to evaluate the ultimate compressive strength of five composite resins after 1 hour, 24 hours, 7 days and 1 month. twenty four cylindrical 4 mm×8mm specimens of each commonly used composite resins in posterior region (nulite-f , z250 , p60, biscore, tetric ceram hb) were prepared. each group of composite resins were divided into four time groups of 1 h, 24 h, 7 days and 1 month. all of specimen...

introduction: although composite resins have improved greatly since their introduction, microleakage is one of the most frequently encountered problems. this study compared the effects of different monomer systems and layering techniques on the bacterial leakage of cl i composite resin restorations. methods: eighty-two sound human third molars were used. the teeth were randomly divided into six...

The objective of this study was to evaluate the tensile (σt) and shear bond strength (σs) of a glass-infiltrated alumina-based zirconia-reinforced ceramic (IZ Vita In-Ceram Zirconia) to a composite resin, testing the hypothesis that silica coating (SC Cojet, 3M-Espe) produces higher bond strength values than other ceramic surface treatments. Specimens were fabricated and tested according to the...

Advances in microsurgical techniques and immunomodulatory protocols have contributed to the expansion of vascularized composite allotransplantation (VCA) with very encouraging immunological, functional, and cosmetic results. Rejection remains however a major hurdle that portends serious threats to recipients. Rejection features in VCA have been described in a number of studies, and an internati...

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...

statement of problem: accumulation of plaque and staining due to a rough surface,  and  penetration  of  colourant  agents  from  food  and  beverages  in to the resin composite results in an incomplete polymerization. there is a little information on the effect of finishing and polishing techniques on the discoloration of nanohybrid and microhybrid composites when exposed to staining solutions...

This study was done in order to evaluate the changes flexural strength and surface roughness dental material restorations after immersion coffee. Bars specimens (2mm x 2mm 25 mm) of Z100 3M/ESPE were made according ISO 4049 using aluminum molds. After curing, then randomly divided into five groups conditioned at 37°C physiological serum. In all groups, except control, samples immersed coffee fo...