title: The effect of multiple uses of disposable diamond burs on restoration leakage.
abstract: BACKGROUND
  The authors tested the clinical longevity of disposable diamond burs. They cut a series of five preparations and assessed the leakage after restoring the tooth.
  
  
  METHODS
  The authors prepared 10 teeth for Class V restorations, and used a new disposable diamond bur for each tooth. The burs were used to cut preparations in extra teeth before being used to prepare a second series of 10 teeth (third use). The authors then cut preparations in extra teeth before preparing a third set of 10 teeth (fifth use). They removed existing restorations in a second group of 30 teeth and extended the preparations using the same regimen of one, three and five bur uses. All preparations were etched and conditioned, and the teeth were restored with resin-based composite. Using a 20-volt direct-current power source and a stainless-steel counter electrode, the authors measured the leakage electrochemically in 1.0 percent sodium chloride for 30 days.
  
  
  RESULTS
  Freshly prepared and restored teeth leaked less than reprepared teeth. Leakage was similar for the first and third uses of the bur, but was far greater for the fifth use (P < .01). The previously restored teeth that were cut with the first- and third-use burs behaved the same, but the third-use bur caused more leakage than the fifth-use bur (P < .01).
  
  
  CONCLUSIONS
  Reuse of disposable burs can affect leakage behavior. With new preparations, use of a disposable bur to cut more than three preparations increased leakage. For teeth that were reprepared and restored, greater leakage occurred than it did with new preparations, although repeated use of a bur may reduce leakage.
  
  
  CONCLUSIONS
  Disposable diamond burs may cut preparations in up to three teeth before adversely affecting leakage behavior. Restoration removal and repreparation of teeth results in greater leakage than that with freshly prepared teeth.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University of Maryland School of Dentistry, Baltimore, MD 21201, USA. AVF001@dental.umaryland.edu
authors.forename: Joseph A
authors.initials: JA
authors.lastname: von Fraunhofer
authors.forename: Troy A
authors.initials: TA
authors.lastname: Smith
authors.forename: Kyle R
authors.initials: KR
authors.lastname: Marshall
mesh_terms: D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003762:Dental Instruments / Q000009:adverse effects*; D003763:Dental Leakage / Q000209:etiology*; D018130:Diamond; D004209:Disposable Equipment; D017743:Equipment Reuse; D006801:Humans; D019233:Retreatment
chemical_list: D018130:Diamond