**Author details**

*Photodynamic Therapy - From Basic Science to Clinical Research*

irrespective of power output used.

tis [85, 86].

**6. Conclusion**

response is very important.

most from the properties of PDT.

The authors declare no conflicts of interest.

**Conflict of interest**

PDT3 group for the zirconia dental implants were comparable to PDT1 and PDT2. This can suggest that LED light with additional improvements in light distribution and parameters can have an antimicrobial effect. As mentioned before there are conflicting results regarding the antimicrobial effect of using LED. Several studies reported beneficial results following use of LED lights, as a light source [77, 78]. On the other hand, several studies reported insignificant improvement in the treatment outcomes using LED light for PDT [74]. However, it is difficult to compare the results of present study with the previous ones, mainly due to the differences in the

study protocols and lack of studies conducted on zirconia implant surfaces.

titanium or zirconia implant surface at a magnification of 1:250.

The use of diode lasers in many studies has been shown to be safe in regard to the implant surface, compared to Nd:YAG, Er:YAG, CO2 and Ho:YAG lasers, which can damage the implant surfaces [57]. Castro et al. [79] concluded that 980 nm diode laser irradiation does not damage titanium implant surfaces and seems to be safe

In the present research, no structural changes on the implant surfaces following therapy was observed. PDT1, PDT2 and PDT3, did not cause visible damage on

Regarding the clinical use of PDT, several studies reported conflicting results. Many studies demonstrated improvement in clinical outcomes of patients with peri-implantitis when aPDT was combined with mechanical debridement [60, 80, 81]. Romeo et al. [82] suggested that PDT is a useful adjunct therapy but it could not replace the mechanical and surgical treatment of peri-implantitis. Similarly other studies suggest that the PDT improves the outcomes of peri-implantitis [60, 83, 84]. On the other hand, there are several studies that report no added benefit from using PDT when compared to conventional treatment modalities for peri-implanti-

The results of this *in vitro* study should be considered preliminary, since it cannot be generalized to *in vivo* and clinical conditions. The biggest concern related to future *in vivo* and clinical applications is stability of achieved *in vitro* results (short term beneficial effects in reducing the number of periopathogens). Also, the presence of plaque formation on implants, degree of salivation and host-immune

It is of utmost importance that further clinical trials be conducted in order to clarify the potential efficacy of PDT as an adjunct therapy to peri-implantitis and clear and effective treatment protocols should be established in order to benefit the

**168**

Dragana Gabrić<sup>1</sup> \*, Ana Budimir<sup>2</sup> , Ivona Bago3 , Luka Marković<sup>4</sup> , Verica Pavlić<sup>5</sup> and Bleron Azizi<sup>6</sup>

1 Department of Oral Surgery, School of Dental Medicine, University of Zagreb, University Hospital Center Zagreb, Zagreb, Croatia

2 Department of Clinical and Molecular Microbiology, University Hospital Centre Zagreb, School of Dental Medicine, University of Zagreb, Zagreb, Croatia

3 Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Zagreb, Croatia

4 Department of Periodontology, School of Dental Medicine, University of Zagreb, Zagreb, Croatia

5 Department of Periodontology and Oral Medicine, Faculty of Medicine, University of Banja Luka, Banja Luka, Bosnia and Herzegovina

6 Faculty of Dentistry, AAB College, Prishtina, Kosovo

\*Address all correspondence to: dgabric@sfzg.hr

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
