statement of problem: in some clinical situations, repair of composite restorations is treatment of choice. improving the bond strength between one new and old composite usually requires increased surface roughness to promote mechanical interlocking since chemical bonding might not be adequate. similarly, the treatment of a laboratory fabricated resin composite restoration involves the same pro...

Context. An in vitro study carried out to evaluate and compare the effect of Cola drink on surface roughness of esthetic restorative materials. Purpose. To compare the effect of different immersion regimes in a Cola drink on surface roughness of esthetic restorative materials. Method. Two hundred samples were grouped into 4 equal groups of 50 samples each: Group I: conventional glass ionomer, G...

This study assessed bonding of orthodontic brackets to porcelain teeth using two different surface preparation techniques and comparing two bonding systems, Fuji Ortho L.C. and Transbond. Four groups of 20 porcelain premolar teeth were bonded with metal orthodontic brackets (0.022 inch Minitwin, 3M Unitek) according to the following protocol: Transbond with a phosphoric acid etch (group 1), Tra...

Nondestructive retrieval of expensive carbon fibres (CFs) from CF-reinforced thermosetting advanced composites widely applied in high-tech fields has remained inaccessible as the harsh conditions required to recycle high-performance resin matrices unavoidably damage the structure and properties of CFs. Degradable thermosetting resins with stable covalent structures offer a potential solution to...

introduction: the aim of this study was to compare the shear bond strength of a self-adhering flowable composite (safc) and resin-modified glass ionomer (rmgi) to mineral trioxide aggregate (mta) and calcium-enriched mixture (cem) cement. methods and materials: a total of 72 acrylic blocks with a central hole (4 mm in diameter and 2 mm in depth) were prepared. the holes were filled with mta (su...

This in vivo study evaluated the clinical performance and appearance of a flowable resin composite and a hybrid resin composite over two years. Twenty-eight (28) pairs of restorations of a flowable resin composite and a conventional hybrid resin composite were placed in non-carious, asymptomatic facial Class V lesions. The restorations were evaluated at baseline, six, twelve, eighteen and twent...

Secondary caries are a worldwide public and socioeconomic problem. The placement of restorations can lead to the development of environmental conditions favorable to microbial colonization, especially on the tooth/restoration interface, which is a predisposing factor for secondary caries. The aim of this study was to evaluate microbial retention on conventional (Chelon-Fil and Vidrion R) and re...

Purpose: To compare in vitro fracture resistance of endodontically treated premolars restored with bonded amalgam or resin composite. Materials and Methods: Fifty intact and caries-free premolars that had been extracted for orthodontic treatment were selected. All teeth were subjected to endodontic procedures and MOD cavity preparation. They were then randomly divided into the five following gr...