Bactericidal Effect of Erbium-Doped Yttrium Aluminum Garnet Laser and Photodynamic Therapy on Aggregatibacter Actinomycetemcomitans Biofilm on Implant Surface

Abstract

Purpose: Peri-implantitis is a common complication of dental implants. The first step of treatment is elimination of bacterial biofilm and disinfection of the implant surface. This study sought to compare the effects of an erbium-doped yttrium aluminum garnet (Er:YAG) laser, photodynamic therapy using an indocyanin green-based photosensitizer (ICG-based PS) and diode laser, toluidine blue O (TBO) photosensitizer and light-emitting diode (LED) light source, and 2% chlorhexidine (CHX) on biofilm of Aggregatibacter actinomycetemcomitans to sandblasted, large-grit, acid-etched (SLA) implant surfaces. Materials and Methods: Fifty SLA implants were divided into five groups and were incubated with A actinomycetemcomitans bacteria to form bacterial biofilm. Group 1 underwent Er:YAG laser radiation (with 10-Hz frequency, 100-mJ energy, and 1-W power); group 2 was subjected to LED (with 630-nm wavelength and maximum output intensity of 2.000 to 4.000 mW/cm 2 ) and TBO as a photosensitizer; group 3 was exposed to diode laser radiation (with 810-nm wavelength and 300-mW power) and ICG-based PS; and group 4 was immersed in 2% CHX. Group 5 was the control group, and the samples were rinsed with normal saline. The number of colony-forming units (CFU) per implant was then calculated. Data were analyzed using one-way analysis of variance (ANOVA), and the five groups were compared. Results: Significant differences was found between the control group and the other groups (P < .01). The lowest mean of CFU per implant count was in group 4 (P < .01), and the highest mean belonged to the control group. Photodynamic therapy by TBO + LED and ICG-based PS + diode laser was more effective than Er:YAG laser irradiation in suppression of this organism (P < .01). There was no significant difference between groups 2 and 3. Conclusion: The antibacterial effect of 2% CHX was greater than that of other understudy methods. Int J Oral MaxIllOfac IMplants 2016;31:e71-e78.

Bacterial biofilm formation on implantable devices and approaches to its treatment and prevention

“…When this technique is used to eradicate bacterial cells, it is termed antimicrobial photodynamic therapy [98]. Various light sources have been used in in vitro and in vivo studies, such as yttrium aluminum garnet (YAG) lasers [162, 163], potassium yttrium tungstate (KYW) lasers [164], and femtosecond [165] and near-infrared lasers [166], showing the potential of photodynamic therapy to treat and control biofilm-based infections. Multiple bacterial biofilms have been shown to be eradicated using diode lasers (405–940 nm) and different photosensitizers on acrylic resin, glass, titanium, and zirconia, which in some cases was shown to be synergistic with antibiotic treatment [163, 167, 168, 169, 170, 171, 172, 173, 174].…”

Effect of Photodynamic Therapy Using Toluidine Blue on Eikenella corrodens and Aggregatibacter actinomycetemcomitans Biofilms Adhered to Titanium Discs: An In Vitro Study

“…Similarly, Saffarpour et al demonstrated that the 0.2% CHX group had the lowest colony count. (24) PDT applications have simple concepts but several factors complicate them. Further studies are required for determination of proper and exact parameters for each disease; this includes factors related to photosensitizers such as the transmission method and the duration of application and parameters related to the wavelength, irradiation exposure time, and intensity.…”

“…The diameter of the tip was 8 mm with an energy density of 110 J/cm 2 . (24) The device was placed at a fixed distance of 1 mm, perpendicular to the surfaces of the discs for 2 minutes. The output power of the device was 220 mW, which was measured by a power meter (LaserPoint s.r.l., Mi-plied by 20 to calculate the numbers in each ml.…”

“…(22,24) Irradiation was performed aseptically under a laminar flow hood (Besat, Tehran, Iran) in the dark (Figure 1.B and C). (14,18,23,24) Six discs were assigned to the positive control group (three contaminated with Aa and three infected with Ec) that were disinfected with 2 ml of 0.2% chlorhexidine (CHX; Nazho, Iran Daru Pharmaceutical Co., Tehran, Iran) for one minute without applying aPDT. Six discs of which three were contaminated with Aa and three with Ec were used as the negative control group and received no treatment.…”

“…In order to remove the superficial biofilms from the discs, the microtubes were sonicated (SinapTec, Stuttgart, Germany) for 30 seconds at a 50-Hz frequency with the power of 150 W (Figure 1.D). (24) Moreover, using physiological saline (0.9% sodium chloride (NaCl) solution; Samen Pharmaceutical Co., Mashhad, Iran), serial dilutions (10-1 -10-6 ) were organized in separate test tubes, and 50 µl of each suspension was transferred to the culture medium ( Figure 1.E and F).…”