Effect of Different Light Curing Units on the Surface Hardness of a Composite Resin

Abstract

The aim of this study was to evaluate the effect of various light curing units such as; Quartz Tungsten Halogen light curing unit with standard tip and turbo tip, LED curing unit and Plasma Arc curing unit on surface hardness of a nanohybrid composite. 210 Standard holes, each 2 mm, 3 mm and 4mm in thickness and 5 mm in diameter were prepared on plexiglass molds and were fılled with a nanohybrid composite resin. Top surface of each speciment was covered with a matrix strip, 1 mm thick glass slide was placed over the matrix strip and pressure was applied to extrude excess material. 10 specimens in 2 mm thickness were polymerized with halogen curing unit with standard tip for 40 seconds. 10 specimens were cured with halogen curing unit with turbo tip for 10 seconds. 10 specimens were cured with LED curing light for 10 sec. whereas 10 specimens were cured with LED curing light for 20 seconds. 10 specimens were cured with PAC curing unit for 3 sec, 10 specimens were cured with PAC curing unit for 6 sec and 10 specimens were cured with PAC curing unit for 10 seconds. Same procedure was applied to the specimens in 3 mm and 4 mm thickness. The light source tip of the curing units were positioned directly over the glass slide for standardization. After light curing, the glass cover and matrix strips were removed and the top surface of each specimen was finished and polished with disks. The specimens were divided into 3 groups according to thickness, then each group was assigned into 7 groups each containing 10 specimens according to the different curing units and polymerization periods. All specimens were placed into dark colored glass containers and were stored at 37°C for one week. After the storing period, composite specimens were washed with distilled water and blotted dry. Surface hardness measurements were made by using Vickers surface hardness measuring device from three different points on the top and bottom surfaces of each specimen. The Vickers hardness of the specimens were recorded and the average values were calculated. The results obtained were subjected to statistical analysis using Kruskal Wallis one-way ANOVA and Mann Whitney Multiple Range test at a significance level of p

Keywords

• Composite resin, polymerization, light curing unit, surface hardness, cavity depth

Kompozit rezinin yüzey sertlik değerleri üzerine farklı ışık cihazlarının etkisi

Abstract

Bu çalışmanın amacı; halojen standart ışık cihazı, halojen turbo uçlu ışık cihazı, LED ışık cihazı ve Plazma Ark ışık cihazı olmak üzere farklı ışık cihazlarıyla polimerize edilen farklı kalınlıktaki nanohibrit kompozit rezinin yüzey sertliğini değerlendirmektir. Bu amaçla 2 mm, 3 mm ve 4mm kalınlıktaki pleksiglass kalıplar üzerinde 5 mm çapında toplam 210 adet yuva hazırlandı ve yuvalara kompozit rezin uygulandı. Üst yüzeyleri önce matriks bant sonra 1 mm kalınlığında bir mikroskop camı ile kapatılarak fazla materyalin uzaklaşması için basınç uygulandı. Bu şekilde hazırlanan örneklerden 2 mm kalınlıkta olanlardan 10 tanesine halojen standart ışık cihazı ile 40 s, 10 tanesine halojen turbo uç ile 10 s, 10 tanesine LED ışık cihazı ile 10 s, 10 tanesine LED ışık cihazı ile 20 s, 10 tanesine PAC ışık cihazı ile 3 s, 10 tanesine PAC ışık cihazı ile 6 s ve 10 tanesine de PAC ışık cihazı ile 10 s süreyle ışık uygulandı. Aynı işlem 3 mm ve 4 mm kalınlıktaki örnekler için tekrarlandı. Tüm örnekler için ışık cihazının ucu cam tabakaya temas edecek şekilde tutularak standardizasyon sağlandı. Işıkla polimerizasyonu takiben matriks bantlar çıkarıldı ve diskler yardımıyla bitirme ve cila işlemleri uygulandı. Örnekler kalınlıklarına göre 3 gruba ayrıldı, gruplar da kendi içinde ışık cihazı ve polimerizasyon sürelerine göre 10 adet örnek olacak şekilde 7 gruba ayrıldı. Bütün deney gruplarındaki örnekler ışığı geçirmeyecek şekilde özellikle kahverengi cam şişelere yerleştirilerek 37°C’de etüvde 1 hafta kuru hava ortamında bek

Keywords

• Kompozit rezin, polimerizasyon, ışık polimerizasyon cihazı, yüzey sertliği, kavite derinliği

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