Complications with PMMA compared with other materials used in cranioplasty: a systematic review and meta-analysis

Abstract Polymethyl methacrylate (PMMA) has been considered a suitable material for cranioplasty. However, no consensus has been reached concerning the best material for cranioplasty with regard to minimizing complications. Thus, this systematic review and meta-analysis aimed to compare the complication rates of PMMA with those of autologous bone and titanium mesh. This review was registered with PROSPERO (CRD42016042725). Systematic searches were conducted on PubMed/MEDLINE, Scopus, and Web of Science. The focus question was, "Do PMMA prostheses used in cranioplasty have complications rates similar to those of autologous bone and titanium mesh?" A meta-analysis of complication rates was performed on the basis of dichotomous outcomes assessed by risk ratio (RR) with corresponding 95% confidence intervals (CI). From 1014 data sources, 11 articles were selected according to eligibility criteria. These articles involved 1,256 individuals and 1,278 cranioplasties using autologous bone (n = 408), PMMA (n = 379), or titanium (n = 151). The follow-up period ranged from 63 days to 54.3 months. No difference was observed between the complication rates of PMMA and autologous bone (p = 0.94; RR, 0.98; 95%CI, 0.54-1.75) or between PMMA and titanium (p = 0.38; RR, 1.59; 95%CI, 0.57-4.48). Sub-analysis of the reasons for craniotomy (trauma/non-trauma) was conducted, which revealed no significant difference (p = 0.91; RR, 0.95; 95%CI, 0.37-2.42). The meta-analysis indicated that the use of PMMA yields complication rates that are near those of autologous bone and titanium mesh.

Bond strength to dentin of total-etch and self-etch adhesive systems / Resistência de união à dentina de sistemas adesivos convencionais e autocondicionante

OBJECTIVE: To assess the bond strength to dentin of the Single Bond (3M ESPE) and XP Bond (Dentsply) total-etch and Adper SE Plus (3M ESPE) self-etch adhesive systems. METHODS: Fifteen healthy human third molars were randomly allocated across three different groups of five teeth each according to the adhesive system. The occlusal portion of each tooth was removed under refrigeration using a flexible diamond disc (EXTEC, Enfield, CT, USA) down to an area of dentin that did not reveal enamel, as confirmed under a 40X stereo microscope (Ramsor, São Paulo, Brazil). A standardized smear layer was created with #600 grit silicon-carbide paper. The adhesive systems were applied as per manufacturer recommendations, with the exception of the Adper SE Plus system, which was triple-polymerized. Composite resin blocks (5 mm) were placed on the dentin surface. The specimens were stored in distilled water for 24 hours at 37ºC. Using a flexible diamond disc (EXTEC, Enfield, CT, USA), toothpick-like specimens with an adhesive area of less than 1 mm² were obtained. A microtensile bond test was then carried out using a universal testing machine (KRATOS) with a crosshead speed of 0.5 mm/min. Analysis of variance (ANOVA) and Tukey's test were used for comparisons. RESULTS: The bond strength values obtained with each adhesive system were as follows: XP Bond, 96.24 MPa; Adper Single Bond, 72.39 MPa; Adper SE Plus, 49.91 MPa. CONCLUSION: In terms of bond strength to dentin, conventional adhesives outperform self-etching systems. .

OBJETIVO: Avaliar o grau de resistência de união à dentina dos sistemas adesivos de condicionamento ácido total Adper Single Bond (3M ESPE) e XP Bond (Dentsply) e autocondicionante Adper SE Plus (3M ESPE). MÉTODOS: Quinze terceiros molares humanos hígidos foram utilizados, divididos aleatoriamente em três grupos de cinco dentes cada, conforme o adesivo que seria utilizado. A porção oclusal foi removida com o auxílio de um disco flexível diamantado sob refrigeração, até expor uma área de dentina que não apresentasse ilhas de esmalte, comprovado em lupa esterioscópica em aumento de 40X. A smear layer foi padronizada em lixa d'água n°600. Na sequência os sistemas adesivos foram aplicados conforme as recomendações do fabricante, exceto o Adper SE Plus que teve seu tempo de polimerização triplicado. Sobre os dentes preparados foram construídos blocos de resina composta com 5mm de altura. As amostras foram armazenadas por 24 horas a 37°C em água destilada. Utilizando o disco flexível diamantado, foram obtidos corpos de prova com formato de palitos com área adesiva menor que 1mm². Em seguida o teste de microtração foi realizado numa Máquina de Ensaios Universal numa velocidade de 0,5 mm/min. Foram utilizados o teste ANOVA e comparações pareadas de Tukey. RESULTADOS: Os valores da resistência de união para cada sistema adesivo em Mpa foram: 96,24 (XP Bond); 72,39 (Adper Single Bond) e 49,91 (Adper SE Plus). CONCLUSÃO: Dessa forma, em relação à resistência de união à dentina, os adesivos convencionais apresentaram desempenho superior ao autocondicionante. .

Influence of etching time and bonding strategies on the microshear bond strength of self- and light-cured pit-and-fissure sealants

This study evaluated the impact of extended etching and bonding strategies on the microshear bond strength of three sealant materials. Two pit-and-fissure sealants [FluroShield, Dentsply (light-cured) and AlphaSeal, DFL (self-cured)] and one light-cured flowable composite resin (Permaflo, Ultradent) were evaluated according to different enamel etching times (15 s or 30 s) and bonding procedures (no adhesive application, application of primer/hydrophobic resin or hydrophobic resin only). Intact enamel blocks were obtained from bovine teeth and sealed via the tested protocols. After 24 h, the microshear bond strength test was performed in a universal testing machine at a crosshead speed of 0.5 mm/min. Failure modes were classified by stereomicroscopy. Data were submitted to a three-way ANOVA and to Tukey's test (α=0.05). There was no statistically significant difference (p>0.05) among the materials. Permaflo showed higher bond strength when etched for 30 s alone. Enamel overetching decreased the bond strength of the light-cured sealant. Primer/bond previous treatment improved bond performance for AlphaSeal. In conclusion, from the tested conditions, all sealant materials presented similar bond strength values in relation to bonding protocol and etching time. The flowable composite can be used as a pit-and-fissure sealant. The use of a three-step adhesive system was essential for the self-cured sealant application.

Este trabalho avaliou o impacto de tempos aumentados de condicionamento ácido e da estratégia adesiva na resistência de união por microcisalhamento de três materiais utilizados como selantes de fóssulas e fissuras. Dois tradicionais selantes, [FluroShield, Dentsply (fotoativado) e AlphaSeal, DFL (quimicamente ativado)] e uma resina composta de baixa viscosidade (Permaflo, Ultradent) foram utilizados de acordo com diferentes tempos de condicionamento ácido (15 s e 30 s) e diferentes estratégias de união (sem aplicação de sistema adesivo, aplicação de um primer + resina hidrófoba, e aplicação apenas de uma resina hidrófoba). Fragmentos de esmalte intacto foram obtidos de incisivos bovinos e os materiais foram aplicados respeitando-se os protocolos anteriormente descritos. Após 24 h, o teste de microcisalhamento foi executado utilizando-se uma máquina de ensaio universal, com velocidade de 0,5 mm/min. O padrão de fratura foi classificado com auxílio de lupa estereoscópica. Os dados foram submetidos aos testes ANOVA a três critérios e de Tukey (α=0.05). Não houve diferenças estatisticamente significantes entre os materiais. Permaflo apresentou maior resistência de união quando o esmalte foi condicionado por 30 s apenas. O sobrecondicionamento do esmalte diminuiu a resistência de união do selante fotopolimerizável. O tratamento prévio do esmalte com primer + resina hidrófoba melhorou a performance adesiva para o AlphaSeal. Todos os materiais apresentaram valores de resistência de união estatisticamente similares em relação ao protocolo adesivo e ao tempo de condicionamento ácido. A resina composta de baixa viscosidade poderá ser utilizada como selante de fóssulas e fissuras. A aplicação de um sistema adesivo de três passos é essencial durante o selamento com selante quimicamente ativado.

In vitro evaluation of incompatibility between simplified adhesive systems and dual-cure resin cement / Avaliação in vitro da incompatibilidade entre sistemas adesivos e cimento resinoso dual

Objective: The aim of this study was to evaluate the incompatibility between simplified adhesive systems and dual-cure resin cement by means of marginal micro-leakage testing. Methods: Standardized cavity preparations were performed in 30 bovine teeth. The adhesive systems Adper Scotchbond Multipurpose Plus (3M ESPE, St. Paul, MN, USA) - Group A, Excite (Ivoclar/Vivadent, AG, Liechtenstein) - Group B, and Adper Prompt L-Pop (3M ESPE, St. Paul, MN, USA) - Group C, were applied and the cavities were filled with dual-cure resin cement (Enforce - Denstply, Milford, DE, USA). The samples were submitted to five hundred thermal cycles, after which they were immersed in 2% buffered methylene blue. Results: Group A presented the lowest mean percentage of micro-leakage (3.34%), followed by Group B (13.60%) and Group C (48.33%). Significant differences were found among the groups after the application of the Kruskal-Wallis statistical test (P=0.00). Conclusion: The highest mean marginal micro-leakage values were shown with the use of the one-bottle etch-and-rinse adhesive system and the all-in-one self-etch system, which demonstrates the incompatibility between these materials.

Objetivo: Avaliar a incompatibilidade entre sistemas adesivos e cimento resinoso dual através de teste de microinfiltração marginal. Métodos: Foram realizados preparos cavitários padronizados em 30 dentes bovinos divididos em 3 grupos: A) Adper Scotchbond Multipurpose (3M ESPE, St. Paul, MN, USA); B) Excite (Ivoclar/Vivadent, AG, Liechtenstein) e C) Adper Prompt L-Pop (3M ESPE, St. Paul, MN, USA). Após aplicação dos adesivos, as cavidades foram preenchidas com cimento resinoso dual Enforce (Denstply, Milford, DE, USA), submetidos à ciclagem térmica (500 ciclos) e imersos em azul de metileno 2% tamponado. Resultados: O grupo A apresentou os menores percentuais de microinfiltração (3,34%), seguido pelo grupo B (13,60%) e pelo grupo C (48,33%). Após aplicação do teste estatístico Kruskal-Wallis, foram detectadas diferenças estatisticamente significativas entre os três grupos (P=0.00). Conclusão: Houve incompatibilidade na associação entre os sistemas adesivos, convencional de dois passos (Excite, Ivoclar/Vivadent, AG, Liechtenstein) e autocondicionante de passo único (Adper Prompt L-Pop (3M ESPE, St. Paul, MN, USA), e o cimento resinoso dual Enforce (Denstply, Milford, DE, USA).

Impact of adhesive and photoactivation method on sealant integrity and polymer network formation

We evaluated the influence of photoactivation method and hydrophobic resin (HR) application on the marginal and internal adaptation, hardness (KHN), and crosslink density (CLD) of a resin-based fissure sealant. Model fissures were created in bovine enamel fragments (n = 10) and sealed using one of the following protocols: no adhesive system + photoactivation of the sealant using continuous light (CL), no adhesive system + photoactivation of the sealant using the soft-start method (SS), HR + CL, or HR + SS. Marginal and internal gaps and KHN were assessed after storage in water for 24 h. The CLD was indirectly assessed by repeating the KHN measurement after 24 h of immersion in 100% ethanol. There was no difference among the samples with regard to marginal or internal adaptation. The KHN and CLD were similar for samples cured using either photoactivation method. Use of a hydrophobic resin prior to placement of fissure sealants and curing the sealant using the soft-start method may not provide any positive influence on integrity or crosslink density.

Resistência ao cisalhamento e padrão de condicionamento de sistemas adesivos autocondicionantes em esmalte intacto e preparado / Shear bond strength and etching pattern of self-etching bonding agents on ground and intact enamel

Objective: The aim of this study was to evaluate the shear bond strength of four self-etching adhesive systems on intact and ground enamel, and also to evaluate the morphology of the enamel surface after etching.Methods: A total of 100 bovine central lower incisors were randomly divided into five groups: Single Bond (3M ESPE, St. Paul, USA), Adper Prompt L Pop (3M ESPE, St. Paul, USA), Clearfil SE Bond (Kuraray America, USA), One-up Bond F (Tokuyama Corp., Shibuya-ku, Tokyo, Japan) and AdheSE (Ivoclar/Vivadent, Schaan, Liechtenstein). Each group was subdivided (n=10), according to the surface preparation (intact or ground enamel). For intact enamel, the teeth were pumiced and ground enamel surfaces were obtained with wet 320-grit SiC paper. A circular (4mm) bonding area was demarcated and resin rods (Filtek Z250, 3M ESPE, St. Paul, USA) were built (5mm) for the shear test, followed by failure mode analysis using Scanning Electron Microscopy. In addition, 12 teeth were prepared for the evaluation of the etching pattern by Scanning Electron Microscopy. Statistical analysis of the data was performed with two-way ANOVA and Tukey?s test (p<0.05). Results: Significant differences were observed between the Shear bond strength values for the adhesive systems (p<0.001). No differences were found between the two substrates (p=0.598) nor any interaction between the adhesive systems versus substrate (p=0.404). The etching patterns were generally observed as mild when compared to phosphoric acid, except for Adper Prompt L Pop (3M ESPE, St. Paul, USA), which was similar to phosphoric acid. Conclusion: Shear bond strength was not influenced by the type of substrate (intact or ground enamel), and no correlation was observed between the Shear bond strength values and the etching pattern of the self-etching adhesives studied.

Objetivo: Avaliar a resistência ao cisalhamento e o padrão de condicionamento de quatro sistemas adesivos autocondicionantes em esmalte intacto e preparado. Métodos: Cem incisivos centrais inferiores bovinos foram aleatoriamente divididos em cinco grupos: Single Bond (3M ESPE, St. Paul, USA), Adper Prompt L Pop (3M ESPE, St. Paul, USA), Clearfil SE Bond (Kuraray America, USA), One-up Bond F (Tokuyama Corp., Shibuya-ku, Tokio, Japan) e AdheSE (Ivoclar/Vivadent, Schaan, Liechtenstein). Cada grupo foi subdividido (n=10) de acordo com o tipo de superfície. Os dentes com esmalte intacto foram limpos com pasta de pedra pommes/água e os com esmalte preparado tiveram a superfície do esmalte desgastada com lixas d?água (n.320). Uma área circular (4mm) foi demarcada para adesão e os cilindros de resina (Filtek Z250, 3M ESPE, St. Paul, USA) foram confeccionados (5mm). Após o ensaio resistência ao cisalhamento, foi realizada a avaliação do modo de fratura. Doze dentes foram preparados para avaliação do padrão de condicionamento em Microscopia Eletrônica de Varredura. A análise estatística dos dados foi realizada através do teste ANOVA para 2 fatores e teste de Tukey (p<0.05). Resultados: Diferenças estatisticamente significante foram observadas para a resistência ao cisalhamento entre os sistemas adesivos (p<0.001). Não foram observadas diferenças entre os substratos (p=0.598) ou ainda interações entre o sistema adesivo versus o substrato (p=0.404). Os padrões de condicionamento observados foram classificados em leve em relação ao padrão após o condicionamento com o ácido fosfórico, com exceção do padrão observado para o adesivo Adper Prompt L Pop (3M ESPE, St. Paul, USA). Conclusão: A resistência ao cisalhamento não foi influenciada pelo tipo de substrato, e, nenhuma correlação entre os valores de resistência ao cisalhamento e padrão de condicionamento dos adesivos autocondicionantes estudados foi observado.

Caninos superiores permanentes impactados: revisión de literatura y presentación de caso clínico / Impacted permanent maxillary canines: review of literature and presentation of clinical case

El proceso de desarrollo de los caninos permanentes superiores es entre todos los dientes el más demorado y de trayecto más largo. En el periodo de transición para la dentición permanente podrá ocurrir la no erupción de estos dientes. El diagnóstico precoz de esta anomalía es fundamental para el correcto desarrollo de la dentición y oclusión y para un tratamiento efectivo y rápido. Por lo tanto, el propósito de este trabajo fue revisar algunos aspectos concernientes a la etiología, diagnóstico y conduta clínica en casos de caninos superiores impactados

he canine development process is the most delayed process of all teeth and also the one that takes the longest path until its eruption. During the period of transition from the mixed denture to the permanent one it may occur some problems of dental impactions. Early diagnosis of this anomaly is of major importance to have a proper occlusion development and to have a more efficient and short treatment. Therefore, it was purpose with this study, to review some aspects concerning to the etiology diagnosis and clinical conduct of canines maxillary impactions

Influencia del tiempo de almacenamiento en la resistencia de unión a la dentina desproteinizada: utilizando tres diferentes adhesivos dentales / Influence of storage time on the bond strength to dentin deproteinized: using three different dental adhesives

Este estudio "in vitro" tuvo como objetivo evaluar a lo largo del tiempo (24 horas y 6 meses), el tratamiento del sustrato dentinario (desmineralización, desproteinización y antioxidante) y su influencia en la resistencia de la unión a la dentina, con tres adhesivos dentales. Noventa terceros molares humanos sanos recién extraídos se utilizaron: 72 para el ensayo de microtracción y 18 para análisis de interfaz en Microscopio electrónico de barrido (MEB). Estos fueron divididos aleatoriamente en tres grupos: AdperTM Scotchbond Multi-Uso (n=24); AdperTM Single Bond 2 (n=24); y XP Bond (n=24). Cada grupo fue dividido en 6 subgrupos (n = 4) de acuerdo con el tratamiento de la superficie dentinaria y el tiempo de evaluación. Sobre la zona de unión de todos los cuerpos de prueba se hizo un cilindro de 5 mm con resina compuesta FiltekTM Z250 (3M ESPE). Para el ensayo de microtracción se obtuvieron palillos (0,8 mm2). El análisis estadístico mostró que, a excepción del adhesivo XP Bond (65,07 ± 23,05), cuando se utilizó NaOCl, las otras medias fueron mayores en el tiempo de 6 meses que en 24 horas. El análisis del MEB mostró un patrón morfológico con capa híbrida uniforme y tags regulares. Considerando los resultados, se concluyó que la técnica con NaOCl dependió del sistema adhesivo y el tiempo, que la neutralización con el ascorbato de sodio revertió los valores obtenidos con NaOCl para ciertos grupos

This in vitro study investigated the influence of time (24h and 6 months) the treatment of the dentin substrate (demineralization, deproteinization, and antioxidant), and its influence on the bond strength using three dental adhesives. Ninety healthy human third molars freshly extracted were used for the microtensile test (n=72) and SEM analysis (n=18) randomly divided into three groups: AdperTM Scotchbond Multipurpose (n = 24); AdperTM Single Bond 2 (n = 24) and XP Bond (n = 24). Each group was further divided into 6 subgroups (n = 4) according to the treatment and evaluation time. A cylinder of 5mm was produced on the area of union using the composite resin Z250 (3M ESPE) and sticks of 0.8mm2 were obtained for the microtensile test. The statistical analysis showed that when NaOCl was used the average bond strength at 6 months was higher for most groups, except for XP Bond (60.48 ± 21.14 MPa). SEM analysis showed an uniform hybrid layer morphology and regular tags. Considering the results the effects of the NaOCl treatment on the bond strength was dependent on the adhesive system and time, and neutralization with sodium ascorbate reversed the values obtained with NaOCl for certain groups

Clinical trials with nanoparticle composite in posterior teeth: a systematic literature review

Aim: The aim of this article is to evaluate clinical trials with nanoparticle composite in posterior teeth through a systematic review of the literature. Methods: This analysis includes controlled clinical trials with nanoparticle composites, with at least 6 months of evaluation, published in the English language between 1997 and 2009. In vitro and retrospective studies and studies on anterior teeth were excluded. Articles were retrieved from the following full-text electronic journal databases: MEDLINE, LILACS and The Cochrane Library. Results: The largest number of articles was found in the MEDLINE database, but only 4 of them met the inclusion and exclusion criteria. No articles were found in the LILACS database; only two articles were selected from The Cochrane Library databases and they coincided with those already included in MEDLINE. Conclusions: The nanoparticle composites give a satisfactory performance for use in posterior teeth for at least 2 years of functional activity, but their performance was not superior to that of the other composites. Long-term studies must be conducted to evaluate the performance after 2 years of functional activity. New controlled and randomized clinical trials are necessary.

Remoção de dentina cariada: abordagem atual / Carious dentine removal: current approach

A odontologia se renova a cada dia mediante os resultados de pesquisas qualificadas. A abordagem quanto à remoção da dentina cariada está passando por questionamentos e inovações. O escopo desse trabalho foi realizar uma revisão literária no sentido de elucidar questões pertinentes à problemática da necessidade ou não de remover completamente a dentina cariada e da possibilidade de restaurar em sessão única, além de discutir a respeito de qual material deve ser aplicado nesse tipo de substrato. Após a análise dos artigos referenciados, concluiu-se que o tratamento expectante controla a progressão da cárie, há uma tendência na literatura de remover a dentina cariada parcialmente em lesões profundas e restaurar de forma definitiva. O cimento de hidróxido de cálcio é um forrador clássico nessas situações, enquanto o cimento de ionômero de vidro e os materiais resinosos representam outras possibilidades de materiais que podem estar em íntimo contato com a dentina remanescente.

Dentistry is renewed day after day through the results of qualified researches. The approach as regards carious dentin removal is going through questioning and innovation. The scope of this study was to perform a literature review in the sense of elucidating questions pertaining to the problem of whether or not it is necessary to completely remove carious dentin, and the possibility of performing restoration in a single session, in addition to a discussion about which type of material should be applied in this type of substrate. After analyzing the referenced articles, it was concluded that the stepwise treatment controls caries progression; there is a trend in the literature to partially remove the carious dentin in deep lesions and perform definitive restoration; Calcium hydroxide cement is a classical liner in these situations, while glass ionomer cement and resinous materials are other possibilities of materials that can be in close contact with the remaining dentin.

Comparative radiopacity of four low-viscosity composites

The aim of this study was to evaluate the radiopacity of four commercially available low-viscosity composites. The lowviscosity composites used in this study were Natural Flow, Flow It, Filtek Flow and Protect Liner F. Five specimens of each material were made in stainless-steel ring moulds of 10 mm diameter and 2 mm height. One specimen of each material and a 10-step aluminium wedge were radiographed in an occlusal film. The reading of the optical density was performed in five different locations in each radiographed specimen. The net optical density was calculated, and then the mean values were obtained, and related with the equivalent thickness of aluminium. The radiopacities of each composite, in millimeters of aluminium were: Flow It (3.24 ± 0.17); Filtek Flow (2.25 ± 0.17); Natural Flow (1.50 ± 0.13); Protect Liner F (<1 mm/Al). Flow It and Filtek Flow presented an acceptable radiopacity according to the ISO Standard 4049. Natural Flow and Protect Liner F did not supply the requirements for radiopacity, thus, these materials could be confounded with secondary caries in some clinical applications, such as restorations or cavity lining.