Advances in oral health knowledge of Greek navy recruits and their socioeconomic determinants

BACKGROUND: The aim of the present study was to evaluate temporal changes on oral health knowledge and attitudes among two populations of young Greek males (age 19–29 years) undergoing their military training. A secondary aim was to identify socioeconomic trends that may have influenced the above. METHODS: A total of 2,764 healthy subjects (1511 in 1985, and 1253 in 1996) answered a standardized questionnaire of oral health issues. Respondents were stratified in 3 groups, according to their educational status (ES); their responses were compared using the chi-square statistic. The evaluation of socioeconomic indicators utilized longitudinal data from the national Household Expenditures Survey. RESULTS: An overall improvement was noted in the majority of "Knowledge" and "Attitudes" variables in 1996, as compared to 1985. Education seems to play an important role in both knowledge and attitudes. These changes may also be partially attributed to a shift in consuming standards from the coverage of main needs to income disposal directed towards the achievement of better quality of life

Low Level Laser Therapy With an 810-nm Diode Laser Affects the Proliferation and Differentiation of Premature Osteoblasts and Human Gingival Fibroblasts In Vitro: LLLT 810nm effect on osteoblasts, gingival fibroblasts and co-cultures

Introduction: Photomodulation is a promising strategy for optimizing tissue healing, but its photomodulatory effects on the synergistic cellular metabolism of gingival and bony tissues remain largely unknown. The aim of the present study was to evaluate the photomodulatory effects of a diode laser (810 nm) on osteoblasts, HGFs, and their co-cultures in vitro.Methods: Primary cultures of HGFs, cultures of immature osteoblastic cells (MG63), and their cocultures were irradiated with a diode laser (810 nm), 15 J/cm2. Cell cultures were examined for cellular proliferation (MTT assay), viability (FDA/PI staining) after 24, 48, and 72 hours, and cell differentiation (qPCR of collagen type 1a – COL1a and alkaline phosphatase expressions - ALP) after 7 days.Results: Photomodulation with an 810-nm diode laser increased cell proliferation at all time points. COL1a gene expression increased both in HGF and co-cultures. ALP expression was up-regulated in osteoblastic cultures, but co-cultures with fibroblasts negated this response.Conclusion: The 810-nm diode laser positively affected cell proliferation and viability in all experimental groups. The statistically significant increased COL1a gene expression at 7 days after irradiation both in the irradiated HGF and co-cultures suggests that low-level laser therapy (LLLT) stimulated extracellular matrix (ECM) formation signaling in both cell types. DOI: 10.34172/jlms.2021.3

Dosage Effects of an 810 nm Diode Laser on the Proliferation and Growth Factor Expression of Human Gingival Fibroblasts: Dose Effects of an 810 nm Diode on Gingival Fibroblasts

Introduction: A substantial amount of evidence supports the positive effect of photobiomodulation on the proliferation and differentiation of various cell types. Several laser wavelengths have been used for wound healing improvement, and their actual outcome depends on the settings utilized during irradiation. However, the heterogeneous wavelengths and laser settings applied in the existing literature make it difficult to draw solid conclusions and comparison of different studies. The aim of the present study is to evaluate and compare the effects of various doses of laser energy, provided by an 810 nm diode, on human gingival fibroblasts in terms of proliferation and expression of growth factors with a pivotal role in wound healing.Methods: Human gingival fibroblasts were cultured on plastic tissue culture and irradiated with 2, 4, 6 or 12 J/cm2. The effects of the low-level laser therapy (LLLT) using an 810 nm diode laser on growth factor expression (EGF, TGF and VEGF) were evaluated by qPCR at 72 hours and 7 days after irradiation. Cell proliferation was evaluated at 24, 48 and 72 hours after LLLT using MTT assay.Results: Energy density of 12 J/cm2 provoked irradiated gingival fibroblasts to demonstrate significantly higher proliferation as well as higher gene expression of Col1, VEGF and EGF. LLLT positive effects were obvious up to 7 days post-irradiation.Conclusion: LLLT with 810 nm presents beneficial effects on proliferation, collagen production and growth factor expression in human gingival fibroblast cells. The application of 12 J/cm2 can be suggested as the optimal energy density for the enhancement of the wound healing process. DOI: 10.34172/jlms.2021.2

Nd:YAG laser radiation (1.064 nm) accelerates differentiation of osteoblasts to osteocytes on smooth and rough titanium surfaces in vitro

BACKGROUND: A number of studies revealed beneficial effects of low-level laser therapy (LLLT) regarding cell proliferation and differentiation. AIM: To investigate the effect of Nd:YAG (1.064 nm) laser radiation in the proliferation and differentiation potential of MG-63 osteoblast-like cells. Additionally, the effects of the surface configurations were to be evaluated. MATERIAL AND METHODS: MG-63 osteoblast cells were cultured on different surfaces: plastic tissue culture, smooth (polished) titanium-PT and rough titanium-SLA. The effects of both titanium surfaces and low-level laser therapy (LLLT) on cell adhesion were evaluated by the gene expression of molecules involved in cell proliferation and differentiation. In addition, scanning electron microscopy (SEM) and MTT proliferation assays were used to examine cell morphology and proliferation, respectively. RESULTS: Compared to smooth (PT) surfaces, SLA surfaces favoured MG-63 cell differentiation. Following the application of Nd:YAG laser irradiation, cells yielded statistically significantly improved differentiation on both smooth and SLA surfaces compared with non-irradiated surfaces. CONCLUSIONS: The findings of this present study suggest that both surface morphology and Nd:YAG laser irradiation influence the proliferation and differentiation potential of MG-63 cells

Effect of Nd:YAG Low Level Laser Therapy on Human Gingival Fibroblasts

Aim. To evaluate the effect of Low Level Laser Therapy (LLLT) on human gingival fibroblasts in terms of proliferation and growth factors’ secretion (EGF, bFGF, and VEGF). Materials and Methods. Primary cultures of keratinized mucosa fibroblasts were irradiated by a Nd:YAG laser 1064 nm with the following energy densities: 2.6 J/cm2, 5.3 J/cm2, 7.9 J/cm2, and 15.8 J/cm2. Controls were not irradiated. Cultures were examined for cell proliferation and growth factors’ secretion after 24, 48, and 72 hours. All experimental procedures were performed in duplicate. Data were analyzed by Student’s t-test (p<0.05). Results. All laser-irradiation doses applied promoted a higher cell proliferation at 48 hours in a dose-response relationship compared to controls. This difference reached statistical significance for the cultures receiving 15.8 J/cm2 (p=0.03). Regarding EGF, all laser irradiation doses applied promoted a higher secretion at 48 hours in a reverse dose-response pattern compared to controls. This difference reached statistical significance for the cultures receiving 2.6 J/cm2 (p=0.04). EGF levels at the other time points, bFGF, and VEGF showed a random variation between the groups. Conclusion. Within the limits of this study, LLLT (Nd:YAG) may induce gingival fibroblasts’ proliferation and upregulate the secretion of EGF. Further studies are needed to confirm these results

Effect of Nd:YAG Low Level Laser Therapy on Human Gingival Fibroblasts

Aim. To evaluate the effect of Low Level Laser Therapy (LLLT) on human gingival fibroblasts in terms of proliferation and growth factors&apos; secretion (EGF, bFGF, and VEGF). Materials and Methods. Primary cultures of keratinized mucosa fibroblasts were irradiated by a Nd:YAG laser 1064 nm with the following energy densities: 2.6 J/cm 2 , 5.3 J/cm 2 , 7.9 J/cm 2 , and 15.8 J/cm 2 . Controls were not irradiated. Cultures were examined for cell proliferation and growth factors&apos; secretion after 24, 48, and 72 hours. All experimental procedures were performed in duplicate. Data were analyzed by Student&apos;s -test ( &lt; 0.05). Results. All laserirradiation doses applied promoted a higher cell proliferation at 48 hours in a dose-response relationship compared to controls. This difference reached statistical significance for the cultures receiving 15.8 J/cm 2 ( = 0.03). Regarding EGF, all laser irradiation doses applied promoted a higher secretion at 48 hours in a reverse dose-response pattern compared to controls. This difference reached statistical significance for the cultures receiving 2.6 J/cm 2 ( = 0.04). EGF levels at the other time points, bFGF, and VEGF showed a random variation between the groups. Conclusion. Within the limits of this study, LLLT (Nd:YAG) may induce gingival fibroblasts&apos; proliferation and upregulate the secretion of EGF. Further studies are needed to confirm these results