3D Airway changes using cone beam computed tomography in patients following mandibular advancement surgery with and without constriction.

OBJECTIVES: The aim of this study was to compare three-dimensional airway changes resulting from mandibular advancement surgery and mandibular advancement surgery with constriction. SETTING AND SAMPLE POPULATION: The University of Michigan School of Dentistry and Medical Center. A total of 42 patients undergoing mandibular advancement with or without simultaneous constriction. MATERIALS AND METHODS: A retrospective airway evaluation of patients undergoing mandibular advancement with or without simultaneous mandibular constriction was performed. Cross-sectional evaluation at standardized locations, minimum cross section and volumetric analysis were performed using Dolphin Imaging TM Version 11.7. RESULTS: Patients undergoing mandibular advancement with or without constriction experienced significant airway increases (P < 0.05). Patients who underwent mandibular advancement only gained nearly twice as much airway volume as mandibular advancement with simultaneous constriction (8.69 mm3 vs 4.3 mm3 ). The largest increase for both groups was observed in the minimum axial area in the oropharynx segment (119.5 mm2 ) and the axial area of the retroglossal region (137.2 mm2 ). CONCLUSIONS: The findings demonstrate mandibular advancement with constriction results in airway enlargement following surgery.

No evidence for DNA double-strand breaks caused by endodontic sealers.

INTRODUCTION: On extrusion, endodontic sealers might come into close contact with the periapical tissues for long periods. The objective of this study was to test possible mutagenicity of resin-based endodontic sealers by evaluating their potential to induce DNA double-strand breaks (DSBs). METHODS: Human gingival fibroblasts were exposed to subtoxic concentrations of eluates from 1 epoxy resin-based endodontic sealer (AH Plus Jet) and 2 methacrylate-based endodontic sealers (EndoRez and Real Seal). As control, Calcicur, a Ca(OH)(2)-based sealer, was used. The γ-H2AX immunofluorescence assay was used to microscopically detect DNA DSBs, and a custom algorithm was developed to quantify them. RESULTS: The cytotoxicity of the 24-hour eluates could be ranked in the following order: AH Plus Jet > Real Seal > EndoRez >> Calcicur. The γ-H2AX assay revealed that 1.3%-4.3% of the cell nucleus was occupied by foci when the cells were exposed to the eluates of the endodontic sealers. This was not significantly different from the negative control group in which the cells had been exposed to medium (2.1%). CONCLUSIONS: No indications for increased risk of genotoxicity of resin-based root canal sealers caused by the induction of DNA DSBs were found in this study.

Elution of TEGDMA and HEMA from polymerized resin-based bonding systems.

OBJECTIVES: In this study the amount of TEGDMA and HEMA eluted from several adhesive systems was quantified. METHODS: The adhesive systems were applied according to manufacturers' instructions in an analytic vial. The adhesive systems used were (abbreviation and producer in parenthesis): cmf adhesive system(®) (CMF) (Saremco), ENAbond (EB) (Micerium), Optibond FL (OB) (Kerr), Adper Scotchbond Multi-Purpose (SB) (3M ESPE), Silorane System Adhesive (SSA) (3M ESPE), Syntac Classic (SC) (Ivoclar Vivadent) and XP Bond (XPB) (Dentsply). After preparation the specimens were immersed in methanol or distilled water for a period from 1d to 30d at 37°C. Eluted TEGDMA and HEMA were determined by gas chromatographic-mass spectrometry (GC-MS). RESULTS: Following TEGDMA elution from adhesives was found (µg/ml; mean and standard deviation(sd); 1d/30d; methanol): SC 0.93(0.8)/0.68(0.5), SSA 0.27(0.09)/0.16(0.04) and XPB 0.25(0.1)/0.19(0.09). TEGDMA eluted from EB, CMF, OB, and SB was always below detection limit. TEGDMA water elution from each adhesive was about 1/5 lower, compared to the corresponding TEGDMA methanol elution. Following HEMA elution was found (µg/ml; mean(sd); 1d/30d; methanol): SB 3.42(0.9)/2.02(1.2), EB 3.07(2.2)/2.15(2.2), XPB 2.47(1.6)/1.89(1.1), OB 1.4(0.7)/0.82(0.2) and SSA 0.44(0.2)/0.17(0.07). HEMA eluted from CMF and SC was always below detection limit. HEMA water elution from each adhesive was about 1/10 lower, compared to the corresponding HEMA methanol elution. SIGNIFICANCE: SC, SSA, and XPB eluted TEGDMA. SB, EB, XPB, OB, and SSA eluted HEMA. CMF eluted neither HEMA nor TEGDMA.