The influence of recent technology on two different adhesive filling materials

Abstract

The present study was conducted to evaluate and compare in vitro two different adhesive filling materials as regards marginal gap distance, roughness and shear bond strength used in the restoration of primary molars. Thirty six human primary molars were included in this study. The teeth were recently extracted due to serial extraction or exfoliated. Immediately after extraction, the teeth were thoroughly cleaned with pumice slurry water to remove blood and then immediately stored in aqueous buffered solution of formal for two hours for infection control. Teeth were stored in tap water until measurements. Standardized Mesio-occlusal class II cavity preparationswere prepared in all molars using a new 330 diamond bur with a head diameter of 2.0 and a head length of 4mm in a high speed hand piece with water cooling for every 3 molar. The thirty six tmolars were randomly divided into six groups according to the type of restorative materials used. Each group contained six molars. Group 1: for teeth restored with conventional composite with total etch adhesive Group 2: for teeth restored with conventional composite with self etch adhesive Group 3: for teeth restored with Nano- composite with total etch adhesive Group 4: for teeth restored with Nano composite with self etch system Group 5: for teeth restored with conventional glass ionomer Group 6: for teeth restored with Nano-ionomer Following the material application, finishing and polishing, all molars were sectioned longitudinally in a bucco-lingual direction through the middle of the restoration to expose superficial dentinesurfaces. The sectioning was done using an air water-cooled diamond disc rotating at low speed (25000 rpm) First measurement for both marginal gap distance between the tooth and the restoration and the roughness were made immediately after preparation and restoration using the stereomicroscope. All samples were subjected to a thermo cycling process consisting of 500 cycles, alternating between hot water 55±2ºC and cold water 5±2ºC with a dwell time of 30 seconds and then restored in artificial saliva. Second measurement was done for only the marginal gap distance after 3 months of storage. The last measurement for both marginal gap distance between the tooth and the restoration and the roughness were made after six months of storage After six months, all samples were collected again for the shear bond strength measurement using the Universal testing machine. For standardization purpose: A large catheter of 0.12mm was brought and cut in pieces of 2 mm length then the cut catheter was put on the flat dentin surface of each tooth and again all the restorations were put inside the catheter and teeth are grouped again for the test according to the groups selected. After setting the catheter was removed and allowed for the test Data were collected and statistically analyzed for all results. The results of this study showed least marginal gap, smoothest surface and better bond strength with the Nano-composite filling material with better values for the Total-Etch group.