Low-level Laser Therapy Effects on Pulp Cells from Human Primary Teeth

AbstractLow-level laser therapy has been investigated as a possible stimulus for enhancement of proliferation and differentiation of various cell types, but few reports relate undifferentiated mouse pulp cells (OD-21) response to irradiation in in vitro models. The aim of this study was to analyze the influence of low-level laser therapy (λ=660 nm), with three different irradiation times, on the behavior of OD-21 cell line. The cells were cultivated and divided into three groups: non-irradiated/control (group I); irradiated with 88 s (group II); irradiated with 177 s (group III) and irradiated with 265 s (group IV). Cell growth and viability were assessed after 7 and 10 days. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests (α=.05). At day 7, there was a higher cell growth in groups I and II, as compared to group IV (p<.01). At the 10th day, group I showed a higher cell growth as compared to group II (p<.05). Cell viability in group IV was significantly lower at the 7th day, as compared to groups I (p<.001), II (p<.01) and III (p<.001). Cell viability in all the groups was over 80%, except in group IV at day 7. Irradiation time of group I influenced positively the proliferation and viability of OD-21 cells in late cell culture period. Keywords: Low-Level Laser Therapy. Cell Culture. Stem Cells. ResumoA terapia a laser de baixa intensidade tem sido investigada como possível estímulo para aumento da proliferação e diferenciação de vários tipos de células, mas poucos relatos relacionam a resposta de células indiferenciadas da polpa dentária de camundongos (OD-21) à irradiação em modelos in vitro. O objetivo deste estudo foi analisar a influência do laser de baixa intensidade (λ=660 nm), com três períodos de irradiação diferentes, no comportamento das células da linhagem OD-21. As células foram cultivadas e distribuídas em três grupos: não irradiado / controle (grupo I); irradiado com 88 s (grupo II); irradiado com 177 s (grupo III) e irradiado com 265 s (grupo IV). O crescimento e a viabilidade celular foram avaliados após 7 e 10 dias. Os dados foram analisados pelos testes de Kruskal-Wallis e Mann-Whitney (α = 0,05). No dia 7, houve crescimento celular maior nos grupos I e II, em comparação ao grupo IV (p <0,01). No décimo dia, o grupo I apresentou crescimento celular superior ao grupo II (p <0,05). A viabilidade celular no grupo IV foi significativamente menor no sétimo dia, em comparação aos grupos I (p <0,001), II (p <0,01) e III (p <0,001). A viabilidade celular em todos os grupos foi superior a 80%, exceto no grupo IV no dia 7. O tempo de irradiação do grupo I influenciou positivamente a proliferação e a viabilidade das células OD-21 no período mais tardio da cultura celular. Palavras-chave: Laserterapia de Baixa Intensidade. Cultura Celular. Células Tronco.

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Assessment of healing of dental implant surgical site following Low-Level Laser Therapy using Bio-Clinical parameters: An Exploratory Study

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-18-00316 ◽

2020 ◽

Author(s):

VARSHA PALLED ◽

DR. JITENDRA RAO ◽

DR. RAGHUWAR DAYAL SINGH ◽

DR. SHUCHI TRIPATHI ◽

DR. KALPANA SINGH ◽

...

Keyword(s):

Laser Therapy ◽

Test Group ◽

Low Level Laser Therapy ◽

Control Group ◽

Clinical Parameters ◽

Implant Stability ◽

Low Level ◽

Implant Stability Quotient ◽

Low Level Laser ◽

Level Laser

The purpose of this study was to evaluate whether Low-Level Laser Therapy (LLLT) improves the healing of the implant surgical site with clinical and biochemical parameters.Thirty patients with an edentulous space spanning a single tooth were selected. The patients were randomly allocated to two groups - the control group and the test group. The test group received laser energy at a power of 2J/cm 2 with a total of 4-6J energy over each implant. Clinical parameters (Implant Stability Quotient, probing index, modified sulcus bleeding index)and osteoprotegerin (OPG) were assessed at baseline and follow-up intervals (2 weeks, 6 weeks, and 3 months).The test group showed significantly higher implant stability quotient compared to thecontrol group at 2 weeks(57.93±3.95 and 35.67±3.08; p<0.01) and 3months(58.86±3.75 and 67.06±3.78; p<0.01). A significant rise in OPG levels of the test group(686.30±125.36pg/ml at baseline and 784.25±108.30pg/ml at 3months;p<0.01) was seen contrary to significant decline in the control group (839.50±249.08pg/ml at baseline,415.30±78.39pg/ml at 3months;p<0.01). Within the limitations of the study, the study suggests that the healing of peri-implant hard and soft tissues may be enhanced with the use of LLLT as an explicit modality during the post-operative period.

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