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Effect of low-power laser irradiation on bone formation

Research Project

Project/Area Number 06454586
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 矯正・小児・社会系歯学
Research InstitutionNihon University

Principal Investigator

IWASAWA Tadamasa  Nihon Univ., Sch.of Dent.at Matsudo, Dept.of Orthodontics, Professor, 松戸歯学部, 教授 (30050016)

Co-Investigator(Kenkyū-buntansha) SAITO Kayo  Nihon Univ., Sch.of Dent.at Matsudo, Dept.of Orthodontics, Subassistant, 松戸歯学部, 副手 (30205637)
SHIMIZU Noriyoshi  Nihon Univ., Sch.of Dent.at Matsudo, Dept.of Orthodontics, Assistant Professor, 松戸歯学部, 講師(専任扱) (40154299)
Project Period (FY) 1994 – 1995
Project Status Completed (Fiscal Year 1995)
Budget Amount *help
¥3,700,000 (Direct Cost: ¥3,700,000)
Fiscal Year 1995: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1994: ¥2,200,000 (Direct Cost: ¥2,200,000)
KeywordsLow-power laser / Bone nodul / Rat calvarial cell / Differentiation / bone formation / osteoblast / bone nodule
Research Abstract

Effects of low-power laser irradiation on bone nodule formation in vitro were assessed. Osteoblast-like cells isolated from rat calvariae of rat fetuses were cultured and were irradiated with a low-power laser for 10 min per day. Both every day and pulsed laser irradiation significantly increased the number of bone nodules formed in a dish. When pulsed irradiation was performed within 1 to 13 d after subculture, bone nodule formation significantly increased. However, irradiation had no effects on bone nodule formation when laser was irradiated after 14 d of subculture. Furthermore, irradiation was performed in the earlier period (within 13 d) after subculture to the cells resulting in larger average size of bone nodules. It is most likely that laser irradiation stimulated differentiation and proliferation of the cells in the earlier period and these cells formed a larger number and size of bone nodules. Therefore, laser irradiation to immature osteoblasts, but not mature osteoblasts ma … More y effective to stimulate bone nodule formation.
The extra-cellular collagen level and alkaline phosphatase (ALP) activity were increased by laser irradiation and increased rates were 20 to 30% suggesting that osteoblasts function may be also stimulated by laser irradiation. When Ca and P contents in mineralized nodules were assessed by JEOL JED-2000 energy-dispersive X-ray microanalyzer, net intensities of Ca and P were significantly higher (Ca : 1.3 fold ; P : 1.3 fold) in laser group than in control group. However, the mean values of Ca/P mole ratio were similar in both groups. It may show that laser irradiation stimulated mineralization of bone nodules.
Effects of pulsed laser irradiation (10min) on gene expression of type 1 collagen and ALP were investigated using RT-PCR method. Gene expression of both collagen and ALP increased 24 h after laser irradiation compared to those in the controls. These data suggest that laser irradiation may directly affect cells and stimulate differentiation and function of rat calvarial cells resulting a large number and size of bone nodule formation. Less

Report

(3 results)
  • 1995 Annual Research Report   Final Research Report Summary
  • 1994 Annual Research Report

Research Products

(7 results)

All Other

All Publications (7 results)

  • [Publications] Y.Ozawa,N.Shimizu,他: "Stimulatory ellects of low-power laser irradiation on bone formation in vitro" Proceeding of SPIE,Advanced Laser Dentistry. 1984. 281-288 (1995)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] S.Saito,N.Shimizu: "Stimulatory effects of low-power laser irradiation on bone regeneration in mid-palatal sature during expansion in rat" American Journal of Orthodontics and Dentofacial Orthepedics. (in press).

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] Yoshiro Ozawa, Noriyoshi Shimizu, Hiroyuki Mishima, Genichiro Kariya, Masaru Yamaguchi, Hisashi Takiguchi, Tadamasa Iwasawa, Yoshimitsu Abiko: "Stimulatory effects of low-power laser irradiation on bone formation in vitro." Proceeding of SPIE,Advanced Laser Dentistry : 1st International Conference, Volume 1984, ed. by Altshuler GB,Blankenau R and Wigdor HA. 281-288 (1995)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] Shiro Saito and Noriyoshi shimizu: "Stimulatory effects of low-power laser irradiation on bone regeneration in mid-palatal suture during expansion in rat" American Journal of Orthodontics and Dentofacial Orthopedics. (in press).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1995 Final Research Report Summary
  • [Publications] Y. Ozawa, N. Shimizu 他6名: "Stimulatory effects of low-power laser irradiation on bone formation in vitro" Proceeding of SPIE, Advanced Laser Dentistry. 1984. 281-288 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] S. Saito 他1名: "Stimulatory effects of low-power laser irradiation on bone regeneration in mid-palatal suture during expansion in rat." American Journal of Orthodontics and Dentofacial Orthopadics. (in press).

    • Related Report
      1995 Annual Research Report
  • [Publications] Yasuhito Ozawa: "Stimulatory Effects of Low-Power Laser Irradiation on Bone Formation in vitro" The international society for optical enginieering(SPIE)proceedings. (in press). (1995)

    • Related Report
      1994 Annual Research Report

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Published: 1994-03-31   Modified: 2016-04-21  

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