Comparison of low level laser and arginine-calcium carbonate alone or combination in the treatment of dentin hypersensitivity: a randomized split-mouth clinical study.

OBJECTIVE: This study aimed to compare the efficacy of low-level laser (LLL) and desensitizing paste (DP) containing 8% arginine-calcium carbonate, in the treatment of dentin hypersensitivity (DH) and also to determine whether their combined application would improve the efficacy of the treatment. BACKGROUND DATA: There are various options for the treatment of DH; however, superiority of one method over others alone has not been currently demonstrated. MATERIALS AND METHODS: Twenty-one patients with 156 teeth affected by DH were included in the study. Selected teeth were randomly divided into five groups: LLL, DP, laser followed by DP (LLL+DP), DP followed by laser (DP+LLL) applied to one of the quadrants, and a control group, consisting of a randomly selected additional tooth in one of the quadrants. Teeth were irradiated by the 685 nm diode laser treatment with 25 mW at 9 Hz for 100sec at 1 cm(2) area (2J/cm(2)) in interrupted mode. Pain response to evaporative stimulus was quantified on a visual analogue scale (VAS) over a 90-day period. RESULTS: All four treatment groups experienced significant and persistent decrease in the mean VAS score immediately post-treatment until the end of the study, whereas the placebo group had high VAS scores throughout the study. On day 90, percent reduction in VAS scores was 72% for LLL, 65.4% for DP, 54.6% for LLL+DP, and 69.6% for DP+LLL, whereas the placebo group showed an increase of 7.8%. CONCLUSIONS: The application of either LLL or DP containing 8% arginine-calcium carbonate appears to be effective in decreasing DH. However, their combined use does not improve the efficacy beyond what is attainable with either treatment alone.

The effect of α-tocopherol and selenium on human gingival fibroblasts and periodontal ligament fibroblasts in vitro.

BACKGROUND: The aim of the present study is to evaluate the effect of α-tocopherol and selenium on gingival fibroblasts (GFs) and periodontal ligament fibroblasts (PDLFs) in terms of proliferation, basic fibroblast growth factor (bFGF) release, collagen type I synthesis, and wound healing. METHODS: Primary cultures of human GFs and PDLFs were isolated. Four test groups and a control group free of medication was formed. In group E, 60 µM α-tocopherol was used, and in groups ES1, ES2, and ES3, the combination of 60 µM α-tocopherol with 5 × 10(-9) M, 10 × 10(-9) M, and 50 × 10(-9) M selenium was used, respectively. Viability, proliferation, bFGF, and collagen type I synthesis from both cell types were evaluated at 24, 48, and 72 hours, and healing was compared on a new wound-healing model at 12, 24, 36, 48, and 72 hours. RESULTS: α-Tocopherol alone significantly increased the healing rate of PDLFs at 12 hours and increased bFGF and collagen type I release from GFs and PDLFs at 24, 48, and 72 hours. The α-tocopherol/selenium combination significantly enhanced the proliferation rate of both cells at 48 hours, decreased the proliferation of PDLFs at 72 hours, and increased the healing rate of GFs at 12 hours and PDLFs at 12 and 48 hours. bFGF and collagen type I synthesis was also increased in both cell types at 24, 48, and 72 hours by α-tocopherol/selenium combination. CONCLUSION: α-Tocopherol and α-tocopherol/selenium combination is able to accelerate the proliferation rate and wound-healing process and increase the synthesis of bFGF and collagen type I from both GFs and PDLFs.

Low-level laser irradiation affects the release of basic fibroblast growth factor (bFGF), insulin-like growth factor-I (IGF-I), and receptor of IGF-I (IGFBP3) from osteoblasts.

OBJECTIVE: It was the aim of the present study to evaluate whether the laser irradiation of osteoblasts could enhance the release of growth factors including basic fibroblast growth factor (bFGF), insulin-like growth factor-I (IGF-I), and receptor of IGF-I (IGFBP3). BACKGROUND DATA: Low-level laser therapy (LLLT) has been shown to have biostimulatory effects on various cell types by enhancing production of some cytokines and growth factors. MATERIALS AND METHODS: Human mesenchymal stem cells (MSCs) were seeded in osteogenic medium and differentiated into osteoblasts. Three groups were formed: in the first group (single dose group), osteoblasts were irradiated with laser (685 nm, 25 mW, 14.3 mW/cm(2), 140 sec, 2 J/cm(2)) for one time; and in the second group, energy at the same dose was applied for 2 consecutive days (double dose group). The third group was not irradiated with laser and served as the control group. Proliferation, viability, bFGF, IGF-I, and IGFBP3 levels were compared between groups. RESULTS: Both of the irradiated groups revealed higher proliferation, viability, bFGF, IGF-I, and IGFBP3 expressions than did the nonirradiated control group. There was increase in bFGF and IGF-I expressions and decrease in IGFBP3 in the double dose group compared to single dose group. CONCLUSIONS: The results of the present study indicate that LLLT increases the proliferation of osteoblast cells and stimulates the release of bFGF, IGF-I, and IGFBP3 from these cells. The biostimulatory effect of LLLT may be related to the enhanced production of the growth factors.

Effects of laser irradiation on the release of basic fibroblast growth factor (bFGF), insulin like growth factor-1 (IGF-1), and receptor of IGF-1 (IGFBP3) from gingival fibroblasts.

Various studies have shown biostimulation effects of laser irradiation by producing metabolic changes within the cells. Little is known about the biological effect of laser irradiation on the oral tissues. Among the many physiological effects, it is important to recognize that low-level laser therapy (LLLT) may affect release of growth factors from fibroblasts. Therefore, the aim of the present study was to determine whether the laser irradiation can enhance the release of basic fibroblast growth factor (bFGF), insulin-like growth factor-1 (IGF-1), and receptor of IGF-1 (IGFBP3) from human gingival fibroblasts (HGF). The number of all samples in the study were 30, and the samples were randomly divided into three equal groups; In the first group (single dose group), HGF were irradiated with laser energy of 685 nm, for 140 s, 2 J/cm(2) for one time, and in the second group, energy at the same dose was applied for two consecutive days (double dose group). The third group served as nonirradiated control group. Proliferation, viability, and bFGF, IGF-1, IGFBP3 analysis of control and irradiated cultures were compared with each other. Both of the irradiated groups revealed higher proliferation and viability in comparison to the control group. Comparison of the single-dose group with the control group revealed statistically significant increases in bFGF (p < 0.01) and IGF-1 (p < 0.01), but IGFBP3 increased insignificantly (p > 0.05). When the double dose group was compared with the control group, significant increases were determined in all of the parameters (p < 0.01). In the comparison of the differences between the two irradiated groups (one dose and two doses), none of the parameters displayed any statistically significant difference (p > 0.05). In both of the laser groups, LLLT increased the cell proliferation and cell viability. The results of this study showed that LLLT increased the proliferation of HGF cells and release of bFGF, IGF-1, and IGFBP3 from these cells. LLLT may play an important role in periodontal wound healing and regeneration by enhancing the production of the growth factors.