Academy of Laser Dentistry

Background and Objective: The aim of this study was to
assess CO 2 laser ability to eliminate bacteria from titanium
implant surfaces. The changes of the surface
structure, the rise in temperature, and the damage of
connective tissue cells after laser irradiation were also
considered. Study Design/Materials and Methods:
Streptococcus sanguis and Porphyromonas gingivalis on
titanium discs were irradiated by an expanded beam of
CO 2 laser. Surface alteration was observed by a light,
and a scanning electron, microscope. Temperature was
measured with a thermograph. Damage of fibroblastic
(L-929) and osteoblastic (MC3T3-E1) cells outside the
R E S E A R C H A B S T R A C T S
I N F LU E N C E O F A N E R B I U M , C H R O M I U M - D O P E D Y T T R I U M ,
S C A N D I U M , G A L L I U M , A N D G A R N E T ( E R , C R : Y S G G ) L A S E R
O N T H E R E E S TA B L I S H M E N T O F T H E B I O C O M PAT I B I L I T Y
O F C O N TA M I N AT E D T I TA N I U M I M P L A N T S U R FA C E S
Frank Schwarz, Enaas Nuesry, Katrin Bieling, Monika Herten, Jürgen Becker
Background: The aim of the present study was to evaluate
the influence of an erbium, chromium-doped
yttrium, scandium, gallium, and garnet (Er,Cr:YSGG
laser [ERCL]) on (1) the surface structure and biocompatibility
of titanium implants and (2) the removal of
plaque biofilms and reestablishment of the biocompatibility
of contaminated titanium surfaces. Methods:
Intraoral splints were used to collect an in vivo
supragingival biofilm on sand-blasted and acid-etched
titanium disks for 24 hours. ERCL was used at an
energy output of 0.5, 1.0, 1.5, 2.0, and 2.5 W for the
irradiation of (1) noncontaminated (20 and 25 Hz) and
(2) plaque-contaminated (25 Hz) titanium disks.
Unworn and untreated nonirradiated, sterile titanium
disks served as untreated controls (UC). Specimens
were incubated with SaOs-2 osteoblasts for 6 days.
Treatment time, residual plaque biofilm (RPB) areas
(%), mitochondrial cell activity (MA) (counts per
Heinrich Heine University, Düsseldorf, Germany
J Periodontol 2006;77(11):1820-1827
B A C T E R I C I DA L E F F I C A C Y O F C A R B O N D I O X I D E L A S E R
A G A I N S T B A C T E R I A - C O N TA M I N AT E D T I TA N I U M I M P L A N T A N D
S U B S E Q U E N T C E L LU L A R A D H E S I O N TO I R R A D I AT E D A R E A
Taku Kato, Haruka Kusakari, Etsuro Hoshino
Niigata University, Niigata, Japan
Lasers Surg Med 1998;23(5):299-309
second), and cell morphology/surface changes (scanning
electron microscopy [SEM]) were assessed. Results: (1)
ERCL using either 0.5, 1.0, 1.5, 2.0, or 2.5 W at both 20
and 25 Hz resulted in comparable mean MA values as
measured in the UC group. A monolayer of flattened
SaOs-2 cells showing complete cytoplasmatic extensions
and lamellopodia was observed in both ERCL and
UC groups. (2) Mean RPB areas decreased significantly
with increasing energy settings (53.8 +/- 2.2 at 0.5 W to
9.8 +/- 6.2 at 2.5 W). However, mean MA values were
significantly higher in the UC group. Conclusion:
Within the limits of the present study, it was concluded
that even though ERCL exhibited a high efficiency to
remove plaque biofilms in an energy-dependent
manner, it failed to reestablish the biocompatibility of
contaminated titanium surfaces.
Copyright 2006 The American Academy of Periodontology nn
irradiation spot and adhesion of the cells to the irradiated
area were also estimated. Results: All the
organisms (10 8 ) of S. sanguis and P. gingivalis were
killed by the irradiation at 286 J/cm 2 and 245 J/cm 2 ,
respectively. Furthermore, laser irradiation did not
cause surface alteration, rise of temperature, serious
damage of connective tissue cells located outside the
irradiation spot, or inhibition of cell adhesion to the
irradiated area. Conclusion: CO 2 laser irradiation with
expanded beam may be useful in removing bacterial
contaminants from implant surface.
Copyright 1998 Wiley-Liss, Inc. nn
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