New Bone Formation around Implants Inserted on Autologous and Xenografts Irradiated or not with IR Laser Light: A Histomorphometric Study in Rabbits

Abstract

Use of biomaterials and light on bone grafts has been widely reported. This work assessed the influence of low-level laser therapy (LLLT) on bone volume (BV) and bone implant contact (BIC) interface around implants inserted in blocks of bovine or autologous bone grafts (autografts), irradiated or not, in rabbit femurs. Twenty-four adult rabbits were divided in 8 groups: AG: autograft; XG: xenograft; AG/L: autograft + laser; XG/L: xenograft + laser; AG/I: autograft + titanium (Ti) implant; XG/I: xenograft + Ti implant; AG/I/L: autograft + Ti implant + laser; and XG/I/L: xenograft + Ti implant + laser. The animals received the Ti implant after incorporation of the grafts. The laser parameters in the groups AG/L and XG/L were λ=780 nm, 70 mW, CW, 21.5 J/cm 2 , while in the groups AG/I/L and XG/I/L the following parameters were used: λ=780 nm, 70 mW, 0.5 cm 2 (spot), 4 J/cm 2 per point (4), 16 J/cm 2 per session, 48 h interval × 12 sessions, CW, contact mode. LLLT was repeated every other day during 2 weeks. To avoid systemic effect, only one limb of each rabbit was double grafted. All animals were sacrificed 9 weeks after implantation. Specimens were routinely stained and histomorphometry carried out. Comparison of non-irradiated and irradiated grafts (AG/L versus AG and XG/L versus XG) showed that irradiation increased significantly BV on both grafts (p=0.05, p=0.001). Comparison between irradiated and non-irradiated grafts (AG/I/L versus AG/I and XG/I/L versus XG/I) showed a significant (p=0.02) increase of the BIC in autografts. The same was seen when xenografts were used, without significant difference. The results of this investigation suggest that the use of LLLT is effective for enhancing new bone formation with consequent increase of bone-implant interface in both autologous grafts and xenografts.

Photobiomodulation in Periodontology and Implant Dentistry: Part 2

“…9 Another animal study was also conducted by Soares et al on implants integration in auto and xenografts in rabbits. 13 They observed an increased bone formation in the bone-implants interface after LLL irradiation. However, it was noted that bone formation was significantly increased in autografts but was not statistically significant with xenografts.…”

“…Most of these studies reported positive effects in terms of promotion of bone formation around Ti implants, and higher bone implant contacts (BICs) were reported ( Table 1). [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Many researchers have confirmed that low-level light therapy can promote bone formation by stimulatory effects on osteoblasts, which can lead to greater osteo-integration of Ti implants. This has been evaluated in different study designs and laser irradiation parameters.…”

Comparison of the effect of three autogenous bone harvesting methods on cell viability in rabbits

“…5 Currently the gold standard graft for reconstructing bone defects is still autogenous bone despite the introduction of different groups of bone substitutes. 6-8 The best advantage of an autograft is maintaining the viability of the transplanted cells. 9-12 However, various factors can affect the viability, including the method used for bone harvesting.…”

Efeito do laser de baixa intensidade na regeneração de defeitos ósseos críticos tratados com osso autógeno e diferentes biomateriais

“…Este material mostrou-se excelente para a formação de novo osso, quando colocado em defeitos cirúrgicos criados em crânios de coelho e tíbias de ratos (ISAKSSON, 1992;FUKUTA et al, 1992;CARVALHO et al, 2002). (SOARES et al, 2013;GERBI et al, 2005). O laser também atua no processo inflamatório, acelera a proliferação celular (KHADRA et al, 2005a; 2005b) e estimula a proliferação de células mesenquimais e osteoblastos (OZAWA et al, 1998;DORTBUDAK et al, 2000;HAMAJIMA et al, 2003;ABRAMOVITCHI et al, 2005;STEIN et al, 2005;FUJIHARA et al, 2006).…”

“…Ao analisar os grupos dos enxertos ósseos utilizados no estudo e seus respectivos grupos com a aplicação do laser pode-se observar que, embora não estatisticamente significativo para todos os grupos, os de associação com o laser apresentaram áreas de novo osso maior que nos grupos em que o laser não foi aplicado, e os grupos tratados com laser apresentaram menor quantidade de partículas em relação aos grupos não irradiados. Esses resultados podem ser explicados devido ao fato do laser atuar na proliferação e diferenciação de células ostogênicas e aumentar a microcirculação local, o que favorece maior migração de células, melhor oxigenação e melhor nutrição para a região tratada (SOARES et al, 2013;GERBI et al, 2005;KHADRA et al, 2005a).…”