112,311 research outputs found

    Effect of cavity design (C-Factor) on micro leakage around class V cavities bonded with three self-etching agents

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    TO EVALUATE MICROLEAKAGE AROUND CLASS V RESIN BASED COMPOSITE RESTORATIONS IN BOX SHAPED VERSUS V-SHAPED CAVITIES BONDED WITH THREE SELF ETCHING AGENTS. CONCLUSION: THE PRESNT STUDY SUGGEST THAT A REDUCTION OF THE C-FACTOR DOES NOT SIGNIFICANTLY REDUCE MICROLEAKAGE WHEN SELF-ETCHING DENTINE BONDING SYSTEMS ARE USED IN CLASS V CAVITIES OF THE SIZE USED IN THE PRESENT STUD

    Influence Of Cavity Configuration On Microleakage Around Class V Restorations Bonded With Seven Self-Etching Adhesives

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    The purpose of this study was to evaluate microleakage around Class V resin composite restorations with different cavity configurations, bonded with one of seven self-etching materials or with an adhesive using the total-etch technique. MATERIALS AND METHODS: Ninety-six human molars and premolars were randomly assigned to eight groups and bonded with one of seven self-etching adhesives--Prompt-L-Pop (3M ESPE, St. Paul, MN, USA), Adper Prompt-L-Pop (3M ESPE), Clearfil SE Bond (Kuraray Medical, Okayama, Japan), Prime & Bond NT/NRC (Dentsply DeTrey, Konstanz, Germany), Xeno III (Dentsply DeTrey), One-Up Bond (Tokuyama Dental, Tokuyama, Japan), AdheSE (Ivoclar Vivadent, Schaan, Liechtenstein)-or with Prime & Bond NT (Dentsply DeTrey) using a separate total-etch technique. Cavities were cut in both the lingual and buccal surfaces and were approximately 3 mm mesiodistally, 1.5 mm deep, and 2.0 mm occlusogingivally. Selected at random, box-shaped cavities were cut on one side and V-shaped cavities were cut on the contralateral side. After bonding, the cavities were incrementally filled with a microhybrid composite (Tetric Ceram, Ivoclar Vivadent), cured, and immediately polished with Sof-Lex (3M ESPE) disks. The teeth were thermocycled, and the specimens were examined for microleakage using Procion Brilliant Red (ICI, Slough, UK) as a marker. RESULTS: Comparisons of both gingival and enamel margins within each of the groups showed no significant difference owing to configuration factor (C-factor; p > .5 in all cases, calculated with Kruskal-Wallis nonparametric analysis of variance [ANOVA]) and Dunn's multiple comparison test). All groups showed microleakage at the gingival margins irrespective of C-factor or bonding agent (box-shaped cavities, p = .8862; V-shaped cavities, p = .9623; using the ANOVA). Microleakage was not observed at all enamel margins regardless of C-factor or bonding agent, and there were no significant differences between the groups (box-shaped cavities, p = .9869; V-shaped cavities, p = .9550; using the Kruskal-Wallis nonparametric ANOVA)

    The effect of the viscosity of luting composite on micro leakage around glass ceramic inserts

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    Scopo: Scopo di questo studio è la valutazione del processo di microinfiltrazione marginale in restauri di V classe eseguiti con l’utilizzo di inserti in vetro ceramica cementati con resine composite fotopolimerizzabili ad alta viscosità e di tipo flow. Materiali e metodi: Sessanta premolari umani, estratti da giovani pazienti (range d’età 11-16 anni), venivano assegnati a random in quattro gruppi di studio. Su tutti gli elementi venivano preparate cavità di V classe che in due gruppi erano restaurate con inserti in vetro ceramica (Lee Pharmaceuticals, South El Monte, USA), fotopolimerizzati in un gruppo con l’ausilio di una resina composita ad alta viscosità (Tetric Cream, Ivoclar Vivadent, Liechtenstein) e nell’altro con una di tipo “flow” (Tetric Flow, Ivoclar Vivadent, Liechtenstein). Negli altri due gruppi, che servivano come controllo, i restauri venivano eseguiti rispettivamente con addizioni incrementali delle due stesse resine, Tetric Ceram o Tetric Flow. In tutti i quattro gruppi è stato utilizzato lo stesso sistema d’adesione (Excite, Ivoclar Vivadent, Liechtenstein) e la cavità standardizzata come segue: con l’ausilio di una fresa a fessura al carburo di tungsteno n° 330, montata su turbina ad alta velocità sotto spray costante di acqua refrigerata, si conferiva un diametro mesio-distale di 3 mm di larghezza ed uno occluso-gengivale di 3 mm di altezza e di 2 mm di profondità; la preparazione è stata rifinita con una fresa diamantata apposita margini cavitari preparati a 90°. Attraverso una selezione a random, 5 denti di ogni gruppo venivano termociclati a 500 cicli ed altri 5 a 5000 cicli in bagno d’acqua riscaldata a 5°C e 55°C; i rimanenti 5 non subivano termociclo e servivano come ulteriore controllo. I campioni venivano quindi preparati ed esaminati per la microinfiltrazione usando come marker fucsina basica. Risultati: nei gruppi restaurati con Inserto più Tetric Ceram, Inserto più Tetric Flow, Tetric Ceram con addizioni incrementali, a zero, 500 e 5000 cicli, non si osservava alcuna differenza statisticamente significativa del grado di microinfiltrazione (p>0.05 in tutti i casi) sia a livello del margine occlusale che gengivale. Di contro, nel gruppo Inserto più Tetric Flow è stata osservata una significativa differenza dopo 5000 cicli, sia a livello del margine occlusale (p = 0.0445) che gengivale (p = 0.0500) quando comparata al controllo a zero cicli. Significato clinico: nelle preparazioni di V classe, di dimensioni uguali a quelle standardizzate nel presente studio, si osserva una riduzione del processo di microinfiltrazione marginale del restauro eseguito con inserti in vetro ceramica quando un composito flow è usato come cemento fotopolimerizzante. Il processo di microinfiltrazione può quindi essere significativamente ridotto in entrambi i margini, occlusale e gengivale, quando l’inserto è utilizzato in associazione ad una resina composita flow. La microinfiltrazione invece non dimostra variazioni significativamente rilevanti quando il restauro con inserto è eseguito in associazione all’utilizzo di un composito viscoso come agente cementante comparato a quello eseguito con il solo composito viscoso.to evaluate microleakage around class v resin restorations restored with glass ceramic inserts luted with a high-viscous composite resin or a flowable composite resin. materials & methods: sixty extracted human premolars (patient age range 11-16 years) were randomly assigned to three groups. class v preparations in two groups were filled using a glass ceramic insert (lee pharmaceuticals, south el monte, usa.) luted with either hybrid, high viscous composite (tetric cream, ivoclar vivadent, liechtenstein.) or a flowable composite (tetric flow, ivoclar vivadent, liechtenstein). the other two groups served as a control and were bulk filled with either tetric ceram or tetric flow. the same bonding agent. (excite, ivoclar vivadent, liechtenstein) was used to in all groups. the preparations were made with a no. 330 tungsten carbide fissure bur in a water-cooled, high-speed hand piece with a mesio-distal width of 3mm, an occluso-gingival height of 3mm and 2mm deep. all margins had butt joints. by random selection, ten teeth in each group were thermo cycled for either 500 or 5000 cycles, between water baths held at 50c and 550c and ten specimens were not thermocycled. the specimens prepared and examined for microleakage using basic fusion as a marker. results: there was no significant difference in micro leakage scores at zero, 500 or 5000 cycle duration, at the occlusal margins or at the gingival margins, [p>0.05 in all cases] between inserts plus tetricceram and inserts plus tetricflow. there was no significant difference in micro leakage scores between inserts plus tetricceram and bulk filled tetricceram at zero, 500 or 5000 cycle duration, or inserts plus tetricflow and bulk filled tetricflow at zero, 500 or 5000 cycle duration: [p>0.05 in all cases] there was a significant difference in micro leakage around inserts luted with the tetric flow occlusally (p = 0.0445) and gingivally (p=0.0500), after 5000 cycles compared to the controls at 0 cycles

    Influence of marginal bevel on microleakage around Class V cavities bonded with seven self-etching agents. 2004;17:257-261

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    To evaluate microleakage around Class V resin-based composite restorations in box-shaped cavities with and without marginal bevels, bonded with one of seven self-etching materials and a non-self etching system. METHODS: 120 extracted human premolars were randomly assigned to eight groups for bonding with the following self-etching agents: Prompt-L Pop, Adper Prompt, Clearfil SE, Prime& Bond NT with NRC, Xeno111, One-Up Bond, AdheSe, or Prime & Bond NT using a total etch technique (36% H2PO4). Box cavities were cut in both the lingual and buocal surfaces. The cavities were made with an ISO 010-fissure diamond bur in a water-cooled high-speed handpiece and were approximately 3 mm wide, 1.5 mm deep, and 2.0 mm high. Selected at random, box-shaped cavities were cut with a 0.5 mm bevel in enamel and dentin on one side and on the contra-lateral side, box-shaped cavities were cut without bevels. Each tooth served as its own control. The teeth were thermocycled and the specimens prepared and examined for microleakage using Procion Red as a marker. RESULTS: All gingival margins leaked whether or not a bevel had been placed, when bonded either with a self-etching agent or using a total etch technique with 36% phosphoric acid. There was no significant difference in leakage between the self-etching groups or those using a total etch technique, at the gingival bevel margins, (P= 0.7384) or the gingival non-beveled margins (P= 0.2307; Kruskal-Wallis Test). Microleakage was found with every agent, both occlusally and gingivally, when bonded either with a self-etching agent or using a total-etch technique. There was no significant difference in leakage between the self-etching groups or those using a total etch technique at the enamel bevel margins, (P= 0.9907) or the enamel non-beveled margins (P= 0.9963; Kruskal-Wallis Test)

    A color is worth a thousand words! A color-based tool to foster communication in culturally-plural teams

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    Design institutions have increasingly adopted collaborative design-based learning in culturally plural classes, which supports the development of soft skills. In this context, teams could face differences in language, background and approaches to design, and students may find difficulties in communicating their own thoughts and feelings when evaluating teamwork, self and peers. The researchers glimpsed the possibility of conveying students’ reflection by using the visual language, focusing on communication through colours. The method was designed with the idea that colours can take on very different meanings for each individual, providing a wider freedom of expression. The paper presents a visual evaluation tool, the Teamwork Colour Matrix (TCM), and its preliminary test within a plural design class. The TCM has been used by students for the spontaneous representation of teamwork by coding the experience through the personal association of feelings with eight given colours. The results showed that all the students were able to evaluate their experiences using colour communication. With the TCM, students find their own individual way of communicating to teammates, through the abstract representation of their personal experience in the team. The test of the TCM shows that even novice designers could communicate complex messages and feelings by using a language based on colours, and that a further development of colour-based tools could represent a useful resource for students and teachers beyond the design discipline
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