No abstract

These results support the promising applications of BMP-7 in therapies aimed at regenerating periodontal tissues lost as a consequence of disease.

The results of this study suggest that MSCs isolated from P and PDL tissues show different cellular behavior. To increase the predictability of MSC-based regenerative treatment, differences in dental tissue-derived MSCs and favorable aspects of cell sources should be further clarified.

Human gingival fibroblasts (HGFs) are the major constituents of the gingival tissues responsible for the synthesis and degradation of the connective tissue while actively participating in immune reactions and inflammation. The aim of this study was to test the impact of lipopolysaccharide (LPS) from Porphyromonas gingivalis (P. gingivalis) on human gingival fibroblasts. Human gingival fibroblasts were treated with different P. gingivalis LPS concentrations. Cell survival rate was evaluated with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) after 24 h. Cell proliferation was determined by counting cells on days 3 and 12. Expression of matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), and pro-inflammatory cytokine transcripts in HGFs was determined by quantitative PCR (Q-PCR) analysis on days 3 and 8. P. gingivalis LPS decreased cell proliferation on day 3 (p < 0.05) compared to the control group without significantly impacting the cell survival (p > 0.05).The experiments showed that P. gingivalis LPS dose-dependently and differentially modulated the expression of MMP-1, 2, and 3 and TIMP-1 and 2 on days 3 and 8. TIMP-1 expression was significantly induced in P. gingivalis LPS-treated cells while TIMP-2 was increased in response to 10 and 30 ng/ml of LPS on day 3. P. gingivalis LPS induced up-regulation of MMP-1/TIMP-1 ratio on day 3 and increased MMP-2/TIMP-2 ratio on day 8 dose-dependently. Expression of interleukin (IL)-6 and IL-8 was stimulated at higher concentrations (1000 and 3000 ng/ml) of LPS. These findings demonstrate that P. gingivalis LPS suppresses cell proliferation and leads to increased pro-inflammatory changes in HGFs, suggesting that P. gingivalis LPS-induced modification of phenotypic and inflammatory characteristics in HGF could potentially be a pathogenic mechanism underlying the tissue destruction.

The aim of this study was to analyze the influence of non-surgical applications of diode laser (940 nm) on the cell proliferation and mRNA expressions of type I collagen and growth factors in human gingival fibroblasts (GF). Gingival fibroblasts were isolated from human gingival connective tissue of systemically healthy individuals. Cells were treated with different laser parameters as follows; (1) Infected pocket setting (power: 2 W, pulse interval: 1 ms, pulse length: 1 ms, 20 s/cm(2)); (2) Perio-pocket setting (power: 1.5 W, pulse interval: 20 ms, pulse length: 20 ms, 20 s/cm(2)); and (3) Biostimulation setting (power: 0.3 W in continuous wave, 20 s/cm(2)). Proliferation of GF was evaluated after different laser applications using a real-time cell analyzer. Total RNA was isolated on day 2 and cDNA synthesis was performed. Type I collagen, insulin-like growth factor (IGF), vascular endothelial growth factor (VEGF) and transforming growth factor-beta (TGF-β) mRNA expressions were determined with quantitative RT-PCR. In a proliferation experiment, no significant differences were observed in the different laser applications when compared to the control group. Statistically significant increases in IGF, VEGF, and TGF-β mRNA expressions were noted in the laser groups when compared to the untreated control group (p < 0.05). A significant increase in collagen type I mRNA expression was noted in only biostimulation set-up of diode laser (p < 0.05). The results of this study demonstrate that non-surgical laser applications modulate behavior of gingival fibroblasts inducing growth factors mRNA expressions and these applications can be used to improve periodontal wound healing.