Marginal microleakage of class II composite resin restorations due to restorative techniques

Abstract

Purpose: To evaluate the marginal microleakage of class II composite resin (CR) restorations due to restorative techniques.Methods: Forty human extracted premolars were assigned to 4 groups (n=10). Class II cavities were prepared (4-mm wide, 2-mm axially, with the gingival margin located 1 mm beyond the cementum-enamel-junction), and the restorative adhesive system Prime & Bond 2.1/TPH 3 (Dentsply) was used. CR was inserted by the oblique incremental technique (OIT) and cured in continuous exposure. The restoratives techniques were: group 1 (control): OIT; group 2: flowable resin (1 mm) applied in the gingival wall + OIT; group 3: OIT + three pre-cured spheres inserted in the first increment of CR; and, group 4: OIT + strip of fiberglass inserted in the first increment of CR. The specimens were subjected to a thermocycling regimen of 500 cycles (1 min at 5º-37º-55ºC), coated with two layers of nail varnish up to 1 mm from the restoration margins, and immersed in 0.5% basic fuchsine solution for 24 h. The extension of dye penetration at the cervical wall (µm) was evaluated using an optic microscope at x40. Data were analyzed using analysis of variance (ANOVA) (α=0.05).Results: The microleakage values were: G1: 370 µm ± 241; G2: 398 µm ± 354; G3: 205 µm ± 119; and G4: 413 µm ± 340. No statistically significant differences were found among the restorative techniques (P=0.081). Conclusion:Marginal microleakage values were not influenced by the different restorative techniques tested.

Comparison of Microleakage and Thickness of Resin Cement in Ceramic Inlays with Various Temperatures

“…For disinfection, the teeth were immersed in 0.05% thymol solution for no longer than 6 months. 9 Standardized Cl V cavities (5 mm in length, 3 mm in width, and 2 mm in depth) were prepared on the buccal and lingual aspects of each tooth, with the gingival wall extending beyond cemento-enamel junction, while the occlusal walls extended to the enamel. An impression was made from the buccal cavities with additional silicone material (Elite HD+, Zhermack, Rovigo, Italy) and sintered feldspathic porcelain inlays (Ceramco, Dentsply, USA) were made for each cavity according to manufacturer’s instructions.…”

Glass microparticle‐ versus microsphere‐filled experimental dental adhesives

“…Failure of dental restorations is usually caused by micro‐ or nanoleakage at the restoration–tooth interface. The need for a biological seal at the tooth–restoration interface is therefore a priority.…”

Gingival Marginal Leakage of Different Tooth Colored Materials Combination as an Intermediate Layer in Class II Composite Restoration : A Comparative in Vitro Study

“…The initial stresses of shrinkage of the composite resin, coefficient of thermal expansion difference between of materials and tooth, cervical area inaccessibility, in particular, are the main problems of bonding to the cervical substrate for class II cavities, and factors that are responsible for micro leakage problems (2) . To achieve good marginal quality it is preferred to place the resin-based composite materials in layers not more than (2 mm) to prevent distortion of the cavity wall and securing adhesion to dentin (3) .…”