Toshiya Kashiwabara

The enhancement effect of three sugar alcohols on the fungicidal effect of benzethonium chloride toward Candida albicans

OBJECTIVE The purpose of this study was to evaluate if the sugar alcohols erythritol, xylitol and sorbitol enhance the fungicidal effect of benzethonium chloride (BTC) toward in vitro candidal biofilms. METHODS An in vitroCandida albicans biofilm was formed on a plastic coverslip coated with type I collagen. The enhancement of the fungicidal effect was evaluated using microbial assay after treating the biofilm with the test solutions (sugar alcohols: erythritol, xylitol, and sorbitol, each containing BTC solution). RESULTS No fungicidal effect was observed with sugar alcohols without BTC. The fungicidal effect of erythritol-containing BTC increased with the erythritol concentration. Further, the level of enhancement of erythritol was the highest in three sugar alcohols. CONCLUSION Sugar alcohols, especially erythritol, enhanced the fungicidal effect of BTC toward in vitro candidal biofilms.

Part-Digitizing System of Impression and Interocclusal Record for Complete Denture Fabrication.

Few studies have reported the application of digital technology to removable dentures, particularly for the process of impression and interocclusal recording for complete denture fabrication. This article describes a part-digitizing system of impression and interocclusal records for complete denture fabrication. The denture foundation area in an edentulous mouth, including the border areas and residual ridge, is outlined by tracing the surfaces with a 3-D pen-type digitizer. Specialized trays for final impressions and interocclusal records were generated using computer-aided design and manufactured using the digital data. Final impression and interocclusal records were carried out using these specialized trays. The computer-aided method using preliminary digital impressions and specialized trays would be feasible for clinical use for complete denture fabrication.

Recording of individual identification information on dental prostheses using fluorescent material and ultraviolet light.

The placement of individual identification on a prosthesis is very important for forensic dentistry and traceability. This article describes the unique naming/labeling of dentures with information for individual identification using a method in which information is invisible under natural light but visible under ultraviolet light-emitting diode/black light exposure. The use of laser beam machining with this method will enable the recording of a large amount of information.

A new method to prevent the corrosion of dental metals, during disinfection using functional water: Sacrificial protection

PURPOSE This paper demonstrates a simple method using sacrificial protection for preventing the corrosion of dental metals. METHODS Dental metals are directly connected or/and wound with a pure commercial aluminum/zinc wire/plate with high ionization tendency, before their immersion into oxidizing functional water. CONCLUSION Dental materials such as Co-Cr alloy wires, stainless steel, and Au-Ag-Pd alloys did not corrode when this method was used. Thus, this method is very simple and effective for preventing corrosion of dental metals during disinfection using functional water.

Digital assessment of preliminary impression accuracy for edentulous jaws: Comparisons of 3-dimensional surfaces between study and working casts.

PURPOSE The aim of this study was to compare 3-dimensional surfaces of study and working casts for edentulous jaws and to evaluate the accuracy of preliminary impressions with a view to the future application of digital dentistry for edentulous jaws. METHODS Forty edentulous volunteers were serially recruited. Nine dentists took preliminary and final impressions in a routine clinical work-up. The study and working casts were digitized using a dental 3-dimensional scanner. The two surface images were superimposed through a least-square algorithm using imaging software and compared qualitatively. Furthermore, the surface of each jaw was divided into 6 sections, and the difference between the 2 images was quantitatively evaluated. RESULTS Overall inspection showed that the difference around residual ridges was small and that around borders were large. The mean differences in the upper and lower jaws were 0.26mm and 0.45mm, respectively. The maximum values of the differences showed that the upward change mainly occurred in the anterior residual ridge, and the downward change mainly in the posterior border seal, and the labial and buccal vestibules, whereas every border of final impression was shortened in the lower jaw. The accuracy in all areas except the border, which forms the foundation, was estimated to be less than 0.25mm. CONCLUSION Using digital technology, we here showed the overall and sectional accuracy of the preliminary impression for edentulous jaws. In our clinic, preliminary impressions have been made using an alginate material while ensuring that the requisite impression area was covered.