title: In Vitro-Activity of Er:YAG Laser in Comparison with other Treatment Modalities on Biofilm Ablation from Implant and Tooth Surfaces.
abstract: OBJECTIVE
  Bacterial biofilms play a major role in the etiology of periodontal and peri-implant diseases. The aim of the study was to evaluate the removal of bacterial biofilms and attachment of epithelial cells (EC), gingival fibroblasts (GF) and osteoblast-like cells (OC) to dentin and titanium surfaces after Er:YAG laser (Er:YAG) in comparison with other treatment methods.
  
  
  METHODS
  Multi-species bacterial biofilms were grown on standardized dentin and titanium specimens with a sand-blasted and acid etched (SLA) surface for 3.5 d. Thereafter, the specimens were placed into artificially-created pockets. The following methods for biofilm removal were used: 1) Gracey (dentin) or titanium curettes (CUR), 2) Er:YAG, 3) photodynamic therapy (PDT) and 4) CUR with adjunctive PDT (CUR/PDT). Colony forming units (CFUs) of the remaining biofilms and attachment of EC, GF and OC were determined. Statistical analysis was performed by means of ANOVA with post-hoc LSD.
  
  
  RESULTS
  All treatment methods decreased statistically significantly (p<0.001) total CFUs in biofilms compared with untreated dentin and titanium surfaces respectively. On dentin, Er:YAG was equally efficient as CUR and PDT but inferior to CUR/PDT (p = 0.005). On titanium, surfaces, the use of Er:YAG resulted in statistically significantly superior biofilm removal compared to the 3 other treatments (each p<0.001). Counts of attached EC, GF and OC were the lowest on untreated contaminated dentin and titanium surfaces each. After CUR/PDT higher EC counts were found on dentin (p = 0.006). On titanium, all decontamination methods statistically significantly increased (p<0.001) the counts of attached EC without differences between groups. Statistically significantly higher counts of GF (p = 0.024) and OC (p<0.001) were observed after Er:YAG decontamination compared with untreated surfaces.
  
  
  CONCLUSIONS
  Ablation of subgingival biofilms and in particular decontamination of titanium implant surfaces with an Er:YAG laser seem to be a promising approach and warrants further investigations.
authors.affiliation: School of Dentistry, Department of Periodontology, University of Bern, Bern, Switzerland.
authors.forename: Sigrun
authors.identifier: http://orcid.org/0000-0002-4619-2461
authors.initials: S
authors.lastname: Eick
authors.affiliation: School of Dentistry, Department of Periodontology, University of Bern, Bern, Switzerland.
authors.forename: Ivan
authors.initials: I
authors.lastname: Meier
authors.affiliation: School of Dentistry, Department of Periodontology, University of Bern, Bern, Switzerland.
authors.forename: Florian
authors.initials: F
authors.lastname: Spoerlé
authors.affiliation: School of Dentistry, Department of Periodontology, University of Bern, Bern, Switzerland.
authors.forename: Philip
authors.initials: P
authors.lastname: Bender
authors.affiliation: Graduate School of Medical and Dental Science, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Aoki
authors.affiliation: Graduate School of Medical and Dental Science, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Izumi
authors.affiliation: School of Dentistry, Department of Periodontology, University of Bern, Bern, Switzerland.
authors.forename: Giovanni E
authors.initials: GE
authors.lastname: Salvi
authors.affiliation: School of Dentistry, Department of Periodontology, University of Bern, Bern, Switzerland.
authors.forename: Anton
authors.initials: A
authors.lastname: Sculean
mesh_terms: D000818:Animals; D018441:Biofilms; D003666:Decontamination / Q000379:methods*; D015921:Dental Implants / Q000382:microbiology*; D003804:Dentin; D053844:Lasers, Solid-State; D010510:Periodontal Diseases / Q000628:therapy*; D013499:Surface Properties; D013552:Swine; D014025:Titanium; D014070:Tooth / Q000382:microbiology*
chemical_list: D015921:Dental Implants; D014025:Titanium