Evaluation of the cytotoxicity of contemporary glass-ionomer cements on mouse fibroblasts and human dental pulp cells.

PURPOSE: This study aimed to evaluate the cytotoxic effects of different types of contemporary GICs on human dental pulp cell (hDPCs) and mouse fibroblast (L929) cultures. METHODS: Three high-viscosity GICs (HVGIC; GC Equia Forte, Riva Self Cure, IonoStar Plus), three resin-modified GICs (RMGIC; Photac Fil, Riva Light Cure, Ionolux), and a metal-reinforced GIC (MRGIC; Riva Silver) were investigated. Twelve disc-shaped specimens of each material were prepared and stored in Dulbecco's modified Eagle medium (DMEM). L929 fibroblasts and DPCs were then cultured in 96-well plates. Uncultured DMEM was used as a negative control. Mitochondrial dehydrogenase activity (MTT) assays were performed to detect cell viability after 24, 48, and 72 h. Data were analysed using Mann-Whitney U and Friedman tests followed by a Bonferroni-corrected Wilcoxon signed rank test, with the statistical significance set at P < 0.05. RESULTS: Toxicity levels varied between the cell-culture systems. MTT assays of L929 cells showed significant differences in percentages of viable cells, as follows: Riva Self Cure = Riva Silver > GC Equia Forte > IonoStar Plus = Riva Light Cure = Photac Fil > Ionolux. MTT assays of DPCs showed the percentages of viable cells to be significantly lower for the Ionolux group when compared to the other GICs, which did not differ significantly from one another. With the exception of Ionolux, none of the other GICs tested showed any toxicity, and in fact, they all induced cell proliferation (> 100% cell viability). CONCLUSIONS: Although the degree of toxicity varied between the two cell-culture systems investigated, all the GICs tested, with the exception of Ionolux, performed favorably with regard to cytotoxicity (> 100% cell viability in both cell systems).

Changes in posterior airway space, pulmonary function and sleep quality, following bimaxillary orthognathic surgery.

Bimaxillary orthognathic surgery (BOS) is commonly used in the correction of severe Class III deformities (mandibular prognathism with maxillary retrognathism). The postural response of the pharyngeal airway after mandibular setback and maxillary advancement procedures is clinically crucial for maintaining optimum respiration. Patients might suffer from obstructive sleep apnoea, postoperatively. The aim of this study was to determine the effects of BOS on pharyngeal airway space, respiratory function during sleep and pulmonary functions. 21 male patients were analysed using cephalometry, spirometry for pulmonary function tests, and a 1 night sleep study for full polysomnography before and 17±5 months after BOS. The data show that the hyoid bone repositioned to the inferior, the tongue and soft palate displaced to the posterior, narrowed at the oropharynx and hypopharynx and widened at the nasopharynx and velopharynx levels significantly (p<0.05). The alterations indicated decreased airway resistance and better airflow. As a consequence of polysomnography evaluation, the sleep quality and efficiency of the patients improved significantly after BOS. Patients who undergo BOS should be monitored with pulmonary function tests and polysomnography pre- and postoperatively to detect any airway obstruction.