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Article
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 casein phosphopeptide-amorphous calcium phosphate on surface roughness of a silorane-based and methacrylate-based composite resin (In vitro comparative study)

Author: Baydaa Hussein بيداء حسين
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 3 Pages: 106-112
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: When using a fluoridated agent for caries-preventive intervention, the clinician should be careful not toallow the agent to come into contact with the composite restorations since topically applied fluorides were found toinduce adverse effects on the morphologic characteristics and composition of composite restorations. A newremineralizing agent "MI Paste" and its fluoridated form "MI Paste Plus" based on Recaldent technology (CPP-ACP)were developed. This study was conducted with the aim of assessing the effect of these new remineralizing agentson surface roughness of two types of composite resin materials.Materials and Method: Cylindrical specimens 12mm in diameter and 2mm in height were prepared from two types ofcomposite resin materials: Filtek™ P90 (a silorane-based composite material) and Filtek™ Z350 XT (a methacrylatebasednanofill composite material). Each specimen was cured against a celluloid strip in a specially designedcylindrical mold using a QTH light curing unit for 40 seconds. Forty specimens were prepared for each compositetype and subdivided into four subgroups of ten specimens each: Subgroup 1: without treatment, dry-stored in anincubator at 37ïC for one week (control subgroup), Subgroup 2: without treatment, stored in deionized water in anincubator at 37ïC for one week, Subgroup 3: treated with MI Paste once daily for one week, and Subgroup 4:treated with MI Paste Plus once daily for one week. Surface roughness of the specimens was obtained with a surfaceprofile testing machine, which used the roughness average (Ra) to assess surface changes. Several measurementswere taken for each specimen and the mean value of these measurements on one specimen was regarded as theRa of that specimen. The mean Ra value of each subgroup was then calculated.Results: The results of this study showed statistically non-significant differences among the different subgroups ofFiltek™ P90 composite resin material. Concerning Filtek™ Z350 XT composite resin material, the results showed astatistically highly significant difference in surface roughness between the subgroup stored in deionized water andthe control one, with statistically non-significant difference between the subgroups treated with MI Paste and MIPaste Plus and the control subgroup. Comparison of significance between the corresponding subgroups of bothcomposite types revealed statistically non-significant differences except for subgroup 2 which showed a statisticallysignificant higher surface roughness in Filtek™ Z350 XT than Filtek™ P90.Conclusions: The daily application of the MI Paste and MI Paste Plus for one week had non significant effect onsurface roughness of the silorane-based composite resin material Filtek™ P90. On the other hand, the application ofthese agents caused surface smoothening of the nanofilled methacrylate-based composite resin material Filtek™Z350 XT.


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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