title: A quantitative method of measuring the microleakage of thermocycled or non-thermocycled posterior tooth restorations.
abstract: This study quantified microleakage in restorations made with three packable resin composites-Solitaire, SureFil and P60; one hybrid resin composite-Z250 and an amalgam-Dispersalloy, with or without the thermocycling process. Sixty sound, freshly extracted human molars were sectioned mesiodistally, creating buccal and lingual blocks. One hundred blocks with the flattest surface were selected. Cylindrical cavities with a diameter of 1.85 +/- 0.05 mm and a depth of 1.5 mm were prepared with a special diamond bur. The blocks were randomly assigned to 10 test groups (n = 10): five restorative materials and two thermal stress groups (thermocycled groups at 3,000 cycles at 5 degrees C and 55 degrees C with a dwell time of one minute at each temperature, or non-thermocycled). After the thermocycling test, the samples were immersed in 2% methylene blue for 12 hours. The samples were ground and the powder prepared for analysis in an absorbance spectrophotometer. All the results were statistically analyzed by the Kruskal-Wallis test and the Mann Whitney test. For the non-thermocycled groups, the means (microg/ml) of microleakage were: Amalgam-4.279 (a); Solitaire-4.148 (ab); Z250-3.418 (abc); P60-3.184 (bc); SureFil-2.890 (c). For the thermocycled groups, the means were: Amalgam-7.572 (a); Solitaire-5.471 (a); Z250-4.330 (ab); P60-3.418 (bc) and SureFil-2.779 (c). Thermocycling analysis showed no significant differences between the thermocycled and non-thermocycled groups for each material tested. It was concluded that no test material prevented microleakage. Only SureFil and P60 showed leakage means significantly lower than amalgam, with SureFil showing lower leakage than Solitaire. P60 only showed lower leakage than Solitaire in the thermocycled groups and Z250 showed results similar to the others materials.
authors.affiliation: Department of Restorative Dentistry, Piracicaba School of Dentistry-Campinas State University, SP, Brazil. aguiarfhb@yahoo.com.br
authors.forename: Flávio Henrique Baggio
authors.initials: FH
authors.lastname: Aguiar
authors.forename: Alex José Souza
authors.initials: AJ
authors.lastname: Dos Santos
authors.forename: Fabiana Mantovani Gomes
authors.initials: FM
authors.lastname: França
authors.forename: Luis Alexandre Maffei Sartini
authors.initials: LA
authors.lastname: Paulillo
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Lovadino
mesh_terms: D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation; D003763:Dental Leakage / Q000145:classification*; D003793:Dental Restoration, Permanent; D006801:Humans; D008422:Materials Testing; D008751:Methylene Blue; D013053:Spectrophotometry; D018709:Statistics, Nonparametric; D013696:Temperature
chemical_list: D004396:Coloring Agents; D003188:Composite Resins; D003722:Dental Alloys; C444701:Filtek Z250; C443708:P60 Condensible Resin Composite; C113049:Solitaire composite resin; C403464:SureFil packable composite; C033470:Dispersalloy; D003723:Dental Amalgam; D008751:Methylene Blue