Surface and Mechanical Properties of Different Dental Composites

Research Article

Austin J Dent. 2015;2(2): 1019.

Surface and Mechanical Properties of Different Dental Composites

Dalia A Abuelenain¹, Ensanya A Abou Neel1,3,4*and Ayman Al-Dharrab²

¹Department of Operative Dentistry, King Abdulaziz University, Saudi Arabia

²Department of Oral and Maxillofacial Prosthodontics,King Abdulaziz University Jeddah, Saudi Arabia

³Department of Dentistry, Tanta University, Egypt

4Division of Biomaterials and Tissue Engineering, London

*Corresponding author: Ensanya A Abou Neel,Department of Operative Dentistry, King Abdulaziz University, Saudi Arabia

Received: March 18, 2015; Accepted: April 27, 2015; Published: May 05, 2015


Due to the unlimited revolution in dental composites technology, a wide variety of materials are available in the market. Materials’ selection is therefore a challenge and requires proper analysis of material properties. This study investigated the compressive, flexure, hardness and surface roughness of six commercially available dental composites (Filtek Z250 and 350 XT and P90, Tetric-N-Ceram and Tetric-N-Ceram Bulk Fill and IPS Impress Direct). The results showed that the highest strength and modulus (compressive and flexure) was observed for Filtek Z250 and 350XT. All tested composites showed bottom/ top hardness ratios above the minimum acceptable level (0.8) and surface roughness below the minimum acceptable level (0.2m) except Filtek P90. Accordingly, for high stress bearing applications, the materials of choice would be Filtek Z250 and Z350 XT. For low stress-bearing applications, IPS Empress and Tetric N-Ceram would be materials of choice. With P90 composites, high plaque accumulations would be expected.

Keywords: Dental composites; Compressive and flexure strength; Vicker hardness; Hardness ratio and surface roughness


In recent years, dental composite restorations became the most popular anterior and posterior esthetic resin filling material. This was attributed to the excellent esthetic, near ideal mechanical properties, ease of handling and the rapid progress with enamel and dentin bonding technology that increases the longevity of restorations [1-3]. A wide variety of dental composite filling materials are commercially available in the market. Some of these products are recommended for use in areas bearing high occlusal loads; others are recommended for better esthetic or easy handling/less application time or less polymerization shrinkage. These products vary in composition, initiator/activator system, filler type, loading, and particle size. It has been proved that these variations dramatically influence the composite properties [1,4-7] e.g., degree of resin conversion [8,9]. Accordingly, they put a burden on dental practitioners when selecting a material that fulfills the practical and clinical needs.

Previous work by Gajewski et al. [8] showed that different polymers would have different degree of conversion, reaction kinetics and physical and mechanical properties. Surface hardness would also vary with the degree of conversion [10-12]. Bottom/top hardness ratio was used as an indicator of bottom/top degree of conversion [5]. Due to the unlimited revolution in dental composites technology, a wide variety of materials are available in the market. Investigating the materials’ properties and performance should continue to help dental practitioners select the optimum composite material with the highest possible tolerance to the harsh oral environment.

The aim of the present study was to investigate the compressive and flexure properties as well as surface hardness, hardness ratio (as an indication of bottom to top conversion ratio) and roughness of six different commercially available dental composites having different organic matrix, filler loading and filler types, under the same curing and testing conditions.

The null hypothesis was that, there is no difference in mechanical properties, surface hardness, bottom/top hardness ratio and roughness between different commercially available composite when subjected to the same curing and testing conditions.

Materials and Methods

Six different commercially available composites materials were used throughout this study. Details of the studied composite are presented in Table 1. To standardize the procedures, all samples were cured using the same protocol with a light-emitting diode curing unit (3M ESPE Elipar, Germany) with a 10 mm diameter tip. The light intensity of 1800 mW/cm2 as measured with a specific radiometer (LITEX 682 Dentamirica, USA) was used for light curing. The intensity of the light was checked between samples.