Comparison of the low level laser therapy effects on cultured human gingival fibroblasts proliferation using different irradiance and same fluence*

Abstract

The LLLT acts by improving the in vitro fibroblast proliferation and a smaller laser exposure time results in higher proliferation.

Nutritional stress enhances cell viability of odontoblastlike cells subjected to low level laser irradiation

“…In line with this concept, the present study evaluated different low FBS concentrations in odontoblast-like cell cultures, but respecting the threshold not to cause a harmful cell stress condition [17]. L. Almeida-Lopes et al in 2001 [17] have demonstrated that FBS-free culture medium applied on laser-irradiated fibroblasts did not produce a satisfactory bioestimulatory response when compared to the 5% FBS-enriched medium. In the same way, C.F.…”

“…DMEM supplementation with 2% and 5% FBS to induce cell stress is based on the findings of previous studies that demonstrated that cell cultures responded more effectively to an irradiation stimulus when subjected to nutritional deficit conditions, since the mechanisms of cell response were sensitive to the absorption of irradiation [17,[21][22][23]. In line with this concept, the present study evaluated different low FBS concentrations in odontoblast-like cell cultures, but respecting the threshold not to cause a harmful cell stress condition [17]. L. Almeida-Lopes et al in 2001 [17] have demonstrated that FBS-free culture medium applied on laser-irradiated fibroblasts did not produce a satisfactory bioestimulatory response when compared to the 5% FBS-enriched medium.…”

“…Pereira, et al in 2002 [24] reported an increase in the proliferation of NIH 3T3 cells placed under stress condition, that is seeded in a culture medium supplemented with 2.5% FBS. On the other hand, L. Almeida-Lopes et al in 2001 [17] reported that fibroblasts seeded in culture medium without FBS supplementation did not show growth, while the addition of 5% FBS to the medium resulted in a lower cell proliferation rate than that obtained with the ideal FBS supplementation (10%), but high enough to induce a stress condition in vitro.…”

“…It has been demonstrated that different cell types under stress conditions are more sensitive to the biomodulatory effect of laser irradiation [17][18][19][20]. The cell stress mechanisms may range from alterations in the oxidative agents and the temperature of the culture medium to nutritional deficit (decrease of fetal bovine serum (FBS) concentration in the culture medium), the latter being more effectively used to evaluate the effects laser irradiation on cell metabolism [13,17,[21][22][23].…”

Análise da expressão e mecanismos de ação das proteínas Akt, Hsp90, mTOR e ciclina D1 em cultura de células de carcinoma epidermoide humano e células displásicas após irradiação com laser em baixa intensidade

“…Há resultados distintos em relação à proliferação celular quando diferentes protocolos de LLLT são utilizados (201)(202)(203)(204)(205) . Além destes protocolos, o estado fisiológico da célula também é capaz de interferir nos efeitos proliferativos da luz laser (206) .…”