Shear Bond Strength Of Composite Resin Research Articles

Effect of whitening toothpastes on bonding of restorative materials to enamel of primary teeth.

The aim of this in vitro investigation was to measure shear bond strength (SBS) of a resin composite and a resin-modified glass ionomer to enamel of primary teeth after application of different whitening toothpastes (WTs). Eighty labial enamel surfaces of primary incisors were randomly distributed into 8 groups of 10 each according to the surface treatment and bonding material. G1 and G2, control (brushed with water without WT); G3 and G4, (brushed with Colgate Optic White WT [Colgate-Palmolive Company, New York, NY, USA]), G5 and G6, (brushed with Crest Pro-Health Whitening WT [Procter and Gamble, Cincinnati, OH, USA]) and G7 and G8, (brushed with Arm and Hammer Advance White Extreme Whitening with Stain Defense WT [Church and Dwight Co., Princeton, NJ, USA]). SBS was measured at a crosshead speed of 0.5 mm/min and the type of bond failure was assessed using a stereomicroscope. There was significant difference between SBS of composite resin in groups 1, 3, 5, and 7 (P < 0.001), but no difference between resin-modified glass ionomer in groups 2, 4, 6, and 8 (P < 0.056). SBS of group 1 (control) was greater than groups 3, 5, and 7. There was a significant difference between group 1 and group 2 as well as group 7 and group 8 (P < 0.001). WTs affect SBS of resin composite, but not resin-modified glass ionomer to enamel of primary teeth. No difference of failure modes between different groups of tested materials.

Effect of Long-Term Storage Temperatures on the Bond Strength of Self-Etch Adhesives

Manufacturers often recommend refrigerated storage of self-etching enamel and dentin adhesives. The purpose of this study was to compare the shear-bond strength of composite resin to dentin using two different self-etching adhesives after extended storage at room or refrigerated temperatures. One- and two-step self-etching bonding agents were stored separately at room (23 degrees C) or refrigerated temperatures (5 degrees C) per manufacturer recommendations for 1, 4, or 18 months before testing. After each time period, composite resin was bonded to the dentinal surface of extracted human third molars using a mold and tested in shear on a universal-testing machine. Data were analyzed with analysis of variance/Tukey's test. No significant difference in bond strengths was found on the basis of storage temperature for either adhesive type. The one-step adhesive had a significant loss in bond strength over the 18 months of storage. However, the two-step self-etch adhesive had no loss in bond strength, regardless of storage temperature.

Evaluation of shear bond strength of composite to newly condensed and set amalgam by using two adhesive systems.

The introduction of adhesives has created a new opportunity to bond compositeresin to existing amalgam restoration on aesthetically disturbing surfaces. Further more ,the composite laminate would probably improve the restoration .This in vitro study was conducted to evaluate the shear bond strength ofcomposite resin to fresh and set amalgam by the use of two adhesive systems and to studythe effect of water storage time on the shear bond strength of composite resin to fresh andset amalgamOne hundred and eighty cylindrical specimens, 5mm high x 5 mm in diameter ,composed of 3 mm of amalgam and 2 mm of composite with a layer of bonding materialin between were prepared. Syntac Sc, Excite, control (non bonding) used to bondcomposite resin (Tetric) to the amalgam bases in three groups I, Il and lll (each onecomposed of 60 amalgam bases). Each group divided into two minor groups each of 30amalgam bases one for fresh amalgam bases referred (F) and the other one for setamalgam bases referred (S), each minor group, F and S subdivided into 3 subgroupsaccording to water immersion period into 48hrs, lmonth, 3months,stored at 37 C forscheduled period of time .