title: Efficacy of subgingival calculus removal with Er:YAG laser compared to mechanical debridement: an in situ study.
abstract: OBJECTIVE
  The aim of the present study was to compare the effectiveness of subgingival calculus removal from periodontally involved root surfaces with an Er:YAG laser compared to hand instrumentation in situ.
  
  
  METHODS
  The mesial and distal surfaces of 30 single-rooted teeth with untreated periodontitis were treated either by hand instrumentation (scaling and root planing (SRP)) or by Er:YAG laser irradiation with the aim of achieving a calculus-free root surface. Subgingival plaque samples were obtained before and immediately after treatment for microbiological evaluation by culture and DNA probe analysis. The teeth were extracted and the residual calculus was measured by means of digitized planimetry. The morphology of the root surface was evaluated by scanning electron microscopy, and undecalcified sections were analyzed to determine residual calculus and the extent of cementum removal following both treatments.
  
  
  RESULTS
  Following laser irradiation, 68.4+/-14.4% of the root surface was calculus free in contrast to 93.9+/-3.7% after SRP when both treatments were performed for the same time (2:15+/-1:00 min). If laser irradiation was allowed twice the time used for hand instrumentation, 83.3+/-5.7% of the root surface was devoid of calculus. The effectiveness of both treatments was not related to initial probing depth. The histologic evaluation showed that after SRP 73.2% of root dentin was completely denuded from cementum, while only a minimal cementum reduction was apparent after laser irradiation. Both treatment modalities resulted in a similar reduction of periodontopathogens.
  
  
  CONCLUSIONS
  The present investigation could demonstrate the in vivo capability of the Er:YAG laser to remove calculus from periodontally involved root surfaces, although the effectiveness did not reach that achieved by hand instrumentation. The lack of cementum removal in contrast to SRP may qualify the laser as an alternative approach during supportive periodontal therapy.
authors.affiliation: Departments of Operative Dentistry and Periodontology and Maxillofacial Surgery, University Hospital Schleswig-Holstein, Kiel, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Eberhard
authors.forename: Heiko
authors.initials: H
authors.lastname: Ehlers
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Falk
authors.forename: Yahya
authors.initials: Y
authors.lastname: Açil
authors.forename: Hans-Karl
authors.initials: HK
authors.lastname: Albers
authors.forename: Sören
authors.initials: S
authors.lastname: Jepsen
mesh_terms: D000328:Adult; D003728:Dental Calculus / Q000628:therapy*; D003739:Dental Cementum / Q000293:injuries; D003762:Dental Instruments; D003773:Dental Plaque / Q000382:microbiology; D012534:Dental Scaling / Q000295:instrumentation*; D004871:Erbium; D006801:Humans; D053685:Laser Therapy; D008875:Middle Aged; D014092:Tooth Root / Q000293:injuries
chemical_list: D004871:Erbium