objectives: composite repair is a minimally invasive and conservative approach. this study aimed to evaluate the effect of an additional hydrophobic resin layer on the repair shear bond strength of a silorane-based composite repaired with silorane or methacrylate-based composite. materials and methods: sixty bar-shaped composite blocks were fabricated and stored in saline for 72 hours. the surf...

introduction: the aim of this study was to evaluate the composite surface treated by different powers of erbium-doped yttrium aluminum garnet (er:yag) laser in comparison with bur preparation via scanning electron microscope. methods: fourteen composite resin blocks with 15× 10 × 10 mm dimensions were used in this study. the samples were divided to seven groups as follow: group 1 (power: 1 w, e...

background and aims. bleaching may exert some negative effects on existing composite resin restorations. the aim of this study was to evaluate the effect of home bleaching on microleakage of fiber-reinforced and particle-filled composite resins. materials and methods. ninety class v cavities (1.5×2×3 mm) were prepared on the buccal surfaces of 90 bovine teeth. the teeth were randomly divided in...

background and aims. the aim of the present study was to compare the effect of surface treatment with er; cr:yssg, nd:yag, and co2 lasers on repair shear bond strength of a silorane-based composite resin. materials and methods. sixty eight cylindrical samples of a silorane-based composite resin (filtek silorane) were prepared and randomly divided into 4 groups as follows: group 1: without surfa...

objective: different ceramic repair systems have been reported for fractured ceramics. however, limited information is available concerning the bond strength of these systems especially after thermocycling. the aim of this in-vitro study was to determine the effect of thermocycling on the shear bond strength of composite-resin to feldspathic porcelain with and without silane pretreatment. mater...

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...

objectives: to assess the effect of lactic acid (la) on microleakage of silorane-based composite restorations and methacrylate-based composites with self-etch and etch-and-rinse bonding systems. materials and methods: class v cavities were prepared in 120 extracted human teeth, divided into four groups and restored as follows: 1. silorane-based composite+p90 adhesive system (p90); 2. filtek z25...

objective: despite great advances made in dental composite resins, their use is associated with some concerns regarding their mechanical properties such as their flexural strength. considering the introduction of different composite resins into the market, there is a need to compare their mechanical properties and particularly flexural strength. this study aimed to compare the flexural strength...

The aim of this in vitro study was to compare microleakage of orthodontic brackets between enamel-composite and composite-bracket interfaces at the occlusal and gingival margins, bonded using indirect bonding systems with that of a conventional direct bonding method. Forty freshly extracted human maxillary premolar teeth were randomly divided into two groups. In group 1, the brackets were bonde...

Aim: To compare marginal seal at tooth-material and material-material interfaces in the proximal box in combined amalgam/composite resin restorations. Methods: Mesio-occlusal-distal (MOD) cavities were prepared in 35 premolars and permanent molars with carbide bur. The distal proximal box was restored with amalgam (Permite, SDI) until reaching the height of pulpal floor. Dental tissues were etc...