Effect of flowable composite or glass ionomer liners on shrinkage stress of a composite resin / Efecto de recubrimientos con resinas de baja viscosidad o ionómero vitreo sobre la tensión por contracción de una resina compuesta

ABSTRACT The aim of this study was to evaluate the effect of flowable composite or glass ionomer liners on the shrinkage stress of a restorative composite resin. Fifteen previously sandblasted metal boxes were attached to a universal mechanical testing machine (INSTRON 1011, Instron Corporation). Five of these boxes were filled with Filtek Z350 XT (FXT) Universal Restorative A2 (3M ESPE) (Group 1 or Control). Two further groups of 5 boxes were prepared by interposing a layer of Vitrebond Light Cure Glass Ionomer 3M ESPE (VGI) (Group 2 or G.I.) or Filtek Z350 XT Flowable Restorative A2 3M ESPE (FFR) (Group 3 or Flowable) between the box and the composite resin, completing with the same volume of composite as in Group 1. Upon activating lightcuring, the filled boxes mounted on the testing machine were videoed for 60 seconds (40 s photoactivation and 20 s postcuring), timed with a digital chronometer. Force values were recorded in newtons and converted into stress according to contact surface. Stress values were recorded every 10 s. Results were analyzed using repeated measures ANOVA. Mean and standard deviation in kPa (stress) recorded for each group were: Control group: 126.2 (30.8); G.I.: 48.4 (18); Flowable: 27.9 (19.5). Statistical analysis showed significant differences between the control group and the rest (p<0.01), with no significant difference between groups with glass ionomer liners and flowable resin liners (G.I. and Flowable). Under the experimental conditions of this study, it can be concluded that polymerization shrinkage stress can be reduced by the presence of a liner between the preparation and the restorative material.

RESUMEN El objetivo de este trabajo fue evaluar el efecto de la colocación de una capa de Composite flow o Ionómero vítreo sobre la tensión de contracción de un composite para restauración. Se utilizaron 15 cajas metálicas previamente arenadas y conectadas a la máquina universal para ensayos mecánicos (INSTRON 1011, Instron Corporation). Cinco de estas cajas (G1) se rellenaron con Filtek Z350 XT (FXT) Universal Restorative A2 3M ESPE. Al iniciar la activación de la unidad de curado se comenzaba a registrar con una cámara de video y un cronómetro digital desde el comienzo de la activación de la lámpara hasta 60 s después, registrando los valores post curado durante 20 s. Los valores de fuerza generados por la polimerización fueron registrados en newton de cada 10 s para los 15 ensayos. Los valores fueron convertidos en tensión de contracción según la superficie de contacto. Se realizaron además dos grupos de cajas (5 en cada una) en los cuales se colocaron una capa inicial de Vitrebond Light Cure Glass Ionomer 3M ESPE (VGI) (G2 o IV) y Filtek Z350 XT Flowable Restorative A2 3M ESPE (FFR) (G3 o Flow) y se completó con el mismo volumen de composite de las del GI. Los resultados obtenidos fueron analizados por medio de ANOVA para mediciones repetidas. La media y la desviación estándar en kPa (tensión o estrés de contracción) registrado para cada grupo fueron: Grupo control: 126.2 (30.8); IV: 48.4(18); Flow: 27.9(19.5). El análisis estadístico mostró diferencias estadística mente significativas entre el grupo control y el resto (p=0.00), pero no hubo diferencias significativas entre la presencia de Ionómero vítreo o Composite Flow (IV y Flow). En las condiciones experimentales de este trabajo puede concluirse que la tensión de contracción generada durante la polimerización puede ser disminuida por la presencia de algún material interpuesto entre la preparación y el composite restaurador.

A randomized clinical trial of cavity liners after selective caries removal: one-year follow-up

Abstract Alternatives for the treatment of caries disease, such as minimally invasive approaches, have been developed in recent years. Objective: To carry out clinical and radiographic evaluations of three cavity liners after selective caries removal. Methodology: Thirty-six primary molars with deep occlusal caries lesions without pulp involvement (from children of both genders, aged between 5 and 8 years) were randomly divided into the following groups: calcium hydroxide cement (CHC) group; mineral trioxide aggregate (MTA) group and Portland cement with added zirconium oxide (PCZ) group. The following-up period was 6- and 12-month. The clinical and radiographic success rates were evaluated through chi-square test. The radiographic measurements were compared by ANOVA followed by Tukey's test (p<0.05). Results: Thirty-six patients were included, but thirty-four returned for 12-month follow-up. The overall success rate of the therapy for the three groups was 94.11% and no statistically significant differences occurred in the comparison among groups (p>0.05). Nineteen radiographs were selected to measure the dentin barrier thickness. The intragroup comparison presented a statistically significant increase of the dentin barrier for all groups, at 12-month follow-up. However, the MTA group showed increase of the dentin barrier, over time, 6- to 12-month follow-up. The intergroup comparison revealed no statistically significant differences (p>0.05). Conclusion: The clinical and radiographic data showed that all cavity liners provided effective treatment of primary teeth after selective caries removal.

Marginal adaptation of indirect restorations using different resin coating protocols

This study evaluated the influence of material combinations used in the resin coating technique (RCT) on the marginal adaptation of indirect restorations with gingival margins in enamel (EM) and cement (CM). Eighty third-molars were used. Two cavities were prepared in each tooth. The cavities were distributed into 16 groups. Cavities with EM were filled with the following material combinations: G1: Single-Bond 2 (Sb2), G2: Sb2 + Bond/Scotchbond-Multipurpose (Sb2B), G3: Sb2 + Filtek-Flow Z350 (Sb2Fl), G4: Scotchbond-Multipurpose (SBMP), G5: Clearfil-S3 (CS3), G6: CS3 + Bond/Clearfil-SE Bond (CSE3B), G7: CS3 + Protect Liner F (CS3PL) and G8: Clearfil SE Bond + Protect Liner F (CSEBPL). The same combinations were applied to the cavities in CM: G9, G10, G11, G12, G13, G14, G15, G16, respectively. The fillings were performed with the Sinfony-System (3M/ESPE). After 24 h, the teeth were submitted to thermocycling (2,000 cycles, 5° to 55°C) and load-cycling (50,000 cycles, 50 N). Next, the Caries-Detector (Kuraray) was applied to the restoration margins. Images from the proximal margin were evaluated using the Image-Tool 3.0 software. The results were submitted to ANOVA and Tukey's test (α=0.05). The mean values (%) for the groups were: EM: G1=46.68, G2=15.53, G3=19.83, G4=27.53; G5=59.49, G6=25.13, G7=34.37, G8=15.20; CM: G9=38.38, G10=23.25, G11=26.97, G12=25.85, G13=37.81, G14=30.62, G15=29.17, G16=20.31. The highest percentages of marginal gap on EM or CM were found in the groups that did not use a liner. It can be concluded that the most appropriate RCT combinations were the groups that used a liner.

Este estudo avaliou a influência de diferentes combinações de materiais usados na técnica de selamento dentinário (TSD) sobre a adaptação marginal de restaurações indiretas, cujas margens gengivais localizam-se em esmalte (ME) ou cemento (MC). Oitenta terceiros molares foram selecionados e duas cavidades foram preparadas em cada dente, as quais foram distribuídas em 16 grupos. As cavidades com margem em esmalte foram forradas pelas seguintes combinações de materiais: G1: Single-Bond2 (Sb2), G2: Sb2 + Bond/Scotchbond-Multipurpose (Sb2B), G3: Sb2 + Filtek-Flow Z350 (Sb2Fl), G4: Scotchbond-Multipurpose (SBMP), G5: Clearfil-S3 (CS3), G6: CS3 + Bond/Clearfil-SE Bond (CSE3B), G7: CS3 + Protect Liner F (CS3PL), G8: Clearfil SE Bond + Protect Liner F (CSEBPL). As mesmas combinações foram aplicadas às cavidades com margens em cemento: G9, G10, G11, G12, G13, G14, G15, G16, respectivamente. As restaurações foram confeccionadas usando o sistema Sinfony (3M/ESPE). Após 24 h, os dentes restaurados foram submetidos à ciclagem térmica (2.000 ciclos - 5° a 55° C) e mecânica (50.000 ciclos, 50 N). Em seguida, Carie-Detector (Kuraray) foi aplicado sobre as margens das restaurações. As imagens obtidas da margem proximal foram avaliadas pelo software Image-Tool 3.0. Os resultados foram submetidos aos testes estatísticos ANOVA e Tukey (p<0,05). As médias (%) observadas para os grupos foram: ME: G1=46,68, G2=15,53, G3=19,83, G4=27,53; G5=59,49, G6=25,13, G7=34,37 e G8=15,20; MC: G9=38,38, G10=23,25, G11=26,97, G12=25,85, G13=37,81, G14=30,62, G15=29,17, G16=20,31. Os maiores valores de desadaptação marginal encontrados em ME e MC foram encontrados nos grupos que não utilizaram um "liner". Desta forma, pôde-se concluir que a combinação mais apropriada para a TSD é aquela que faz uso do "liner".

Microleakage of bonded amalgam restorations using different adhesive agents with dye under vacuum: An in vitro study.

Aim: In an effort to minimize tooth preparation, yet provide additional retention to compromised tooth structure, bonded amalgam restorations were introduced. Various resin-based adhesives have been tried earlier under bonded amalgam restorations. Still there are controversies regarding the outcome of bonded amalgam restorations regarding their adaptability to the tooth structure and microleakage. Therefore, this study was undertaken to compare the microleakage of bonded amalgam restorations using different adhesive materials. Materials and Methods: Standard Class I cavities were prepared on occlusal surfaces of 60 human molars. Teeth (n=60) were divided into three groups according to the material employed, as follows: group I: amalgam with glass ionomer cement (GIC) (type I); group II: amalgam with resin cement (Panavia F 2.0) and group III: amalgam with Copalex varnish as a control. Following restoration, the teeth were submitted to thermal cycling. The teeth were subsequently immersed in 2% rhodamine B dye under vacuum for 48 hours and sectioned to allow the assessment of microleakage under stereomicroscope. Results: The values were tabulated and the results were statistically analyzed using analysis of variance (ANOVA), Tukey's post hoc test and Kruskal-Wallis test. Amalgam with type I GIC showed the least leakage with no statistically significant difference (P value 0.226) when compared to amalgam with Panavia F 2.0 and amalgam with varnish (P value 0.107). Conclusion: It can be concluded that bonded amalgam with type I GIC is a good alternative to amalgam with resin cement (Panavia F 2.0) and amalgam with varnish for large restorations, with the added advantages of GICs. Clinical Significance: Bonded amalgam restorations prevent over-preparation and reduce the tooth flexure. GIC type I under amalgam provides chemical bonding in between amalgam and tooth structure and thus reduces the microleakage.

Influence of flowable materials on microleakage of nanofilled and hybrid Class II composite restorations with LED and QTH LCUs.

Background: Class II composite restorations are more frequently being placed with margins apical to the cementoenamel junction (CEJ) and margins within the dentin are prone to microleakage. Aims: This in vitro study was used to evaluate the influence of flowable composite and flowable compomer as gingival liner on microleakage in Class II composite restorations and compare a light-emitting diode (LED) unit with a quartz tungsten halogen (QTH) unit for light-activating composite resins. Materials and Methods: Mesioocclusal and distoocclusal Class II cavity preparations were made in 72 sound extracted premolars. The buccolingual width was 2.5 mm and the gingival margins of all the cavities were placed 1.0 mm apical to the CEJ. The boxes were prepared 1.5 mm deep axially, making 144 slot cavities. Teeth were randomly divided into the following two groups (n = 72): (I) Universal Filtek Supreme XT; Universal Filtek Supreme XT + Flwable Filtek XT and Universal Filtek Supreme XT + Dyract Flow and (II) Filtek Z250; Filtek Z250 + Flwable Filtek XT and Filtek Z250 + Dyract Flow. Flowable materials were injected into the gingival floor of the cavity to a thickness of 1.0 mm. Each increment was cured for 20 s. One-half of the subgroups in each group were cured with QTH and the other half with LED light curing units (LCUs). After 1 week of incubation at 37°C, the specimens were thermocycled (5-55°C, x1500), immersed in 0.5% basic fuchsine dye for 24 h and sectioned and microleakage was evaluated at the gingival margin by two examiners using a 0-3 score scale. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Results: The groups utilizing flowable liners had significantly less microleakage (P < 0.05). No significant difference was identified between Universal Filtek Supreme XT and Filtek Z250 composites with and without flowable materials. There was no significant between utilizing flowable composite or flowable compomer and between each similar subgroup when polymerized with either the LED or the QTH LCUs. Conclusions: A layer of flowable materials at the gingival floor of Class II composite restorations may be recommended to improve the marginal seal of a restoration.

Sealing ability and thermal diffusivity of cavity lining materials: an in vitro study.

AIMS: The purpose of this study was to evaluate and compare the sealing ability and the thermal insulating capability of four different cavity lining materials. MATERIALS AND METHODS: Forty noncarious human mandibular second premolars that were extracted for orthodontic treatment were collected, cleaned, and stored in distilled water. These premolars were randomly divided into four groups of ten teeth each for treatment with the different cavity lining materials. Group I teeth were treated with cavity varnish, group II teeth with amorphous calcium phosphate (ACP), group III teeth with dentin bonding agent, and group IV teeth with resin-modified glass ionomer cement (RMGIC). Electrical resistance and the difference in the time-temperature curve of the external surface and the pulp side [A D -A P ] of each tooth following heat and cold application for 120 s were measured before and after cavity lining placement to determine the sealing ability and thermal insulating property, respectively. Data collected were subjected to statistical analysis. For paired data, paired t-test and Wilcoxon's signed rank test were used. One-way ANOVA was used for comparisons between multiple groups and the Mann-Whitney U test for comparisons between pairs. RESULTS: The mean difference in electrical resistance (in K ohm) of different cavity lining materials were as follows: group I = +3.53, group II = -1.00, group III = +20.43, and group IV = +11.44. The mean differences in the area (A D -A P ) under the time-temperature curve following heat application were as follows: group I = 6.6 mm 2 , group II = 15.3 mm 2 , group III = 130.5 mm 2 , and group IV = 412.0 mm 2 . The mean differences in the area (A D -A P ) under the time-temperature curve following cold application were as follows: group I = 24.5 mm 2 , group II = 3.2 mm 2 , group III = 314.9 mm 2 , and group IV = 480.5 mm 2 . CONCLUSION: Dentin bonding agent and RMGIC provided effective sealing of the dentinal tubules and significant thermal insulation when compared to the other tested cavity lining materials.

Restauraciones metálicas fundidas: evaluación in vitro de la microinfiltración marginal con terminaciones cervicales y agentes cementantes diferentes / Fused metallic restoration: in vitro evaluations of the marginal microinfiltration with different cervical termination and cementant agent

Las restauraciones metálicas fundidas son indicadas con relativa frecuencia en los procedimientos clínicos; su longevidad está directamente ligada a una precisa indicación, donde los cuidados con la terminación cervical yla selección del agente cementante son primordiales. En esta investigación, fueron usados cuarenta molares humanos, los cuales fueron sometidos a preparaciones cavitarias mesio-ocluso-distales (MOD), con el objetivo de evaluar la microinfiltración marginal en las paredes cervicales, los tipos de terminaciones cervicales, en chamfer o en inclinación doble y los diferentesagentes cementantes, CIVMR Vitremer (3M®) y el cemento resinoso Enforce (Dentsplay®). Las muestras fueron termocicladas por 300 ciclos a 5º C y 55º C por 30 segundos e inmersas en Rhodamina B al 2 por ciento por 24 horas. Al análisis estadístico conKruskal-Wallis y Mann-Whitney se evidenció que la terminación cervical no interfirió en la microinfiltración, pero el agente cementante mostro diferencia estadísticamente significativa.

The fused metallic restorations are indicated with frequency in the clinical procedures; your longevity has relation with a correct indication, where the cares whit cervical termination and the cementant agent selection are very important. In this research were used fourthly human molars, witch were put under cavity preparation mesio-ocluso-distal (MOD), with the objective to evaluated marginal microfiltration in the cervical walls, the type of the cervical termination, chamfer or double inclination and different cement agent, CIVMR Vitremer (3M®) and the resinous cement Enforce (Dentsplay®). The samples were thermociclated for 300 cycles in 5º C and 55º C for 30 seconds and submerged in Rhodamina B to 2 percent for 24 hours. The static analyze with Kruskal-Wallis and Mann-Withney show what the cervical termination was not related in the microfiltration, but de cementant agent show statistically significant difference.

Experiencias en la aplicación de biomateriales en cirugía maxilofacial / Experiencies in the application of biomaterials in maxillofacial surgery

Se realizó un estudio prospectivo longitudinal para demostrar la efectividad del Apafill-G, HAP-2000 y Tisuacryl, biomateriales obtenidos en Cuba para el empleo de implantes óseos en lesiones osteolíticas maxilofaciales, como relleno de la cavidad ósea y en el cierre de heridas faciales y de la mucosa bucal originadas por trauma o tratamiento quirúrgico, con la finalidad de que estos sean de conocimiento y utilidad en las instituciones, servicios estomatológicos y sus especialidades. Un total de 389 pacientes fueron tratados quirúrgicamente. El biomaterial más usado fue el Tisuacryl, seguido por Apafill-G y HAP 2000. Los tratamientos quirúrgicos que predominaron fueron las extracciones múltiples, plastias auriculares, irregularidad ósea maxilar y mandibular, dientes retenidos y cirugía periapical. Los pacientes tratados quirúrgicamente evolucionaron de forma satisfactoria clínica y radiográficamente. Se concluyó que la aplicación de estos biomateriales producidos en Cuba en el cierre de heridas de los tejidos blandos y relleno de cavidades óseas, constituye una alternativa de tratamiento en cirugía bucal y maxilofacial; la hidroxiapatita cubana (Apafill-G y HAP-2000) utilizada en este estudio posee una alta biocompatibilidad y biofuncionabilidad, por lo que constituye un material implantológico ideal. No se reportaron reacciones adversas en los pacientes estudiados

Effects of cleaning agents on bond strength to dentin

A limpeza das paredes cavitárias é um passo importante na clínica odontológica e visa otimizar os procedimentos adesivos e a longevidade das restauracões. O presente estudo comparou o efeito de três agentes de limpeza cavitária - jato abrasivo de bicarbonato de sódio/ar/água (Profi II, Dabi Atlante, São Paulo, Brasil); pasta de pedra-pomes e água, somada a um detergente biológico (Tergestesim, Probem, São Paulo, Brasil); e spray de ar/água - na resistência adesiva entre dentina e dois tipos de adesivos dentais: Clearfil SE Bond ("self-etching") (Kuraray, Kioto, Japão) e Scotchbond Multi-Purpose Plus ("all-etching") (3M-ESPE, São Paulo, Brasil). Seis grupos de espécimes (n = 10) obtidos a partir de elementos dentais humanos extraídos por indicacão foram preparados e cada um recebeu um dos tratamentos de superfície. Após aplicacão dos adesivos, uma porcão tronco-cônica de resina composta (AP-X, Kuraray, Kioto, Japão/Z-100; 3M-ESPE, São Paulo, Brasil) foi construída sobre os espécimes, com o auxílio de uma matriz bipartida de teflon e uma mesa metálica adaptadora para adaptacão na máquina de ensaio de tracão. Após armazenamento em água destilada a 37ºC por 7 dias, os mesmos foram submetidos às provas de tracão. Dois pares de cada grupo foram escolhidos aleatoriamente e processados para observacão ao microscópio eletrônico de varredura (MEV). A análise estatística dos valores obtidos demonstrou que não houve diferencas significantes entre as técnicas de limpeza empregadas e nem entre a interacão destas com os adesivos dentais, e as observacões ao MEV revelaram uma predominância de fraturas mistas ocorridas na interface dentina/resina. Baseados nas análises estatísticas e nas observacões ao MEV, concluiu-se que as técnicas de limpeza empregadas não interferem na resistência adesiva entre a dentina e os sistemas adesivos estudados, nas condicões experimentais adotadas.

Effect of resin liners on the microleakage of class V dental composite restorations

OBJETIVO: O objetivo desse estudo foi avaliar os efeitos da aplicação de um adesivo em diferentes espessuras ou em associação com um adesivo com carga ou com compósito de baixa viscosidade na microinfiltração marginal de restaurações com compósito odontológico. MÉTODOS: Quarenta incisivos bovinos foram selecionados e cavidades circulares (4mm de diâmetro X 2mm de profundidade) foram preparadas na região da junção cemento-esmalte. Os dentes foram então divididos em quatro grupos de acordo com o forramento utilizado: 1: (controle) aplicação do sistema de união Scotchbond Multi Uso (SBMU) - 1 camada de adesivo; 2: aplicação de 3 camadas do adesivo SBMU; 3: aplicação do SBMU, seguido pela aplicação de uma camada do adesivo Optibond FL; 4: aplicação do SBMU seguido pela aplicação de forramento com o compósito de baixa viscosidade Flow-it. Todas as cavidades foram restauradas com o compósito Z100. O teste de microinfiltração foi conduzido de acordo com a ISO (TR11405). Os dados foram analisados pelo teste de Kruskall-Wallis (p>0,05). RESULTADOS: O grupo 4 apresentou redução significativa dos níveis de infiltração quando comparado ao grupo 1. Os grupos 2 e 3 apresentaram valores intermediários e não foram detectadas diferenças significativas quando estes grupos foram comparados aos grupos 1 e 4. CONCLUSÃO: O uso de forramento com compósito de baixa viscosidade pode reduzir os níveis de infiltração marginal, possibilitando melhora na qualidade das restaurações em compósito odontológico.

O ensino dos procedimentos restauradores em molares decíduos nos cursos de Odontologia no Brasil / The teaching of primary molares restorative procedures in brazilian dental schools

O objetivo deste estudo foi avaliar as condutas de tratamento restaurador em molares decíduos adotados pelas disciplinas de Odontopediatria, nos diversos cursos de Odontologia existentes no Brasil. Foi enviado um questionário para a disciplina de Odontopediatria de103 cursos de odontologia, nas diversas regiões do país. Este averiguou dados sobre materiais forradores e restauradores "provisórios" e "definitivos" em preparos cavitários oclusais e ocluso-proximais de molares decíduos. Foram devolvidos 57 questionários respondidos (55,3 porcento do total). Os resultados demonstraram que em cavidades rasa houve uma predominância nanão indicação de forramento (69,64 porcento ocluso-proximais). Em cavidades médias, o forramento mais indicado foi o cimento de ionômero de vidro (CIV) em 35,72 porcento para as cavidades oclusais, e em 37,28 porcento para as ocluso/proximais. Nas cavidades profundas, a maior indicação foi para o hidróxido de cálcio + CIV em 70 porcento nas oclusais e em 70,17 porcento nas ocluso-proximais. Quanto aos materiais restauradores "provisórios" o CIV foi indicado em 71,21 porcento (oclusais) e 66,17 porcento (ocluso-proximais). Para as restaurações oclusais "definitivas", a resina composta híbrida foi indicada em 32,60 porcento. Nas restaurações ocluso-proximais "definitivas" indicou-se a resina composta híbrida em 35,58 porcento. Conclui-se que existe uma grande diversidade na indicação de materiais forradores e restauradores tanta nas cavidades oclusais como ocluso-proximais de molares decíduos

Avaliaçäo de diferentes sub-bases, para uso após polpotomia com pasta proposta por Guedes-Pinto / Evaluation of different sub-basis produts used after pulpomy with a paste propoted by Guedes-Pinto

Os autores avaliaram quatro diferentes sub-bases, para uso sobre a pasta proposta por Guedes-Pinto após técnica de polpotomia. Pretendia-se encontrar um material que cumprisse essa finalidade e de fácil manipulaçäo, compatível com a pasta terapêutica, que näo se misturasse com a mesma além de oferecer sustentaçäo para a colocaçäo de uma base e do material restaurador. Foram utilizadas como sub-base os seguintes materiais, o pó do iodofórmio sobre a pasta, verniz cavitário, guta percha, oxído de zinco e eugenol. Após observaçäo de 5 amostras para cada sub-base, concluiu-se que a de guta-percha foi a que apresentou melhores resultados