Effect of Ceramic Thickness on the Bond Strength to Resin-Luting Agents before and after Thermal Cycling

Abstract This study investigated microshear bond strength (µSBS) of two (2) dual-cured resin-luting agents (RelyX™ Ultimate and RelyX™ U200) when photoactivated through varying thicknesses of lithium disilicate, with or without thermal cycling. Discs of IPS e.max Press of 0.5, 1.5, and 2 mm in thickness were obtained. Elastomer molds (3.0 mm in thickness) with four cylinder-shaped orifices 1.0 mm in diameter, were placed onto the ceramic surfaces and filled with resin-luting agents. A Mylar strip, glass plate, and load of 250 grams were placed over the filled mold. The load was removed and the resin-luting agents were photoactivated through the ceramics using a single-peak LED (Radii Plus.) All samples were stored in distilled water at 37oC for 24 h. Half of the samples were subjected to thermal cycling (3,000 cycles; 5ºC and 55ºC). All samples were then submitted to µSBS test using a universal testing machine (Instron 4411) at a crosshead speed of 0.5 mm/min. Data were submitted to three-way ANOVA and Tukey post-hoc test (α=0.05). The mean µSBS at 24 h was significantly higher than after thermal cycling (p<0.05). No statistical difference was found between resin-luting agents (p > 0.05). The mean µSBS for groups photoactivated through 0.5 mm ceramic were significantly higher than 1.5 mm and 2.0 mm (p < 0.05). In conclusion, increased ceramic thicknesses reduced the bond strength of tested resin-luting agents to lithium disilicate. No differences were found between resin-luting agents. Thermal cycling reduced the bond strength of both resin-luting agents.

Resumo: Este estudo investigou a resistência de união ao microcisalhamento (RUµC) de dois (2) agentes de cimentação de resina dual (RelyX™ Ultimate e RelyX™ U200) quando fotoativados através de diferentes espessuras de dissilicato de lítio, com ou sem ciclagem térmica. Discos do IPS e.max Press de 0,5, 1,5 e 2 mm de espessura foram obtidos. Moldes de elastômero (3,0 mm de espessura) com quatro orifícios cilíndricos de 1,0 mm de diâmetro foram colocados sobre as superfícies cerâmicas e preenchidos com agentes de cimentação de resina. Uma tira Mylar, placa de vidro e carga de 250 gramas foram colocadas sobre o molde preenchido. A carga foi removida e os agentes de cimentação resinosos foram fotoativados através da cerâmica usando um LED de pico-único (Radii Plus). Todas as amostras foram armazenadas em água deionizada a 37oC por 24 h. Metade das amostras foi submetida a ciclagem térmica (3.000 ciclos; 5ºC e 55ºC). Todas as amostras foram então submetidas ao teste de RUµC usando uma máquina de teste universal (Instron 4411) com velocidade de 0,5 mm/min. Os dados foram submetidos à Análise de Variância três fatores e ao teste post-hoc de Tukey (α = 0,05). A média de RUµC em 24 h foi significativamente maior do que após a ciclagem térmica (p < 0,05). Não houve diferença estatística entre os cimentos resinosos (p > 0,05). As médias de RUµC para grupos fotoativados através de cerâmica de 0,5 mm foram significativamente maiores do que 1,5 mm e 2,0 mm (p < 0,05). Em conclusão, o aumento da espessura da cerâmica reduziu a resistência de união dos agentes de cimentação resinosos ao dissilicato de lítio. Não foram encontradas diferenças entre os agentes de cimentação resinosos. A ciclagem térmica reduziu a resistência de união de ambos os agentes de cimentação resinosos.

The "Phase Down" of Dental Amalgam Restorations - What are the Criteria for Replacement and Indication?

ABSTRACT Objective: To guide professionals about the criteria for replacing amalgam restorations and inform them about the new guidelines regarding the use/indication of this (amalgam) material after the Minamata Convention - COP-4. Material and Methods: The articles were selected from the databases (PubMed, Scielo, Bireme), and relevant articles on the subject between the years 2003-2021 were selected. Recently, social media have been flooded with dental treatments that aim to perform restorations only with composite resins or other types of esthetic material and completely replace all dental amalgam restorations, irrespective of their time in place, size, and functionality. Results: Although improperly, it has been noted that this information reaches patients, and they are led to believe in the inaccurate data that is passed on, such as, for example, (that amalgam leads to) permanent contamination by mercury, causing systemic problems and the loss of the tooth. Conclusion: The "phase down" of amalgam in research and teaching has previously been observed in several countries worldwide; however, its use is still necessary given particular circumstances, which, theoretically, make it a material with exact indication.

Clinical longevity of metallic versus fiberglass intraradicular posts: a systematic review / Longevidade clínica de pinos intraradiculares metálicos versus de fibra de vidro: uma revisão sistemática

Objective: This systematic review aims to compare the clinical longevity of metallic and fiberglass intraradicular posts in teeth with severely compromised crowns, utilizing randomized clinical trials and case reports published in the last eleven years. Material and Methods: The research was conducted on PubMed, Medline, Lilacs, and BBO databases using the first search strategy with the descriptors 'dental posts,' 'longevity,' 'fiberglass-reinforced posts' or 'metallic posts.' The second search strategy involved analyzing the references of articles identified by the first search. Both studies were carried out with stringent inclusion and exclusion criteria. Results: No statistically significant and clinically relevant differences in longevity were observed between metallic and fiberglass posts. Conclusion: The clinical success and durability of the restorative procedure using intraradicular posts primarily depend on the remaining amount around the post (ferrule), the type and position of the tooth in the arch (impacting the masticatory forces exerted on the restored tooth), and the correct application of the cementation technique. It is noteworthy that fiberglass posts offer substantial advantages by presenting a modulus of elasticity similar to dental structure, ensuring a more homogeneous distribution of masticatory forces and reducing the risk of fractures. These findings have practical implications for material selection in restorative procedures involving intraradicular posts.(AU)

Objetivo: Esta revisão sistemática visa comparar a longevidade clínica de pinos intrarradiculares metálicos e de fibra de vidro em dentes com coroas severamente comprometidas, através de estudos clínicos randomizados e relatos de casos, publicados nos últimos onze anos. Material e Métodos: A pesquisa foi conduzida nas bases de dados PubMed, Medline, Lilacs e BBO, utilizando a primeira estratégia de busca com os s 'pinos dentais' e 'longevidade' e 'pinos reforçados com fibra de vidro' ou 'pinos metálicos'. A segunda estratégia de busca consistiu na análise das referências dos artigos identificados pela primeira estratégia. Ambos os estudos foram delineados com critérios rigorosos de inclusão e exclusão. Resultados: Não se constataram diferenças estatisticamente significativas e clinicamente relevantes na longevidade entre pinos metálicos e de fibra de vidro. Conclusão: O êxito clínico e a durabilidade do procedimento restaurador empregando pinos intrarradiculares dependem primordialmente da quantidade de remanescente ao redor do pino (férula), do tipo e posição do dente na arcada (o que impacta nas forças mastigatórias exercidas sobre o dente restaurado) e da aplicação correta da técnica de cimentação.Destaca-se que o pino de fibra de vidro oferece vantagens substanciais ao apresentar módulo de elasticidade similar à estrutura dentária, assegurando uma distribuição mais homogênea das forças mastigatórias e reduzindo o risco de fraturas (AU)

Cytotoxicity evaluation, antibacterial effect, and degree of conversion of QAM-containing adhesives

Abstract The aim of this study was to evaluate the influence of adding quaternary ammonium methacrylates (QAMs) to experimental adhesives by assessing the degree of conversion (DC), cytotoxicity against keratinocytes and fibroblasts, and antibacterial activity against biofilm formation. Two QAMs were added to an experimental adhesive: dimethylaminododecyl methacrylate bromododecane (DMADDM) or dimethylaminododecyl methacrylate bromohexadecane (DMAHDM) at three concentrations each: 1, 2.5, and 5 wt.%. Experimental adhesive without QAMs (control group) and commercially available Transbond XT Primer (3M Unitek, Monrovia, California, USA) were used for comparisons. The adhesives were tested for DC, cytotoxicity against keratinocytes and fibroblasts, and antibacterial activity against biofilm formation. DC, cytotoxicity against fibroblasts, and antibacterial activity were analyzed using one-way ANOVA and Tukey's multiple comparisons. Cytotoxicity against keratinocytes was evaluated using the Kruskal Wallis and Dunn's post-hoc (α = 5%) tests. Transbond showed lower DC as compared to 5% DMAHDM, 1% DMADDM, and 5% DMADDM (p < 0.05). However, all groups presented proper DC when compared to commercial adhesives in the literature. In the evaluation of cytotoxicity against keratinocytes, Transbond induced higher viability than 2.5 wt.% groups (p < 0.05). Against fibroblasts, Transbond induced higher viability as compared to 5 wt.% groups (p < 0.05). DMAHDM at 5 wt.% reduced biofilm formation when compared to all the other groups (p < 0.05). Despite their cytotoxic effect against keratinocytes, gingival fibroblasts showed higher viability. DMAHDM at 5 wt.% decreased Streptococcus mutans viability. The incorporation of DMAHDM at 5 wt.% may be a strategy for reducing the development of white spot lesions.

Research progress on dental materials for preventing root caries / 口腔疾病防治

@#The high incidence and untreated rate of root caries, a common and frequently occurring oral disease with challenging treatment in elderly individuals, is the main cause of tooth loss among elderly people, as rapid development results in pulpitis and periapical periodontitis or residual crown and root, which has been regarded as one of the common chronic oral diseases seriously affecting the quality of life of elderly people. Thus, early intervention and prevention are important. Traditional dental materials for preventing root caries have been widely used in clinical practice; however, they have the disadvantages of tooth coloring, remineralization and low sterilization efficiency. A series of new dental materials for preventing root caries have gradually become a research hotspot recently, which have the advantages of promoting the mineralization of deep dental tissue, prolonging the action time and enhancing adhesion. Future caries prevention materials should be designed according to the characteristics of root surface caries and the application population and should be developed toward simplicity, high efficiency and low toxicity. This review describes current research regarding anti-caries prevention material application, serving as a theoretical underpinning for the research of root caries prevention materials, which is important for both promotion in the effective prevention of root caries and improvement in the status of oral health and the quality of life among old people.

Surface Analysis of a Universal Resin Composite and Effect of Preheating on its Physicochemical Properties

Abstract This study was aimed at analyzing the surface properties of a universal resin composite and evaluating the effect of preheating on its physicochemical properties. Two commercial resin composites were used under two conditions: Filtek Universal Restorative (UR); UR preheated (URH); Filtek Supreme (FS) and FS preheated (FSH). The film thickness (FT) test (n = 10) was done using two glass slabs under compression. Flexural strength (FLS) and modulus (FLM) were evaluated using a three-point flexion test (n = 10). Polymerization shrinkage stress (PSS) was evaluated in a universal testing machine (n = 5). Gap width (GW) between composite and mold was measured in internally polished metallic molds (n = 10). The degree of conversion (DC) was evaluated by Fourier Transform Infrared spectroscopy (n = 3). The morphology of the filler particles was checked by scanning electron microscope (SEM) and EDX analysis. Surface gloss (SG) and surface roughness (SR) were evaluated before and after mechanical brushing (n = 10). The outcomes were submitted to 2-way ANOVA and Tukey's test (α = 0.05). Lower mean values of FT were observed for the preheated groups when compared to the non-preheated groups. URH and FSH showed higher mean values of FLS and FLM when compared with UR and FS. No differences were observed between groups in the PSS test. The GW was higher for the UR and FS groups when compared with URH and FSH. The DC was higher for preheated resin composites when compared to the non-preheated groups. The SR of the UR composite was higher than the FS after mechanical brushing, while the SG was higher for the FS groups. In conclusion, the universal resin composite tested generally presented similar physicochemical properties compared with the nanofilled resin composite and either similar or slightly inferior surface properties. The preheating improved or maintained all properties evaluated.

Resumo Neste estudo avaliou-se propriedades físico-químicas e de superfície de um compósito universal pré-aquecido e comparado a um compósito convencional. Foram utilizados dois compósitos comerciais: Filtek Universal Restorative (UR); UR pré-aquecido (URH); Filtek Supreme (FS) e FS pré-aquecido (FSH). O teste de espessura de película (EP) (n = 10) foi feito usando duas placas de vidro sob compressão. A resistência à flexão (RF) e o módulo flexural (MF) foram avaliados por meio do teste de flexão de três pontos (n = 10). A tensão de contração de polimerização (TCP) foi avaliada em uma máquina de teste universal (n = 8). A largura da fenda (LF) entre o compósito e o molde foi medida em moldes metálicos polidos internamente (n = 10). O grau de conversão (GC) foi avaliado por espectroscopia de infravermelho com transformada de Fourier (n = 3). A morfologia das partículas de carga foi observada em microscopia eletrônica de varredura (MEV) e sua composição em EDX. Brilho superficial (BS) e rugosidade superficial (RS) foram avaliados antes e após escovação mecânica (n=10). Os resultados foram submetidos à ANOVA 2-fatores e as médias comparadas pelo teste de Tukey (α = 0,05). Menores valores médios de EP foram observados para os grupos pré-aquecidos quando comparados aos grupos não pré-aquecidos. URH e FSH apresentaram maiores valores médios de RF e MF quando comparados com UR e FS. Não foram observadas diferenças entre os grupos no teste TCP. A LF foi maior para os grupos UR e FS quando comparados com URH e FSH. O GC foi maior para os compósitos pré-aquecidos quando comparados aos não pré-aquecidos. A RS do compósito UR foi maior que o FS após a escovação mecânica, enquanto o BS foi maior para os grupos FS. Em conclusão, o compósito universal testado geralmente apresentou propriedades físico-químicas semelhantes em comparação ao compósito nanoparticulado e propriedades de superfície semelhantes ou ligeiramente inferiores. O pré-aquecimento melhorou ou manteve todas as propriedades avaliadas.

Biomechanical Behavior Evaluation of a Mandibular Full-Arch Implant-Supported Prosthesis on ZrO2 and TiO2 Monotype Dental Implants / Evaluación del Comportamiento Biomecánico de una Prótesis Implante Soportada de Arcada Completa Mandibular sobre Implantes Dentales Monotipos de ZrO 2 y TiO

This in silico study aimed to evaluate the biomechanical behavior of a full-arch implant-supported prosthesis on titanium and zirconia monotype implants. A 3D mandible containing 1.0 mm thick cortical and cancellous bone was modeled. Four dental implants (3.3 x 10 mm) were inserted into the jaw model in each model. The implants consisted of Titanium (Ti-S group) and Zirconia Monotype/one-piece (Zr-S group). Fixed full-arch implant-supported prostheses were cemented onto the implant. The models were exported to the analysis software and divided into meshes composed of nodes and tetrahedral elements. All materials were considered isotropic, elastic, and homogeneous. Therefore, all contacts were considered bonded, the mandible model was fixed in all directions, applying a static structural axial load of 300 N on the bottom of the fossa of the left mola r teeth. Microstrain and von-Mises stress (MPa) were adopted as failure criteria. Comparable stress and strain values were shown in the peri-implant bone for both groups. However, the Ti-S group presented a lower stress value (1,155.8 MPa) than the Zr-S group (1,334.2 MPa). Regarding bone tissues, the Ti-S group presented 612 µε and the Zr-S group presented 254 µε. The highest strain peak was observed in bone tissues around the implant closer to the load for both groups. Evaluating monotype zirconia and titanium implants, it is suggested that the greater the rigidity of the implant, the greater the concentration of internal stre sses and the less dissipation to the surrounding tissues. Therefore, monotype ceramic implants composed of yttrium-stabilized tetragonal polycrystalline zirconia may be a viable alternative to titanium implants for full-arch prostheses.

El objetivo de este estudio in silico fue evaluar el comportamiento biomecánico de una prótesis implanto soportada de arcada completa sobre implantes monotipo de titanio y zirconia. Se modeló una mandíbula en 3D que contenía tejido óseo cortical y esponjoso de 1,0 mm de espesor. En cada modelo, se insertaron cuatro implantes dentales (3,3 x 10 mm) en el modelo de mandíbula. Los implantes consistieron en Monotipo de Titanio y Zirconia. Sobre el implante se cementaron prótesis implanto soportadas de arcada completa fija. Los modelos se exportaron al software de análisis y se dividieron en mallas compuestas por nodos y elementos tetraédricos. Todos los materiales se consideraron isotrópicos, elásticos y homogéneos. Por lo tanto, todos los contactos se consideraron cementados, el modelo mandibular se fijó en todas las direcciones, aplicando una carga vertical estructural estática de 300 N en el fondo de la fosa de los dientes molares izquierdos. Se seleccionaron la microesfuerzo y la tensión de Von-Mises (MPa) como criterios de falla. Se mostraron valores de tensión y deformación comparables en el hueso periimplantario para ambos grupos. Sin embargo, el grupo Ti-S presentó un valor de estrés menor (1.155,8 MPa) que el grupo Zr-S (1.334,2 MPa). En cuanto a los tejidos óseos, el grupo Ti-S presentó 612 µε y el grupo Zr-S presentó 254 µε. La mayor concentración de deformación en el tejido óseo se observó en los tejidos alrededor del implante más cerca de la carga para ambos grupos. Al evaluar los implantes monotípicos de zirconia y titanio, se sugiere que cuanto mayor sea la rigidez del implante, mayor será la concentración de tensiones internas y menor la disipación a los tejidos circundantes. Por lo tanto, los implantes cerámicos monotipo compuestos de zirconia policristalina tetragonal estabilizada con itrio pueden ser una alternativa viable a los implantes de titanio para prótesis de arcada completa.

In vitro comparison of marginal infiltration between a conventional resin and a bulk-fill resin, in the relocation of cervical margins technique / Comparación in vitro de la infiltración marginal entre una resina convencional y una resina bulk-fill, en la técnica de reubicación de márgenes cervicales

Introduction: Proximal lesions that exceed the cement enamel limit (ACE) under the gingival margin complicate impressions and the adhesive technique. Compare the magnitude of micro infiltration between conventional resin and bulk fill resin in the cervical margin relocation technique. Materials and Methods: 48 samples of human teeth re-ceived two preparations: occluso-mesial (OM) and occluso-distal (OD) under LAC; first they received the cervical margin relocation technique (RMC) with bulk fill and conventional resin; then restored with semi-direct resinous inlays. Sample analysis: immersion in 50% colloidal silver nitrate solution, 24 hours, 37°C and cut mesiodistally. Observed under a stereoscopic magnifying glass to assess dye penetration and digitally photographed, analyzed with "Image J" software. Results: Sample of 96 cavities in two groups of 48 units; control group restored with conventional resin with incremental technique and study group restored with bulk fill resin, mono-incremental technique. Probabilistic sampling. No statistically significant diffe-rences in percentage of microinfiltrated area between Filtek™ Z250™ and Filtek™ Bulk Fill™ (p-value= 0.68). Discussion: Various studies show that the presence of marginal microinfiltration exist independent of: restorative technique, consistency, adhesive mechanism and polyme-rization technique. The research carried out is no exception, observing a similar degree for both systems. Conclusions: Results allow us to conclude that conventi-onal resin and bulk fill resin did not show significant differences in microleakage percentages for the RMC technique. Outside the study framework, bulk fill resins would have comparative advantages; better behavior against light in depths greater than 2 mm, less sensitivity to the "C" factor, and less clinical time.

Introducción: Las lesiones proximales que superan el límite cemento esmalte (ACE) por debajo del margen gingival complican las impresiones y la técnica adhesiva. Comparar la magnitud de la microinfiltración entre la resina convencional y la resina de relleno en la técnica de reubicación del margen cervical. Materiales y Métodos: 48 muestras de dientes humanos recibieron dos preparaciones: ocluso-mesial (OM) y ocluso-distal (OD) bajo LAC, primero recibieron la técnica de reubicación del margen cervical (RMC) con relleno en bloque y resina convencional; luego restaurado con incrustaciones resinosas semidirectas. Análisis de la muestra: inmersión en solución de nitrato de plata coloidal al 50%, 24 horas, 37°C y corte mesiodistal. Observado bajo una lupa estereoscópica para evaluar la penetración del tinte y fotografiado digitalmente, analizado con el software "Image J". Resultados: Muestra de 96 cavidades en dos grupos de 48 unidades; grupo control restaurado con resina convencional con técnica incremental y grupo estudio restaurado con resina bulk fill, técnica mono-incremental. Muestreo probabilístico. No hubo diferencias estadísticamente significativas en el porcentaje de área microinfiltrada entre Filtek™ Z250™ y Filtek™ Bulk Fill™ (p-value = 0,68) Discusión: Diversos estudios evidencian presencia de microinfiltración marginal, independiente de técnica restauradora, consistencia, mecanismo adhesivo y técnica polimerizadora. La investigación realizada no es excepción, observándose grado similar para ambos sistemas. Conclusiones: Los resultados permiten concluir que resina convencional y resina bulk fill no presentaron diferencias significativas en porcentajes de microinfiltración para técnica RMC. Fuera del marco del estudio, resinas bulk fill tendrían ventajas comparativas; mejor comportamiento frente a la luz en profundidades superiores a 2 mm, menor sensibilidad al factor "C", y menor tiempo clínico.

Research progress on fluoride-releasing restorative materials for caries control / 口腔疾病防治

@#Restorative materials such as conventional glass ionomer cement (CGIC), resin-modified glass ionomer cement (RMGIC), polyacid-modified composite resin (compomer), and giomer have the properties of fluoride release and refill, which may prevent or slow down the progression of caries. The caries resistance of these materials was evaluated according to the following criteria: fluorine-releasing ability, antibacterial activity, mechanical properties and anti-aging properties. The anti-caries effect of these materials mainly depends on the effect of fluoride ions on mineralization. However, materials with strong fluorine release ability, such as CGIC, are mainly used in pediatric dentistry and temporary restoration due to their poor mechanical properties. It is difficult to achieve both fluoride ion release potential and mechanical strength, and there are few materials that can provide ideal mechanical strength while maintaining a high standard of fluoride release. The fluoride releasing and recharging capacity of CGIC, RMGIC, compomer and giomer decrease successively. The trend of material modification, to a certain extent, tends to sacrifice the fluoride release capacity of materials to maintain the ideal mechanical strength. In recent years, scholars have tried to add a variety of fillers to further enhance the anti-cracking ability of materials and add antibacterial agents to compensate for the anti-caries effect to reduce the loss of fluoride release.

Selamento de lesões cariosas em molares decíduos / Sealing of carious lesions in deciduous molars

Objetivo:Investigar a eficácia do selamento de lesão de cárie dentinária em comparação com a remoção parcial de cárie seguida de restauração em molares decíduos. Material e Método: O estudo clínico randomizado foi planejado ser realizado em 60 crianças com idade entre 3 e 8 anos. As crianças foram randomizadas por sorteio, com alocação para os 3 grupos, sendo 20 em cada grupo: Grupo 1 (G1) constituído por crianças que receberam o selamento de cárie com resina fluida; Grupo 2 (G2) com crianças que receberam o selamento de cárie com cimento de ionômero de vidro de alta viscosidade e Grupo controle (G3) com crianças onde a remoção parcial da cárie foi seguida por restauração com cimento de ionômero de vidro resinoso. Foram feitos acompanhamentos clínicos e radiográficos antes e após a intervenção, bem como a cada 4 meses durante 1 ano, investigando-se se houve fratura no selamento ou na restauração (infiltração marginal), paralização, regressão ou evolução do processo carioso nos 3 grupos. Resultados: A amostra foi reduzida para 49 crianças pois durante a fase de controle clínico radiográfico, 11 não foram localizadas por mudança de endereço.O grupo G1 apresentou 50% dos casos com regressão e 50% dos casos em paralização. O grupo G2 apresentou 62,5% dos casos com regressão e 37,5% dos casos com paralização e o grupo G3 com 60% dos casos com regressão e 40% com paralização. Não houve associação estatisticamente significativa entre o tipo de grupo e a progressão da lesão, não havendo diferença entre os grupos (valor de p = 0,74). Conclusão: Não houve diferença entre os grupos quanto à progressão de lesão de cárie quando tratados somente com o selamento com resina fluida ou com cimento de ionômero de vidro de alta viscosidade ou com restauração convencional com cimento de ionômero de vidro resinoso após a remoção do tecido cariado.

Aim: To investigate the effectiveness of sealing a dentin caries lesion compared to the removal of partial caries followed by restoration in deciduous molars. Methods: The randomized clinical trial was planned to be performed on 60 children, aged 3 to 8 years. Children were randomized by lot, with allocation into 3 groups, 20 per group: Group 1 (G1) consisted of children who received a sealing of caries using fluid resin; Group 2(G2) included children who received the sealing of caries performed with high viscosity glass ionomer cement, and Group 3(G3) conducted with children where the removal of partial caries was followed by restoration with resinous glass ionomer cement. Clinical and radiographic follow-ups were performed before and after the intervention, as well as every four months for one year, investigating whether there was a fracture in the sealing or restoration (marginal infiltration), paralysis, regression, or evolution of the carious process in the three groups. Results: The sample was reduced to 49 children given that, during the radiographic clinical control phase, 11 were not located due to a change of address. The G1 group presented 50% cases with regression and 50% cases with paralysis. The G2 group presented 62.5% of the cases with regression and 37.5% of the cases with paralysis, while the G3 group showed 60% of the cases with regression and 40% with paralysis. There was no statistically significant association between the type of group and the progression of the lesion, with no difference found between the groups (p value=0.74). Conclusion: There was no difference between the groups regarding the progression of carious lesions when treated only with fluid resin sealing or with high viscosity glass ionomer cement or with conventional restoration with resinous glass ionomer cement after the removal of decayed tissue.

A new proposal for evaluating of the solubility of bioceramic materials in dentin tubes after immersion in PBS: a laboratory investigation / Nova proposta para avaliação da solubilidade de materiais biocerâmicos em tubos de dentina após imersão em PBS: um estudo laboratorial

Introdução: Materiais reparadores devem apresentar baixa solubilidade. Solução salina tamponada com fosfato (PBS) permite simular condição clínica e interação com dentina pode ser importante para correta avaliação da perda de massa de cimentos biocerâmicos. Objetivo: Avaliou o efeito da imersão em água destilada (AD) ou PBS na solubilidade de Bio-C Repair (BCR, Angelus) ou MTA Repair HP (MTAHP, Angelus) usando modelo de tubo de dentina. Material e método: Tubos de dentina bovina foram confeccionados com 4 mm de comprimento, 1,5 mm de diâmetro interno e 1 mm aproximadamente de espessura de parede. Os espécimes foram imersos em AD por 24h, posteriormente preenchidos com BCR ou MTAHP (n = 14) e armazenados em estufa a 37°C e umidade 95% por 24h. Após serem pesados em balança de precisão para determinação da massa inicial, os corpos de prova foram imersos em AD (pH 6,5) ou PBS (pH 7,0) (n = 7) por 28 dias. Tubos vazios também foram utilizados para o cálculo de perda de massa da dentina (n=4). Após esse período, os espécimes foram pesados até a estabilização da massa final (0,001g). A solubilidade de cada material foi avaliada. Testes estatísticos ANOVA e Tukey foram realizados (α=0,05). Resultado: BCR e MTAHP apresentaram ganho de massa em AD e perda de massa em PBS (p<0,05). Conclusão: A solução de imersão influencia a solubilidade de BCR e MTAHP usando modelo de tubo de dentina. Nova proposta metodológica poderá ser uma alternativa às normas ISO para testar a solubilidade de cimentos biocerâmicos

Introduction: Repair materials must have low solubility. Phosphate buffered saline (PBS) allows simulating clinical condition and interaction with dentin may be important for the correct evaluate of mass loss of bioceramic cements. Objective: To evaluate the effect of distilled water (DW), or PBS immersion on the solubility of Bio-C Repair (BCR, Angelus) or MTA Repair HP (MTAHP, Angelus) using a dentin tube model. Material and method: Bovine dentin tubes with a length of 4 mm, an internal diameter of 1.5 mm and walls thickness of approximately 1 mm were made. The specimens were immersed in DW for 24h, then filled with BCR or MTAHP (n = 14) and stored in an oven at 37°C and 95% humidity for 24h. After being weighed on a precision balance to determine the initial mass, the specimens were immersed in DW (pH 6.5) or PBS (pH 7.0) (n = 7) for 28 days. Empty tubes also were used for calculating the mass loss of the dentin (n=4). After this period, the specimens were weighed until stabilization of the final mass occurred (0.001g). The solubility of each material was evaluated. ANOVA and Tukey statistical tests were performed (α=0.05). Result: BCR and MTAHP showing gain of mass in DW and mass loss in PBS (p<0.05). Conclusion: The immersion solution influenced the solubility of BCR and MTAHP using dentin tube model. The new methodological proposal could be an alternative to ISO standards for testing the solubility of bioceramic cement

Non-Invasive Methods and the Use of Infiltrating Resins for the Control of Caries Progression in Deciduous Teeth: A Systematic Review and Meta-Analysis

ABSTRACT Objective: To evaluate the influence of non-invasive treatment associated with the use of infiltrating resin for managing caries lesions in primary teeth. Material and Methods: A systematic review was performed by selecting articles from 6 online databases, using a search algorithm and eligibility criteria for data extraction and data synthesis for the papers included. Clinical trials involving primary teeth with incipient caries lesions (1/2 of the enamel or 1/3 of the outer dentin) were included, presenting full text and answering the study's guiding question. This study used the RoB 2 tool for the risk of bias assessment and GRADE for certainty of evidence. Random effects meta-analyses were implemented, and lesion progression treatment effects were estimated through relative risk (RR) and associated 95% confidence intervals. Results: A total of 440 studies were found. After analyzing the inclusion criteria and removal of duplicates, eight studies were analyzed for quality evidence. Five of the eight studies included in this review contributed to the meta-analysis, all with some reflections regarding the risk of bias. Overall, the results of the meta-analysis showed that non-invasive treatment, when associated with the use of infiltrating resins, significantly reduced the risk of caries progression in relation to the treatment without this addition for follow-up periods ranging from 12 months to 2 years (RR 0.51 [0.40-0.65]). Conclusion: There is moderate certainty of evidence that the use of infiltrating resins associated with non-invasive treatments decreases the risk of caries progression in primary teeth with incipient caries lesions (1/2 of the enamel or 1/3 of the dentin outer) when combined with non-invasive control methods alone.

Materiais restauradores em odontopediatria: preferência de pais e crianças e análise bibliométrica-altimétrica / Restorative materials in pediatric dentistry: children's and adults' preference and bibliometric-altmetric analysis

Atualmente, diversos materiais restauradores encontram-se disponíveis para aplicabilidade em Odontopediatria. Os avanços dos materiais restauradores conduzem à necessidade de novos estudos nessa temática. O presente estudo apresenta duas propostas de investigação: 1) Estudo transversal com objetivo de avaliar a preferência de pais/responsáveis e crianças quanto ao emprego do compômero colorido (Twinky Star®, Voco, Alemanha); 2) Estudo bibliométrico altimétrico com objetivo de analisar 50 artigos mais citados referente aos materiais restauradores utilizados em Odontopediatria e o alcance dessa informação científica nas mídias on-line. O estudo transversal envolveu 260 pares de pais/responsáveis e crianças de 5 a 11 anos de idade de dois serviços de saúde da região metropolitana de Belo Horizonte-MG. Exame quanto à cárie dentária foi realizado por examinadora calibrada para o critério da Organização Mundial da Saúde. Um manequim odontológico contendo restaurações com compômeros coloridos e materiais convencionais (resina composta, ionômero de vidro e amálgama) foi apresentado aos participantes do estudo e realizou-se inquérito sobre a preferência dos materiais dentários. O Questionário de Estilo e Dimensões dos Pais (PSDQ) e o Eysenck Personality Questionnaire Junior (EPQ-J) foram aplicados, este último apenas para pais/responsáveis de crianças de 5 e 6 anos de idade. Análises descritivas, bivariadas e regressão multivariada de Poisson foram realizadas. A maioria dos pais/responsáveis (74,2%) preferiu materiais convencionais. A idade da criança (p=0,006), a renda familiar (p= 0,001) e o nível de escolaridade (p< 0,001) associaram se a essa escolha. A análise multivariada demonstrou que crianças menores de 7 anos apresentaram 1,20 vezes maior probabilidade de escolher compômeros coloridos do que seus pares mais velhos (p< 0,001), assim como pais/responsáveis com menos de 11 anos de escolaridade e cujos filhos eram menores de 7 anos apresentaram 2,17 e 1,74 maior probabilidade para escolher compômeros coloridos, respectivamente. Concluiu-se que responsáveis com maior escolaridade apresentaram maior resistência às restaurações coloridas e crianças menores de 7 anos aceitaram melhor este material. O estudo bibliométrico-altimétrico adotou estratégia de busca em três bases (Web of Science, Scopus e Google Scholar), independente da data de publicação. Após seleção dos artigos por um grupo de cinco pesquisadores, em março de 2023, foram incluídos estudos que avaliassem qualquer material restaurador empregado em dentes decíduos e analisados dados referentes ao título, número de citações, país/continente, autoria, periódico, instituição, desenho do estudo, tipo de material restaurador, e escore altimétrico. Os artigos, publicados entre 1991 a 2002, apresentaram variação de citações de 19 a 113. Os autores com maior número de citações foram Qvist V e Teglers PT. O estudo experimental foi o principal delineamento de estudo observado e o cimento de ionomero de vidro foi o material mais reportado. A Europa foi o continente, e o Brasil, o país com maior número de citações. O escore altimétrico esteve presente em 23 artigos, com ênfase para dois artigos (43/6º e 73/7º). Concluiu-se que o cimento de ionômero de vidro foi o material mais estudado. Ficou evidente o distanciamento entre a posição dos trabalhos nas análises bibliométrica e altimétrica, apontando necessidade de disseminação da informação além dos círculos acadêmicos.

Currently, an arsenal of restorative materials is available for applicability in pediatric dentistry. The advances in restorative materials conducted to need for further studies in this thematic. The present study presents two investigation proposals: 1) Cross-sectional study aiming to evaluate the preference of parents and children regarding the use of colored compomer (Twinky Star®, Voco, Germany); 2) Bibliometric-altmetric study aiming to analyze the 50-most cited papers regarding to restorative materials used in pediatric dentistry and the dissemination of scientific information in online media. The cross-sectional study included 260 pairs of caregivers/children aged 5 to 11, in two public health services, in the metropolitan region of Belo Horizonte-MG. Examination for dental caries was performed by an examiner calibrated to the criteria of the World Health Organization. A dental mannequin containing colored compomers restorations and conventional materials (composite resin, glass ionomer cement and dental amalgam) was presented to the population and a survey was conducted about the preference of dental materials. Parents' Style and Dimensions Questionnaire (PSDQ) and Eysenck Personality Questionnaire Junior (EPQ-J) were applied, the last one only for parents/caregivers of children aged 5 to 6. Descriptive, bivariate and Poisson regression analyzes were performed. Most adults (74.2%) preferred conventional materials. Family income (p= 0.001) and education level (p< 0.001) were associated with its choice. Age up to 7 (p< 0.001) associated with children's choice for colored restorations (72.3%). Children younger than 7 had 1.20 higher probability to choose colored compomers than their older pairs, while adults with children younger than 7 and less than 11 years of schooling had 1.74 and 2.17 higher probability to choose colored compomers, respectively. It was concluded that caregivers with higher educational level showed greater resistance to use of colored restorations and children younger than 7 had better acceptance of colored material. The bibliometrics-altmetrics study adopted a search strategy in three databases (Web of Science, Scopus and Google Scholar), independent of the year of publication. After selection of papers by a panel of five researchers, in March 2023, any restorative material used in deciduous teeth was included and data about the title, number of citations, country/continent, authorship, journal, design of the study, type of restorative material, university and altmetrics score were analyzed. The papers, published between 1991 and 2002, ranged from 19 to 113 citations. The authors with the highest number of citations were Qvist V and Teglers PT. The experimental study was the main study design observed. Analyzing the continent and country with the highest number of citations, Europe highlighted and Brazil was predominant. The altmetric score was present in 23 papers, emphasizing two articles (43/6th and 73/7th). It was concluded that glass ionomer cement was the most studied material. A gap between the position of the papers correlating the bibliometrics and altmetrics analyzes was evident, demonstrating the need to disseminate the information beyond academic circles.

Does radiation therapy affect adhesion of tricalcium silicate cements to root dentin?

Abstract Objective This study aimed to analyze the effect of irradiation on the push-out bond strength of mineral trioxide aggregate (MTA) and Biodentine to radicular dentin. Methodology A total of 60 extracted mature human teeth with single root canals were categorized into two groups (irradiated and non-irradiated) (n=30). Each group was further divided into two sub-groups based on cements used (Biodentine and MTA). Then, a cumulative radiation dose of 60 Gy was divided into 30 fractions (two Gy for every fraction) and administered for five successive days per week over six weeks. Obturation was then performed using MTA and Biodentine. Afterwards, 1.5 mm thick horizontal sections were procured from the middle one-third of all the specimens and then subjected to push-out bond test. Results were analyzed using one-way analysis of variance with post-hoc Tukey's test. Results The bond strength of Biodentine and MTA to irradiated teeth was lower than non-irradiated teeth. Highest push-out bond strength was observed in non-irradiated specimens filled with Biodentine (p=0), followed by irradiated specimens filled with Biodentine (p=0); non-irradiated specimens filled with MTA (p=0); and irradiated specimens filled with MTA (p=0.9). Conclusion The push-out bond strength of Biodentine and MTA to root canal dentin decreased significantly post irradiation.

An engineering perspective of ceramics applied in dental reconstructions

Abstract The demands for dental materials continue to grow, driven by the desire to reach a better performance than currently achieved by the available materials. In the dental restorative ceramic field, the structures evolved from the metal-ceramic systems to highly translucent multilayered zirconia, aiming not only for tailored mechanical properties but also for the aesthetics to mimic natural teeth. Ceramics are widely used in prosthetic dentistry due to their attractive clinical properties, including high strength, biocompatibility, chemical stability, and a good combination of optical properties. Metal-ceramics type has always been the golden standard of dental reconstruction. However, this system lacks aesthetic aspects. For this reason, efforts are made to develop materials that met both the mechanical features necessary for the safe performance of the restoration as well as the aesthetic aspects, aiming for a beautiful smile. In this field, glass and high-strength core ceramics have been highly investigated for applications in dental restoration due to their excellent combination of mechanical properties and translucency. However, since these are recent materials when compared with the metal-ceramic system, many studies are still required to guarantee the quality and longevity of these systems. Therefore, a background on available dental materials properties is a starting point to provoke a discussion on the development of potential alternatives to rehabilitate lost hard and soft tissue structures with ceramic-based tooth and implant-supported reconstructions. This review aims to bring the most recent materials research of the two major categories of ceramic restorations: ceramic-metal system and all-ceramic restorations. The practical aspects are herein presented regarding the evolution and development of materials, technologies applications, strength, color, and aesthetics. A trend was observed to use high-strength core ceramics type due to their ability to be manufactured by CAD/CAM technology. In addition, the impacts of COVID-19 on the market of dental restorative ceramics are presented.

Use of Restorative Materials in Primary Teeth - A Retrospective University-Based Study

ABSTRACT Objective: To investigate the types of restorative materials used for restorative treatment in primary teeth through a retrospective university-based study. Material and Methods: The sample consisted of all clinical records of children attended at the Pediatric Dentistry Clinic at the School of Dentistry of Ribeirão Preto at the University of São Paulo in Brazil. Inclusion criteria were primary anterior and posterior teeth that received dental restorations for treatment of dental caries lesions, dental trauma or dental development defects from 2013 to 2018. Restoration repairs and interim restorations during this period were also recorded. Descriptive analyzes were performed to assess the distribution according to the type of restorative material used over the years. Results: A total of 5,236 restorative procedures were performed in primary teeth, including restoration repair and interim restorations. Of those, 69% were done in posterior teeth and 31% in anterior teeth. Sixty percent of the procedures performed during this period were made of composite resin and a lower percentage of glass ionomer cement (18%) followed by silver amalgam (1%). The number of interim restorations was smaller but proportional to those of composite resin over the years. Conclusion: A tendency to carry out restorative treatment of primary teeth with composite resin during the 6 years of follow-up was observed.

Background and surrounding colors affect the color blending of a single-shade composite

Abstract This study evaluated the background and effect of surrounding colors on the color blending of a single-shade composite used in a thin layer. Disc-shaped specimens (1.0 mm thickness) were built with the Vittra APS Unique composite surrounded (dual specimens) or not surrounded (simple specimens) by a control composite (shade A1, A2, or A3). Simple specimens were also built with only control composites. The specimen color was measured against white and black backgrounds with a spectrophotometer (CIELAB system). The whiteness index for dentistry (WID) was calculated for simple specimens. Differences (ΔE00) in color and translucency parameters (ΔTP00) between the simple/dual specimens and the controls were calculated. The translucency adjustment potential (TAP) and color adjustment potential (CAP) were estimated based on the ratios between data from simple and dual specimens. The Vittra APS Unique composite showed higher WID values than the controls. No differences between ΔTP00_SIMPLE and ΔTP00_DUAL were observed for any of the shades. The composite shade did not affect TAP values. The lowest values of ΔE00_SIMPLE and ΔE00_DUAL were observed for shade A1 regardless of the background color. For the white background, ΔE00_SIMPLE values did not differ from those of ΔE00_DUAL for all shades. Only A1 showed ΔE00_DUAL values lower than ΔE00_SIMPLE when the black background was used. The highest modulus of CAP (negative values for the white background) was observed when shade A1 surrounded the Vittra APS Unique composite. The color blending ability of the single-shade resin composite used in a thin layer was affected by both the surrounding shade and background color.

Bottom/top hardness ratio and dentin bonding stability of conventional and bulk-fill resin composites

Aim: To evaluate the bottom/top hardness ratio (B/T) and the dentin bonding stability of conventional and bulk-fill resin composites in high c-factor preparations. Methods: Regular conventional (Tetric N-Ceram ­ TNC, and Polofil Supra ­ PFS), regular bulk-fill (Tetric N-Ceram Bulk fill ­ TBF, and Admira Fusion X-tra ­ AFX), and low viscosity bulk-fill resin composites (Tetric N-flow ­ TNF, and X-tra Base ­ XTB) were used to restore 180 dentin conical preparations. The specimens were randomly distributed in 12 groups (n = 15) according to the resin composites and storage time-points (24 h and six months) tested. After 24 h storage, all specimens were subjected to the bottom/top hardness ratio analysis. Then, the push-out bond strength test was performed in half of the specimens and the other half were maintained for six months on water storage before testing. The failure modes were analyzed in a stereomicroscopic. The data were analyzed statistically using one- and two-way ANOVA and Tukey post-test (p <0.05). Results: There were no statistically significant differences for the bottom/top hardness ratio among the resin composites (p>0.05). Regardless of the storage timepoint, regular bulk-fill resin composites showed the highest bond strength values statistically (p<0.05). Only conventional resin composites showed statistically lower bond strength values at six-month storage (p<0.05). Adhesive failures were more predominant for low-viscosity bulk-fill resin composites. Conclusion: Although the DoC was not affected by different materials tested, only bulk-fill resin composites did not present dentin bond strength loss after six-month of water storage

Influence of bioactive particles and onium salt on the physicochemical properties of experimental infiltrants

Abstract This study evaluated physicochemical properties of experimental infiltrants after addition of hydroxyapatite nanoparticles (HAp) or 58S bioactive glass (BAG) and diphenyliodonium hexafluorophosphate (DPI). The resin matrix was composed of TEGDMA/Bis-EMA (3:1), 0.5 mol% CQ, and 1 mol% EDAB. The blends received or not 0.5 mol% DPI and 10% wt BAG or HAp. Icon was used as commercial control. The groups were characterized by XRD, FT-IR spectrometry, and SEM before and after simulated body fluid (SBF) immersion for up to 7 days. Polymerization kinetics (n =3 ), water sorption and solubility (n=10), and viscosity (n = 3) were surveyed. For polymerization kinetics, the samples were polymerized for 5 min and the data were obtained from 40 s and 5 min. Statistical analysis was made using ANOVA and Tukey's test (a = 0.05). After 7 days of SBF immersion, XRD and FT-IR showed that the HAp crystalline phase was present only in the HAp groups. A lower degree of conversion (DC) and polymerization rate were observed for the Icon and BAG groups, whereas HAp showed higher values. For the BAG group, DPI increased polymerization rate and DC in 40 s. After 5 min, all groups presented DC above 80%. In groups with particles, the HAp groups exhibited higher viscosity, whereas DPI groups showed a decrease in viscosity. Icon had the highest water sorption. To conclude, BAG neither improved the physicochemical properties studied, nor did it show bioactive properties. The addition of DPI reduced viscosity caused by particle addition and also attenuated the DC decrease caused by BAG addition. The addition of bioactive particles to infiltrants should be seen with caution because they increase viscosity and may not bring major clinical improvements that justify their use. DPI might be indicated only if any component is added to the infiltrant to act as a compensation mechanism.

The possible association between the types of soft palate and gag reflex: a preliminary study / A possível associação entre os tipos de palato mole e o reflexo de vômito: um estudo preliminar

Objective: whether gag reflex, a common problem encountered during dental procedures, is associated with the different types of the soft palate has not been addressed so far. This preliminary study sought to assess the potential association between the different types of soft palate and gag reflex. Material and Methods: one hundred dental patients were recruited. The type of soft palate was determined. Subjective (self-reported) gag reflex was recorded based on many questions and past experience and on a 0-6 VAS. Objective assessment of gag reflex was done using different maneuvers where the posterior part of the tongue and the soft palate were touched by dental mirror, and by taking impression for the upper arch. The association between the types of soft palate and the subjective and objective recorded gag reflex were statistically tested. Results: there were 53 (53%), 33 (33%) and 14 (14%) of the participants with class I, class II and class III soft palate, respectively. A significant association was found between the type of the soft palate and gag reflex in response to one of the subjective items (P= 0.039), more prominent among females (P= 0.009). Concerning the objective assessment, no significant associations were found among males. Meanwhile more females with class II and class III suffered gag reflex and/or actual gagging upon taking the impression (P = 0.001). Conclusion: this study illustrated an association between the type of soft palate and gag reflex, and its severity in females (more specifically soft palate types II and III) more than in males (AU)

Objetivo: o reflexo de vômito, um problema comum encontrado durante procedimentos odontológicos, está ou não associado aos diferentes tipos de palato mole, não foi ainda abordado até o momento. Este estudo preliminar procurou avaliar a possível associação entre os diferentes tipos de palato mole e o reflexo de vômito. Material e Métodos:cem pacientes odontológicos foram recrutados. O tipo de palato mole foi determinado. O reflexo de vômito subjetivo (auto-relatado) foi registrado com base em muitas perguntas e experiências anteriores e em um VAS de 0-6. A avaliação objetiva do reflexo de vômito foi feita por meio de diferentes manobras onde a parte posterior da língua e o palato mole foram tocados por espelho dental e por meio de moldagem da arcada superior. A associação entre os tipos de palato mole e o reflexo de vômito subjetivo e objetivo registrado foi testada estatisticamente. Resultados: houve 53 (53%), 33 (33%) e 14 (14%) participantes com palato mole classe I, classe II e classe III, respectivamente. Foi encontrada associação significativa entre o tipo de palato mole e o reflexo de vômito em resposta a um dos itens subjetivos (P= 0,039), mais proeminente no sexo feminino (P= 0,009). Em relação à avaliação objetiva, não foram encontradas associações significativas entre os homens. Enquanto isso, mais mulheres com classe II e classe III sofreram reflexo de vômito e/ou engasgo real ao receber a impressão (P = 0,001). Conclusão: este estudo ilustrou uma associação entre o tipo de palato mole e reflexo de vômito e sua gravidade em mulheres (mais especificamente palato mole tipos II e III) mais do que em homens. (AU)