PURPOSE
The accuracy of denture bases was compared among injection molding, milling, and rapid prototyping (RP) fabricating method.
MATERIALS AND METHODS
The maxillary edentulous master cast was fabricated and round shaped four notches were formed. The cast was duplicated to ten casts and scanned. In the injection molding method, designed denture bases were milled from a wax block and fabricated using SR Ivocap injection system. Denture bases were milled from a pre-polymerized block in the milling method. In the RP method, denture bases were printed and post-cured. The intaglio surface of the base was scanned and surface matching software was used to measure inaccuracy. Measurements were performed between four notches and two points in the mid-palatal suture to evaluate inaccuracy. The palatine rugae resolution was evaluated. One-way analysis of variance was used for statistical analysis at α=.05.
RESULTS
No statistically significant differences in distances among four notches (
P
>.05). The accuracy of the injection molding method was lower than those of the other methods in two points of the mid-palatal suture significantly (
P
<.05). The degree of palatine rugae resolution was significantly higher in the injection molding method than that in other methods (
P
<.05).
CONCLUSION
The overall accuracy of the denture base is higher in milling and RP method than the injection molding method. The degree of fine reproducibility is higher in the injection molding method than the milling or RP method.
A biocompatible silk fibroin‐based carbon quantum dot (SF‐CQD) is first synthesized under microwave irradiation for a short time. This fast and environmentally safe technique produce well‐defined nanosized SF‐CQDs. The SF‐CQDs have good crystallinity, a strong emission peak in the blue‐color region, high quantum yield, and the potential for modification with various functional groups on the surface. These SF‐CQDs demonstrate stable emission, good water dispersity, low toxicity, and good biocompatibility. These properties show the great potential of these SF‐CQDs for use in biomedical applications including bioimaging, biosensing, and drug delivery systems.
A miniature fiber-optic dosimeter (FOD) system was fabricated using a plastic scintillating fiber, a plastic optical fiber, and a multi-pixel photon counter to measure real-time entrance surface dose (ESD) during radiation diagnosis. Under varying exposure parameters of a digital radiography (DR) system, we measured the scintillating light related to the ESD using the sensing probe of the FOD, which was placed at the center of the beam field on an anthropomorphic thorax phantom. Also, we obtained DR images using a flat panel detector of the DR system to evaluate the effects of the dosimeter on image artifacts during posteroanterior (PA) chest radiography. From the experimental results, the scintillation output signals of the FOD were similar to the ESDs including backscatter simultaneously obtained using a semiconductor dosimeter. We demonstrated that the proposed miniature FOD can be used to measure real-time ESDs with minimization of DR image artifacts in the X-ray energy range of diagnostic radiology.
For real-time dosimetry in electron beam therapy, an integrated fiber-optic dosimeter (FOD) is developed using a water-equivalent dosimeter probe, four transmitting optical fibers, and a multichannel light-measuring device. The dosimeter probe is composed of two inner sensors, a scintillation sensor and a Cerenkov sensor, and each sensor has two different channels. Accordingly, we measured four separate light signals from each channel in the dosimeter probe, simultaneously, and then obtained the scintillation and Cerenkov signals using a subtraction method. To evaluate the performance of the integrated FOD, we measured the light signals according to the irradiation angle of the electron beam, the depth variation of the solid water phantom, and the electron beam energy. In conclusion, we demonstrated that the pure scintillation and Cerenkov signals obtained by an integrated FOD system based on a subtraction method can be effectively used for calibrating the conditions of high-energy electron beams in radiotherapy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.