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Microleakage Evaluation of a Silorane-Based and Methacrylate-Based Packable and Nanofill Posterior Composites (in vitro comparative study)

Author: Manhal A. Majeed منهل عبد الرحمن مجيد
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2012 Volume: 1 Issue: 2 Pages: 19-26
Publisher: Tikrit University جامعة تكريت

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Abstract

This study compared in vitro the microleakage of a new low shrink silorane-based posterior composite (Filtek™ P90) and two methacrylate-based composites: a packable posterior composite (Filtek™ P60) and a nanofill composite (Filtek™ Supreme XT) through dye penetration test. Thirty sound human upper premolars were used in this study. Standardized class V cavities were prepared at the buccal surface of each tooth. The teeth were then divided into three groups of ten teeth each: (Group 1: restored with Filtek™ P90, Group 2: restored with Filtek™ P60, and Group 3: restored with Filtek™ Supreme XT). Each composite system was used according to the manufacturer's instructions with their corresponding adhesive systems. The teeth were then thermocycled, immersed in 1% methylene blue dye for 24 hours at room temperature, embedded in auto-polymerizing acrylic resin and sectioned longitudinally bucco-lingually. Microleakage was evaluated by assessing the linear dye penetration at the tooth/restoration interface occlusally and gingivally. The highest microleakage score occlusally or gingivally was recorded and the results were analyzed statistically using SPSS version 13. The results of this study showed that the silorane-based posterior composite Filtek™ P90 showed significantly less microleakage than the methacrylate-based packable composite (Filtek™ P60) and the nano-filled composite (Filtek™ Supreme XT) when the tooth-restoration interface is located in enamel.


Article
Effect of curing mode on immediate and post-irradiation depth of cure of a silorane-based and methacrylate- based posterior composites (in vitro comparative study)

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Abstract

Background: Incomplete polymerization of composite restorations compromises the restoration both mechanicallyand biologically. Recently, composite curing lights have been developed that have higher intensities and shortercuring cycles which help speed the resin-based curing. This study was conducted with the aim of evaluating theeffect of conventional and high intensity light curing units on the depth of cure of three different types of compositeresin.Materials and Method: Forty eight cylindrical specimens 4mm in diameter and 8mm in height were prepared fromthree types of composite resin (Filtek™ P60,Tetric EvoCeram and Filtek™ P90) using a two-piece aluminum mold. Halfof the specimens were cured with a QTH for 40 seconds, while the other half of the specimens were cured with theFlashMax P3 high intensity light curing unit for 3 seconds. The cured specimens of each composite type were thensubdivided into three subgroups of eight specimens each according to the aging period prior to curing depthmeasurement (immediate, after 24 hours, or after 7 days). The depth of cure was measured using the scrapingmethod (scratch test).Results: The results of this study showed that Filtek™ P60 showed the highest mean depth of cure, followed by TetricEvoCeram and Filtek™ P90 which showed the lowest curing depth regardless of the curing mode or aging period,and the difference was statistically highly significant (p< 0.01). The results of the study also showed that the specimenscured with the QTH had higher curing depth than those cured with the FlashMax P3 regardless of the composite typeand aging period and the difference was also statistically highly significant (p< 0.01). Concerning the effect of aging,there was an increase in curing depth till 24 hours for Filtek™ P60 and Tetric EvoCeram, while for Filtek™ P90 theincrease in curing depth continued till 7 days.Conclusions: The packable composite Filtek™ P60 showed the highest curing depth as compared with the nanofilledcomposite Tetric EvoCeram and the silorane-based composite Filtek™ P90. However, there was a continuousincrease in curing depth of the silorane-based composite with time. All composite resins cured with the conventionalQTH light curing unit presented higher curing depths than those cured with the FlashMax P3 high intensity light curingunit.


Article
Evaluation of marginal gap at the composite/enamel interface in Class II composite resin restoration by SEM after thermal and mechanical load cycling (An in vitro comparative study)

Authors: Mais Yaroub ميس يعرب --- Mohammed R. Hameed
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 4 Pages: 63-70
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: This study compared in vitro the marginal adaptation of three different, low shrink, direct posteriorcomposites Filtek™ P60 (packable composite), Filtek™ P90 (Silorane-based composite) and Sonic fill™ (nanohybridcomposite) at three different composite/enamel interface regions (occlusal, proximal and gingival regions) of astandardized Class II MO cavity after thermal changes and mechanical load cycling by scanning electronmicroscopy.Materials and methods:Thirty six sound human maxillary first premolars of approximately comparable sizes weredivided into three main groups of (12 teeth) in each according to the type of restorative material that was used:group (A) the teeth were restored with Filtek™ P60 and single bond™ Universal adhesive using horizontal incrementaltechnique, group (B)the teeth were restored with Filtek™ P90 and P90 system adhesive using horizontal incrementaltechnique and group (C) the teeth were restored with Sonic fill™ composite and single bond™ Universal adhesiveusing bulk technique.After specimens were stored in distilled water at 37°C for 7 days, all specimens were subjectedto thermocycling at (5° to 55 °C), then submitted to mechanical load cycling (intermittent axial force of 49N and atotal of 50.000 cycles). The specimens were observed under scanning electron microscope at (2000 X) to measuremarginal gap width (the distance between the dental wall and the restoration) at occlusal, proximal and gingivalregions in micrometer using Tescan software, version 3.5. Data were analyzed statistically by one way ANOVA testand least significant difference tests.Results:The results showed that the silorane-based posterior composite (Filtek™ P90) showed significantly the leastmarginal gap width at the occlusal, proximal and gingival regions after the application of thermal changes andmechanical load cycling in comparison to the two methacrylate-based posterior composite Filtek™ P60 (packable)and the Sonic fill™ (nano-hybrid). Sonic fill™ bulk fill composite that relied on the vibration concept to lower theviscosity of high filler loaded composite material showed significantly lesser marginal gaps width at occlusal, proximaland gingival composite/enamel interface regions in comparison with Filtek™ P60 (packable composite) usinghorizontal incremental technique. The silorane-based composite (Filtek™ P90) showed non-significant difference inmarginal gaps width at the three different regions. While, both methacrylate based Filtek™ P60 and Sonic fill™composite showed significantly lesser marginal gap width at the occlusal region in comparison with gingival regions.Conclusion: None of the low-shrinkage composite restorative materials tested in this study totally prevented microgapformation at composite/enamel interfaces of Class II MO cavity

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