Publication: Seramik laminalarda kırılma direncinin in vitro olarak değerlendirilmesi
Abstract
Dt. Burçin Akoğlu ÖZET SERAMİK LAMİNALARDA KIRILMA DİRENCİNİN İN VİTRO OLARAK DEĞERLENDİRİLMESİ Bu çalışmanın amacı, minede sonlanan preparasyonlara uygulanan laminalar ile geniş miktarda dentin açığa çıkmış olan preparasyonlar üzerine uygulanan laminaların kırılma dirençlerinin değerlendirilmesidir. Bu çalışmada 75 adet homojen boyutlara sahip olan, çekilmiş üst santral kesici diş kullanıldı. Dişlerde çürük ve restorasyon olmamasına dikkat edildi ve 15 dişten oluşan 5 gruba ayrıldı. 1) 2 mm insizal indirgeme, minede hazırlanan preparasyon, 2) 4 mm insizal indirgeme, minede hazırlanan preparasyon, 3) 2 mm insizal indirgeme, dentinde hazırlanan preparasyon, 4) 4 mm insizal indirgeme, dentinde hazırlanan preparasyon, 5) Kontrol amacı ile prepare edilmemiş dişler. Preparasyonda insizal kenarda düz bitim hattı oluşturulurken, iç açıları yuvarlatılmış, mine sement sınırının 1 mm üzerinde sonlanan preparasyonlar yapıldı. IPS Empress (Ivoclar, Schann, Liechtenstein) tam seramik lamina restorasyonlar hazırlandı ve Syntac Classic adeziv sistem ve Variolink II (Ivoclar, Schann, Liechtenstein) rezin simanla simante edildi. Dişlere 30 saniyelik süre ile 5 ± 1 Cº - 55 ± 1 Cº arasında 3500 termal siklus uygulandı. Universal test cihazı kullanılarak, palatinal yüzeyden insizal kenarın 2,5 mm altından 90ºlik açı ile 0,5 mm/ dak hızda kırma testi gerçekleştirildi. Deney grupları için elde edilen ortalama kırılma değerleri: Grup 1: 262,36 N, Grup 2: 189, 0733 N, Grup 3: 239, 52 N, Grup 4: 161,90 N, Grup 5: 277,2 N. Sonuç olarak prepare edilmemiş kontrol dişleri ile 2 mm insizal indirgeme yapılarak mine ve dentinde hazırlanan gruplar arasındaki fark istatistiksel olarak anlamlı bulunmamıştır. İki mm insizal indirgeme yapılarak mine yüzeyinde hazırlanan preparasyonlar ile 4 mm insizal indirgeme yapılarak mine ve dentinde hazırlanan preparasyonlar arasında istatistiksel olarak anlamlı farklılık gözlendiği tespit edilmiştir. 2 mm insizal indirgeme yapılarak dentin yüzeyinde hazırlanan preparasyonlar ile 4 mm insizal indirgeme yapılarak dentinde hazırlanan preparasyonlar arasında istatistiksel olarak anlamlı farklılık gözlendiği tespit edilmiştir. Porselen lamina restorasyonlar, dentin, kırılma dayanıklılığı
FRACTURE RESISTANCE OF CERAMIC VENEERS: AN IN VITRO STUDY The purpose of this in vitro study was to examine the fracture load of ceramic veneers with preparations at enamel or at dentin. For this study 75 extracted intact human maxillary central incisors with homogeneous dimensions were selected. Each tooth was free of dental caries or restorations. Teeth were divided in 5 groups of 15 specimens: 1) 2 mm incisal reduction, preparation entirely in enamel, 2) 4 mm incisal reduction, preparation entirely in enamel, 3) 2 mm incisal reduction, preparation entirely in dentin, 4) 4 mm incisal reduction, preparation entirely in dentin, 5) Unrestored, intact teeth as control. All the preparations had a butt joint incisal finish line, rounded internal line angles and the cervical finish lines were 1 mm above the cementoenamel junction. All veneers were fabricated with IPS Empress staining technique (Ivoclar, Schann, Liechtenstein) and cemented with Syntac Classic Adhesive system and Variolink II (Ivoclar, Schann, Liechtenstein) composite resin cement. The teeth were thermocycled between 5 ± 1ºC and 55± 1ºC for 3500 cycles with a dwell time of 30 seconds. The fracture loads were determined using a universal testing machine. The load was applied at a 90º angle to the lingual surface of the test tooth. The load was consistently applied at 2.5 mm from the incisal edge. The plunger was attached to the load cell, and crosshead speed was 0.5 mm/ min. The mean fracture loads (N) are: Group 1: 262,36 N, Group 2: 189, 0733 N, Group 3: 239, 52 N, Group 4: 161,90 N, Group 5: 277,2 N. There wasn’t any significant difference between fracture strengths of the control group and the groups with 2 mm incisal reduction. There was significant difference between Group 1 and Group 2 – Group 4. There was significant difference between Group 3 and Group 4. Porcelain laminate veneers, dentin, fracture resistance
FRACTURE RESISTANCE OF CERAMIC VENEERS: AN IN VITRO STUDY The purpose of this in vitro study was to examine the fracture load of ceramic veneers with preparations at enamel or at dentin. For this study 75 extracted intact human maxillary central incisors with homogeneous dimensions were selected. Each tooth was free of dental caries or restorations. Teeth were divided in 5 groups of 15 specimens: 1) 2 mm incisal reduction, preparation entirely in enamel, 2) 4 mm incisal reduction, preparation entirely in enamel, 3) 2 mm incisal reduction, preparation entirely in dentin, 4) 4 mm incisal reduction, preparation entirely in dentin, 5) Unrestored, intact teeth as control. All the preparations had a butt joint incisal finish line, rounded internal line angles and the cervical finish lines were 1 mm above the cementoenamel junction. All veneers were fabricated with IPS Empress staining technique (Ivoclar, Schann, Liechtenstein) and cemented with Syntac Classic Adhesive system and Variolink II (Ivoclar, Schann, Liechtenstein) composite resin cement. The teeth were thermocycled between 5 ± 1ºC and 55± 1ºC for 3500 cycles with a dwell time of 30 seconds. The fracture loads were determined using a universal testing machine. The load was applied at a 90º angle to the lingual surface of the test tooth. The load was consistently applied at 2.5 mm from the incisal edge. The plunger was attached to the load cell, and crosshead speed was 0.5 mm/ min. The mean fracture loads (N) are: Group 1: 262,36 N, Group 2: 189, 0733 N, Group 3: 239, 52 N, Group 4: 161,90 N, Group 5: 277,2 N. There wasn’t any significant difference between fracture strengths of the control group and the groups with 2 mm incisal reduction. There was significant difference between Group 1 and Group 2 – Group 4. There was significant difference between Group 3 and Group 4. Porcelain laminate veneers, dentin, fracture resistance