title: Effects of ultrasonic instrumentation on microleakage in composite restorations with glass ionomer liners.
abstract: The aim of this study was to determine the effect of ultrasonic instrumentation on composite resin restorations lined with glass ionomer cement by measuring the extent of dye penetration at the restoration/tooth interface. Preparations, 2.0 mm in diameter and 2.5 mm in depth, were made with a 331 bur in 96 human molar teeth without a bevel. The teeth were restored with glass ionomer cement liners (Shofu) and one of two types of composite resin (Silux and P-30). Half of the samples were ultrasonically instrumented for 10 s. The teeth were immersed in 0.5% methylene blue dye solution and vertically sectioned. Microleakage was scored visually using a scale of 0 to 4. Statistical comparisons were made with chi 2 analysis and the Mann-Whitney U-test at the P less than 0.05 level. Microleakage was significantly different between both resin types (P less than 0.001), and between the lined and unlined resins (P less than 0.001) that were instrumented, particularly in the P-30 restorations. Although P-30 restorations exhibited much less microleakage than Silux, the use of a glass ionomer liner did not reliably reduce microleakage in either type of material after instrumentation with an ultrasonic device.
authors.affiliation: Department of Operative Dentistry, Baylor College of Dentistry, Dallas, Texas 75246.
authors.forename: C J
authors.initials: CJ
authors.lastname: Arcoria
authors.forename: J P
authors.initials: JP
authors.lastname: Gonzalez
authors.forename: B A
authors.initials: BA
authors.lastname: Vitasek
authors.forename: M J
authors.initials: MJ
authors.lastname: Wagner
mesh_terms: D000134:Acid Etching, Dental; D017438:Bisphenol A-Glycidyl Methacrylate; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003736:Dental Cavity Lining; D003738:Dental Cements / Q000737:chemistry; D003763:Dental Leakage / Q000517:prevention & control*; D003793:Dental Restoration, Permanent; D012534:Dental Scaling / Q000295:instrumentation; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008751:Methylene Blue; D019279:Resin Cements; D014464:Ultrasonic Therapy / Q000295:instrumentation
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D005899:Glass Ionomer Cements; D019279:Resin Cements; C048711:P-30 composite resin; D017438:Bisphenol A-Glycidyl Methacrylate; C041330:Scotchbond; D008751:Methylene Blue