title: In vitro comparison of ceramic burs and conventional tungsten carbide bud burs in dentin caries excavation.
abstract: OBJECTIVE
  To compare the efficiency of ceramic burs with that of conventional tungsten carbide bud burs in vitro.
  
  
  METHODS
  Fifty extracted teeth were split in the center of a caries lesion. The 100 specimens were randomly divided into 5 groups. Five clinicians were asked to excavate 10 teeth each: half with ceramic burs and the corresponding half with conventional bud burs. The time needed for caries excavation was measured. Subsequently, the prepared teeth were sectioned to produce histologic specimens, which were analyzed by light microscope after Mallory-Azan staining. The thickness of remaining caries was measured (less or more than 1 mm). The time consumption was analyzed using the paired t test. The results were analyzed for remaining caries and the thickness of the carious layer for every specimen using the nonparametric Wilcoxon test for combined random samples.
  
  
  RESULTS
  From 50 teeth, 531 histologic sections were obtained, of which 264 had been treated with ceramic burs and 267 with tungsten carbide burs. Of the sections treated with ceramic burs, 89.8% were caries-free, as were 92.1% of specimens treated with conventional burs. After excavation with ceramic burs, in 3.7% of the sections, the remaining caries was thicker than 1 mm compared with 0% in the control group. The average time to excavate a cavity with ceramic burs was 159.12 seconds (+/- 68.17) versus 170.62 seconds (+/- 72.30) with conventional bud burs. None of the recorded differences between the 2 burs was statistically significant (P > .05).
  
  
  CONCLUSIONS
  In this study, ceramic burs were as effective as conventional tungsten carbide bud burs in dentin caries excavation.
authors.affiliation: Department of Operative Dentistry, Westphalian Wilhelms-University, München, Germany. tillda@uni-muenster.de
authors.forename: Till
authors.initials: T
authors.lastname: Dammaschke
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Vesnic
authors.forename: Edgar
authors.initials: E
authors.lastname: Schafer
mesh_terms: D002516:Ceramics; D003731:Dental Caries / Q000628:therapy*; D003737:Dental Cavity Preparation / Q000295:instrumentation*; D003762:Dental Instruments; D003804:Dentin; D006801:Humans; D013997:Time Factors; D017973:Tungsten Compounds; D015040:Zirconium
chemical_list: D017973:Tungsten Compounds; C002802:tungsten carbide; D015040:Zirconium; C028541:zirconium oxide