Flexural strength and Vickers hardness of milled and 3D-printed resins for provisional dental restorations

Various forms of temporary resins are offered on the market; however, the properties of temporary resins obtained by milling and 3D printing have not been fully examined. This study aimed to compare the flexural strength and Vickers hardness of milled and 3D-printed resins. Methods: Three resins were tested: Evolux PMMA (milled resin), Cosmos Temp (3D-printed resin), and Structur 2 SC (bis-acrylic resin, group control). Specimens were prepared with rectangular shapes (n = 12) for flexural strength measurements and disc shapes (n = 9) for Vickers hardness tests. Flexural strength tests were performed at a crosshead speed of 0.75 mm/min, and the Vickers hardness was measured under a load of 20 N for 10 s. The obtained data were subjected to the Kruskal­Wallis test. Results: A significant difference (p < 0.05) in flexural strength was observed among the three sample groups: Evolux PMMA (111.76 MPa), Structur 2 SC (87.34 MPa), and Cosmos Temp (56.83 MPa). No significant difference (p < 0.05) was observed between the Vickers hardness values of Structur 2 SC (33.37 VHN) and Evolux PMMA (29.11 VHN); however, both materials were statistically superior to Cosmos Temp (10.90 VHN). Conclusion: While the mechanical properties of the milled resin were superior or similar to those of the bisacrylic resin, the 3D-printed resin was statistically inferior to both the milled and bis-acrylic resins

Immediate prosthetic rehabilitation of lower molars with hybrid internal tapered implants: report of two cases / Reabilitação protética imediata de molares inferiores com implantes cônicos internos híbridos: relato de dois casos

ABSTRACT The immediate rehabilitation of the posterior region of the mandible with dental implants, expands the set of possible actions for the dental surgeon, in the face of tooth loss. The purpose of this study is to describe two cases of single rehabilitation of mandibular molars with hybrid internal tapered implants indicated for immediate loading in post-extraction socket, associated with the maintenance of the prosthetic and peri-implant space. Implants with macrogeometry and surface treatment (Hydrophilic) were used to optimize primary stability, as well as the type of internal connection and prosthetic abutments that allows better accommodation and healing of adjacent tissues, and protection of the bone graft. Different methodologies of surgical guides did not influence the final result. The predictability of associating techniques and components can be observed in the 2-year follow-up. The initial planning combined with the new technologies enable to achieve stable and functional final restorations.

RESUMO A reabilitação imediata da região posterior da mandíbula com implantes dentários, amplia o conjunto de ações possíveis ao cirurgião dentista, frente as perdas dentárias. O intuito desse estudo é descrever dois casos de reabilitação unitária de molares inferiores com implantes cônicos internos híbridos indicados para carregamento imediato em alvéolos pós-extração, associado a manutenção do espaço protético e peri-implantar. Foram utilizados implantes com macrogeometria e tratamento de superfície que otimizassem a estabilidade primária (Hidrofílicos), bem como o tipo de conexão interna e abutments protéticos que permitisse melhor acomodação e cicatrização dos tecidos adjacentes, e proteção do enxerto ósseo. Diferentes metodologias de guias cirúrgicos não influenciaram o resultado final. A previsibilidade da associação de técnicas e componentes pode ser observada no follow-up de 2 anos. O planejamento inicial aliado às novas tecnologias permite restaurações finais estáveis e funcionais.

Factors associated with decision-making for replacing the temporary coronal restoration after endodontic treatment

Aim: This study aimed to evaluate the decision-making by patients to replace temporary restorations with permanent restorations after endodontic treatment and to verify the associated factors and evaluate the quality/integrity of the temporary restorative material within one month. Methods: This is a cross-sectional study using non-probabilistic sampling which analyzed patients after one month of endodontic treatment. The self-administered questionnaire contained sociodemographic, treatment decision-making and endodontic treatment questions. The restoration present in the mouth was evaluated in the clinical oral examination. The Poisson Regression test was used to verify the prevalence ratio. Results: The prevalence failure to perform permanent restorations was 61.1% of patients, and 42.7% reported not having adhered. The reasons are lack of time and not knowing the importance of replacing the restoration with a definitive one. The glass ionomer temporary restorative frequency was higher among those who chose not to replace the temporary restoration with a permanent one (PR=5.19; 95%CI 2.10-12.33). In addition, there was an association between the quality of the restorative material and the type of material, and the best clinical quality of the restoration was statistically associated with glass ionomer and composite resin. Conclusions: The findings show the importance of guidance by the dental surgeon in helping patients decide to replace their temporary restoration

The impact of provisional intraradicular retainers cementation with temporary methacrylate-based resin in the bond strength of glass fiber posts to root dentin.

Chemical composition of temporary cements interferes in the bond strength and quality of the bond interface of glass fiber posts to root dentin. The aim of the present study was to evaluate the influence of different temporary cements on the bond strength of fiberglass posts and resin cement. Thirty-two maxillary central incisor roots were standardized at 15 mm length. The root canals were prepared with Reciproc R50 and filled with a R50 single cone and AH Plus. Ten mm of filling material was removed with a heated Schilder condenser, leaving 5 mm of apical filling material. The roots were randomly distributed into 4 groups (n = 8). In the control group, the root canal was prepared with a standard drill according to the post diameter (DC #1, FGM, Joinville, Brazil), irrigated with 5 mL of distilled water and immediately received the fiberglass post cemented with self-adhesive resin cement. For the other groups, cores were made with temporary intraradicular retainers cemented with different temporary cements: methacrylate-based resin (Bifix Temp - Voco), calcium hydroxide-based (Provicol - Voco) and zinc oxide-based - eugenol-free (Relyx Temp NE - 3M). After 7 days, mechanical removal of the temporary retainers, preparation, irrigation of the root canal and cementation of the fiberglass post were performed, following the same protocol that had been performed in the control group. The roots were sectioned to obtain 3 slices per root third. The most cervical section of each third was used for the push-out test and failure pattern analysis, while the most apical section was subjected to analysis of the adhesive interface by scanning electron microscopy (SEM). The BS data were compared between groups using the two-way ANOVA and Tukey post-test. The failure pattern results were expressed in percentage and compared between groups using the chi-square test and the material adaptation data at the bond interface were evaluated using the Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. The results showed higher BS in the cervical third, with a higher value in the control group (10.8 ± 0.94) and Bifix Temp group (9.78 ± 0.71), with no statistically significant difference between these groups (P > .05). The middle and apical thirds showed no statistically significant difference (P > .05). As regards the type of failure, a higher percentage of mixed adhesive failures was observed for all groups. Analysis of the adhesive interface by SEM showed that the temporary cement Bifix Temp showed greater adaptation at the bond interface. It was concluded that the methacrylate-based resin temporary cement showed the highest bond strength values and best adaptation to root dentin than the zinc oxide-based and calcium hydroxide-based temporary cements.

Influence of different separating mediums applied on the immediate dentin sealing in the tensile strength of temporary restorations / Influência de diferentes agentes isolantes aplicados sobre o selamento dentinário imediato na resistência à tração de restaurações provisórias

Objective: To evaluate the ability of different separating mediums to prevent adhesion between provisional restorations and hybridized dentin surfaces when used with the Immediate Dentin Sealing technique (IDS). Material and Methods: 120 extracted human teeth ­ 40 premolars and 80 molars ­ were selected to integrate acrylics samples separated into 4 different groups (n=10) according to the separating medium used for IDS protection. Forty samples were made of three teeth mounted in a self-cure acrylic resin block (Jet, Classic, São Paulo, Brazil) arranged side by side, simulating the positioning and proximal contacts present in the dental arch between the second premolar, first molar and second molar. A standard dental preparation for ultra-thin occlusal veneer was performed and complete occlusal dentin exposure was achieved by selective removal of the occlusal enamel with a high-speed conical round burr (Code: 1801.4138 FG, KG Sorensen, Medical Burs Ind. e Com. de Pontas e Brocas Cirúrgicas Ltda, São Paulo, Brazil). Dentin hybridization were performed on the control group and 3 different groups of separating mediums (n=10): PC­commercial provisional separating agent (Pro-V Coat, Bisco, Schaumburg, USA); GG­glycerin gel (K-Y Gel; Johnson & Johnson Industry and Commerce LTDA, São Paulo, Brazil); PJ­petroleum jelly (Rioquímica, São Paulo, Brazil). Provisionalization were manufactured on the prepared teeth. After 2 weeks, the tensile test was performed, and the analysis of the failure pattern was performed by 3D laser confocal microscopy and Scanning Electron Microscopy (SEM). The data were analyzed with the 1-way ANOVA and the Tukey test (α = 0.05). Results: Significantly lower tensile strength values were found for the commercial provisional separating agent (30.39 ± 10.01 N) compared to others (p < 0.05). Conclusion: The commercial provisional separating agent showed greater effectiveness on protecting hybridized dentin against the provisional restorations (AU)

Objetivo: Avaliar a capacidade de diferentes agentes isolantes em prevenir a adesão entre as restaurações provisórias e a superfícies de dentina hibridizadas quando usados com a técnica do Selamento Dentinário Imediato (IDS). Material e Métodos: 120 dentes humanos extraídos - 40 pré-molares e 80 molares - foram selecionados para integrar as amostras de acrílico divididas em 4 grupos diferentes (n = 10) de acordo com o meio de separação usado para proteção IDS. Foram confeccionadas 40 amostras de três dentes montados em um bloco de resina acrílica autopolimerizável (Jet, Classic, São Paulo, Brasil) dispostos lado a lado, simulando o posicionamento e os contatos proximais presentes na arcada dentária entre o segundo pré-molar, primeiro molar e segundo molar. Um preparo dentário padrão para laminado oclusal ultrafino foi realizado e a exposição completa da dentina oclusal foi obtida pela remoção seletiva do esmalte oclusal com uma broca cônica arredondada de alta rotação (Código: 1801.4138 FG, KG Sorensen, Medical Burs Ind. E Com. de Pontas e Brocas Cirúrgicas Ltda, São Paulo, Brasil). A hibridização da dentina foi realizada no grupo controle e em 3 grupos diferentes de agentes isolantes (n = 10): PC - agente de separação provisório comercial (Pro-V Coat, Bisco, Schaumburg, EUA); GG ­ gel de glicerina (K-Y Gel; Johnson & Johnson Industry and Commerce LTDA, São Paulo, Brasil); PJ ­ vaselina (Rioquímica, São Paulo, Brasil). As restaurações provisórias foram fabricadas nos dentes preparados. Após 2 semanas, foi realizado o teste de tração, e a análise do padrão de falha foi realizada por microscopia confocal a laser 3D e Microscopia Eletrônica de Varredura (MEV). Os dados foram analisados com a ANOVA de 1 fator e o teste de Tukey (α = 0,05). Resultados: Valores de resistência à tração significativamente menores foram encontrados para o agente separador provisório comercial (30,39 ± 10,01 N) em comparação com os demais (p < 0,05). Conclusão: O agente separador provisório comercial mostrou maior eficácia para a proteção da dentina hibridizada contra as restaurações provisórias (AU)

Marginal Fit of Temporary Restorations Fabricated by the Conventional Chairside Method, 3D Printing, and Milling.

Objectives: This study aimed to compare the marginal fit of temporary restorations fabricated by the conventional chairside method, 3D printing, and milling. Materials and Methods: In this in vitro, experimental study, 14 temporary restorations were conventionally fabricated over an implant abutment and analog that had been mounted in a phantom model at the site of canine tooth, using auto-polymerizing acrylic resin and putty index. In digital manufacturing, the original model was scanned, and the final restoration was designed. Fourteen temporary restorations were milled out of polymethyl methacrylate (PMMA) blocks, and 14 others were printed by a 3D printer. Temporary crowns were placed on the abutment, and images were obtained from specific areas under a stereomicroscope at x100 magnification to measure the amount of marginal gap. Data were analyzed using one-way ANOVA and Tukey's test (α=0.05). Results: The mean marginal gap values for the temporary crowns in the 3D printing, milling, and chairside groups were 91.40, 75.28 and 51.23 µm, respectively. The crowns that were conventionally fabricated chairside exhibited the lowest marginal gap, and the difference in this respect was significant among the three groups (P<0.05). Conclusion: Temporary crowns fabricated by the chairside method showed significantly smaller marginal gap; however, the marginal gap of all three groups was within the clinically acceptable range.

Resistência flexural e adaptação marginal dos materiais restauradores provisórios utilizados em dentes tratados endodonticamente / Flexural strength and marginal adaptation of temporary restorative materials used in endodontically treated teeth

Avaliar a resistência flexural e a adaptação marginal dos materiais restauradores provisórios Clip F (CF),Bifix Temp (BT), Systemp.onlay (SO), Fill Magic Tempo (FT) e Provi Master F (PF), na dentina da coroa dentária de dentes tratados endodonticamente. Métodos: Inicial-mente, foram confeccionados dez espécimes de cada um dos materiais restauradores, que foram individualmente submetidos ao teste de resistência flexural, na máquina de ensaio eletromecânica. Para avaliar a adaptação marginal,a câmara pulpar de cinquenta pré-molares superiores foi restaurada com um dos materiais avaliados (n=10). Após sete dias, a interface entre a dentina e o material restaurador, no terço médio da coroa dentária, foi submetida à análise em microscopia eletrônica de varredura. A extensão de desadaptação dos materiais e os gaps formados com a dentina foram mensurados com o software Image J.Resultados: CF e BT demonstraram o maior e o menor valor de resistência flexural, respectivamente (p<0,05).Os valores demonstrados por SO, FT e PF foram similares entre si (p>0,05). Por outro lado, CF demonstrou a menor extensão de desadaptação marginal (em porcentagem)e extensão de gaps (em µm) (p<0,05) na interface com a dentina. BT apresentou valor intermediário, mas menor do que os dos SO, FT e PF (p<0,05) que, por sua vez, foram similares entre si (p>0,05). Conclusões: O CF demonstrou o maior índice de resistência flexural e menor extensão de desadaptação marginal e gaps, em comparação aos demais materiais restauradores provisórios (AU).

Objectve: This study evaluated the flexural strength and marginal adaptation of Clip F (CF), Bifix Temp (BT), Systemp.onlay (SO), Fill Magic Tempo (FT) and Provi Master F (PF) in endodontically-treated coronal dentin. Methods: Firstly, ten specimens of each restorative material were prepared, and submitted to flexural strength test using eletromechanical testing machine. Then, the pulp chamber of 50 maxillary premolar were restored using one of the provisional restorative materials (n = 10) in order to evaluate the marginal desadaptation extension. After 7 days, the interface between dentin and temporary restorative material, in crown middle third, was subjected to scanning electron microscopy (500X). Marginal desadaptation and gaps extensions in dentin-temporary restorations interface were measured using Image J software. Results: CF and BT presented the highest and the lowest flexural strength values, respectively (p <0.05). SO, FT and PF showed similar values (p> 0.05). In relation to marginal desadaptation (%) and gap extensions (µm), CF presented the lowest marginal desadaptation and gaps incidence values (p < 0.05). BT showed intermediate values, but lower than SO, FT e PF (p < 0.05), which were similar among them (p > 0.05). Conclusion: CF presented the best flexural strength and the lowest marginal desadaptation and gaps extension (AU).

Tendências atuais no tratamento endodôntico por cirurgiões dentistas no Brasil / Current trends in endodontic treatment by dental surgeons in Brazil

Objetivo: conhecer as principais práticas adotadas atualmente por cirurgiões dentistas, clínicos gerais e endodontistas na realização do tratamento endodôntico. Material e Métodos: um questionário contendo 21 perguntas de múltipla escolha foi enviado para os profissionais, nas cinco regiões do país. As perguntas abordaram o tempo de experiência, tipos de técnicas, materiais e recursos auxiliares. Resultados: a maior parte dos respondentes são do Sudeste e Sul, endodontistas há menos de 10 anos. Realizam até 20 tratamentos/mês, utilizam localizador apical, instrumentação manual com limas de aço inoxidável associada a brocas gates glidden/largo, lupa e isolamento absoluto. O hipoclorito de sódio (2,5 a 5%) e o EDTA são os irrigantes mais utilizados juntamente com o ultrassom. O tratamento é feito em sessão única, porém o diagnóstico pulpar pode alterar o número de sessões. Quando é necessário o uso de medicação intracanal, o hidróxido de cálcio associado a outras formulações é a primeira escolha. Para obturação do sistema de canais radiculares é utilizada a técnica de condensação lateral e o cimento à base de óxido de zinco e eugenol. O selamento coronário entre sessões é feito com coltosol e com cimento de ionômero de vidro ao término do tratamento, quando os pacientes são encaminhados a outro profissional para restauração final. Atualizam-se através de artigos científicos e mostram abertura para testar novos produtos. Conclusão: a maioria dos participantes aderem a práticas atuais com uso de novas tecnologias durante o tratamento e se atualizam através da leitura de artigos científicos

Objective: to be aware of the main practices currently adopted by general dentists and endodontists when performing endodontic treatments. Material and methods: a questionnaire containing 21 multiple-choice questions was sent to professionals in the five regions of Brazil. These questions covered experience time, techniques, materials and auxiliary resources. Results: most participants are from the Southeast and South regions of Brazil and have been specialized in endodontic for less than 10 years. They perform up to 20 treatments per month, use apex locator, manual instrumentation with stainless steel files associated with gates-glidden or largo burs, magnifying loupes and absolute isolation. Sodium hypochlorite (2.5 to 5.0%) and EDTA are the most used substances for irrigation associated with ultrasound. The treatment is done in a single visit, but pulp diagnosis might alter the number of visits. When intracanal medication is required, calcium hydroxide associated with other formulations is the first choice. For root canal filling, lateral condensation technique, zinc oxide and eugenol based sealers are used. Coronal sealing between sessions is done with Coltosol® and glass ionomer cement at the end of treatment, when patients are referred to another professional for final restoration. These professionals update their knowledge with scientific articles and show availability to test new products. Conclusion: most participants have been adhering to current practices (new technologies) during treatment and has kept updated by reading scientific articles

Color stability and surface roughness of chitosan- and nanodiamond-modified bisacrylic resin

Abstract: The aim of this study is to evaluate the effect of chitosan or nanodiamond incorporation on the color stability and surface roughness of a bisacrylic resin subjected to artificial aging. Four bisacrylic resins were evaluated, namely, control, chitosan-modified material, nanodiamond-modified material, and chitosan-nanodiamond-modified material. Twenty-four specimens were prepared for each material. The surface roughness was determined using a profilometer with a cut-off of 0.25 mm. The baseline color was measured according to the CIE L*a*b* system using a reflectance spectrophotometer. After these tests, the specimens were individually immersed in cola soft drink, red wine, or distilled water (n = 8) for 28 days. After the aging, the surface roughness and final color were re-evaluated. The color stability was determined using the difference between the coordinates obtained before and after the aging process. The data on roughness and color change were evaluated using ANOVA and the Tukey test (α = 0.05). The results show that the incorporation of nanodiamonds and chitosan into a bisacrylic resin provided a better color stability to the materials (p = 0.007). The storage in red wine resulted in a higher variation in the surface roughness values, especially when only the nanodiamond was incorporated to the material (p < 0.05). The incorporation of both chitosan and nanodiamonds are promising in providing an improvement in the properties of the bisacrylic resin when they are simultaneously incorporated in the product.

Marginal adaptation of provisional crowns made of acrylic and bisacrylic resins using different impression materials

Aim: To evaluate the marginal adaptation of provisional crowns made of acrylic and bisacrylic resins using different impression materials. Methods: a metal die and a matrix applied through a direct technique were used to fabricate the specimens. The impression materials used as a matrix were divided into four groups: Irreversible hydrocolloid(IH), laboratory silicone (LS), condensation silicone (CS), and addition silicone (AS). After the impression procedures, each matrix was loaded with the provisional prosthetic materials, Alike, Duralay, Protemp 4, and Structur 3 (n = 12). Marginal discrepancy was evaluated using a stereomicroscope at ×45 magnification. The images obtained were transferred to the Corel Draw X7 program, and the distances from the cervical margins of the specimen to the reference lines at the metal die were measured vertically. The data were analyzed by using 2-way ANOVA followed by the Tukey test (α=.05). Results: the acrylic resins had higher values ​​of marginal discrepancy compared to the bisacrylic resins. A statistically significant difference was found between all impression materials, and the irreversible hydrocolloid presented higher values of discrepancy (303.28­613.31 µm), whereas addition silicone had the lowest (48.61­190.06 µm). Conclusions: the bisacrylic resins had a better marginal adaptation compared to the acrylic resins. The addition silicone promoted a better marginal adaptation of the provisional prosthetic materials tested, followed by condensation silicone, laboratory silicone, and irreversible hydrocolloid

Evaluation of the marginal accuracy of provisional restorations made of acrylic resins

Aim: To evaluate the marginal accuracy of provisional crowns made with acrylics resins and to identify the surface(s) with the highest marginal discrepancy. Methods: A direct technique was used to fabricate 96 provisional restorations with 8 materials: Dencrilay, Dencôrlay, Dencôr, Vipicor, Duralay, Resinlay Speed, Refine Bright and Alike (n=12). The provisional crowns were made on a prepared molar-shaped metal die with a vinyl polysiloxane impression as a matrix. Marginal discrepancy of provisional restorations was analyzed at buccal, lingual, mesial and distal surfaces of metal die finish line in a stereomicroscope lupe at 100X. The images obtained were transferred to the Corel Draw X7 program and the distances from the cervical margins of the specimen to the reference lines were measured vertically. Comparisons were made with 1-way analysis of variance and the Tukey test (p <0.05). Results: The Alike resin exhibited the lowest marginal discrepancy (0.018 mm) and was significantly different from the Dencôrlay (0.037 mm), Filter Bright (0.034 mm), Duralay (0.033 mm) and Vipicor (0.032) resins. The buccal surface showed the highest marginal discrepancy (0.040 mm) compared to those of other surfaces (distal 0.029mm, lingual 0.028mm and mesial 0.024mm). Conclusion: The marginal adaptation of all materials and surfaces tested in this study were within a clinical acceptable limit. The Alike resin showed the best performance compared to Dencôrlay, Refine Bright, Duralay, and Vipicor resins. The buccal surface showed the highest marginal discrepancy than those of the other tested surfaces

Implante com estética imediata em região anterior da maxila: relato de caso / Implant with immediate aesthetics in the anterior region of the maxilla: case report

A reabilitação oral com o uso de implantes dentários teve um avanço significativo nos últimos anos. Sendo assim, a ausência dentária faz com que os profissionais e, principalmente, os pacientes procurem por alternativas imediatas para a substituição do dente perdido. Nessa perspectiva de otimização do tratamento, o implante com estética imediata passou a ser uma opção bastante viável e aceitável na Odontologia. Dessa forma, objetivou-se relatar um caso clínico de reabilitação do incisivo central superior com implante imediato, seguido de restauração provisória com finalidade estética. Conclui-se que a instalação imediata do implante após a exodontia está associada à redução da reabsorção óssea do alvéolo dentário, à diminuição do tempo de tratamento e ao resultado estético imediato, além de proporcionar ao paciente uma maior satisfação, devido à eliminação de um segundo procedimento cirúrgico para a instalação do implante

Oral rehabilitation with the use of dental implants has made significant progress in recent years. Thus, dental absence causes professionals and, especially, patients to seek immediate alternatives for the replacement of the missing tooth. In this perspective of optimization of the treatment, the implant with immediate aesthetics became a viable and acceptable option in implantology. In this way, it was aimed to report a clinical case of rehabilitation of the superior central incisive with immediate implant, followed by temporary restoration with aesthetic purpose. It is concluded that the immediate implantation of the implant after the extraction is associated with the reduction of bone resorption of the dental alveolus, reduction of the treatment time and immediate aesthetic result, besides giving the patient greater satisfaction due to the elimination of a second procedure for implant installation

Effect of colorant solutions on the color stability of provisional prosthetic materials

Aim: To evaluate the color stability of acrylic and bis-acrylic resins after immersion in 3 staining solutions. Methods: Forty-eight samples (10 x 2 mm) of each provisional restorative material (Duralay, Dencrilay, Structur 2 and Protemp 4) were fabricated and distributed into four groups (n = 12): G1 ­ distilled water (control group); G2 ­ a cola flavored soft drink; G3 ­ wine and G4 ­ coffee. The specimens were immersed for seven days at 37°C in the solutions, which were changed every 24 hours. The color of all specimens was measured with a spectrophotometer (VITA Easyshade Advance) before (T0) and after immersion (T1), and the color changes (ΔE) were calculated. Nonparametric Kruskal-Wallis tests were used, followed by Dunn's test with a significance level of 5%. Results: For the acrylic resins (Duralay and Dencrilay), the largest color change values were obtained in group G4 ­ coffee, whereas in the bis-acrylic resins (Protemp 4 and Structur 2), the largest color difference was observed in groups G3 ­ wine and G4 ­ coffee. The acrylic resins showed statistically significantly less color change than the bis-acrylic resins. Conclusions: The coffee and the wine promoted larger color changes in the provisional prosthetic materials tested in this study. The acrylic resins showed more color stability than the bis-acrylic resins

Marginal leakage of temporary restoration after intraradicular post preparation with or without waterproofing / Infiltração marginal de restauração temporária após o preparo de pino intrarradicular com ou sem impermeabilização

Objective: This study evaluated the leakage volume of 1% Rhodamine B which received or not an internal waterproofing material. The hypothesis is that the waterproofing reduces microleakage. Material and Methods: Forty-two human teeth were selected for this study. After access, preparation, and filling of root canals, the teeth were divided into 3 groups: GI ­ sealed with Cimpat Blanc®, without intraradicular post/core preparation; GII - sealed with Cimpat Blanc®, with intraradicular post/core preparation, and GIII ­ sealed with Cimpat Blanc®, with intraradicular post/core preparation and internal waterproofing material with ethyl cyanoacrylate. T-test was used to analyze difference between initial and final weight and there was difference (p < 0.05). To analyze infiltration of the colorant, the volume was the comparison variable. Results: Shapiro Wilktest was applied and showed normal distribution of the variables. ANOVA (p = 0.0013 / p< 0.5). Conclusion: In endodontically treated teeth receiving temporary restoration, the use of ethyl cyanoacrylate as internal waterproofing material is effective in preventing microleakage. (AU)

Objetivos: Este estudo avaliou o volume de infiltração de Rhodamine B 1% com ou sem impermeabilização interna. A hipótese é que a impermeabilização reduz a microinfiltração. Material e Métodos: Foram selecionados 42 dentes humanos para este estudo. Após o acesso, o preparo e a obturação dos canais radiculares, os dentes foram divididos em 3 grupos: GI - sem preparo para núcleo intrarradicular e selado com Cimpat Blanc®; GII - com preparo para núcleo intrarradicular e selado com Cimpat Blanc®, e GIII - com preparo para núcleo intrarradicular, impermeabilizado internamente com cianoacrilato de etila e selado com Cimpat Blanc®. O teste T foi utilizado para analisar a diferença entre o peso inicial e o peso final (p < 0,05). Para analisar a infiltração do corante, o volume era a variável de comparação. Resultados: o teste de Shapiro Wilk foi aplicado e mostrou distribuição normal das variáveis. O teste ANOVA (p = 0,0013 / p < 5%) foi aplicado e determinou uma diferença estatística entre os grupos. Ao comparar os grupos em conjunto, GIII mostra a menor taxa de vazamento quando comparado aos outros grupos, sendo estatisticamente diferente (teste de Tukey - p < 0,5). Conclusão: Nos dentes endodonticamente tratados com restauração temporária, o uso de cianoacrilato de etila como material impermeabilizante interno é eficaz na prevenção da microinfiltração (AU)

Evaluation of color stability of different temporary restorative materials / Avaliação da estabilidade de cor de diferentes materiais restauradores provisórios

Introduction: Temporary restorative materials are widely used, however, little is know about their color stability. Objective: to evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage. Material and method: Four materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) and 30 test specimens (15 mm in diameter and 2 mm thick) per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee) and storage time intervals (2, 5, 7 and 15 days). Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%. Result: Acrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767). As regards solutions tested, coffee showed the highest color change values (p<0.001), and the longer the storage time interval, the greater was the color change in all the temporaryrestorative materials analyzed (p<0.001). Conclusion: Acrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.

Introdução: Os materiais restauradores provisórios são amplamente utilizados, porém pouco se sabe a respeito de sua estabilidade de cor. Objetivo: Avaliar a estabilidade de cor de materiais restauradores provisórios: resina acrílica e resinas bisacrílicas, após a imersão em soluções pigmentantes, durante diferentes períodos de armazenamento. Material e método: Quatro materiais foram testados (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) sendo confeccionadas 30 amostras (15 mm de diâmetro e 2 mm de espessura) por material. Estes foram divididos de acordo com o meio de imersão (saliva artificial, saliva + refrigerante tipo cola e saliva + café) e período de armazenamento (2, 5, 7 e 15 dias). As mensurações de cor foram realizadas antes e após as imersões, com auxílio de um espectrofotômetro, através do sistema CIE L*a*b*. Os dados foram analisados com análise de variância (ANOVA) e Tukey, com nível de significância à 5%. Resultado: A resina acrílica apresentou maior estabilidade de cor quando comparada às resinas bisacrílicas (p<0,001). Comparando as resinas bisacrílicas, não foi observado diferença significativa entre as resinas Structur e Luxatemp (p=0,767). Em relação as soluções testadas, o café apresentou os maiores valores de alteração de cor (p<0,001), sendo que quanto maior o período de armazenamento, maior foi a alteração de cor de todos os materiais provisórios analisados (p<0,001). Conclusão: A resina acrílica apresentou maior estabilidade de cor, quando comparada às bisacrílicas. O café causou a maior alteração de cor, e o tempo de imersão foi determinante na estabilidade de cor dos materiais provisórios analisados.

In Vitro Fit and Cementation Resistance of Provisional Crowns for Single Implant-Supported Restorations

Abstract: This study aimed to verify marginal fit and the effect of cement film thickness standardization on retention of provisional crowns made with prefabricated acrylic cylinders on abutments, using two temporary luting agents subjected or not to mechanical cycling. Provisional crowns were made from bis-acryl (Luxatemp Fluorescence) or methyl methacrylate (Duralay) resins on acrylic cylinders and marginal fit and cement film thickness were evaluated. For retention evaluation, crowns were cemented with two temporary luting agents: non-eugenol zinc oxide (Tempbond NE) or calcium hydroxide-based (Hydcal) cements and subjected to tensile strength in a universal testing machine. After cleaning, debonded crowns were cemented again, subjected to mechanical cycling and retention was reassessed. The results of marginal fit and cement film thickness were analyzed by Student's t-test while retention of cements before and after mechanical cycling was analyzed using a mixed linear model. Methyl methacrylate crowns presented greater marginal misfit (p=0.001) and occlusal cement film thickness (p=0.003) than the bis-acryl ones. No difference was observed at axial cement film thickness (p=0.606). Resins (p=0.281) did not affect crown retention, but luting agents (p=0.029) and mechanical cycling (p=0.027) showed significant effects. The only significant interaction was mechanical cycling*luting agents, which means that luting agents were differently affected by mechanical cycling (p=0.002). In conclusion, the results showed that bis-acryl resin associated to calcium-hydroxide luting agent provided the best retention and lower cement thickness.

Resumo: O objetivo deste estudo foi avaliar a adaptação marginal e o efeito da espessura da camada de cimento na retenção de coroas provisórias fixadas sobre os pilares com o auxílio de cilindros acrílicos pré-fabricados, utilizando dois cimentos provisórios submetidos ou não à ciclagem mecânica. Coroas provisórias foram confeccionadas com resina bis-acrilíca (Luxatemp Flourescence) ou resina à base de metil metacrilato (Duralay) sobre os cilindros, para posterior avaliação da influência das diferentes resinas na adaptação marginal e na espessura da linha do cimento. Para a avaliação da resistência à tração, as coroas foram cimentadas com dois cimentos provisórios: à base de óxido de zinco sem eugenol (Temp Bond NE) ou hidróxido de cálcio (Hydcal) e submetidas ao teste de tração em máquina universal de ensaio. Após o ensaio, as coroas foram limpas e novamente cimentadas para serem submetidas à ciclagem mecânica e posterior avaliação da resistência à tração. Os resultados obtidos para adaptação marginal e espessura do cimento foram analisados pelo teste t de Student, enquanto os resultados de resistência à cimentação antes e após a ciclagem mecânica foram analisados pelo modelo linear de efeitos mistos. As coroas confeccionadas com a resina de metil metacrilato apresentaram maiores valores para desadaptação marginal (p=0,001) e espessura do cimento (p=0,003) na parede oclusal quando comparadas com as coroas de resina bis-acrílica. Não houve diferença na espessura do cimento (p=0,606) na parede axial das coroas provisórias. As diferentes resinas não afetaram a resistência à cimentação das coroas (p=0,281), mas os diferentes cimentos (p=0,029) e a ciclagem mecânica (p=0,027) mostraram efeitos significantes. A única interação significante foi ciclagem mecânica ?#61482; agente cimentante, o que significa que os cimentos foram diferentemente afetados pela ciclagem mecânica (p=0,002). Em conclusão, a associação resina bis-acrílíca e cimento de hidróxido de cálcio proporcionou melhor resistência à tração e menor espessura de cimento.

Infiltração marginal microbiana em selamento coronário duplo / Marginal microbial infiltration in coronary double sealing

Introdução: O selamento coronário deve ser eficiente em impedir a penetração de saliva e seus contaminantes para o interior do sistema de canais radiculares. Objetivo: Avaliar o grau de infiltração microbiana em selamento duplo coronário utilizando Coltosol® associado ao MaxxionR® e ao Bioplic®. Material e método: Foram utilizados dentes pré-molares humanos extraídos, nos quais foram realizadas aberturas coronárias padronizadas com seis milímetros de profundidade. Os grupos foram divididos de acordo com os cimentos restauradores provisórios: Grupo I - Bioplic®; Grupo II: Bioplic® + Coltosol®; Grupo III: Maxxion R®; Grupo IV: Maxxion R® + Coltosol®; Grupo V - Coltosol®; Grupo controle. Foi confeccionado um dispositivo adaptando-se os dentes na porção inferior de tubos Eppendorf®, de modo que dois terços se projetem para fora do tubo plástico. O dispositivo foi fixado em frasco de vidro, contendo 7 mL de caldo estéril "Brain Heart Infusion". Na porção superior do tubo Eppendorf, foi realizada a inoculação de Enterococcus faecalis. A leitura foi realizada a cada 24h, durante 30 dias, avaliando-se a turvação no meio de cultura em contato com o ápice dentário. Os resultados foram submetidos ao teste estatístico Kruskal-Wallis (p<0,05). Resultado: Houve infiltração em todos os grupos ao final dos 30 dias e os grupos I e IV apresentaram 50% de infiltração. Os grupos IV e V apresentaram infiltração em cinco dias e o grupo III, em 26 dias. Conclusão: A associação entre os cimentos restauradores provisórios não impediu nem diminuiu a infiltração marginal de Enterococcus faecalis. .

Introduction: The coronal sealing should be effective in preventing the penetration of saliva and its contaminants into the root canal system. Objective: To evaluate the degree of microbial coronal leakage in double sealing using Coltosol® associated MaxxionR® and Bioplic®. Material and method: premolars extracted human teeth were used, in which standardized with 6 mm deep coronary openings will be held. The groups were divided according to provisional restorative cements : Group I - Bioplic®; Group II - Bioplic® +Coltosol®; Group III - Maxxion R®; Group IV - Maxxion R® + Coltosol®; Group V - Coltosol®; Control Group. One adapting the teeth in the lower portion of Eppendorf® tubes device was manufactured so that two-thirds to protrude out of the plastic tube. The device was fixed to a glass vial containing 7 ml of sterile broth "Brain Heart Infusion". In the upper portion of the Eppendorf tube was inoculated with Enterococcus faecalis performed. The reading was performed every 24 hours for 30 days evaluating turbidity in the culture medium in contact with the tooth apex. The results were analyzed by Kruskal -Wallis test (p < 0.05) statistical test. Result: There was infiltration in all groups at the end of 30 days, and groups I and IV showed 66% infiltration. Groups IV and V showed infiltration in 5 days and group III in 26 days. Conclusion: The association between the provisional restorative cements not prevented nor decreased the leakage of Enterococcus faecalis. .

Renaissance or dimming hope - The dilemma of managing multi-surface dental carious lesions in primary dentition using an Atraumatic Restorative Treatment (ART)

Introduction: Atraumatic restorative treatment (ART) has been in use for the last couple of years. The survival rate of multi-surface restorations using this method has generally been very low for any given follow-up period. Most commonly quoted as the causes for the low survival rate included early restoration loss, poor choice of the cavity to be restored, operator factors, material factors and patient related factors, among other factors. Speculation has been that the premature loss may not actually denote failure to preserve the carious dental element, and that probably, the fluoride leach from the glass ionomer cement used with the technique, might be helping elongate the survival of the restored tooth. The question is whether, therefore, it is important to only look at the survival of the ART restoration or to also consider the survival of the tooth with premature restoration loss. Objective: To determine the current general survival rates of multi-surface ART restorations in the primary dentition, while simultaneously considering any consequences of the premature loss of these restorations in the primary dentition. The data for the study was obtained through Pubmed/Medline search for publications on multi-surface ART restorations from 2000 to 2011. Only publications on ART in the primary dentition were included and analyzed for survival rate, premature loss of restoration and effect of such loss. Conclusion: While the survival rates of multi-surface ART restorations in the review studies were low, the restorations appeared to provide some beneficial effects to the retention-longevity of the restored tooth even after the premature loss of restorations...

Avaliação da rugosidade superficial de três resinas acrílicas para restauração provisória submetidas a diferentes métodos de polimento / Evaluation of surface roughness of three temporary resins submittted in different methods of polishing

A lisura das restaurações provisórias proporciona saúde ao periodonto. O presente trabalho teve por objetivo verificar a rugosidade diante de diferentes métodos de polimento sobre três marcas comerciais de resinas acrílicas. Foram confeccionados 90 corpos de prova (cp) e estes foram divididos em seis grupos experimentais e três grupos controle. Para cada resina testada foi determinado um grupo controle, um grupo com polimento mecânico e outro com polimento químico. De acordo com os resultados obtidos, pôde-se concluir que a resina Clássico (termopolimerizável) permite um melhor polimento quando comparada às resinas bisacrílicas e à resina autoativada, respectivamente, e o polimento mecânico diante do químico mostrou-se mais efetivo nos três tipos de resina.

The provisional restorations are extremely important because they anticipate the definitive treatment. The smoothness of those restorations should get closer to reality to provide periodontal health. This study aims to verify the roughness on different methods of polishing on three brands of acrylic resins. Ninety specimens were made and these were divided into nine groups. Each resin tested was given a control group. From the data obtained by descriptive statistics, were tested within groups. Statistical inference was made by two-tailed tests. Results: we concluded that the resin Classic thermicpolymerized allows a better polish when compared with Luxatemp® Bis-Acryl resins and Dencor® thermoactivated respectively and mecanical polishing was more effective than chemical ones the three types of resin.

Antimicrobial activity of three temporary endodontic coronal sealers / Atividade antimicrobiana de três seladores coronários temporários em Endodontia

Objective: The object of the present study is to analyze, in vitro, the antimicrobial activity of three temporary endodontic coronal sealers.Methods: The materials tested were Tempo® (Vigodent, Rio de Janeiro, Brazil), IRM® (Dentsply, Petrópolis, Brazil) and Coltosol® (Vigodent, Rio de Janeiro, Brazil). The agar diffusion method was used for this analysis. Nine plates containing the agar blood culture medium were inoculated withhuman saliva and in each plate three equidistant cavities were made and filled with one of the materials tested. Two plates were not inoculatedand served as the negative control of the culture medium. All the plates were incubated in bacteriological incubators, in aerobiosis, for 48 hours, at 37oC. The inhibition halos of bacterial growth were measured in millimeters. Results: Tempo® (Vigodent, Rio de Janeiro, Brazil) did not show a inhibition halo of bacterial growth in any of the nine plates. Coltosol® (Vigodent, Rio de Janeiro, Brazil) produced halos in all plates, and IRM® (Dentsply, Petrópolis, Brazil) in 4 out of 9 plates. In all the tests, the halos produced by Coltosol® (Vigodent, Rio de Janeiro, Brazil) were more pronounced than the ones produced by IRM® (Dentsply, Petrópolis, Brazil) (p<0.05). The temporary coronal sealer Coltosol® (Vigodent, Rio de Janeiro, Brazil) presented the most prominent antimicrobial activity, followed by the temporary coronal sealer IRM® (Dentsply, Petrópolis, Brazil). Conclusion: Among the materials tested, it was concluded that the Coltosol® (Vigodent, Rio de Janeiro, Brazil) presented the highest antimicrobial activity.

Objetivo: Avaliar, in vitro, a atividade antimicrobiana de três seladores coronários temporários utilizados em Endodontia. Métodos: Os materiais testados foram o Tempo® (Vigodent, Rio de Janeiro, Brasil), IRM® (Dentsply, Petrópolis, Brasil) e Coltosol® (Vigodent, Rio de Janeiro, Brasil). O método utilizado para a avaliação foi o teste de difusão em ágar. Nove placas contendo o meio de cultura ágar-sangue foram inoculadas com saliva humana e em cada uma foram confeccionados 3 furos eqüidistantes sendo cada um preenchido com um dos materiais testados. Duas placas foram inoculadas e serviram como controle negativo do meio de cultura. Todas as placas foram incubadas em estufa bacteriológica, em aerobiose, por 48 horas, à temperatura de 37ºC. Os halos de inibição do crescimento bacteriano foram medidos em milímetros.Resultados: O selador temporário Tempo® (Vigodent, Rio de Janeiro, Brasil) não apresentou halo de inibição do crescimento bacteriano nas nove placas. Coltosol® (Vigodent, Rio de Janeiro, Brasil) produziu halo de inibição em todas as placas enquanto que o IRM® (Dentsply, Petrópolis, Brasil) produziu halo em 4 das 9 placas. Em todos os testes, os halos produzidos pelo Coltosol® (Vigodent, Rio de Janeiro, Brasil) foram maispronunciados que os do IRM® (Dentsply, Petrópolis, Brasil) (p<0.05). O selador coronário temporário Coltosol® (Vigodent, Rio de Janeiro,Brasil) apresentou a atividade antimicrobiana mais pronunciada, seguido pelo IRM® (Dentsply, Petrópolis, Brasil). O selador temporário Tempo®(Vigodent, Rio de Janeiro, Brasil) não apresentou qualquer atividade antimicrobiana. Conclusão: Dentre os materiais testados, podemos concluir que o Coltosol® (Vigodent, Rio de Janeiro, Brasil) é o que apresenta maior atividade antimicrobiana.