The evaluation of the surface micro-hardness values in different depth of resin blocks
Journal Title: Cumhuriyet Dental Journal - Year 2018, Vol 21, Issue 4
Abstract
Objective: Computer-aided design and manufacturing technology has shown great improvement in dentistry since the 1980s. This technology is based on a one-stage restoration using prefabricated blocks. Two main types of materials are used during CAD / CAM indirect restorations: glass-ceramic / ceramic and resin composite. CAD / CAM resin blocks are polymerized under high temperature and pressure. Polymerization depth affects the surface hardness of composite resins. When preparing a restoration, different depth layers of the resin block are used. The aim of this study is to show that adequate polymerization is achieved in each layer of the resin blocks and that the hardness of each layer is the same. Two composite resin block materials and one hybrid resin block material were included in this study. Material and method: The CAD/CAM block materials evaluated in this study were Cerasmart, Lava and Vita Enamic Square specimens (n=5/material) of approximate dimensions 10×10×2 mm blocks were sectioned (5 slices/block) from commercially available CAD-CAM materials using a diamond saw (exakt 300 cl Apparatebau, Norderstedt, Germany) with water cooling. All specimens were abraded followed by 500,1200,2500 grid using SiC abrasive paper (exakt 400 cs Apparatebau, , Norderstedt, Germany). After storage in distilled water at 37 °C for 24 hours the Knoop hardness test was performed using a hardness testing machine (Buehler MMT 3 digital micro hardness tester, Lake Bluff, IL, USA) using a load of 500 gf and a loading time of 10s. Results: The material with the highest hardness number was Vita Enamic block, whereas the lowest numbered group was the Cerasmart. The rank order of surface hardness was as follows: Vita Enamic> Lava Ultimate >Cerasmart. Conclusion: The hardness measurements of the layers of blocks were similar.
Authors and Affiliations
Zeliha Gonca BEK KÜRKLÜ, Hamdi Oğuz YOLDAŞ
PREVALENCE OF VERTICAL ROOT FRACTURE IN EXTRACTED ENDODONTICALLY TREATED TEETH: A PROSPECTIVE STUDY
Objectives: Vertical root fracture (VRF) is one of the complications of endodontic treatment which results extraction of the related tooth. The purpose of this prospective study was to evaluate prevalence of VRF in extra...
The evaluation of the surface micro-hardness values in different depth of resin blocks
Objective: Computer-aided design and manufacturing technology has shown great improvement in dentistry since the 1980s. This technology is based on a one-stage restoration using prefabricated blocks. Two main types of ma...
Comparison of the Microtensile Bond Strength Of Four Different Bulk-Fill Resin Composites Of Class I Cavities With Dentin
Objectives: The aim of our study is to compare the microtensile bond strengths of four different bulk-fill composites and a microhybrid composite to the dentin. Materials and methods: 4 bulk-fill composites and a microh...
Effect of Ozone Pretreatment on the Microleakage of Class V Cavities Following Office Bleaching with Diode Laser
Objective: This study investigated the effect of ozone treatment on the microleakage of class V composite restorations after using two different bleaching agents with laser activation. Materials and Methods: Forty non-...
Assessment of the relationships between deleterious oral habits that may cause orthodontic anomalies and psychological and socio-demographic factors
Objectives: The aim of this study is to identify the relation between the deleterious oral habits (DOH) which can cause orthodontic anomalies such as finger sucking, nail biting, lip chewing, bruxism and psychological an...