3 year clinical and laboratory evaluation of class i and class II highly viscous glass ionomer cement restorations

A three year clinical and laboratory evaluation of class I and H highly viscous glass ionomer restorations was conducted. Medifil IX glass ionomer capsules were used. The clinical evaluation included testing vitality, retention, structural integrity, anatomic form, secondary caries, marginal adaptation. interfacial staining, sensitivity, surface smoothness, surface staining, and patients satisfaction. The laboratory study included a three year leakage study for class I and M cavities using rhodamyne red dye to assess leakage at the axial and gingival margins using the Stereo Micro-scope. The cut specimens were later examined under the TSM [Conofocal Microscope]. The axial and gingival dap distances were also measured using the stereomicroscope and image analysis system. The clinical study revealed a 92% success rate after three years for class I restorations and a 79% success rate for class II restorations. For class I and classll cavities leakage scores were maximum at 24 hours, minimal at one year and increased more at two and again at three years. Gingival maiUnal gap distances were statistically lower than the axial gaps. There was no significant differences in axial and gingival gap distances between the different time intervals. It was concluded that such a material performed satisfactorily for three years in class I cavities. In class II cavities, whenever a heavy load is anticipated its use should be limited to two years only

Contribution to application of some natural silicate, sulfate and carbonate minerals as inserts on the fracture resistance and hermetic seal of composite resin restorations

The use of natural and bio-inserts in composite resin restorations was introduced in an attempt to reduce polymerization shrinkage, by minimizing the volume of the composite material used, which is the forerunner of composite failures. The question ,whether they can bond perfectly to composites to prevent them acting as stress raisers, was always in mind. Also their influence on the fracture resistance and leakage of the restorations was to be tested accounting for their influence on minimizing shrinkage. A group of natural silicates, sulfates and carbonates beside biogenic aragonite derived from fish bones were used as natural inserts. The used silicate minerals were represented mainly by Quartz [Tectosilicates] while the sulfates were represented by celestite [SrSO4], and the used carbonates minerals were biogenic aragonite, magnesite and dolomite. These inserts were treated with silane and Vivadent bonding agent to improve the bond strength with the associated composite material. Shear bond strength of the inserts, after the different treatments, to composites was evaluated. The treated samples were subjected to Petrographic, and SEM investigations to evaluate their effects on the hermetic seal of the composite resin restorations. The fracture resistance of the teeth with the class five composite restorations was tested. The study also included testing micro-leakage in class V composite restorations including the inserts inside using the image analysis system and stereomicroscope. It was concluded that the use of natural and bio-inserts in composite restorations enhanced the fracture resistance of the tooth restoration complex and minimized micro-leakage, which can be secondary influences to lower polymerization shrinkage. Silane treated inserts were more efficient in achieving their goal than the ones treated with dentin bonding agents. The aragonite inserts were statistically significantly more effective than the other four types