OBJECTIVES: We aimed to compare the apical sealing properties of three endodontic sealers, namely, C-Root SP (C-R), iRoot SP, and GuttaFlow Bioseal (GFB) in vitro. METHODS: Eighty-two single-rooted premolars and anterior teeth were prepared by using M3 machine with nickel-titanium file and randomly divided into six experimental groups (n=12) and two control groups (n=5). Group A1: single-cone technique (SC)+C-R; group B1: SC+iRoot SP; group C1: SC+GFB; group A2: single-cone with ultrasonic activation (SU)+C-R; group B2: SU+iRoot SP; group C2: SU +GFB; group D: positive control group, and group E: negative control group. Dye penetration length and lateral root canal filling in each group were measured by dye penetration test. A scanning electron microscope (SEM) was used to observe the interface between gutta pertscha, root canal sealer, and dentin wall. Dye penetration length was measured and analyzed by Kruskal-Wallis test, and data on lateral root canal filling were evaluated using Chi-square. RESULTS: The dye penetration length in group A1 was lower than that in groups C1 and A2 (P<0.05) but was not significantly different from the other groups (P>0.05). Lateral root canal filling was not significantly different among all groups (P>0.05). SEM showed that GFB was slightly better than C-R and iRoot SP in binding to gutta pertcha and dentin wall. CONCLUSIONS GFB, C-R, and iRoot SP demonstrate excellent apical sealing ability. Under the conditions tested in this study, SU did not yield significantly improve the apical sealing ability of the three root canal sealers.
Root Canal Filling Materials/chemistry* ; Humans ; Gutta-Percha ; Microscopy, Electron, Scanning ; Root Canal Obturation/methods* ; Ceramics ; Dimethylpolysiloxanes ; Drug Combinations

OBJECTIVES: This study aimed to evaluate the filling effects of three biomaterial root canal sealers [iRoot SP, C-Root SP, and GuttaFlow Bioseal (GFB)] by using Micro-CT. METHODS: Sixty single-canal detached premolars were selected. After crown amputation, their uniform working length was set at 12 mm and prepared to a 06 taper 30# with M3 nickel-titanium file. The samples were randomly divided into six groups with different sealers and obturation techniques: iRoot SP+single-cone technique (SC), C-Root SP+SC, GFB+SC, iRoot SP+single cone-mediated ultrasonic technique (SU), C-Root SP+SU, and GFB+SU. Samples were scanned by Micro-CT, and the total and segmented filling rates were calculated with Mimics 22.0 software after 3D reconstruction. RESULTS: The overall filling rate of the three biomaterial root canal sealers was higher than 90%. The overall and coronal third and middle third segment filling rate of groups iRoot SP+SC, C-Root SP+SC was higher than that of group GFB+SC (P<0.01), with no significant difference between groups iRoot SP+SC and C-Root SP+SC (P>0.05). On the apical third, no significant difference was found among each group (P>0.05). The overall and segment filling rate of groups iRoot SP+SU and C-Root SP+SU was higher than that of GFB+SU (P<0.01), with no significant difference between groups iRoot SP+SU and C-Root SP+SU (P>0.05). The filling rate of the apical 1/3 of group C-Root+SC was lower than that of group C-Root+SU (P<0.01), and the filling rate of the coronal 1/3 of group GFB+SC was higher than that in the GFB+SU (P<0.01). Nevertheless, no significant difference was found in other filling rate of two obturation techniques (P>0.05). CONCLUSIONS The overall filling rate of the three biomaterial root canal sealers using SC and SU are satisfactory. iRoot SP and C-Root SP have similar filling rates, which are significantly higher than that of GFB. C-Root SP combined with SU technique can improve the filling quality of the root apical.
Root Canal Filling Materials ; X-Ray Microtomography ; Humans ; Root Canal Obturation/methods* ; Gutta-Percha ; Dimethylpolysiloxanes ; Drug Combinations ; Dental Pulp Cavity/diagnostic imaging* ; Bicuspid

The rapid screening of tumor markers is a challenging task for early diagnosis of cancer. This study aims to use highly sensitive chemiluminescent protein microarray technology to efficiently screen a variety of low abundance tumor related markers. A new material, termed integrated polydimethylsiloxane modified silica gel (iPDMS), was obtained by adding a surface polymerization initiator with olefin end to the conventional polydimethylsiloxane, and fixing into the three-dimensional structure of polydimethylsiloxane by thermal crosslinking through silicon hydrogen bonding. In order to make the iPDMS material resistant to non-specific protein adsorption, a poly(OEGMA) polymer brush was synthesized by surface-initiated atom transfer radical polymerization at the active initiation site. Finally, 20 tumor-related antigens were printed into the specific areas of the microarray by high-throughput spray printing technology, and assembled into 48-well detection microtiterplates of the iPDMS microarray. It was found the VEGFR and VEGF121 autoantibodies that obtained from 8 common tumors (breast cancer, lung cancer, colon cancer, gastric cancer, liver cancer, leukemia, lymphoma and ovarian cancer) can be used as potential tumor markers. The chemiluminescence labeled iPDMS protein microarray can be used for the screening of tumor autoantibodies at early stage.
Adsorption ; Autoantibodies ; Dimethylpolysiloxanes ; Protein Array Analysis ; Silica Gel ; Surface Properties

For improved examination of video capsule endoscopy (VCE) and device-assisted enteroscopy (DAE), bowel preparation is an essential issue. Multiple factors like air bubbles, food material in the small bowel, and gastric and small bowel transit time affect the small bowel visualization quality (SBVQ), diagnostic yield (DY) and cecal completion rate (CR). Bowel preparation with polyethylene glycol (PEG) solution enhances SBVQ and DY, but it has no effect on CR. Bowel preparation with PEG solution 2 L is similar to PEG 4 L in SBVQ, DY, and CR. Bowel preparation with fasting or PEG solution combined with anti-foaming agents like simethicone enhance SBVQ, but it has no effect on CR. Bowel preparation with prokinetics is not commonly recommended. Optimal timing for purgative bowel preparation has yet to be established. However, the studies regarding bowel preparation for DAE are not sufficient. European Society of Gastrointestinal Endoscopy (ESGE) recommends 8–12 hours fasting from solid food and 4–6 hours fasting from liquids prior to the antegrade DAE. For retrograde DAE, colonoscopy preparation regimen is recommended. This article reviews the literature and ESGE, 2013 Korean published guidelines regarding bowel preparation for VCE and DAE, following suggestion for optimal bowel preparation for VCE and balloon enteroscopy.
Capsule Endoscopy ; Cathartics ; Colonoscopy ; Endoscopy, Gastrointestinal ; Fasting ; Polyethylene Glycols ; Simethicone

Antispasmodics are effective in reducing abdominal pain and controlling spasm. Irritable bowel syndrome (IBS) patients have characteristic key factors such as intestinal motility disorder and visceral hypersensitivity. So antispasmodics have been used in the treatment of IBS for decades. Mebeverine blocks intestinal peristalsis but are not significantly better than placebo. Alverine citrate combined with simethicone is effective treatment option in IBS. Otilonium and pinaverium bromide are poorly absorbed agents, so they have mostly local effect with minimal systemic adverse events. Phloroglucinol controls acute exacerbation of abdominal pain effectively. Tiropramide reduce abdominal discomfort without serious adverse events. Fenoverine control spasm in spastic colon but does not affect normal contraction. Trimebutine have dual actions that it inhibits hyperactive colon and activates hypomotile colon. Each drug has advantages and disadvantages. Antispasmodics are considered as the first treatment option of pain-dominant IBS.
Abdominal Pain ; Citric Acid ; Colon ; Gastrointestinal Motility ; Humans ; Hypersensitivity ; Irritable Bowel Syndrome ; Muscle Spasticity ; Parasympatholytics ; Peristalsis ; Phloroglucinol ; Simethicone ; Spasm ; Trimebutine

BACKGROUND/AIMS: There are no studies that looked into the bubble eliminating efficacy of polyethylene glycol with ascorbic acid (PEGA), which has been one of the shortcomings of polyethylene glycol (PEG). In this study, we compared newly introduced PEGA regimen by adding either simethicone or 1 L of water. METHODS: A prospective randomized controlled study was carried out at Dongguk Universtiy Gyeongju Hospital from July 2014 to September 2014. A total of 90 patients were randomly assigned to 3 groups; PEGA group (n=30) which served as control, simethicone addition group (n=30) to which simethicone 400 mg was additionally prescribed, and water addition group (n=30) to whom additional 1 L of water was given. Cleansing effectiveness, gas elimination efficacy, side effects, and patient satisfaction were compared between the groups. RESULTS: PEGA group demonstrated the highest cleansing effectiveness, but there was no statistically significant difference among the groups. Simethicone addition group showed significantly lesser amount of bubbles than the other groups (2.57±2.05 vs. 1.10±1.83 vs. 2.60±2.84, p=0.017). The rates of side effects in each group were 20.00% vs. 16.77% vs. 53.33%. Water addition group had significantly more side effects than the PEGA group and the simethicone addition group (p=0.003). The patient satisfaction score of each group was 3.37±0.85 vs. 3.73±0.74 vs. 3.20±0.66 with simethicone addition group showing significantly higher satisfaction than water addition group (p=0.020). CONCLUSIONS: PEGA bowel preparation agent showed satisfactory bowel cleansing despite the decrease in dosage, and addition of simethicone resulted in better bubble elimination.
Adult ; Ascorbic Acid/*chemistry ; Cathartics/adverse effects/chemistry/*pharmacology ; Colon/*drug effects ; Colonoscopy ; Female ; Humans ; Male ; Middle Aged ; Patient Compliance ; Polyethylene Glycols/adverse effects/*chemistry/pharmacology ; Prospective Studies ; Simethicone/*chemistry ; Water/*chemistry

Intraocular pressure detection has a great significance for understanding the status of eye health, prevention and treatment of diseases such as glaucoma. Traditional intraocular pressure detection needs to be held in the hospital. It is not only time-consuming to doctors and patients, but also difficult to achieve 24 hour-continuous detection. Microminiaturization of the intraocular pressure sensor and wearing it as a contact lens, which is convenient, comfortable and noninvasive, can solve this problem because the soft contact lens with an embedded micro fabricated strain gauge allows the measurement of changes in corneal curvature to correlate to variations of intraocular pressure. We fabricated a strain gauge using micro-electron mechanical systems, and integrated with the contact lens made of polydimethylsiloxane (PDMS) using injection molding. The experimental results showed that the sensitivity was 100. 7 µV/µm. When attached to the corneal surface, the average sensitivity of sensor response of intraocular pressure can be 125.8 µV/mm Hg under the ideal condition.
Contact Lenses, Hydrophilic ; Dimethylpolysiloxanes ; Glaucoma ; Humans ; Intraocular Pressure ; Tonometry, Ocular ; instrumentation

Polydimethylsiloxane (PDMS) and hydroxyapatite (HA) were combined in our laboratory to fabricate an elastic porous cell scaffold with pore-forming agent, and then the scaffold was used as culture media for rat bone marrow derived mesenchymal stem cells (rBMSCs). Different porous materials (square and circular in shape) were prepared by different pore-forming agents (NaCl or paraffin spheres) with adjustable porosity (62%-76%). The HA crystals grew on the wall of hole when the material was exposed to SBF solutions, showing its biocompatibility and ability to support the cells to attach on the materials.
Animals ; Biocompatible Materials ; chemistry ; Dimethylpolysiloxanes ; chemistry ; Durapatite ; chemistry ; Mesenchymal Stromal Cells ; cytology ; Porosity ; Rats ; Tissue Scaffolds

OBJECTIVEThe biological safety of a new developed silicone rubber for inflatable silastic prosthesis (SRISP) was evaluated.

METHODSFollowing the GB/T 16886.10-2005 standard, YY/T 0127.13-2009 standard, and GB/T 16886.11- 2011 standard, samples were prepared and tested by animal experiments, such as guinea pig maximization test, oral mucous membrane irritation test, and short-term systemic toxicity test (oral route).

RESULTSNo obvious erythema and edema in the guinea pig abdominal skin were observed after 24, 48, and 72 h of stimulating touch, thus indicating that SRISP does not cause potential skin sensitivity. No local response to SRISP was found, and the visual observation and pathological findings of oral mucosa were normal and similar to that of the control group. Therefore, SRISP had no irritation response to oral mucosa. No clinical signs of toxicity were observed in rats, and no significant differences in weight and weight relative growth rate between extract group and blank control group (P > 0.05) were found. Thus, SRISP had no short-term systemic toxicity.

CONCLUSIONThese results indicated that SRISP met the requirement of biomedical materials and had good bio- security.

OBJECTIVETo compare shear bond strength (SBS) between two types of silicone soft liner and polymethyl methacrylate (PMMA) under the condition of heat curing and room temperature curing.

METHODSA total of 48 PMMA specimens (50 mm x 10 mm x 3 mm) were made by water-bath heating method, and randomly divided into four groups. By using Ufi Gel P (UGP) as soft liner material, group A1 was prepared under heat curing, and group A2 was prepared under room temperature curing. To form the other two groups, Silagum-Comfort (SLC) as soft-liner material was used. Group B1 was prepared under heat curing, and group B2 was prepared under room temperature curing. Shear bond strength (SBS) was tested by using the electronic universal testing machine. The adhesives layer and surface of silastic and PMMA were observed by optical microscope and scanning electron microscopy (SEM).

RESULTSThe SBS of groups A1, A2, B1, B2 were (2.39 +/- 0.24), (1.74 +/- 0.27), (3.09 +/- 0.26), and (2.21 +/- 0.29) MPa, respectively. Significant differences were found between A1 and A2, B1 and B2, A1 and B1, and A2 and B2 (P < 0.05). Optical microscope showed numerous bubbles in the cured UGP, and no air bubbles in the SLC. The surface of PMMA was rough. SEM images showed that each group had continual consistent adhesive interface and a whisker hump on the adhesive layer of A2 and B2.

CONCLUSIONThe SBS ofUGP, SLC, and PMMA achieved minimum clinical standard of 0.44 MPa. The SBS of UGP and PMMA were higher than that of SLC and PMMA. The polymerization method of heat curing was higher than room temperature curing.