İleri derecede madde kaybı olan dişlerde fiber reinforced kompozit kullanımı

Abstract

BÖLÜM VII ABSTRACT Decay and restorative procedures such as cavity preparation can cause loosening of tooth structures. In large cavities due to tooth loss cusp fractures can occur. Nowadays, improvements of dental materials are used to solve these kind of problems. Recently, fibers are been widely used in dentistry to strengthen tooth structures. Fibers are used as prostodontic framework for implants, fixed prostodontic restorations, periodontal splint, orthodontic retainer and endodontic post material. The aim of this study is to investigate reinforcing effects and mechanical effects of fibers using direct composite restorations. In our study, we used flexural strength, three point bending test, shear bond strength test and finite element analysis. In our test we investigated the effects of mechanical forces on weakened teeth using fiber reinforced composites. In fracture resistance test, 50 maxillary premolar teeth extracted for orthodontic purposes were used. Cavity preparations were performed according to Mount GJ and Hume WR Classifications in three groups. Five groups of specimens were prepared: unrestorated cavity, intact teeth, composite resin, polyethelen fiber and glass fiber. Then fracture resistance test were used using 'Instron' machine. For three point bending test, 30 specimen (2x2x25 mm-metal mold) of 1 0 groups were prepared. The groups were consisted of polyethylene fiber, composite resin and glass fiber. Flexural strength was tested with a 3-point bending test using 'Instron' machine. 109kaviteler hazırlandı. Örnekler boş kavite, sağlam diş ve kompozit resin, polie- tilen fiber, cam fiberle restore edilmiş 5 grup şeklinde hazırlandı. Daha sonra tüm örneklerin Instron cihazında basma dayanıklılığı test edildi. Üç nokta eğme testi için; 2x2x25 mm boyutlarında metal kalıpta kompozit resin, polietilen fiber, cam fiber içeren, her grupta 10 örneğin bulunduğu 30 adet model hazırlandı. Örneklere Instron cihazında üç nokta eğme testi uygulandı. Makaslama gerilimi testinde; 30 adet çürüksüz maksiller premolar diş kron kısmından kesilerek bukkal yüzleri açıkta kalacak şekilde polivinilklorit yüzükler gömüldü. Dentin yüzeyleri açığa çıkıncaya kadar aşındırıldı. Her grupta 1 0'ar diş olmak üzere kompozit resin, polietilen fiber, cam fiberi içeren örnekler hazırlandı. Tüm örneklerin makaslama gerilim dirençleri Instron cihazında test edildi. Sonlu elemanlar analizinde; üst premolar dişlerin üç boyutlu modelinde kompozit resin polietilen ve cam fiber materyalinde çiğneme kuvvetleri sonu cu oluşan çekme- bası gerilim değerleri incelendi. Tüm veriler önem aralığı p<0.05'e göre one-way ANOVA ve Student- Newman-Kuels testleri ile istatistiksel olarak değerlendirildi. Basma dayanıklı lığı testinde, sağlam dişin direncine en yakın değer cam fiberle restore edil miş dişlerde tespit edilmiştir. Üç nokta eğme testinde, en yüksek direnci cam fiberle desteklenmiş örnekler vermiştir. Makaslama gerilimi testinde, polietilen fiberle güçlendirilmiş örnekler cam fiberle güçlendirilmiş örneklerden daha yüksek bağlanma dayanıklılığı göstermiştir. Sonlu elemanlar analizinde, tüm örneklerde çeki ve bası gerilme değerleri kuvvetin uygulandığı mine, denti, 107For shear bond strength test, 30 non-carious maxillary premolar teeth were used. The crowns were embedded in polyvinyl rings. They were grinded until dentin surfaces are seen. In every group,. polyethylene fiber, composite resin and glass fiber 10 specimens were used. 'Instron' machine was used to test shear bond strength. In finite element analysis, contraction and expansion values resulting from masticating forces were investigated using polyethylene fiber, composite resin and glass fiber. All datas were at a significance level p<0.05 (ANOVA and Student- Newman-Kuels). In fracture resistance, the nearest value of fracture resistance of intact teeth were observed as glass fiber restorated teeth. In threepoint bending test, glass fibers increase the flexural strength. In shear bond strength test, polyethylene reinforced specimens have showed greater strength than glass reinforced specimens. In finite element analysis, in all specimens contraction and expansion values decreased from oclusal margin to servical area. No stress were found in root area. As a result, fiber-reinforced composite resin restorations exhibite greater fracture resistance and it's an effective and simple treatment method to reinforce composite restorations. 110

BÖLÜM VII ABSTRACT Decay and restorative procedures such as cavity preparation can cause loosening of tooth structures. In large cavities due to tooth loss cusp fractures can occur. Nowadays, improvements of dental materials are used to solve these kind of problems. Recently, fibers are been widely used in dentistry to strengthen tooth structures. Fibers are used as prostodontic framework for implants, fixed prostodontic restorations, periodontal splint, orthodontic retainer and endodontic post material. The aim of this study is to investigate reinforcing effects and mechanical effects of fibers using direct composite restorations. In our study, we used flexural strength, three point bending test, shear bond strength test and finite element analysis. In our test we investigated the effects of mechanical forces on weakened teeth using fiber reinforced composites. In fracture resistance test, 50 maxillary premolar teeth extracted for orthodontic purposes were used. Cavity preparations were performed according to Mount GJ and Hume WR Classifications in three groups. Five groups of specimens were prepared: unrestorated cavity, intact teeth, composite resin, polyethelen fiber and glass fiber. Then fracture resistance test were used using 'Instron' machine. For three point bending test, 30 specimen (2x2x25 mm-metal mold) of 1 0 groups were prepared. The groups were consisted of polyethylene fiber, composite resin and glass fiber. Flexural strength was tested with a 3-point bending test using 'Instron' machine. 109For shear bond strength test, 30 non-carious maxillary premolar teeth were used. The crowns were embedded in polyvinyl rings. They were grinded until dentin surfaces are seen. In every group,. polyethylene fiber, composite resin and glass fiber 10 specimens were used. 'Instron' machine was used to test shear bond strength. In finite element analysis, contraction and expansion values resulting from masticating forces were investigated using polyethylene fiber, composite resin and glass fiber. All datas were at a significance level p<0.05 (ANOVA and Student- Newman-Kuels). In fracture resistance, the nearest value of fracture resistance of intact teeth were observed as glass fiber restorated teeth. In threepoint bending test, glass fibers increase the flexural strength. In shear bond strength test, polyethylene reinforced specimens have showed greater strength than glass reinforced specimens. In finite element analysis, in all specimens contraction and expansion values decreased from oclusal margin to servical area. No stress were found in root area. As a result, fiber-reinforced composite resin restorations exhibite greater fracture resistance and it's an effective and simple treatment method to reinforce composite restorations. 110