Introduction: Hardness is one of the basic properties of dental materials, specially composite resins which is relevant to their polymerization. The aim of this study was to evaluate the effect of light curing distance and the color of clear Mylar strips on surface hardness of Silorane-based (SCR) and Methacrylate-based composite resins (MCR).
Materials And Methods: 40 samples of MCRs (Filtek Z250) and SCRs (Filtek P90) were prepared in size of 5 mm×2 mm (80 samples in total). The samples divided into 8 groups (10 samples in each one) based on the color of clear Mylar strips (white or blue) and distance from light curing source (0 mm or 2 mm). All the samples cured for 40 second and stored in incubator for 24 hours in 37°C temperature. Surface hardness test was done by Vickers test machine and the collected data were analyzed by one-way ANOVA and paired T-test by using SPSS software version 13 at significant level of 0.05.
Results: MCRs cured with blue Mylar strips from 0 mm distance had the highest (114.5 kg/mm(2)) and SCRs cured with white Mylar strips from 2 mm distance had the lowest (42.2 kg/mm(2)) mean of surface hardness. Also, the results of comparison among SCRs and MCRs showed significant differences among all groups (all P values <0.01).
Conclusion: The hardness decreased as the distance increased and the blue Mylar strips provided higher hardness than clear ones. Also, Filtek Z250 showed higher hardness compared to Filtek P90.
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http://dx.doi.org/10.2174/1874210601408010144 | DOI Listing |
BMC Oral Health
November 2024
İzmir Training Dental Hospital, İzmir, Turkey.
Background: The aim of this study was to evaluate variations in the surface roughness and gloss of different single-shade resin composites after polishing with a range of systems.
Methods: In total, 120 specimens were prepared from three different types of single-shade resin composites (supra-nanospherical-Omnichroma, nanohybrid-Charisma Diamond One, and microhybrid- Essentia Universal). The specimens were placed in distilled water and stored at 37 °C for 24 h.
Acta Odontol Latinoam
September 2024
Universidad Científica del Sur, Lima, Lima, Perú.
Unlabelled: Giomers are bioactive hybrid restorative materials consisting of composite resin and glass ionomer filler pre-reacted on the surface, which maintain acceptable clinical qualities over time. One of the main factors that explains this is the surface hardness that is achieved by inhibiting the oxygen layer.
Aim: To compare the effect of blue and conventional Mylar strips used as oxygen inhibiting agents on the surface microhardness of giomer restorative materials.
Sci Rep
October 2024
Department of Restorative Dentistry, Faculty of Dentistry, Mersin University, Mersin, Turkey.
Am J Dent
October 2024
Department of Restorative Dentistry, Faculty of Dentistry, Eskisehir Osmangazi University, Eskisehir, Turkey.
Purpose: To evaluate the surface roughness and color stability of a single-shade composite resin after thermal cycling with different finishing and polishing systems.
Methods: A total of 91 specimens were prepared with standard molds using a single-shade resin composite Omnichroma. The specimens were randomly separated into seven groups: Control (Mylar strip only), grit (600 grit SiC abrasive paper), OneGloss, Clearfil Twist Dia, Sof-Lex Diamond Polishing System, EVE Diacomp Plus Twist, and OptiDisc.
Indian J Dent Res
April 2024
Department of Conservative Dentistry, College of Dentistry, Mustansiriyah University, Baghdad, Iraq.
Context: Long-term color stability of composite resins is one of the most important factors influencing the clinical longevity of aesthetic restorations.
Aims: This study evaluated the effect of novel reduced steps and gold standard multiple steps polishing systems of two composite resins; a nano-filled (Filtek Z350XT) versus a supra-nanofill (Palfique LX5) on their color stability after submitting to thermocycling with common beverages.
Materials And Methods: Sixty disc-shaped specimens were fabricated from both composite resins ( n = 30).
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