The effect of preheating on microhardness and flexural strength of bulk-fill resin composites: an in-vitro study

Abstract

Purpose: The objective of this study was to assess the impact of preheating on the microhardness and flexural strength of bulk-fill resin composites. Materials and Methods: In this in vitro study, forty-two specimens were prepared of each composite, X-tra fil and Opus Bulk Fill, resulting in 84 disk-shaped specimens for microhardness testing and 84 bar-shaped specimens for flexural strength analysis. The specimens were divided into four groups as follows: Group 1: X-tra fil composite with preheating (at 68°C for 15 minutes), group 2: X-tra fil composite without preheating (at room temperature), group 3: Opus Bulk Fill composite with the same preheating method, group 4: Opus Bulk Fill composite without preheating. Microhardness was assessed using the Vickers test with a diamond indenter, and flexural strength was measured using a 3-point flexural test. Statistical comparisons were performed on the calculated results. Results: In the preheated groups, both X-tra fil and Opus Bulk Fill composites exhibited significantly higher mean flexural strength compared to the non-preheated groups (p<0.001). However, there was no significant difference in the mean microhardness between the two groups for either type of composite (p=0.719). Additionally, the mean flexural strength and microhardness of X-tra fil composite, in both preheated and non-preheated conditions, were higher than those of the Opus Bulk Fill composite (p<0.001). Conclusion: Preheating bulk-fill composites to 68°C has no detrimental effect on their microhardness and increases the flexural strength of these materials. Furthermore, the degree of microhardness and flexural strength in bulk-fill composites varies between brands and is influenced by their chemical compositions.

Keywords

• composite resins
• heating
• x-tra fil composite resin
• vickers test
• microhardness

Ön ısıtmanın yığın dolgulu reçine kompozitlerin mikrosertliği ve eğilme mukavemeti üzerindeki etkisi: in vitro bir çalışma

Abstract

Amaç: Bu çalışmanın amacı, ön ısıtmanın yığın dolgulu reçine kompozitlerin mikrosertliği ve eğilme mukavemeti üzerindeki etkisini değerlendirmektir. Gereç ve Yöntem: Bu in vitro çalışmada, X-tra fil ve Opus Bulk Fill kompozitlerinin her birinden kırk iki örnek hazırlandı; sonuçta mikro sertlik testi için 84 disk şeklinde örnek ve eğilme mukavemeti analizi için 84 çubuk şeklinde örnek elde edildi. Örnekler şu şekilde dört gruba ayrıldı: Grup 1: Ön ısıtmalı X-tra fil kompozit (68°C'de 15 dakika), grup 2: Ön ısıtmasız X-tra fil kompozit (oda sıcaklığında), grup 3: Opus Aynı ön ısıtma yöntemine sahip Bulk Fill kompoziti, grup 4: Ön ısıtmasız Opus Bulk Fill kompoziti. Mikro sertlik, elmas uçlu Vickers testi kullanılarak değerlendirildi ve bükülme mukavemeti, 3 noktalı bükülme testi kullanılarak ölçüldü. Hesaplanan sonuçlar üzerinde istatistiksel karşılaştırmalar yapıldı. Bulgular: Ön ısıtmalı gruplarda hem Xtra fil hem de Opus Bulk Fill kompozitleri, ön ısıtmasız gruplarla karşılaştırıldığında önemli ölçüde daha yüksek ortalama eğilme mukavemeti sergiledi (p<0.001). Ancak her iki kompozit türü için de iki grup arasında ortalama mikrosertlik açısından anlamlı bir fark yoktu (p=0,719). Ayrıca, X-tra fil kompozitinin ortalama eğilme mukavemeti ve mikrosertliği, hem ön ısıtmalı hem de ön ısıtmasız koşullarda, Opus Bulk Fill kompozitininkinden daha yüksekti (p<0.001). Sonuç: Bulk-fill kompozitlerin 68°C'ye kadar önceden ısıtılmasının mikrosertlikleri üzerinde zararlı bir etkisi yoktur ve bu malzemelerin eğilme mukavemetini arttırır. Ayrıca, toplu dolgulu kompozitlerdeki mikro sertlik ve bükülme mukavemetinin derecesi markalar arasında farklılık gösterir ve kimyasal bileşimlerinden etkilenir.

Keywords

• kompozit reçineler
• ısıtma
• xtra fil kompozit reçine
• vickers testi
• mikrosertlik

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