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Previous issue date: 2013-01-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Low level laser irradiation (LLLI) has been used in Dentistry to promote wound
healing and tissue regeneration. The literature shows a positive effect of LLLI
on cell proliferation, but little is known about their effectiveness in promoting
stem cells proliferation. The aim of this study was to evaluate the effect of LLLI
on the proliferative rate of human periodontal ligament stem cells. Extracts of
periodontal ligament were isolated from two third molars removed by surgical
and/or orthodontic indication. After enzymatic digestion, the cells were grown in
α-MEM culture medium supplemented with antibiotics and 15% fetal bovine
serum. On the third subculture, the cells were irradiated with a InGaAlP-diode
laser, using two different energy densities (0,5J/cm
2
- 16 seconds and 1,0J/cm?
- 33 seconds), with wavelength of 660nm and output power of 30mW. A new
irradiation, using the same parameters, was performed 48h after the first. A
control group (non irradiated) was kept under the same experimental culture
conditions. The Trypan blue exclusion test and the mitochondrial activity of the
cells measured by MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium
Bromide] essay were performed to assess the cell proliferation in the intervals
of 0, 24, 48 e 72 h after irradiation. The data of cell counts were submitted to
nonparametrical statistical tests (Kruskal-Wallis and Mann-Whitney),
considering a confidence interval of 95%. DAPI (4 -6-Diamidino-2-phenylindole)
staining of the cells was performed at 72h interval to evaluate possible nuclear
morphological changes induced by LLLI. The results of this study show that the
energy density of 1,0 J/cm? promoted greater cell proliferation compared to the
other groups (control and 0,5 J/cm?) at intervals of 48 and 72h. The
mitochondrial activity measured by MTT essay showed similar results to the
Trypan blue cell counting test. The group irradiated with 1,0J/cm? exhibited a
significantly higher MTT activity in the intervals of 48 and 72h, when compared
to the group irradiated with 0,5J/cm?. No nuclear morphological change was
observed in the cells from the three groups studied. It is concluded that LLLI
has stimulatory effects on the proliferation of human periodontal ligament stem
cells. Therefore, the use of laser irradiation in this cell type may be important to
promote future advances in periodontal regeneration / O laser de baixa intensidade (LBI) tem sido utilizado na Odontologia com a
finalidade de promover cicatriza??o e regenera??o dos tecidos. A literatura
mostra um efeito positivo do LBI na prolifera??o celular, por?m pouco se sabe
sobre a sua efic?cia na prolifera??o de c?lulas-tronco. O objetivo deste estudo
foi avaliar o efeito da irradia??o do LBI na taxa proliferativa de c?lulas -tronco do
ligamento periodontal humano. Extratos de ligamento periodontal foram
isolados de dois terceiros molares h?gidos removidos por indica? ?o cir?rgica
e/ou ortod?ntica. Ap?s a digest?o enzim?tica, as c?lulas foram cultivadas em
meio de cultura α-MEM suplementado com antibi?ticos e 15% de soro fetal
bovino. No terceiro subcultivo, as c?lulas foram irradiadas com um laser diodo
InGaAlP, utilizando-se duas diferentes densidades de energia (0,5J/cm
2
- 16
segundos e 1,0J/cm? - 33 segundos), comprimento de onda de 660nm e
pot?ncia de 30mW. Uma nova irradia??o, utilizando os mesmos par?metros, foi
realizada 48 h ap?s a primeira. Um grupo controle (n?o irradiado) foi mantido
nas mesmas condi??es experimentais de cultivo. O m?todo de exclus?o por
azul de Tripan e a atividade mitocondrial das c?lulas medida atrav?s do ensaio
de MTT [brometo de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetraz?lio], nos intervalos
de 0, 24, 48 e 72 h p?s-irradia??o, foram utilizados a fim de avaliar a
prolifera??o celular. Os dados das contagens celulares foram submetidos a
testes estat?sticos n?o param?tricos de Kruskal-Wallis e Mann-Whitney,
considerando um intervalo de confian?a de 95%. Com o objetivo de verificar
poss?veis altera??es morfol?gicas nucleares induzidas pelo laser, as c?lulas
foram submetidas ? marca??o com DAPI (4 -6-Diamidino-2-phenylindole) no
intervalo de 72 h. Os resultados do presente estudo mostraram que a
densidade de energia de 1,0 J/cm? promoveu maior prolifera??o das c?lulas em
compara??o com os outros grupos (controle e laser 0,5 J/cm?) nos intervalos de
48 e 72 h. A atividade mitocondrial, medida pelo ensaio de MTT, apresentou
resultados semelhantes ?s contagem celulares com azul de Tripan, com o
grupo irradiado com 1,0 J/cm? exibindo uma atividade significativamente maior
do MTT nos intervalos de 48 e 72 h, quando comparado com o grupo irradiado
com 0,5 J/cm?. Nenhuma altera??o morfol?gica nuclear foi observada, tanto
das c?lulas do grupo controle quanto nas c?lulas irradiadas. Conclui-se que o
LBI apresenta efeitos estimulantes sobre a prolifera??o de c?lulas-tronco do
ligamento periodontal humano. Portanto, a aplica??o da laserterapia neste tipo
celular pode ser importante para futuros avan?os na regenera??o periodontal
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17838 |
| Date | 25 January 2013 |
| Creators | Soares, Diego Moura |
| Contributors | CPF:67269621420, http://lattes.cnpq.br/5004397230198722, Silva, Jos? Sandro Pereira da, CPF:59241144653, http://lattes.cnpq.br/7625795408417124, Lins, Ruthn?ia Di?genes Alves Uch?a, CPF:87808838420, http://lattes.cnpq.br/4462076152744400, Seabra, Eduardo Jos? Guerra, CPF:91566070406, http://lattes.cnpq.br/2882454174218035, Barbosa, Carlos Augusto Galv?o |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Sa?de Coletiva, UFRN, BR, Sa?de P?blica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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