title: Lack of antimicrobial effect on periodontopathic bacteria by ultrasonic and sonic scalers in vitro.
abstract: BACKGROUND
  The purpose of this study was to assess the antimicrobial effects of a sonic and ultrasonic scaler generally used for subgingival scaling on gram-negative and gram-positive periodontopathic bacteria.
  
  
  METHODS
  Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Campylobacter rectus, or Peptostreptococcus micros were suspended in Schaedler's broth medium and treated by a sonic or a magnetostrictive ultrasonic scaler for 30 s and 150 s in vitro. Bacterial suspensions treated by an ultrasonic cell disruptor served as a positive control and untreated bacterial suspensions served as a negative control. Following sonication, samples were serially diluted, streaked on blood agar plates and incubated for 2-5 days at 37 degrees C.
  
  
  RESULTS
  Treatment by the sonic or ultrasonic scaler for up to 150 s did not reduce the viability of any of the tested periodontal pathogens. Compared to untreated controls, the viability of A. actinomycetemcomitans and P. gingivalis was significantly (p<0.05) reduced only following ultrasonication with the cell disruptor after 30 s (0.72 and 0.54 log CFU/ml, respectively) and of A. actinomycetemcomitans, P. gingivalis, C. rectus, and P. micros after 150 s (1.98, 1.34, 1.95 and 1.98 log CFU/ml, respectively).
  
  
  CONCLUSIONS
  The data of the study may indicate that the assessed sonic and ultrasonic scaler used for subgingival debridement do not result in killing of the tested periodontal pathogens.
authors.affiliation: Clinic of Operative Dentistry and Periodontology, Ludwig Maximilian University, Munich, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Schenk
authors.forename: T F
authors.initials: TF
authors.lastname: Flemmig
authors.forename: S
authors.initials: S
authors.lastname: Lob
authors.forename: G
authors.initials: G
authors.lastname: Ruckdeschel
authors.forename: R
authors.initials: R
authors.lastname: Hickel
mesh_terms: D015169:Colony Count, Microbial; D012534:Dental Scaling / Q000295:instrumentation* / Q000706:statistics & numerical data; D005069:Evaluation Studies as Topic; D006090:Gram-Negative Bacteria; D006094:Gram-Positive Bacteria; D006801:Humans; D066298:In Vitro Techniques; D010510:Periodontal Diseases / Q000382:microbiology*; D013696:Temperature; D013997:Time Factors; D014464:Ultrasonic Therapy / Q000295:instrumentation* / Q000706:statistics & numerical data