title: Glass ionomer microleakage from preparations by an Er/YAG laser or a high-speed handpiece.
abstract: OBJECTIVE
  The purpose of this study was to compare microleakage of glass ionomer materials (GIC) using two different modes of cavity preparation: a high-speed hand piece and an erbium/yttrium-aluminum-garnet (Er/YAG) laser.
  
  
  METHODS
  Eighty caries free permanent molar teeth had class V preparations cut on both the buccal and lingual surfaces. The high-speed hand piece was used to prepare a class V cavity preparation on the buccal surface and an Er/YAG laser was used to prepare a class V cavity preparation on the lingual surface. GIC or resin modified GIC was used as the restorative material. The teeth were thermocycled for 7000 cycles, placed in 2% basic fushin for 24h, sectioned in the center of each restoration, and analyzed under a stereomicroscope.
  
  
  RESULTS
  There was no statistical difference in microleakage between the two modes of cavity preparations. The gingival margins had more microleakage than the occlusal margins for both GIC materials and the resin modified GIC showed significantly more leakage than the conventional GIC.
  
  
  CONCLUSIONS
  The Er/YAG laser provided an equivalent method of tooth removal when evaluated for microleakage of GIC materials compared to a high-speed hand piece.
authors.affiliation: Department of Paediatric Dentistry, 337A College of Dentistry, University of Illinois at Chicago, 801 South Paulina Street, Chicago, IL 60612-7212, USA.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Quo
authors.forename: James L
authors.initials: JL
authors.lastname: Drummond
authors.forename: Anne
authors.initials: A
authors.lastname: Koerber
authors.forename: Shahrbanoo
authors.initials: S
authors.lastname: Fadavi
authors.forename: Indru
authors.initials: I
authors.lastname: Punwani
mesh_terms: D000538:Aluminum Silicates; D003737:Dental Cavity Preparation / Q000145:classification / Q000295:instrumentation*; D003739:Dental Cementum / Q000648:ultrastructure; D003743:Dental Enamel / Q000648:ultrastructure; D003754:Dental High-Speed Equipment; D003763:Dental Leakage / Q000145:classification*; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000648:ultrastructure; D004871:Erbium; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation*; D008963:Molar / Q000648:ultrastructure; D019279:Resin Cements / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry; D012394:Rosaniline Dyes; D018709:Statistics, Nonparametric; D013816:Thermodynamics; D019237:Tooth Cervix / Q000648:ultrastructure; D015019:Yttrium
chemical_list: D000538:Aluminum Silicates; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D019279:Resin Cements; D012117:Resins, Synthetic; D012394:Rosaniline Dyes; C084541:Fuji glass-ionomer lining cement; D015019:Yttrium; C025485:basic fuchsin; D004871:Erbium