Both at-home and in-office bleaching agents have an influence on the adhesive interface of resin restorations, producing changes and inducing marginal leakage.