Decontamination of dental implant surfaces by means of photodynamic therapy

Abstract

Several implant surface debridement methods have been reported for the treatment of peri-implantitis, however, some of them can damage the implant surface or promote bacterial resistance. Photodynamic therapy (PDT) is a new treatment option for peri-implantitis. The aim of this in vitro study was to analyze implant surface decontamination by means of PDT. Sixty implants were equally distributed (n = 10) into four groups and two subgroups. In group G1 there was no decontamination, while in G2 decontamination was performed with chlorhexidine. G3 (PDT − laser + dye) and G4 (laser, without dye) were divided into two subgroups each; with PDT performed for 3 min in G3a and G4a, and for 5 min in G3b and G4b. After 5 min in contact with methylene blue dye (G3), the implants were irradiated (G3 and G4) with a low-level laser (GaAlAs, 660 nm, 30 mW) for 3 or 5 min (7.2 and 12 J). After the dilutions, culture media were kept in an anaerobic atmosphere for 1 week, and then colony forming units were counted. There was a significant difference (p < 0.001) between G1 and the other groups, and between G4 in comparison with G2 and G3. Better decontamination was obtained in G2 and G3, with no statistically significant difference between them. The results of this study suggest that photodynamic therapy can be considered an efficient method for reducing bacteria on implant surfaces, whereas laser irradiation without dye was less efficient than PDT.

Effect of low-level laser therapy on odontoblast-like cells exposed to bleaching agent

“…Due to the deleterious effects caused by components of bleaching agents, which have been demonstrated in both in vitro [6][7][8][9][10] and in vivo studies [3,5,11], the evaluation of other bleaching techniques that can prevent or reduce pulp damage is needed. Thus, laser is promising coadjutant treatment that can be used in the photodynamic therapy [12,13], stimulate cell differentiation, reduction of inflammation, and tissue repair [14][15][16][17]. Previous studies demonstrated that the specific parameters of low-level laser therapy LLLT can stimulate the deposition of collagen by fibroblasts [18] and proliferation of osteoblasts [19], as well as increase the mitochondrial activity and synthesis of ATP [20].…”

Antimicrobial effect of photodynamic therapy using methylene blue and red color diode laser on biofilm attached to sandblasted and acid-etched surface of titanium

“…The results were in agreement with previous studies in the literature. Marotti et al [24] reported that PDT using methylene blue and a GaAlA low-level diode laser on anodized implant surface is highly effective in bacterial decontamination. However, they reported that laser irradiation alone is less efficient than PDT.…”

Influência da terapia fotodinâmica na manutenção da crista óssea alveolar periimplantar

“…Atualmente, buscam-se meios de descontaminação alternativos e a PDT desponta como uma das terapias de grande destaque na literatura com resultados animadores Wilson, 1994;Usacheva et al, 2001;Dortbudak et al, 2001;Yilmaz et al, 2002;Shibli et al, 2003;Chan;Lai, 2003;Pfitzner et al, 2004;Gad et al, 2004;Hayek et al, 2005;Sigusch et al, 2005;Shibli et al, 2006;Andersen et al, 2007;Braun et al, 2008;Marotti et al, 2013). Porém, ainda não existe um consenso sobre os parâmetros utilizados, seja para o laser, como para o corante.…”

“…Inúmeros trabalhos têm associado a terapia fotodinâmica ou PDT (Photodynamic Therapy) como um complemento para a desinfecção de vários procedimentos clínicos, dentre eles a periimplantite (Bombeccari et al, 2013;Bassetti et al, 2014;Marotti et al, 2013). Sua ação se deve à associação de um laser de baixa potência a um fotossensibilizador.…”

“…Este, quando ativado, passa a absorver os fótons, convertendo-se em um estado excitado. A energia transferida para as moléculas vizinhas resulta na formação de moléculas reativas, como o oxigênio singleto, os íons superóxidos, as hidroxilas e outros radicais livres, que podem danificar ou matar as células bacterianas (Zanin et al, 2002;Marotti et al, 2013), além de neutralizar os fatores de virulência presentes após a morte bacteriana (Bhatti et al, 1997).…”