title: Er:Yag Laser application on titanium implant surfaces contaminated by Porphyromonas gingivalis: an histomorphometric evaluation.
abstract: OBJECTIVE
  The aim of this study was to evaluate the in-vitro application of Erbium Yag Laser (ERL) on implant surfaces contaminated by Porphyromonas gingivalis (Pg.). Moreover, this study evaluated the surface characteristics of irradiated implants.
  
  
  METHODS
  A total of 60 implants was evaluated (20 for each surface group). Each group was divided in two subgroups composed of 10 implants (test and a control). Implants were contaminated by Pg. reference strains. After proper incubation, test implants were irradiated with ERL. Laser parameters were the following: 2 940 nm wavelength, 20 mus pulse duration, 10 Hz frequency and 30 MJ pulse energy. A periodontal fiber was used to irradiate the implant threads on the axial surface with a 45 degrees angle of incidence and performing apex-crown motions for 16 s. Histomorphometric evaluation of implant surfaces (test and control) was made at different magnifications (1 000x, 6 000x,11 000x). Pg. counts were calculated on a 4 800-mm2 surface utilizing a 10-mm grid. Statistical evaluation was made with Fisher and Student's t test (P<0.05).
  
  
  RESULTS
  No surface alterations on test implants were observed. Counting results showed the following decontamination values: 76.2% for machined test implants, 90.9% for titanium plasma spray implants and 98.3% for sandblasted and etched implants. A minimal residual bacterial presence was observed in all groups.
  
  
  CONCLUSIONS
  The results of the following study showed that ERL application has decontamination effectiveness on different implant surfaces. The modification of laser time application and working parameters could easily determine complete bacterial removal from all the implant surfaces analyzed.
authors.affiliation: Division of Periodontology School of Dental Hygiene B and C La Sapienza University, Rome, Italy. s40ale@yahoo.it
authors.forename: A
authors.initials: A
authors.lastname: Quaranta
authors.forename: C
authors.initials: C
authors.lastname: Maida
authors.forename: A
authors.initials: A
authors.lastname: Scrascia
authors.forename: G
authors.initials: G
authors.lastname: Campus
authors.forename: M
authors.initials: M
authors.lastname: Quaranta
mesh_terms: D015921:Dental Implants / Q000382:microbiology*; D053844:Lasers, Solid-State; D008855:Microscopy, Electron, Scanning; D016966:Porphyromonas gingivalis / Q000302:isolation & purification / Q000528:radiation effects*; D013499:Surface Properties; D014025:Titanium
chemical_list: D015921:Dental Implants; D014025:Titanium