: Although the use of resin composites has grown considerably, many drawbacks are associated with their use in the posterior region, such as polymerization shrinkage, gap formation, occlusal wear, and color instability. To overcome these clinical challenges, manufacturers developed materials and techniques for indirect construc- tion of resin composite restorations. Freshly extracted eighty premolar teeth were taken for the study which were free from caries, hypoplastic defects and cracks on visual examination. All teeth were cleaned to remove surface debris and calculus by ultrasonic scaler. The teeth were disinfected with 0.1% thymol solution and randomly divided into eight groups of ten (n=10), each based on the storage time, placement of classII cavity gingival margin and the type of luting agent used. Teeth were mounted. Standardized class II inlay box cavities were prepared on each tooth. Out of 80 samples, in 40 samples, the gingival margin was kept 1mm coronal to CEJ i.e supragingival, and for the remaining 40 samples, the gingival margin was kept 1mm apical to CEJ i.e subgingival. Following that, separating medium was applied, composite (Te – economy plus, Ivoclar Vivadent AG, Shaan, Liechtenstein) was placed incrementally and cured initially (40 sec) using halogen light curing unit (spectrum 800, densply sirona) with an intensity 650 mW/cm. Then, the composite inlays were removed from the teeth and post cured in polymat light curing unit (DeltaDental).For group I, III,V,VII, the multilink N was used as luting agent for semi indirect inlays.For group II, IV, VI, VIII the multilink speed was used as luting agent for semi indirect inlays. The luting cements were mixed and applied as per the manufacturers instructions. The samples were thermocycled using Willy tech thermocycler for 500 cycles at 5ºc and 55ºc, with 30 seconds dwell time and 5 seconds transfer. The sections were mounted on slides and the degree of dye penetration was recorded under stereomicroscope with X20 magnification. Leakage was evaluated according to scores mentioned below for the degree of dye penetration. There was no statistically significant difference of microleakage values between the two luting cements for a storage period of 24 hours (P=0.067) (Table 1) whereas there was statistically significant difference between them for a storage period of 2 months (P=0.035) for both supra and sub gingival groups seen at the cervical margin. Within the limitations of the present study, it can be concluded that Within 24 hours storage period there is no much difference in micro leakage between Multilink N (self-etch primer adhesive resin cement) and Multilink speed (self-adhesive resin cement). The greatest level of cervical microleakage was observed in Multilink speed (self-adhesive resin cement) than Multilink N (self-etch primer adhesive resin cement) after 2 months storage period
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Oct 1, 2024
Kemal Işıklı + 3
Open Access
