Marginal leakage of polyacid-modified composite resin restorations in primary molars: an in vitro study

Abstract

The purpose of this in vitro study was to compare the marginal leakage in primary molars restored with 2 polyacid-modified composite resins (Dyract AP - Dentsply and F2000 - 3M) and a composite resin (Filtek Z250 - 3M) as control. First and second primary molars were used for preparation of cavities on the proximal surfaces, with extension of the gingival margin to the cementoenamel junction. Restorations were accomplished after total etching and application of the respective adhesive system, and were divided into groups according to the restorative system and the number of adhesive layers used. The teeth were stored in distilled water for 7 days, followed by thermocycling with 500 cycles at 5ºC - 55ºC, with one minute in each bath. Thereafter, teeth were prepared for immersion in 0.5% methylene blue solution for four hours. The teeth were sectioned in mesiodistal direction for assessment of dye penetration. According to the results of the Kruskal-Wallis test, the three restorative materials employed did not completely avoid marginal leakage at the gingival margin of primary molars. The marginal leakage of PMCR F2000 (4.06 and 3.95) displayed to be higher than the marginal leakage observed for the materials Dyract AP (2.7 and 2.55) and Filtek Z250 (2.25 and 2.43). The number of adhesive layers did not influence the degree of leakage of the three materials.

Evaluation of Gingival Microleakage of Colored Compomers in Primary Teeth: an in vitro Study

“…Cristina et al compared the marginal leakage of compomer restorations in primary molars and reported different rates of microleakage for two compomers; one compomer showed less microleakage and the other showed more microleakage than a composite. (5) Also, in some studies, researchers achieved similar microleakage between compomers and composites. (10,11,12,13) There is controversy about of microleakage of conventional compomers.…”

“…(2,4) Material's ability to seal a cavity preparation can be influenced by its composition, plastic deformation, flow properties, coefficient of thermal expansion, modulus of elasticity, and mechanical stresses caused by type of cavity preparation. (5) Generally, because of the homogenicity of the structure of enamel and lack of dentinal fluid, adhesion to enamel is easily achievable. However, due to the heterogenicity and outward movement of dentinal fluid and its higher organic content, formation of an appropriate bond to dentin is not easy.…”

“…These findings are in accordance with the findings of other studies. (5,15) In the study of Cleide Cristina et al…”

“…(5) The magnitude of polymerization shrinkage is dependent on the extent of the reaction, the stiffness of the material, and its ability to flow. Higher filler loading of composites results in a higher degree of stiffness, which ultimately causes high shrinkage stress.…”

In vitro Evaluation of Microleakage of Class V Cavities Restored with new Flowable Compomers on the Primary Teeth

“…Therefore, providing good and sufficient adhesion with restorative material and learning the adhesive properties of materials will make the clinic procedure easier. Although, there were studies about the microleakage of GICs (4, 12) and packable compomers (13, 14), to the best of our knowledge, no studies have evaluated microleakage of flowable compomers in the Class V cavities of primary teeth. Hence, the purpose of this study was to evaluate the in vitro microleakage of new flowable compomers in the Class V cavities of primary teeth.…”