The effect of laser irradiation and doxycycline application on the production of matrix metalloproteinase‑8 and collagen I from cultured human periodontal ligament cells

Periodontal ligament fibroblasts (PDLF) play a key role in periodontal wound healing and tooth‑supporting structures. Various approaches have been tried to enhance the fibroblastic activity such as laser irradiation or doxycycline application. The current study explored the influence of laser irradiation and doxycycline application on human PDLF. The aim of the study was the effect of low‑level laser treatment and doxycycline application on the expression of collagen I and matrix metalloproteinase‑8 (MMP8) from cultured human periodontal ligament cells.

In this experimental study After preparation of human PDLF in three replications, they were divided into five treatment groups. The first group was day 0, which was used for standardization. The second group was the control group, which received no treatment within 4 days of the study. The third group was treated with doxycycline 30, µm cc daily for 4 consecutive days. The fourth group was treated with diode laser 2 J cm2 daily for 4 consecutive days. The fifth group was treated with both doxycycline and laser irradiation pertaining to the third and fourth groups. After 4 days of treatment, cells were tested for collagen I and MMP‑8 secretion through real‑time‑polymerase chain reaction and ELISA reader. The data were analyzed using the ANOVA and least significant difference pair tests ( P < 0.05 ).

Treatment of human PDLF either with diode laser or doxycycline reduced the secretion of MMP‑8 significantly. The maximum reduction was related to doxycycline application. Regarding collagen, I, only doxycycline application significantly increased collagen I secretion. Other groups showed no significant increase in collagen I secretion.

This study showed that treatment of human PDLF either with diode laser or doxycycline significantly reduced MMP‑8. Treatment with doxycycline significantly increased the secretion of collagen I.