Orhun EKREN, Işın ÇALIŞKAN, Yurdanur UÇAR

The ceramic fracture evaluation of metal-ceramic restorations fabricated by casting and laser sintering: a prospective clinical study

Purpose: The aim of this clinical study was to evaluate and compare ceramic fracture of Co-Cr metal-ceramic restorations fabricated by (Direct Metal Laser Sintering) DMLS or conventional cast methods. Methods: 86 patients with a need of fixed partial dentures without any sign of bruxial behaviors or symptoms were randomly divided into 2 groups. In the first group metal substructures were fabricated by laser sintering using Co-Cr alloy powder. In the second group substructures were fabricated by lost-wax casting technique using Co-Cr alloy ingots. Patient follow up was done 1 year after cementation. Ceramic fractures were evaluated and classified. Student T-test, Mann Whitney U, Ki Square and Fisher tests were used in statistical analysis (α=.05). Results: The success rate was 96.2% for DMLS group and 97.4% for cast group. There was statistically no significant difference between DMLS group (3.8%) and cast group (2.6%) in terms of ceramic fractures and fracture degrees (P=.447). The ceramic fractures in men (5.8%) were significantly higher than women (1.4%). (P=.004) Conclusions: Within the limitations of the current study it was concluded that the ceramic fractures in metal-ceramic fixed partial dentures fabricated by DMLS and conventional casting methods showed statistically no significant differences.

Lazer sinterleme ve döküm metal-seramik restorasyonların seramik kırıklarının değerlendirmesi: prospektif klinik çalışma

Amaç: Bu çalışmanın amacı direkt metal lazer sinterleme ve döküm yöntemleri ile hazırlanan Co-Cr altyapılı metal-seramik restorasyonlarda oluşan porselen kırıklarının klinik olarak değerlendirilmesi ve karşılaştırılmasıdır. Gereç ve Yöntem: Sabit protetik restorasyon ihtiyacı olan, bruksiyel davranış ve semptom göstermeyen 86 hasta 2 gruba ayrılmıştır. Birinci grubun metal-seramik restorasyonlarının altyapıları Co-Cr toz alaşımının lazer ile sinterlenmesiyle, ikinci grubun metal-seramik restorasyonlarının altyapıları ise Co-Cr alaşımının mum atım yöntemiyle dökülmesi ile elde edilmiştir. Hastalara metal-seramik restorasyonlarının simantasyonundan itibaren 1 yıl sonraya kontrol randevusu verilmiştir. Kontrol randevusunda restorasyonlarda oluşan porselen kırıkları değerlendirilmiş ve sınıflandırılmıştır. Sonuçların istatistiksel analizinde Student T, Mann Whitney U, Ki Kare ve Fisher test istatistiği kullanılmıştır. (α=0.05). Bulgular:DMLS grubunda başarı oranı %96,2, döküm grubunda %97,4 bulunmuştur. Porselen kırığı görülme açısından DMLS gurubu (3.8%) ve döküm grubu (2.6%) arasında istatistiksel olarak anlamlı fark bulunmamıştır (P=.447). Erkek hastalarda görülen porselen kırığı (5.8%) kadın hastalarda görülen porselen kırığından (1.4%) anlamlı olarak daha fazla bulunmuştur. (P=.004) Sonuç: Çalışmanın sınırları dâhilinde metal-seramik sabit protezlerde porselen kırığı komplikasyonu görülme açısından, altyapının DMLS yöntemi veya döküm yöntemi ile yapılması arasında bir fark olmadığı görülmüştür.

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