PURPOSE: Comparing the accuracy of casts produced from digital workflow to that of casts produced from conventional techniques. MATERIALS AND METHODS: Whole arch alginate (ALG) and polyvinyl siloxane (PVS) impressions were taken with stock trays and custom trays, respectively. The ALG impressions were poured with type III dental stone, while the PVS impressions were poured with type IV dental stone. For the digital workflow, IOS impressions were taken and physical casts were produced by 3D printing. In addition, 3D printed casts were produced from images obtained from a laboratory scanner (LS). For each technique, a total of 10 casts were produced. The accuracies of the whole arch and separated teeth were virtually quantified. RESULTS: Whole arch cast accuracy was more superior for PVS followed by LS, ALG, and IOS. The PVS and ALG groups were inferior in the areas more susceptible to impression material distortion, such as fossae and undercut regions. The LS casts appeared to have generalized errors of minor magnitude influencing primarily the posterior teeth. The IOS casts were considerably more affected at the posterior region. On the contrary, the IOS and LS casts were more superior for single tooth accuracy followed by PVS and ALG. CONCLUSION: For whole arch accuracy, casts produced from IOS were inferior to those produced from PVS and ALG. The inferior outcome of IOS appears to be related to the span of scanning. For single tooth accuracy, IOS showed superior accuracy compared to conventional impressions.
Jupiter ; Polyvinyls ; Printing, Three-Dimensional ; Siloxanes ; Tooth

BACKGROUND: Compared to an equivalent sized polyvinyl chloride (PVC) double-lumen tube (DLT), a silicone DLT has a shorter endobronchial segment. The aim of this study was to compare the incidence of clinically significant displacement of left-sided PVC and silicone DLTs after a positional change to a lateral position from a supine position and determine its effect on the need for DLT repositioning for successful lung separation in patients undergoing thoracic surgery. METHODS: One hundred eight adult patients requiring one-lung ventilation were randomly divided into group P (PVC DLT, n = 54) and group S (Silicone DLT, n = 54). The position of the DLT was observed before and after lateral positioning to assess the effect of the position change. The incidence of clinically significant displacement (>10 mm) of DLT was compared between the groups. RESULTS: DLTs were clinically significantly displaced in group P (17/48, 35.4%) and group S (18/52, 34.6%) after lateral positioning (p = 0.933). A proximal displacement (31.3% [group P] and 25.0% [group S]) was more common than distal displacement (4.2% [group P] and 9.6% [group S]), with no significant intergroup difference (p = 0.494). After lateral positioning, critical malposition of DLT with bronchial herniation to the right main bronchus was 8.3% (group P) and 7.9% (group S, p = 0.906). CONCLUSION: Left-sided PVC and silicone DLTs produced comparable incidences of clinically significant displacement and, consequently, required similar rates of repositioning for successful lung separation after lateral positioning.
Adult ; Bronchi ; Bronchoscopy ; Humans ; Incidence ; Intubation, Intratracheal ; Lung ; One-Lung Ventilation ; Polyvinyl Chloride ; Polyvinyls ; Posture ; Silicon ; Silicones ; Supine Position ; Thoracic Surgery ; Thoracic Surgical Procedures

PURPOSE: This study was performed to evaluate the dimensional accuracy of digital dental models constructed from cone-beam computed tomographic (CBCT) scans of polyvinyl siloxane (PVS) impressions and cast scan models.MATERIALS AND METHODS: A pair of PVS impressions was obtained from 20 subjects and scanned using CBCT (resolution, 0.1 mm). A cast scan model was constructed by scanning the gypsum model using a model scanner. After reconstruction of the digital models, the mesio-distal width of each tooth, inter-canine width, and inter-molar width were measured, and the Bolton ratios were calculated and compared. The 2 models were superimposed and the difference between the models was measured using 3-dimensional analysis.RESULTS: The range of mean error between the cast scan model and the CBCT scan model was −0.15 mm to 0.13 mm in the mesio-distal width of the teeth and 0.03 mm to 0.42 mm in the width analysis. The differences in the Bolton ratios between the cast scan models and CBCT scan models were 0.87 (anterior ratio) and 0.72 (overall ratio), with no significant difference (P>0.05). The mean maxillary and mandibular difference when the cast scan model and the CBCT scan model were superimposed was 53 µm.CONCLUSION: There was no statistically significant difference in most of the measurements. The maximum tooth size difference was 0.15 mm, and the average difference in model overlap was 53 µm. Digital models produced by scanning impressions at a high resolution using CBCT can be used in clinical practice.
Calcium Sulfate ; Cone-Beam Computed Tomography ; Dental Models ; Orthodontics ; Polyvinyls ; Siloxanes ; Tooth

PURPOSE: Tracheal intubation in a hemorrhagic airway is a difficult procedure because the visibility can be obscured by blood or vomitus. Several devices and methods have been developed to overcome such obstacles, but they are not available at all practical sites. Therefore, this study was conducted to assess the time and success rate of tracheal intubation according to the type of suction tip used in a hemorrhagic airway manikin model. METHODS: This study was a randomized crossover manikin simulation study. We recruited 18 emergency physicians to perform intubation with suction using a Yankauer suction tip and a polyvinyl chloride (PVC) catheter suction tip in a hemorrhagic airway manikin model. We then measured the time and success rate of intubation for each suction tip. RESULTS: The mean intubation time using the Yankauer suction tip was 42.3 seconds, and the mean intubation time using the PVC catheter suction tip was 91.1 seconds (p < 0.001). Two cases of esophageal intubation occurred when the PVC catheter suction tip was used (success rate, 88.9%). In contrast, there was no esophageal intubation when the Yankauer suction tip was used (success rate, 100%) (p=0.217). CONCLUSION: Intubation of a hemorrhagic airway manikin model can be performed in a shorter time when a Yankauer suction tip is used than when a PVC catheter suction tip is used.
Catheters ; Emergencies ; Hemorrhage ; Intubation ; Manikins ; Polyvinyl Chloride ; Polyvinyls ; Suction

BACKGROUND AND OBJECTIVES: Although polyvinyl acetate (Merocel®) has been widely used as a packing material after septoplasty, removable nasal packing can increase patient discomfort, local pain, and pressure. Furthermore, the removal of nasal packing has been described as the most uncomfortable and distressing feature associated with septoplasty. The purpose of this study was to investigate the efficacy of polyvinyl acetate with carboxymethyl cellulose sheet (Rhinocel®) nasal packing on patient subjective symptoms, degree of bleeding, hemostasis, and wound healing following septoplasty. SUBJECTS AND METHOD: Forty patients with nasal septum deviation requiring septoplasty were included. Following surgery, one nasal cavity was packed with Rhinocel® and the other one with Merocel®. Patient subjective symptoms while the packing was in situ, hemostatic properties, pain on removal, degree of bleeding on removal, duration of hemostasis after removal, postoperative wound healing, and the cost of the pack were evaluated. RESULTS: Although the two types of packing materials were equally effective in controlling postoperative bleeding after septoplasty, Rhinocel® was significantly more comfortable while in situ and less painful on removal than Merocel®, which was associated with significantly more bleeding on removal and so more time was needed to control hemorrhage. There was no significant difference in postoperative wound healing or pack cost. CONCLUSIONS: The use of Rhinocel® after septoplasty has less discomfort, greater patient satisfaction, and less bleeding on removal with no adverse reactions compared to Merocel® packing. Therefore, Rhinocel® may be a useful packing material after septoplasty.
Biocompatible Materials ; Carboxymethylcellulose Sodium* ; Hemorrhage ; Hemostasis ; Humans ; Methods ; Nasal Cavity ; Nasal Septum ; Nose ; Patient Satisfaction ; Polyvinyls* ; Postoperative Care ; Wound Healing

The purpose of the study is to compare and analyze the accuracy of digital images obtained from impression and stone model with model scanner and to find out clinical effectiveness. A mandibular left first molar composite resin tooth was made for abutment. Digital models were obtained with a same model scanner(Ceramill Map 400, Amann Girrbach, Austria); (1) Fabricated resin model was scanned(Group C). (2) 10 impressions were taken with putty and polyvinyl siloxane, then were scanned (Group I). (3) Type IV stone was poured in each impressions made in step(2) and 10 stone models were scanned(Group S). 3 dimensional super-impositional program (Geomagic control X, 3D Systems, USA) was used to analyze the STL files. Stone model scan(Group S) showed lower deviation than impression scan(Group I) compared to the control group(P < 0.001). Both Group I and Group S showed signs of expansion in the occlusion surface and margin surface while showing contraction in the axial surface. The deviations were smaller in order of occlusal plane, horizontal plane of margin and axial plane. Within the limited boundary of this study, the digital model obtained from stone model scan showed smaller deviation than the digital model obtained from impression scan.
Dental Occlusion ; Molar ; Polyvinyls ; Siloxanes ; Tooth ; Treatment Outcome

OBJECTIVESTo explore the forensic application value of MPure-12 automatic nucleic acid purification （MPure-12 Method） for DNA extraction by extracting and typing DNA from bloodstains and various kinds of biological samples with different DNA contents.

METHODSNine types of biological samples, such as bloodstains, semen stains, and saliva were collected. DNA were extracted using MPure-12 method and Chelex-100 method, followed by PCR amplification and electrophoresis for obtaining STR-profiles.

RESULTSThe samples such as hair root, chutty, butt, muscular tissue, saliva stain, bloodstain and semen stain were typed successfully by MPure-12 method. Partial alleles were lacked in the samples of saliva, and the genotyping of contact swabs was unsatisfactory. Additional, all of the bloodstains （20 μL, 15 μL, 10 μL, 5 μL, 1 μL） showed good typing results using Chelex-100 method. But the loss of alleles occurred in 1 μL blood volume by MPure-12 method.

CONCLUSIONSMPure-12 method is suitable for DNA extraction of a certain concentration blood samples．Chelex-100 method may be better for the extraction of trace blood samples．This instrument used in nucleic acid extraction has the advantages of simplicity of operator, rapidity, high extraction efficiency, high rate of reportable STR-profiles and lower man-made pollution.

Alleles ; Blood Stains ; Chelating Agents ; DNA/isolation & purification* ; DNA Fingerprinting ; Forensic Medicine/methods* ; Genotype ; Humans ; Male ; Polymerase Chain Reaction/methods* ; Polystyrenes ; Polyvinyls ; Resins, Synthetic ; Saliva ; Semen/chemistry*

OBJECTIVETo compare the efficacy, clinical characteristics, safety, injection time and radiation exposure of Onyx embolization using a long-distance injection method and routine injection method for management of dural arteriovenous fistula (DAVF).

METHODSThe clinical data were retrospectively analyzed in 59 patients with DAVF treated with Onyx embolization using long-distance injection method (28 patients) and routine injection method (31 patients). The efficacy, safety, injection time and radiation exposure during Onyx embolization were compared between the two injections methods.

RESULTSThe average radiation dose exposure to the surgeon per procedure was significantly lower in the long-distance injection group than in the routine group. The injection time (P=0.53), injection volume (P=0.78), number of supply arteries (P=0.80), Cognard types (P=0.67), and effect of embolization (P=0.88) were all similar between the two groups.

CONCLUSIONEndovaseular treatment of intracranial DAVF with Onyx embolization using the long-distance injection method is feasible, safe and effective and can reduce the radiation exposure to the surgeon.

Arteries ; Central Nervous System Vascular Malformations ; therapy ; Dimethyl Sulfoxide ; therapeutic use ; Embolization, Therapeutic ; Humans ; Polyvinyls ; therapeutic use ; Retrospective Studies ; Treatment Outcome

The author has encountered a 67-year-old man with dural arteriovenous fistula (AVF) presenting as a non-traumatic chronic subdural hematoma (CSDH). This previously healthy patient was hospitalized due to progressive headache with subacute onset. He underwent burr-hole surgery twice for evacuating the left CSDH that was thickest at the posterior temporal area. The operative procedure and finding was not extraordinary, but subdural hematoma slowly progressed for days following the revision surgery. After investigation by super-selective external carotid angiography, a dural AVF found near the transverse-sigmoid sinus was diagnosed. Dural AVF was completely occluded with trans-arterial injecting polyvinyl alchol particles into the petrosquamosal branch of the middle meningeal artery. The patient showed a good neurological outcome with no additional intervention. Brain surgeons have to consider the possibility of dural AVF and perform cerebral angiogram if necessary when they manage the cases that have a spontaneously occurred and repeatedly recurring CSDH.
Aged ; Angiography ; Arteriovenous Fistula* ; Brain ; Central Nervous System Vascular Malformations ; Headache ; Hematoma, Subdural ; Hematoma, Subdural, Chronic* ; Humans ; Meningeal Arteries ; Polyvinyls ; Surgeons ; Surgical Procedures, Operative

OBJECTIVES: This study aims to evaluate the size-dependent toxicity of spherical silver nanoparticles (Ag NPs) to an endemic benthic organism, Glyptotendipes tokunagai. METHODS: Ag nanoparticles of three nominal sizes (50, 100, and 150 nm) capped with polyvinyl pyrrolidone (PVP-Ag NPs) were used. Their physicochemical properties, acute toxicity (48 hours), and bioaccumulation were measured using third instar larvae of G. tokunagai. RESULTS: The aggregation and dissolution of PVP-Ag NPs increased with exposure time and concentration, respectively, particularly for 50 nm PVP-Ag NPs. However, the dissolved concentration of Ag ions was not significant compared with the median lethal concentration value for AgNO3 (3.51 mg/L). The acute toxicity of PVP-Ag NPs was highest for the smallest particles (50 nm), whereas bioaccumulation was greatest for the largest particles (150 nm). However, larger PVP-Ag NPs were absorbed and excreted rapidly, resulting in shorter stays in G. tokunagai than the smaller ones. CONCLUSIONS: The size of PVP-Ag NPs significantly affects their acute toxicity to G. tokunagai. In particular, smaller PVP-Ag NPs have a higher solubility and stay longer in the body of G. tokunagai, resulting in higher toxicity than larger PVP-Ag NPs.
Chironomidae ; Ions ; Larva ; Nanoparticles* ; Polyvinyls ; Silver* ; Solubility