Resin Plate Research Articles

Application of cranioplasty materials in the past 60 years in China

Cranioplasty is one of the oldest and most common surgeries. Cranioplasty materials developed with this surgery. Many kinds of material have been applied to cranioplasty such as gold, silver, aluminum, lead, platinum, titanium, autogenous bone, allograft, acrylic resin, polyethylene, silicone rubber, carol, ceramic, hydroxyapatite and calcium phosphate cement. In the past 60 years, autogenous bone, acrylic resin, silicone rubber, hydroxyapatite, phosphate cement, titanium sheet and computer-designed plastic ti-alloy plate are the most commonly used materials. Among the materials, computer-designed plastic ti-alloy plate is the preferred material. It is ideal cranioplasty material with high histocompatibility, plasticity and chemical stability, and which has not been found until now to be cytotoxic or immunogenic.

Disinfecting the acrylic resin plate using electrolyzed acid water and 2% glutaraldehyde: a comparative microbiological study

Marked bactericidal activity of the electrolyzed acid water (EAW) and its less undesirable effects on biological tissues and the environment has been successfully utilized in dental practice. A review of literature reveals that not many studies have been performed to determine the disinfection effect of EAW on heat cured acrylic denture bases. The objective of the study is to determine the efficacy of EAW in disinfecting heat cured acrylic resin specimens as compared to the efficacy of disinfecting the specimens using 2% glutaraldehyde. Heat cured acrylic resin plates were immersed in Bacteria suspensions of Staphylococcus aureus and later disinfected using EAW which was produced using a custom made electrolyzing apparatus and 2% glutaraldehyde for different time intervals. The numbers of surviving bacteria were counted. As the control, the bacteria attached on the specimens were counted with out any disinfection treatment. The results obtained were statistically analyzed using ANOVA and post-hoc test. The disinfection potential of 2% glutaraldehyde was better than EAW when the specimens were disinfected for 1 and 3min. Where as when the disinfection time was increased to 5min there was no difference between EAW and 2% glutaraldehyde. However considering that the disinfecting time can be easily extended to 5min, EAW can be effectively used for disinfecting the acrylic denture.

Visualization of the Fleming’ s Left Hand Rule Using the Vortex Motion Caused by Motion of Ion Species During Electrochemical Reactions in the Magnetic Field

To visualize the Fleming’ s left hand rule using ion species as charged particles in aqueous solution, the discharge reactions of the Daniel’ s cell and the redox reaction of Fe2+/Fe3+ were carried out under vertical magnetic field. A copper tube was united with a circular transparent acryl resin plate, which was employed as an electrolytic cell. A zinc or carbon rods was centrally inserted into the acryl resin plate of the cell. The cell was placed on a permanent magnets (neodymium and ferrite magnets) or an originally prepared electromagnet. The geometrical arrangement was shown in Fig. 5. The cell was filled with electrolyte solution : 0.1 mol/L CuSO4 aqueous solution for the discharge reaction of the Daniel’ s cell and 0.1 mol/L H2SO4 aqueous solution containing 0.1 mol/L FeSO4 and 0.1 mol/L Fe2 (SO4) 3 for the redox reaction of Fe2+/Fe3+. The vortex motion of the electrolyte solutions originated from the Lorentz’ s force was clearly observed as soon as the cell reactions and the redox reaction took place under the vertical magnetic field caused by the electromagnet. The vortex motion visualized Fleming’ s left hand rule. The magnitude of the vortex motion was estimated by the rotation rate (rotation number a second) . The higher the rate became, the larger the electrolytic current of the redox reaction of Fe2+/Fe3+or the stronger the magnetic field was, which showed the quantitative relationship of the Lorentz’ s force. On the other hand, for the Daniel’ s cell, the rate decreased accompanying a decrease of the discharge current in time. The experiment was introduced for college students as estimators.

Evaluating the Effectiveness of Applying Phenolic Resin as Thermal Barrier in Buildings during Summer and Winter

Taiwan is limited in space with dense population, and is located in sub-tropical region with high ambient temperature and humidity. In this research, the phenolic resin is proposed as building materials to use its thermal insulation property for developing a comfortable living and working indoor environment. The phenolic resin is an environmental friendly material, and an excellent thermal barrier. The literature also points out that using phenolic resin plates in buildings will decrease or increase the indoor room temperatures by 1°C during summer and winter, respectively, with 10% savings of energy consumption. In this research, the effectiveness of applying phenolic resin as building materials is evaluated for both winter and summer conditions. The results show that the daytime indoor temperature is 5-8°C lower than outside temperature in summer whereas the indoor temperature can be maintained at 20-22°C in winter..

Candida albicans adherence on acrylic resin plates immersed in black tea steeping

Background: Black tea or Cournelia sinensis is one of known tea varieties in Indonesia. Actually, black tea is consumed daily as beverage that can function as antiseptics and fungicides. Black tea containing antibacterial and fungicide properties can reduce the number of Candida albicans (C. albicans) colony attachment on the surface of acrylic resin plates. Purpose: This study was done to determine the effective concentration of black tea steeping used as the immersion material of acrylic resin plates towards the number of Candida albicans colonies. Methods: In this study, acrylic resin plates with the size of 10 × 20 × 1 mm were immersed in black tea steeping with the following concentrations, 3.33%, 6.66%, and 13.33%, for one hour. The growth of C. albicans colonies were then detected by counting the number of colonies growing on Sabouraud’s dextrose medium. Data was analyzed by using both One-Way ANOVA with the significance level of 5%, and Tuckey’s multiple comparison tests (Tuckey’s HSD test). Results: There were significant differences in the number of C. albicans colonies in acrylic resin plates immersed in black tea with the concentration of 3.33%, 6.66%, and 13.33%. Conclusion: It can be concluded that the higher concentration of black tea (13.33%) used to immerse acrylic resin plates, the greater the decreased number of C. albicans colonies. Latar belakang: Teh hitam atau Cournelia sinensis adalah salah satu macam teh yang dikenal di Indonesia. Teh hitam seringkali dipakai sebagai minuman sehari- hari dan berkhasiat sebagai antiseptik maupun fungisid. Teh hitam yang mengandung sifat antibakteri dan fungisid dapat menurunkan jumlah koloni Candida albicans (C. albicans) yang melekat pada permukaan lempeng resin akrilik. Tujuan: Untuk mengetahui konsentrasi efektif seduhan teh hitam sebagai bahan perendam lempeng resin akrilik terhadap jumlah koloni C. albicans. Metode: Pada penelitian ini lempeng resin akrilik ukuran 10 × 20 × 1 mm direndam dalam seduhan teh hitam konsentrasi 3,33%, 6,66%, 13,33% selama 4 jam. Pertumbuhan jumlah koloni C. albicans dilakukan dengan cara menghitung jumlah koloni yang tumbuh pada media Sabouraud’s dextrose. Analisis data menggunakan uji anova satu arah dengan taraf kemaknaan 5%, uji pembanding ganda tuckey HSD. Hasil: Terdapat perbedaan yang bermakna jumlah koloni C. Albicans yang melekat pada lempeng resin akrilik yang direndam dalam seduhan teh hitam dengan konsentrasi 3,33%, 6,66% dan 13,33%. Kesimpulan: Konsentrasi 13,33% atau makin pekat seduhan teh hitam yang digunakan untuk merendam lempeng resin akrilik menyebabkan penurunan jumlah koloni C. albicans.

Composite structure composed of overlapped fibre bundles, thermoplastic resin and metal plate for secondary forming process

A simple shape of a composite is preferable in mass production, while a curved or stretched shape is sometimes preferable for final products. High formability would enable the composite to deform into a preferable shape by secondary forming. In this paper, a structure for a composite is proposed to enhance formability. The composite is composed of reinforcing fibre bundles, thermoplastic resin as the matrix and metal plates. The reinforcing fibre bundles are discontinuous, and are intentionally overlapped in the longitudinal direction. The resin including fibre bundles is sandwiched between the metal plates. As the thermoplastic resin is melted at an adequate temperature, heating would enhance the mobility of thermoplastic resin resulting in high formability at the secondary forming. If the overlapped length is adequately designed, the composite would still maintain high strength after the secondary formation. The validity of the concept was checked by finite element analyses and experiments.

J0402-2-6 Zero group velocityラム波を用いた不飽和ポリエステルの劣化評価([J0402-2]超音波計測・解析法の新展開(2))

A lot of FRP storage tanks are used in chemical plants due to its superior anti-corrosion performance. However, it is difficult to estimate degree of degradation of FRP by an eye inspection. This study aims to evaluate the degree of degradation of an unsaturated polyester resin plate which is used as a matrix of FRP by zero-group-velocity (ZGV) lamb waves. The samples were degraded by immersing the resin into hot water of 90 ℃. ZGV Lamb wave was generated and detected by a Q-switched YAG laser with diameter of 4 mm and a heterodyne type laser interferometer with probe diameter of 0.1 mm. Measured Frequency of ZGV lamb wave for degraded samples decreased with immersion period. This Drop of the measured frequency means that elastic properties of the degraded samples reduced. Depth of discolored area of cross-section of the samples observed by optical micro-scope increased with immersion period and corresponded with gradated depth of the sample. However, no cracks were not observed in the discolored area. It is found that ZGV lamb wave can detect early stage of degradation of the resin.

21418 ボルト締結部における疲労き裂の超音波評価(一般講演 疲労・残留応力)

The ultrasonic measurement of the bolted specimen of acryl resin plates was carried out by pausing the fatigue tester (the in-process measurement) and synchronizing ultrasonic pulsation with a fatigue cycle in the fatigue testing. The reflection from the fatigue crack was detected in the fatigue testing, and steeply increased after appearance of the fatigue crack. By synchronizing measurement, the change in the reflection of the crack wave obtained, that took almost the constant value in a fatigue cycle because of larger length of the crack.

Inhibiting microbial adhesion to denture base acrylic resin by titanium dioxide coating

Mechanical cleaning of dentures is effective in preventing infections such as aspiration pneumonia and denture stomatitis. For denture wearers with a physical handicap and the elderly, however, mechanical cleaning can present problems. The aim of this study was to investigate the effect of coating denture base acrylic resin with titanium dioxide (TiO(2)) in the inhibition of oral microbial adhesion. We prepared uniformly sized acrylic resin plates (10 mm x 10 mm x 0.5 mm), which were divided into two groups (a non-coated group and a TiO(2)-coated group). The plates were immersed in cultured Streptococcus sanguinis or Candida albicans and incubated for 24 h. After incubation, each plate was washed to remove loosely adherent microorganisms, and then incubated for a further 24 h. Adenosine triphosphate (ATP) content of the microorganisms was evaluated using a reagent containing benzalkonium, which extracts intra-cellular ATP. In addition, to determine biofilm formation, we also observed each plate by scanning electron microscopy (SEM). We found that the ATP content of both S. sanguinis and C. albicans was reduced by the TiO(2) coating (P = 0.000). Observation by SEM confirmed that the TiO(2) coating inhibited biofilm formation. The results indicate that a TiO(2) coating on a denture base acrylic resin inhibits adhesion of S. sanguinis and C. albicans.

Titanium Oxide Film Deposition on Acrylic Resin by Atmospheric TPCVD

A dye-sensitized solar cell (DSC) is a solar cell that uses an anatase film as a photovoltaic device. Since the anatase film and dye play the roles of electron carrier and electron generator, respectively, in the DSC, porous anatase films are desirable. In this paper, in order to develop a low-cost fabrication process for the photovoltaic device of the DSC, photocatalytic titanium oxide film deposition was carried out by atmospheric thermal plasma CVD. Ar gas, which served as the working gas for the plasma jet and substrate, and a 20 × 40 × 3 mm transparent acrylic resin plate were used. Titanium tetra iso butoxide was used as feedstock. Consequently, by cooling the substrate, an anatase-dominant film could be deposited at 773 K in deposition temperature without meltdown of the substrate on the condition of 100 mm in deposition distance, even in the case of acrylic resin substrate use. By wettability and methylene-blue decoloration tests, it was confirmed that the film showed hydrophilic and decolored methylene blue perfectly by 8-h UV irradiation. Furthermore, the DSC in which the titanium oxide film deposited by this technique was included as a photovoltaic device generated a photoelectromotive force of 25 mV. From these results, these thermal plasma processes were found to have high potential for DSC fabrication.

Biocompatibility of acrylic resin after being soaked in sodium hypochlorite

Background: Acrylic resin as basic material for denture will stay on oral mucosa for a very long time. The polymerization of acrylic resin can be performed by conventional method and microwave, both produce different residual monomer at different toxicity. Acrylic resin can absorb solution, porous and possibly absorb disinfectantt as well, that may have toxic reaction with the tissue. Sodium Hypochlorite as removable denture disinfectant can be expected to be biocompatible to human body. The problem is how biocompatible acrylic resin which has been processed by conventional method and microwave method after being soaked in sodium hypochlorite solution. Purpose: The aim of this study was to understand in vitro biocompatibility of acrylic resin which has polimerated by conventional method and microwave after being soaked in sodium hypochlorite using tissue culture. Methods: Four groups of acrylic resin plate were produced, the first group was acrylic resin plate with microwave polymeration and soaked in sodium hypochlorite, the second group was acrylic resin plate with microwave polymeration but not soaked, the thirdwas one with conventional method and soaked and the last group was one with conventional method but not soaked, and in 1 control group. Each group consists of 7 plates. Biocompatibility test was performed in-vitro on each material using fibroblast tissue culture (BHK-21 cell-line). Result: The percentage between living cells and dead cells from materials which was given acrylic plate was wounted. The data was analyzed statistically with T test. Conclusion: The average value of living cells is higher in acrylic resin poimerization using microwave method compared to conventional method, in both soaked and non soaked (by sodium hypochlorite) group. This means that sodium hypochlorite 0.5% was biocompatible to the mouth mucosa as removable denture disinfectant for 10 minutes soaking and washing afterwards.

Selection of a solid layer for high-resolution acoustic imaging of IC packaging defects under dry-contact conditions

This paper describes a way to select a solid layer for performing the high-resolution acoustic imaging of integrated circuit (IC) packaging defects under the dry-contact conditions. High frequency ultrasound exited with the 100 MHz focused ultrasonic transducer is transmitted into a sample through a solid layer. The use of two polymer films and two rubber membranes as a solid layer are examined by conducting ultrasonic testing of the acrylic resin plate and the silicon chip sample. The transmission efficiency and the lateral resolution in the cases of polymer-contacts and rubber-contacts are determined, and the selection of a solid layer for clearly visualizing the IC packaging defects by means of the dry-contact technique is discussed. We demonstrate the acoustic imaging of an encapsulated package and a bare chip package via the selected layers. The delamination parts and the debondings in the IC packages are clearly visualized under dry-contact conditions as if the acoustic imaging is performed under water immersion.

A new, simple maxillary‐sparing tongue depressor for external mandibular radiotherapy: A case report

In external radiotherapy, the use of leaded intraoral devices to shield adjacent tissues is well described, but stabilization of the mandible is often realized with standard bite blocks, which do not allow a good stabilization of the mandible. A 40-year-old patient presenting with a local recurrence of a tumor of the floor of the mouth underwent external radiotherapy. To shield the maxilla during mandibular irradiation and to ensure mandible and tongue immobility during external radiotherapy, a custom-made device was realized. The apparatus consists of a polymethylmethacrylate resin plate and 2 wedges. Only 2 steps are needed. The realization is simple and cheap, the apparatus is comfortable, and modifications are easy. It can be used in all patients, except in patients with totally mandibular edentulous with severe bone resorption.

熱可塑性樹脂のレーザ溶着における温度と光弾性縞の同時観察(機械要素,潤滑,工作,生産管理など)

熱可塑性樹脂のレーザ溶着における温度と光弾性縞の同時観察(機械要素,潤滑,工作,生産管理など)

Microfabrication of Transparent Thermoplastic Resin Plates by Dry Etching

This paper describes the microfabrication of transparent thermoplastic plates, polymethyl-methacrylate, polycarbonate, and cyclic olefin polymer by an electron cyclotron resonance-reactive ion etching (ECR-RIE) system. The system was adopted for the microstructure with smooth surface and high-aspect ratio. The etching was carried out using O2/CF4 plasma. The etching conditions are set at 13.56 MHz high-frequency output of 100 W (self-bias voltage: -430 V--310 V) and the stage temperature of -15°C. We have examined the surface roughness and the optical properties at the range of process pressure 0.05-0.5 Pa. The surface roughness of etched substrates is below 20 nm and the average transmittance is over 98% at the process pressure of 0.05 Pa.

Pengaruh Minuman Kopi terhadap Perubahan Warna pada Resin Komposit

Objective: The aim of this research was to investigate the influence of coffee beverage on hybrid composite resin discoloration. Material and method: This study used hybrid composite resin with A3 color, and was done by soaking composite resin plates in coffee solution for 1, 3, 5, and 7 days, corresponding to equivalent coffee usage for 6 months, 1, 1.5, and 2 years. The same measurements of reflectance were done before and after soaking into coffee solution. In the measurement, a beam from He-Ne laser is reflected by the sample to a photovoltaic cell type BOY-47, which provides a voltage signal accordig to the intensity of reflected light. Results: There was a significant difference between composite resin plates before and after soaking into coffee dilution for 1, 3, 5, and 7 days. Conclusion: Composite resin is discolored after soaking into a coffee solution, suggesting that coffee usage will have a discoloring effect on dental composite resin.

Stereolithographic Fabrication and Microwave Properties of 1D Tunable Photonic Crystals Composed of YIG and Alumina Plates in Resin

One‐dimensional (1D) photonic crystals composed of a center polycrystalline yttrium iron garnet (YIG) plate sandwiched with alternate alumina and resin plates were fabricated using stereolithography. The formed crystals showed a transmission mode of microwave in band gap as a result of resonance at the YIG plate. The transmission frequency and intensity were controlled by applying an external magnetic field. These phenomena can be explained by Faraday and Voigt effects of YIG in magnetic field. The propagation characteristics of microwaves agreed well with the calculated results using the finite element method.

The transversal strength of acrylic resin plate after being immersed soaking in noni fruit (Morinda citrifolia Linn.) juice

The disadvantages of acrylic resin plate are liquid absorption and porosity, allowing microorganisms to grow and multiply resulting in inflammation in the oral cavity. The juice of the noni fruit (Morinda citrifolia Linn.) contains active flavonoid and atsiri oil. Flavonoid is a phenol substance that degrades acrylic resin plate in prolonged contact. The purpose of this study was to examine the transversal strength of acrylic resin plate after being immersed in noni fruit juice. An acrylic resin plate of 65 × 10 × 2.5 mm was immersed in 4%, 6%, 8%, 10%, and 12% concentrations of noni fruit juice and distilled water in a control group for 31, 46, and 61 days. The transversal strength of acrylic resin plate was tested using an autograph with a crosshead speed of 1/10mm/second; the distance for the two supporting parts was 50 mm. The data was analyzed by using a One–Way ANOVA test. There was no significant difference in the transversal strength of the plate after being soaked for 31, 46, and 61 days in 4%, 6%, 8%, 10%, and 12% concentrations of the juice. This study showed that the soaking of acrylic resin plate for 31, 46, and 61 days in 4%, 6%, 8%, 10%, and 12% concentrations of noni fruit juice does not decrease the transversal strength.

THE REDUCTION OF STRESS WAVE PROPAGATION THROUGH POROUS MATERIALS

Impact stress wave propagating through porous materials is investigated in order to examine the ability of the shock absorbing effect. The specimens are modeled as the porous medium with different porous diameters made of the acrylic resin plate. When these models are impacted with different impact velocities, the impact stress waves propagating before and after the porous parts are measured using the strain gages in the experiments. As the reduction effect of the impact stress wave propagating in the porous medium, we pay attention to the maximum stresses and the duration times from the histories of the impact stress waves. One-dimensional wave theory and dynamic element method simulated this model are applied in order to explain these phenomena.

Discrimination of heavy ions using copolymers of CR-39 and DAP

Mixtures of allyl diglycol carbonate (CR-39) and diallyl phthalate (DAP) were cast into resin plates under same polymerizing conditions. The copolymer plates were irradiated with many kinds of ions at the medium energy beam irradiation room or biological irradiation room of National Institute of Radiological Sciences (NIRS)-Heavy Ion Medical Accelerator in Chiba (HIMAC). After etching in an aqueous solution of KOH, whether enlarged ion tracks exist or not was determined by using an optical microscope. It was found that every plate has a characteristic value in LET as threshold for track formation. The threshold increases with the concentration of DAP. It has been shown that the threshold is adjustable by changing the ratio of CR-39 and DAP. It is expected that the copolymers can be used for the discrimination of heavy ions in cosmic rays.