Effects of metformin on human gingival fibroblasts: an in vitro study.

OBJECTIVE: To investigate the effects of metformin (MF) treatment on the matrix metalloproteinases (MMPs) and proinflammatory cytokines production from lipopolysaccharide (LPS) - stimulated human gingival fibroblasts (HGFs). METHODS: HGFs were obtained from subcultures of biopsies from clinically healthy gingival tissues of patients undergoing oral surgeries. Cell cytotoxicity assay was used to determine the effect of different concentrations of MF on viability of HGFs. HGFs were then incubated and treated with different concentrations of MF and Porphyromonas gingivais (Pg) LPS. MMP-1, MMP-2, MMP-8, MMP-9, IL-1ß, and IL-8 expression analysis was performed using xMAP technology (Luminex 200, Luminex, Austin, TX, USA). Student's t-test for a single sample was used to compare the mean values of the study groups with the control value. A p-value of <0.05 and 95% confidence intervals were used to report the statistical significance and precision of mean values. RESULTS: Concentrations of 0.5, 1- and 2-mM MF had a minimal non-significant cytotoxic effect on the HGFs and caused statistically significant reduction of MMP-1, MMP-2, MMP-8 and IL-8 expressed by the LPS-stimulated HGFs. CONCLUSION: The results of the present study confirm that MF suppresses MMP-1, MMP-2, MMP-8 and IL-8 in LPS-stimulated HGFs suggesting an anti-inflammatory effect of MF and potential adjunct therapeutic role in the treatment of periodontal diseases.

Non-surgical periodontal therapy with adjunct photodynamic therapy for the management of periodontal inflammation in adults using nicotine-free electronic-cigarette: A randomized control trial.

OBJECTIVE: The aim was to assess the effect of non-surgical periodontal therapy (NSPT) with adjunct photodynamic treatment (PDT) for the management of periodontal inflammation in young electronic cigarette (E-cig) users. METHODS: Patients with periodontal inflammation were included. Patient demographics and information related to E-Cig usage were recorded. Scores of plaque index (PI), bleeding index (BI), clinical attachment loss (AL) and probing depth (PD) recorded at baseline and at 3-months' follow-up. Patients were randomly divided into test (NSPT + PDT) and control groups (NSPT) alone. Sample-size estimation was done using data from a pilot investigation and group comparisons were done. Correlation between periodontal parameters and duration of E-cig use was assessed using regression analysis models. Group-comparisons were done using the Mann Whitney U test; and logistic regression was done to correlate periodontal parameters with age, gender, frequency of vaping, number of puffs inhaled and oral hygiene maintenance protocols. Level of significance was set at P<0.01. RESULTS: Twenty-three and 23 individuals were randomly allocated to the test- and control-group, respectively. At baseline, PI, BI and PD were comparable in all patients. There was a significant reduction in PI (P<0.01), BI (P<0.01) and PD (P<0.01) in the test and control groups at 3-months' follow-up when compared with their respective baseline scores. At 3-months' follow-up, there was no significant difference in PI, BI and PD among patients in the test and control groups. There was no clinical evidence of clinical AL among patients in the test- and control groups at baseline and at 3-months' follow-up. CONCLUSION: In the short-term, PDT is as effective as NSPT for the management of periodontal inflammation in young E-Cig users.