Academy of Laser Dentistry

In their articles on the adjunctive use of lasers in
implantology, Dr. Kutkut et al. (270-275) and Drs. Avi
Reyhanian and Donald Coluzzi (276-281) mention the
bactericidal potential of laser irradiation of implant
surfaces. The notion of utilizing laser energy to reduce
surface bacteria on intraoral implants as a means to
help ensure successful osseointegration and reduce the
incidence of periimplantitis has been studied by a
number of researchers investigating a variety of wavelengths,
including excimer, diode, Nd:YAG, erbium, and
carbon dioxide lasers. Abstracts from a sampling of
published papers representing various wavelengths
appear below.
Most researchers to date have investigated the
antimicrobial effect, primarily due to heat generated by
various lasers, on implant surfaces in in vitro experiments.
Heinrich and colleagues take a different
approach: use a KrF excimer (248 nm) laser to promote
mucosal adhesion as a biological barrier against bacterial
infection. Another group (Dörtbudak et al.) studied
the effects of “soft” diode laser exposure on implants in
patients.
Overall, results are mixed. Certain lasers do appear to
have bactericidal potential on selected microorganisms
on certain types of implants under certain conditions.
Questions regarding the relative efficacy of laser vs.
conventional treatment remain, as do concerns related to
potential alteration of implant surface morphology,
thermal damage to adjacent tissues, and inability to
reestablish the biocompatibility of contaminated surfaces.
Nevertheless, the potential for laser application in
promoting long-term implant success via bacterial reduction
exists. Further study is warranted, especially to
determine effectiveness and safety in a clinical environment,
with special emphasis placed on appropriate
parameter settings and duration of laser exposure.
R E S E A R C H A B S T R A C T S
Editor’s Note: The following material is excerpted and expanded from the Research Abstracts of
the J Laser Dent 2007;15(3):156-160. These nine abstracts are offered as topics of current interest.
Readers are invited to submit to the editor inquiries concerning laser-related scientific topics
for possible inclusion in future issues. We’ll scan the literature and present relevant abstracts.
L A S E R B A C T E R I C I DA L E F F E C T S O N
I N T R A O R A L I M P L A N T S : A N U P DAT E
In order to more closely approximate a clinical situation
in their in vitro investigation, Hauser-Gerspach
and colleagues examined the microbicidal effect of 810nm
diode and CO 2 lasers on selected bacterial species
(Streptococcus sanguinis and Porphyromonas gingivalis)
adhering to dental implant materials and in
suspension (planktonic cells), “because a fraction of
peri-implant bacteria are present as floating cells.”
They point out that a key to success is adequately
controlling the laser energy density and dose, factors
that vary with the manual guidance and experience of
the operator; that is, having sufficient laser energy
present to promote a bactericidal effect without leading
to undesirable alterations of the implant surface can be
difficult to achieve, depending upon the laser wavelength
and how it is used. Even when significant
reductions in bacterial counts are realized through
laser irradiation, they conclude that “the question
remains unanswered whether a short-term drastic
reduction of P. gingivalis in the peri-implant pocket
achieved by low laser energy is sufficient for stable
clinical improvements. … In periodontitis therapy, a
statistically significant reduction of periodontopathogenic
bacteria does not guarantee clinical success
because reinfection from other oral sites may occur or
bacteria may survive intracellularly at the treated
site.”
For U.S. readers, no laser has been cleared by the
U.S. Food and Drug Administration for “decontaminating”
or inducing bactericidal effects on intraoral
implants.
As always, clinicians are advised to review the
specific indications for use of their lasers and to review
their operator manuals for guidance on operating
parameters before attempting similar techniques on
their patients. nn
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