OBJECTIVE: The purpose of this study was to analyze the influence of two different irradiation times with 85 mW/cm(2) 830 nm laser on the behavior of mouse odontoblast-like cells. BACKGROUND DATA: The use of low-level laser therapy (LLLT) to stimulate pulp tissue is a reality, but few reports relate odontoblastic responses to irradiation in in vitro models. METHODS: Odontoblast-like cells (MDPC-23) were cultivated and divided into three groups: control/nonirradiated (group 1); or irradiated with 85 mW/cm(2), 830 nm laser for 10 sec (0.8 J/cm(2)) (group 2); or for 50 sec (4.2 J/cm(2)) (group 3) with a wavelength of 830 nm. After 3, 7, and 10 days, it was analyzed: growth curve and cell viability, total protein content, alkaline phosphatase (ALP) activity, calcified nodules detection and quantification, collagen immunolocalization, vascular endothelial growth factor (VEGF) expression, and real-time polymerase chain reaction (PCR) for DMP1 gene. Data were analyzed by Kruskall-Wallis test (α=0.05). RESULTS: Cell growth was smaller in group 2 (p<0.01), whereas viability was similar in all groups and at all periods. Total protein content and ALP activity increased on the 10th day with 0.8 J/cm(2) (p<0.01), as well as the detection and quantification of mineralization nodules (p<0.05), collagen, and VEGF expression (p<0.01). The expression of DMP1 increased in all groups (p<0.05) compared with control at 3 days, except for 0.8 J/cm(2) at 3 days and control at 10 days. CONCLUSIONS: LLLT influenced the behavior of odontoblast-like cells; the shorter time/smallest energy density promoted the expression of odontoblastic phenotype in a more significant way.
OBJECTIVE: The purpose of this study was to analyze the influence of two different irradiation times with 85 mW/cm(2) 830 nm laser on the behavior of mouse odontoblast-like cells. BACKGROUND DATA: The use of low-level laser therapy (LLLT) to stimulate pulp tissue is a reality, but few reports relate odontoblastic responses to irradiation in in vitro models. METHODS: Odontoblast-like cells (MDPC-23) were cultivated and divided into three groups: control/nonirradiated (group 1); or irradiated with 85 mW/cm(2), 830 nm laser for 10 sec (0.8 J/cm(2)) (group 2); or for 50 sec (4.2 J/cm(2)) (group 3) with a wavelength of 830 nm. After 3, 7, and 10 days, it was analyzed: growth curve and cell viability, total protein content, alkaline phosphatase (ALP) activity, calcified nodules detection and quantification, collagen immunolocalization, vascular endothelial growth factor (VEGF) expression, and real-time polymerase chain reaction (PCR) for DMP1 gene. Data were analyzed by Kruskall-Wallis test (α=0.05). RESULTS: Cell growth was smaller in group 2 (p<0.01), whereas viability was similar in all groups and at all periods. Total protein content and ALP activity increased on the 10th day with 0.8 J/cm(2) (p<0.01), as well as the detection and quantification of mineralization nodules (p<0.05), collagen, and VEGF expression (p<0.01). The expression of DMP1 increased in all groups (p<0.05) compared with control at 3 days, except for 0.8 J/cm(2) at 3 days and control at 10 days. CONCLUSIONS: LLLT influenced the behavior of odontoblast-like cells; the shorter time/smallest energy density promoted the expression of odontoblastic phenotype in a more significant way.
Authors: Adenilson de Souza da Fonseca; Andre Luiz Mencalha; Vera Maria Araújo de Campos; Samara Cristina Ferreira Machado; Antonio Augusto de Freitas Peregrino; Mauro Geller; Flavia de Paoli Journal: Lasers Med Sci Date: 2012-09-02 Impact factor: 3.161