Comparative evaluation of antimicrobial effects of different wavelengths of diode lasers on

smooth implant surfaces: preliminary results

N.A. Valente, T.S. Mang, M.N. Hatton, L.M. Mikulski, S. Andreana School of Dental Medicine, University at Buffalo, Buffalo, NY, USA

ABSTRACT

RESULTS

CONCLUSIONS

INTRODUCTION

MATERIALS AND METHODS

REFERENCES

Klinge B, Meyle J. EAO Consensus Report: Peri-implant tissue destruction. The Third EAO Consensus Conference 2012. Clin. Oral Impl. Res. 23 (Suppl. 6), 2012, 108–110 Lindhe J, Meyle J. Peri-implant diseases: Consensus Report of the Sixth European Workshop on Periodontology. J Clin Periodontol 2008; 35 (Suppl. 8):282–285 Lang NP, Berglundh T on Behalf of Working Group 4 of the Seventh European Workshop on Periodontology: Periimplant diseases: where are we now? – Consensus of the Seventh European Workshop on Periodontology. J Clin Periodontol 2011; 38 (Suppl. 11): 178–181. Heitz-Mayfield LJ. Peri-implant diseases: diagnosis and risk indicators. J Clin Periodontol. 2008 Sep;35(8 Suppl):292-304. Haas R, Dortbudak O, Mensdorff-Pouilly N, Mailath G. Elimination of bacteria on different implant surfaces through photosensitization and soft laser. An in vitro study. Clin Oral Implants Res. 1997 Aug;8(4):249-54. Sennhenn-Kirchner S, Klaue S, Wolff N, Mergeryan H, Borg von Zepelin M, Jacobs HG. Decontamination of rough titanium surfaces with diode lasers: microbiological findings on in vivo grown biofilms. Clin. Oral Impl. Res. 18, 2007; 126–132

Aim: To assess the surface decontamination potential of diode laser, with different wavelengths on smooth implant surfaces. Material and Methods: Fresh porcine ribs were cut in blocks and sterilized. Eleven sterile implants per group were placed into the blocks. A standardized circumferential bony defect was created around the implant body. Defects were inoculated with 3 μL of S. sanguinis. Blocks were incubated in a 5% CO2, 37 °C atmosphere for 24hours, then the implants were subjected to different treatment protocols: 810nm or 980nm diode laser plus a control group that was not treated, for a total of 3 groups. The laser tip was placed into the defects for 30 seconds set at 1.0W continuous in an up-and-down motion. The defects were rinsed with TSB and fluid plated. Implants were retrieved and acquired media plated. Colony forming units (CFU) were counted 48 hours after incubation. Results: There is a clear evidence that both laser's wavelengths minimize the CFU counts, with the difference being statistically significant. After removing the outliers the mean CFU count for the control group was 704.3, while the mean CFU count for the 810nm group was 411.7, and for the 980nm group was 418.2 with no statistically significant difference between the two different wavelengths.Conclusion: The use of diode lasers was efficacious in this ex-vivo study in reducing the colony counts on smooth implant surfaces regardless the wavelength used.

Peri-implant disease has become a main focus in terms of prevention and treatment. Several consensus conference have tried to outline the main features and the possible prospective in the management of such a complication (3rd EAO Consensus Conference, 6th and 7th EFP Workshops Consensus Reports). Experimental and clinical studies have tried to identify the diagnostic criteria and the risk factors involved in the onset of periimplantitis (Heitz-Mayfield 2008). As of today the risk factors for development of periodontal diseases can be listed as: • Susceptibility to periodontitis • Untreated periodontitis (residual pockets)• Poor oral hygiene (FMPS >30%)• Non-cleanseable reconstructions• Residual cement rests• Neglected SPTWithin the possibility explored and experimented for the treatment of periimplantitis the use of laser is giving good results.The antimicrobial activity of laser light, which depends on its photothermic effects, has been described by a number of authors in vitro (Haas et al. 1997) and in vivo (Sennhenn- Kirchner et al. 2007). The antimicrobial efficacy comparing the 810nm and 980nm wavelength of the diode lasers has been previously demonstrated in vitro (Sennhenn-Kirchner et al. 2007).

The use of two different wavelengths of diode lasers, 810nm and 980nm, was efficacious in this ex-vivo pilot study in reducing the colony counts on smooth implant surfaces as compared to the control group, regardless the wavelength used. Further investigations will be needed to confirm these results with a larger sample size.

This research was an ex vivo experimental study. Swine ribs were used for placing implants. The ribs were cut into blocks and then sterilized (steam autoclave). Sterile implants were placed according to manufacturing instructions. Bony defects were created using a counterbore bur. The defect exposed the side of the implant that is in the bone so that the bacteria can adhere to the implant, which is what occurs in vivo, and causes the bone defect. Three bony specimens were placed in triptyc soy broth to verify that no bacteria would grow on the bone and to prove sterility. The samples were divided into 2 experimental groups and one control group, the first group division was according to the laser wavelength: 810nm or 980nm. Control group was left untreated. The periimplant defects were inoculated with 3 microliters of S. Sanguinis transported in triptych soy broth. The pieces of bone were then be placed in an incubator with the atmosphere of 5% CO2 at 37 degrees Celsius for 24 hours to allow the bacteria to grow. The bone pieces containing the implants were kept in sterile screw cap glasses. After 24 hours the experimental groups implants were treated with a different wavelength diode laser depending on the group to which they were belonging to, which was not initiated (to initiate a laser you place the heated laser tip on something that can deposit pigments on the tip of the fiberoptic laser and the pigment will concentrate the heat of the laser making the tip used more like a surgical tool. Non initiated means not depositing pigments on the laser tip and using the heat given off of the tip as is). The laser will be present in each defect for 30 seconds in an up and down fashion continuously moving the tip from the bottom of the defect to the top of the defect. After the laser treatment the implant defect was rinsed using transport media made of tryptic soy broth. This was done to ensure that the S. Sanguinis is successfully retrieved from the defect. Each defect was rinsed 3 times and the samples was then placed in 200 microliters of this transport media. The implants were retrieved from the bone block and put in 600 microliters of transport media, then vortexes and the transport media containing each implant diluted and plated. The samples were plated on tryptic soy agar plates. Three sets of plates were used. In one set the samples were diluted, in a second set the dilution of the transport media containing the implant was plated and the remaining plates were the sample not diluted. The dilution we used was 1:100. After the S. Sanguinis samples were plated the plates were placed in an incubator with the atmosphere of 5% CO2 at 37 degrees Celsius for 48 hours. After incubation the colony forming units were counted on each plate by eye and recorded. As per a pilot study conducted in the LABOS facility, the wattage used was 1.0W and the two wavelength were 810nm (2.4 G Odyssey Ivoclar Vivadent) and 980nm (Sirona SIROLaser ) diode lasers.The statistical analysis was done through analysis of variance (ANOVA).

Mean CFU count for the control group is 704.3, while for the 810nm and 980nm groups is 411.7, and 418.2. CFU count for laser treatment is statistically significant lower than control. (p=0.4, α=0.5)

Laser 810nm

Laser 980nm

Control

1 2576 60 1484

2 58 3040 708

3 1328 159 3

4 5 0 150

5 1 0 4130

6 8 0 1

7 0 2816 2310

8 7904 1136 111

9 109 11 3

10 32 0 2070

11 0 0 202

12 0 0 2

810nm laser 980nm laser

sample

S.Sanguinis CFUs growing on agar plate

SEM x2.50k and x10.0k images of S.Sanguinis colonizing the implant surface