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The effect of the viscosity of luting composite on micro leakage around glass ceramic inserts
No full textScopo: 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
Marginal microleakage and interfacial morphology of self-etching adhesives of different pH values around class V resin composite restorations
No full textThe effect of cavity design (C-factor) on microleakage around class V cavities bonded with three self-etching agents
No full textInfluence Of Cavity Configuration On Microleakage Around Class V Restorations Bonded With Seven Self-Etching Adhesives
No full textThe 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)
Influence of marginal bevel on microleakage around Class V cavities bonded with seven self-etching agents. 2004;17:257-261
No full textTo 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)
The effect of cavity margin design on microleakage around class V cavities bonded with three self-etching agents
No full textEffect of cavity design (C-Factor) on micro leakage around class V cavities bonded with three self-etching agents
No full textTO 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
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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