الفهرس 
ACKNOWLEDGEMENTOnly 14 pages are availabe for public view
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Abstract
The improvement of existing dental materials and the development of new materials for use in the dental area is an expanding field in the health care sector and thus questions regarding the marginal sealing of specific materials have been raised. GIC used in dentistry was initially limited by its slow setting time and lack of strength; however modern formulations of the material have yielded materials with properties that are clinically useful in dentistry.
The RMGI have produced materials with superior properties. However, their improvements are as yet insufficient for them to compete in such high stress bearing areas as class II. However, CRGI posterior restorative exhibit high compressive strength combined with unique ceramic reinforcement for added durability and high radiopacity.
The present study was conducted to evaluate the microleakage of ceramic-reinforced glass ionomer in class II primary molars and compared to that of resin modified glass ionomer and conventional glass ionomer cements.
The study was carried out on thirty sound exfoliated or extracted for orthodontic purpose primary molars. Standardized class II cavities were prepared. Following cavity preparation, the specimens were conditioned with 20% polyacrylic acid gel. The teeth were divided into three equal groups of ten teeth each according to the type of the restorative material used. Group I were restored with ceramic reinforced glass ionomer, group II were restored with resin modified glass ionomer and group III were restored with conventional glass ionomer. All steps were done according to the manufacturer’s instructions. All teeth were stored in distilled water at 37C inside an incubator unit for 24 hours.
After storage, the teeth were thermocycled in a water bath for 1000 cycles alternating between 5C and 55C with a dwell time 30 seconds using the thermocycling machine. The pulp chamber, root apices and furcations were sealed with acrylic resin and sticky wax, teeth surface were coated with three layers of nail polish except the surface of restorations and the surrounding 1mm. The teeth were immersed in 2% methylene blue solution for 24 hours. The teeth were sectioned mesiodistally using a diamond saw through the center of the restoration. Each tooth produced two specimens and the extent of dye penetration was detected using a light stereomicroscope X20 magnification.