Evaluation of fluroride release ability of three different types of GIC:An in Vitro Study

Statement of problem: Secondary caries are the prime concern after the restoration and tooth receiving crown. As time progresses the chances of secondary caries increases if suitable restorative material is not used. Aim of the study : This study evaluate the fluoride releasing ability of three different types of Glass Ionomer formulation including Glass Ionomer cement(GC-9, Gold lable), Glass Ionomer FX-II (shofuJapan), Ketac Molar(3M). Methodology : A total of 10 cylindrical specimen for each of 3 materials were prepared followed by manufacturer instructions & immersed independently in 25 ml of artificial saliva & stored as group-1 to 3. The Fluoride release was evaluated on 1 st , 7 th & 28 th day using fluoride ion specific electrode. Summary of Result : Our study showed that all 3 types of glass-ionomer cements released fluoride. The most important fluoride release took place during the first 24 hours. It then gradually increased and became constant during the following days of the study. Our results in the first 24hrs demonstrated that the concentrations of fluorine ions released were insignificantly higher in all three groups. But release of fluoride is comparatively lower in FX-II than GC-9 and Ketac molar.There is considerable increase in fluoride release was seen in all three groups in at 7 th day. Though FX-II has maintained lower release compared to GC-9 and Ketac molar. Over all release of fluoride is diminished at the 28 th day Introduction Fluoride gives hardness and durability to the tooth and protects it against caries. It has been successful to add fluoride to the tooth enamel in a soluble and absorbable form.” Erhad`t 1874. Low concentrations of fluoride have a beneficial effect on dental hard tissues and in the prevention of caries. However, after fluoride treatments, salivary fluoride concentrations decrease to very low concentrations within a few hours. Therefore, fluoride releasing dental materials can be alternative systems in order to maintain long-term fluoride release in the oral environment. The anticariogenic effects of fluoride may be due to several mechanisms. Fluoride taken up by the tooth reduces demineralization and enhances remineralization. Fluoride ions also play a role in the interference of pellicle and plaque formation and the inhibition of microbial growth. Many authors suggest that fluoride in low concentrations is necessary in oral fluids in order to decrease caries incidence.4-6 Caries incidence decrease is due to a reduction in enamel solubility to FLUORIDE RELEASE ABILITY OF THREE DIFFERENT TYPES OF GIC 3(1);2017 22 Journal Of Applied Dental and Medical Sciences 3(1);2017 oral acids, as well as inhibition of bacterial enzymes elicited by the fluoride. One of the common causes for the post-operative failure of restorations is secondary or recurrent caries. It is a well-established fact that the incidence and severity of secondary caries are reduced around restorations that release fluoride. The leached fluoride acts as a topical application to increase the fluoride content of the surrounding tooth structure, thereby minimizing caries by forming fluorapatite crystals, which are more resistant to acid attack. The ability of glass ionomer cements (GIC’s) to release fluoride has been known for some 20 years and has been a significant factor in their increasing use in dentistry The fluoride release of glass ionomers depends on the type of glass ionomer, the initial fluoride content of the glass, mixing and setting times, and pH changes in the environment. Studies have also shown that glass ionomers take up fluorides, which are lost from leaching in the oral environment and release it again in a dynamic process, thereby enabling the material to be looked upon as a “re-chargeable slow-release fluoride system.” The presence of fluoride in the oral environment thus guarantees long-term fluoride release, from these restorations in the oral cavity the fluoride binds chemically to the glass ionomer and it gradually releases it, and a continuous release uptake process thereby occurs. Two big disadvantages of the conventional glass ionomer cement (GIC) are its opaqueness that gives it poor esthetics and poor edge strength. Hence, modifications of GICs are being introduced to overcome the deficiency. Some of the modifications are the resin-modified GICs, compomer, Type VII, IX GP.Certain intrinsic variables are involved in the fluoride release process. They are mainly determined by the way the cement is manufactured: the composition of the aluminumsilicate glass and polyalkenoic acid, the size of the powder particle, the relative proportion of components (glass/polyacid/tartaric acid/water) in the mixed cement, and finally, the mixing process. When the components of the glass ionomer are mixed, they experience a reaction involving neutralization of acid groups elicited by the solid base of the glass powder. Important amounts of fluoride are released during the mixing process and after the reaction: this release is higher during the first days. Studies have shown that GICs are the most effective fluorine-releasing materials. Considering the importance of fluoride release and the significant role it plays in caries resistance and reducing its progression, the following study was conducted to evaluate the fluoride release and uptake from different types of GIC. MATERIALS AND METHOD: Ten specimens were made for each of the following three materials and were grouped as Group IGlass ionomer cement (GC-9, Gold label), Group II: Ketac Molar (3M) and Group III: Glass Ionomer FX-II