Biocompatibility evaluation of orthodontic composite by real-time cell analysis.

INTRODUCTION: The aim of this study was to evaluate the cytotoxic effects of three different light-cured orthodontic composites. MATERIAL AND METHODS: Light Bond (Reliance orthodontic products), Grengloo (Ormco corporation), and Kurasper F (Kuraray Europe GmbH) were selected for the experiment. Specimens were prepared according to the manufacturers' instructions, measuring 5 mm in diameter and 2 mm in thickness. Fibroblast cells were obtained from healthy gingival connective tissues. The composite cylinders were incubated in Dulbecco's modified Eagle's culture medium for 72 h according to ISO 10993-5 standards. The xCELLigence method was used to evaluate fibroblast cell vitality. After seeding 200 mL of the cell suspensions into the wells (20,000 cells/well) of the E-plate 96, gingival fibroblasts were treated with bioactive components released by the orthodontic composite materials and monitored every 15 min for 121 h. RESULTS: There were no significant differences between the human gingival fibroblast (HGF) cell indexes of the control and all testing groups (p > 0.05) at 24 and 48 h. Light Bond demonstrated statistically significant decrease in HGF index (p < 0.05) at 72 h, but there was no significant difference among the Kurasper F, Grengloo, and untreated control groups (p > 0.05). Light Bond (p < 0.001) and Grengloo (p < 0.05) groups had lower HGF cell index values when compared to untreated control group, but Kurasper F demonstrated no significant differences between the control groups at 96 h (p > 0.05). CONCLUSION: Orthodontic composite materials include biologically active components and may change oral tissue. So, biocompatible orthodontic bonding composites should be used.

Cytotoxicity of hemostatic agents on the human gingival fibroblast.

BACKGROUND: Achieving of moisture control especially gingival bleeding control is great challenge in clinical practice. Various hemostatic agents and techniques have been promoted for bleeding control during dental operation. But few studies have focused on the cytotoxicity of hemostatic solutions. AIM: The aim of this study was to evaluate cytotoxic effect of hemostatic agents on human gingival fibroblast cells by using real-time cell analysis method. MATERIALS AND METHODS: Two hemostatic solutions, Hemoban (Sultan Healthcare, Hackensack, NJ, USA) and Hemasatic Solutions (W.P. Dental, Hamburg, Germany) that includes mainly aluminum chloride were used with different concentration. Gingival fibroblasts were isolated from gingival connective tissue during crown lengthening surgery of systemically healthy subjects. Gingival fibroblasts were maintained with Dulbecco's modified eagle medium containing 10% fetal bovine serum. A real-time cell analyzer (RT-CES, xCELLigence; Roche Applied Science, Mannheim, Germany, and ACEA Biosciences, San Diego, CA, USA) was used to evaluate cell survival. After seeding 200 mL of the cell suspensions into the wells (10,000 cells/well) of the E-plate 96, gingival fibroblasts were treated with hemostatic solutions (1/2, 1/4 and 1/8 dilutions) and monitored every 15 minutes for 72 hours. For the proliferation experiments, the statistical analyses used were 1-way analysis of variance (ANOVA) and Tukey HSD multiple comparisons tests. RESULTS: According to statistically analysis, when evaluated at 48 and 72 hours, there were significant differences between the cell indexes of the control and all hemostatic agents groups (p < 0.001). Agent reduced cell index value significantly when compared to untreated control group. CONCLUSIONS: The results indicate that using of Hemoban or Hemostatic Solutions as astringent solutions have a significant cytotoxic effect on gingival fibroblast cells.

The response of cementoblasts to calcium phosphate resin-based and calcium silicate-based commercial sealers.

AIM: To investigate cell viability and gene expression of cementoblasts (OCCM.30) exposed to extractable components released by resin-based sealers with different chemical composition Hybrid Root Seal (HRS), SimpliSeal (SS), Real Seal (RS) and AH Plus (AH) and by a MTA-based sealers Tech Biosealer Endo (TBE). METHODOLOGY: Discs of all materials were prepared and allowed to set in humid conditions at 37° for 48 h. The discs were then incubated for 72 h at 37 °C to obtain material extracts (1/1) in DMEM. The extracts containing the components released by the sealers were filtered and other dilutions (1/2, 1/4) were prepared from the original solution (1/1). Original and diluted solutions were tested on the cementoblasts. Impedance-based real-time cell analysis (RTCA) was used to evaluate cell viability, quantitative real-time polymerase chain reaction (QRT-PCR) was used to examine the expression of mineralization-related genes (osteocalcin; OCN, Runt-related transcription factor-2; Runx2, collagen type 1; COL I, alkaline phosphatase; ALP). For statistical analysis, one-way analysis of variance (anova) and Tukey's honestly significant difference (HSD) tests were used. RESULTS: TBE (1/2), RS (1/2, 1/4), and HRS (1/2, 1/4) significantly decreased cell viability (P < 0.001). AH (1/2, 1/4) and SS (1/2, 1/4) had similar cell viability to the control at 30 h. All tested materials significantly decreased cell viability when compared to the control group except AH (1/2, 1/4) and SS (1/4) at 90 h. All of the tested sealers reduced COL I mRNA expressions when compared to the control. SS was associated with significant increases in OCN and Runx2 mRNA expressions when compared to the control (P < 0.001). Whereas all of the dilutions of TBE, RS and HRS significantly decreased BSP mRNA expressions (P < 0,001), 1/2 and 1/4 dilutions of SS increased BSP mRNA expression (P < 0,001). Except the 1/4 dilutions of AH and SS, all the sealer dilutions significantly reduced ALP mRNA expression in cementoblasts (P < 0,001). CONCLUSIONS: SimpliSeal and AH Plus resulted in more favourable response to cementoblasts because of their regulation potential on the mineralized tissue-associated protein's mRNA expressions.

Stress hyperglycemia in minimally invasive surgery.

This study examined the selected hormonal responses to, and hormone-mediated glucose metabolism during minimally invasive surgery in, patients undergoing laparoscopic cholecystectomy for symptomatic gallstone disease. Thirty-two patients with symptomatic gallstone disease were included in this study and scheduled for open or laparoscopic procedure in a randomized trial. Results are expressed as mean and standard error of the mean. Statistical evaluations were performed with Mann-Whitney U and Wilcoxon signed-rank tests. Blood cortisol, glucagon, insulin, and glucose concentrations were measured immediately in the preoperative period and 6 h after surgery. Blood cortisol, glucagon, and glucose concentrations increased significantly after open and minimally invasive surgery, while insulin levels and the insulin:glucagon ratio remained unchanged. The rise of glucagon and cortisol values was found to be significantly higher in the postoperative period of the open procedure, than in the laparoscopic approach. However, in the patients who underwent open surgery, the increase in glucose concentrations was not significantly higher in the postoperative period. Surgery-induced hormonal effects on the islets increase glucagon and suppress insulin secretion. The glucagon-mediated increase in hepatic glucose production is excluded by the posttraumatic insulin levels from the insulin-sensitive tissues. A bihormonal setting favors a greater rate of hepatic glucose production in both open and laparoscopic surgery. Hormonal changes do reflect the degree of surgical stress, but their metabolic consequences are not parallel to the grade of surgical trauma in minimally invasive surgery.