Recently, a new system has been developed, in which it is possible to produce dental components ranging from inlay and crown to metallic plate and multipurpose gold alloy exclusive low-fusing porcelain are used to produce porcelain-fused cast crown. In our department, we are currently performing studies with the purpose of applying a system using multipurpose gold alloy and exclusive low-fusing porcelain to improve esthetic appearance of cone-outer crown by applying the above system for anterior embellishment of outer crown.
In this respect, we performed comparative study on porcelain in DUCERA GOLD system (DUCERA) and Golden Gate system (Degussa) by using multipurpose gold alloy and exclusive low-fusing porcelain. Also, by applying DUCERA GOLD system, it was attempted to comparatively study the difference on metal surface treatment and also the influence on porcelain fusing strength between the case where bonding porcelain was used and the case where it was not used. Further, bonding strength of porcelain was determined by 3-point bending test, and fluorescent X-ray analysis and X-ray diffraction test were carried out on porcelain powder.
Fusing strength of multipurpose gold alloy showed almost the same value as the conventional type. In porcelain hardness, body porcelain exhibited the highest value. Next followed bonding porcelain and opaque porcelain.
Fusing strength was at the highest under surface treatment conditions where blast treatment (4060μm) was performed and bonding porcelain was used.
The results of porcelain bonding test revealed the highest value in the bonding porcelain. Next followed body porcelain and opaque porcelain.
In the result of fluorescent X-ray analysis and X-ray diffraction test on porcelain powder, SnO₂ and leucite which are useful for the bonding of metal with porcelain were found in most cases.

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The bonding efficacy of dentin adhesive to caries-affected and caries-free dentin was examined by measuring the wall-to-wall polymerization contraction gap width and micro-tensile bond strength. The morphology of the adhesive interface was observed with a Scanning Electron Microscope (SEM). The cavity wall prepared in the caries-affected or the caries-free dentin was conditioned by 0.5 mol/L EDTA and restored with a commercial resin composite (Silux Plus) mediated with a commercial dentin bonding agent (Clearfil Photo Bond) with or without priming of 35 vol% glyceryl mono-methacrylate (GM). In GM priming groups, complete cavity adaptation was observed in all of the specimens of both caries-free and caries-affected dentin. When the GM priming was omitted, contraction gap width in the caries-affected dentin cavity was significantly decreased compared with that in the caries-free dentin cavity. The micro tensile bond strengths of the caries-free dentin without GM priming were significantly lower than those of the other three groups. It was possible to conclude that the efficacy of the dentin bonding system to caries-affected dentin was never inferior to that of the caries-free dentin. The sclerotic dentin is a defense tissue against carious invasion should be preserved. For a resin composite restoration in a caries-affected dentin cavity, it should not be applied with strong acid for the dentin conditioning.

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The purpose of this study was to evaluate the patients who visited the Examination section of Department of Fixed Prosthodontics, Showa Dental Hospital, between October 2001 and September 2002.
The results were as follows :
1. The total number of patients was 913 that consists of males 333 (36.5%) and females 580 (63.5%).
2. The patient's average age was 59.8 years old.
3. The ratio of introduction from the Department of General Clinic was 48.8%. The ratios of introduction from the Department of Oral and Maxillofacial Surgeons and Department of Conservative Dentistry were 25.6% and 10.9%, respectively.
4. The main chief complaints of new patients were Crown-Bridge, Denture and TMD, and those ratios were 52.2%, 26.6%, and 11.3%.
5. The main chief complaints of the patients without appointment were Denture and Crown-Bridge, and those ratios were 42.4% and 37.2%, respectively.

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With the recent development of high-resolution digital cameras, intraoral photos are now being stored as digital records rather than slides. Presently, however, there are still cost problems with high-resolution digital imaging, despite the improved computer processing ability. Moreover, it is not clear what resolution is sufficient for the clinical application of intraoral photos. Therefore, we examined the conditions used to obtain digital photographs to determine the minimum standards for the clinical application of the existing mixture of digital and analogue images. It was found that sufficient picture quality could be obtained with a VGA (640×480 pixel) digital camera.

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