Modern crown-bridge restorations have been achieved by the introduction of casting gold alloys and the lost wax precision casting technique. When esthetic restorations are needed, porcelain and composites are used as veneering materials. These techniques are conventional manual processes in dental technology. On the other hand, application of CAD/CAM (computer-aided design and computer-aided manufacturing) for the fabrication of crown-bridge restorations has been developed in dental schools and companies worldwide since the 1980s. With the introduction of zirconia and networked centre-driven CAD/CAM technology, dental CAD/CAM has become very popular in dentistry. Application of CAD/CAM has several merits such as the application of new materials, improvement of working circumstances, economics and quality control of restorations. We suggest that general practitioners need to understand the advantages and limits of CAD/CAM processing, adhere to clinical protocols, and collaborate with dental technicians to make dental CAD/CAM more popular in dentistry.

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Purpose: The advantages of aesthetic restoration materials are good biocompatibility and lack of toxicity compared with metal restorations. Glass-fiber-reinforced composite material Targis/Vectris (Ivoclar-Vivadent, FL) was observed by a microscope and the composition analyzed. As a result, it was judged that the material was good for clinical use. This material was used in dental treatments in 1997. However, the glass-fiber-reinforced restorations often fractured. The purpose of this study was to evaluate the clinical strength of the glass-fiber-reinforced restorations by cohort analysis.
Methods: The glass-fiber-reinforced restorations were made according to the manual of the manufacturer. A total of 29 patients who had 73 glass-fiber-reinforced restorations were investigated by questionnaire survey between June 25th, 1999 and September 7th, 2000 at Aichigakuin University Dental Hospital.
Result: These restorations were investigated after a maximum of 8 years. In all, 35 of 73 (47.9%) restorations were fractured, including cracks and chipping; 6 of 14 inlays (42.9%), 14 of 43 crowns (32.5%), 15 of 16 bridges (93.8%) were fractured. Survival rate calculated according to Kaplan-Meier Product-Limit method suggested that 57.1% of inlays, 69.0% of crowns, and 6.7% of bridges will remain unbroken in 8 years' time.
Conclusions: Clinicians should not use materials developed by new concepts or techniques too quickly. Instead we think that long-term clinical evaluation is needed for safety and durability.

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Purpose: To evaluate the shear bond strength of six self-adhesive resin cements to five restorative metal materials.
Methods: Five restorative metal materials blocks were obtained by casting and polishing with #600 silicon carbide papers: (1) titanium, (2) nickel-chromium alloy, (3) gold alloy type 3, (4) silver-palladium-copper-gold alloy, (5) metal-ceramic gold alloy. The following six self-adhesive resin cements: Maxcem (MA), Unicem (UN), Breeze (BR), Biscem (BI), Set (SE), Clearfil SA luting (CL) and one conventional resin cement: Resicem (RE) were used to bond to five restorative metal materials in this study. Prior to testing specimens were stored in distilled water (37°C) for 24 h. The bond strength tests were performed in a universal testing machine (cross-head speed: 0.5 mm/min). Data were analyzed using Kruskal-Wallis test and the Wilcoxon rank sum test for multiple pairwise comparisons. Failure modes were recorded and the interfacial morphologies of debonded specimens were observed by scanning electron microscope (SEM).
Results: The mean values of shear bond strength were 2.6 ± 1.9 MPa for gold alloy type 3, 2.2 ± 1.7 MPa for silver-palladium-copper-gold alloy, 5.0 ± 2.3 MPa for metal-ceramic gold alloy, 10.2 ± 5.4 MPa for titanium, and 9.9 ± 7.8 MPa for nickel-chromium alloy.
Conclusion: Self-adhesive resin cement is not suitable to bond noble metal without surface treatment. The shear bond strengths of BR, BI, and CL to non-precious metals were significantly higher than other resin cements.

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Purpose: To investigate bleaching effect of Blue-Violet-Diode-Laser irradiation to tooth enamel with TiO₂ agent.
Methods: Blue-Violet-Diode-Laser (Nichia), Light Surge (Osada) and Opelaser 03SII (Yoshida) were used as light source for the experiment. TiO₂ as the bleaching agent was applied to human enamel, and the surface was irradiated by Blue-Violet-Diode-Laser. The tooth color was evaluated by L*a*b* color system. A handysurf E-30A (Tokyo Seimitsu) was used for measuring the roughness of the enamel surface (Ra) before and after treatment.
Results: ΔE levels in the Blue-Violet-Diode-Laser irradiation groups were significantly higher than the other laser treatment groups. The post-treatment Ra in the two groups showed no signi.cant difference compared with the pre-treatment levels.
Conclusion: This study suggest that the Blue-Violet-Diode-Laser irradiation could enhance the bleaching effect with TiO₂.

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Purpose: To evaluate the shear bond strength and bonding durability of different self-adhesive resin cements to dental zirconia.
Method: The following self-adhesive resin cements were used in this study: G-luting, SA luting, RelyX Unicem and Smartcem. The specimens of zirconia were embedded into acrylic resin. Each specimen was then cemented in bonding area that was regulated with plastic tape (3.0 mm in diameter) using self-adhesive resin cement (self-curing mode) with a stainless steel rod (10 mm in diameter), after it was prepared using wet 600-grits silicone carbide paper. Each self-adhesive resin cement was prepared for each of the 14 specimens. Prior to performing the shear bond strength test, all bonded specimens (n = 14) were stored at 37°C -100% relative humidity for 1 hour and stored in 37°C distilled water for 23 hours. Half the specimens (n = 7) were repeatedly thermal cycled for 5000 cycles between 5 °C and 55°C. The shear bond strength of self-adhesive resin cement to zirconia was measured in a universal testing machine.
Results: The mean shear bond strength of the self-adhesive resin cements to zirconia varied from 7.5 to 66.1 MPa after storage in 37°C distilled water for 23 hours, and from 0.8 to 71.0 MPa after repeated thermal cycling. The shear bond strengths of the self-adhesive resin cements containing phosphoric acid ester monomer were slightly higher than for those containing carboxyl acid monomer. Observation of fracture mode determined that fractures did not occur at the interface with the stainless steel rods. All fractures occurred either at the interface between the zirconia surface and the cement (adhesive mode) or within the cement (cohesive mode).
Conclusion: Self-adhesive resin cements containing adhesive monomers such as phosphoric acid ester monomer showed slightly less accelerative degradation than other cements when bonded to dental zirconia.

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Patient: A 53-year-old male patient had undergone segmental resection of mandible and mandibular bone reconstruction by the fibula under the diagnosis of ameloblastoma. A removable partial denture featuring a rigid support design with adequate diagnosis was inserted to improve the functional disorder postoperatively.
Discussion: Remarkable improvements of esthetics, pronunciation, and chewing were admitted by installation of the removable partial denture. As of 6 years follow up of the remaining teeth, periodontal structure, and intercuspal position remain in good condition and the patient has not complained of any problems with the partial denture.
Conclusion: The removable partial denture was effective in this case.

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Patient: A 53-year-old male patient with severe periodontitis came to our hospital with masticatory and esthetic disorders. After periodontal treatment, a few teeth remained. The provisional denture was delivered to reconstruct adequate occlusal relationships. Finally, prosthetic treatment with crown and sleeve-coping telescopic denture brought longitudinally stable oral functions.
Discussion: Sufficient support was acquired by improvement of the axis and crown roots ratio of remaining teeth.
Conclusion: Prosthodontic treatment by crown and sleeve-coping telescopic denture was effective to restore masticatory function and esthetics for a patient with few remaining teeth.

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Patient: A 67-year-old female had a chief complaint of mastication disorder. The mandibular edentulous jaw had severe ridge resorption. This case was diagnosed as having poor retention and stability of mandibular complete denture, and decreasing of the occlusal vertical dimension by attrition of artificial teeth. The positions of teeth arrangement were determined using flange technique to be in harmony with function movement.
Discussion: Attrition of artificial teeth and positions of teeth were considered causative of mastication disorder. Acrylic resin was applied on the occlusal surface of previous denture teeth used as a treatment denture, and the flange technique applied for arranging teeth of new denture to obtain stabilization and retention.
Conclusion: Application of teeth arrangement in the neutral zone conveyed a good prognosis in a patient with mastication disorder and severe ridge resorption.

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Patient: A 48-year-old female complained of masticatory disturbance caused by maxillary and mandibular distal extension missing. The patient complained of discomfort of maxillary removable denture. After maxillary sinus floor elevation, the treatment provided occlusal reconstruction with implant-supported fixed prostheses for maxilla and mandible.
Discussion: The implant prosthesis resulted in a good outcome with no mobility and no morbid bone resorption around implants during periodical recall. The patient was very satisfied with function and esthetics by the implant treatment. Establishment of occlusal support by implants also presented stabilizing of existing teeth.
Conclusion: The implant treatment effectively improved the patient's requirements for comfort in maxillar bilateral free-end missing.

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Patient: A 59-year-old woman visited our hospital with a chief complaint of masticatory dysfunction due to breakage of lower bilateral distal extension missing denture. After temporary repairs, a fixed partial denture at upper anterior teeth was detached. Full mouth restoration was done to correct the defect of occlusal support with sunk dentures and slight infraocclusion. During 6 years of follow-up, only one tooth was extracted due to root fracture, thus the prognosis was considered stable.
Discussion: Occlusal reconstruction for decrease of occlusal support with active prosthesis is considered to prevent occlusal collapse in the long term.
Conclusion: Concerning case of Eichner classification B2, the recovery of function and aesthetics mainly using removable partial denture provides good prognosis.

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Patient: This case report describes the use of immediate denture in a severe case of chronic periodontitis. A 60-year-old female patient presented with a chief complaint of disability of chewing and aesthetics problem. An immediate denture was served to achieve adequate occlusion. Due to applying of immediate denture in early stage, her occlusion and aesthetic problem were improved, and .nal prosthetics treatment performed.
Discussion: According to immediate denture, her chewing disability and aesthetic problem were improved, and time was allowed to perform pre-treatment before .nal prosthetic treatment.
Conclusion: The aim of this case report is to show achievement of a functionally and aesthetically satisfying result with applying immediate denture. In addition, it is thought that removable partial denture is an effective treatment as a prosthetic device of a severe case of chronic periodontitis.

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Patient: A 68-year-old edentulous female patient complained of masticatory dysfunction and also had increasingly strong demands for aesthetic restorations and conversation. The case was diagnosed as losing retention and stability of mandibular complete denture during mastication and conversation. The position of artificial tooth arrangement and shape of the polished surface were determined using the flange technique in new denture, and palatal form was determined using a static palatogram.
Discussion: It was considered that masticatory dysfunction and speech disturbance were improved by gaining the retention and stability of mandibular complete denture.
Conclusion: Fabrication of new denture using functional approach to an edentulous patient with complicated complaints achieved a favorable prognosis.

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Patient: An 18-year-old female patient with aesthetic complaint caused by diastema in the anterior dental region. The first premolar and first molar of the right side were congenitally missing and uneven space was noted at premolar region and anterior teeth. Anterior teeth were treated with ceramic laminate veneers, and premolar region was treated with osseointegrated implant prosthesis after realignment of anterior teeth by minor tooth movement method (MTM).
Discussion: Functionally and aesthetically satisfactory result has been maintained for 3 years since treatment completion. It is considered that an appropriate dental realignment and proper dental arch that fits to the size of the patient's tongue have achieved aesthetic result and prevented recurrence of diastema.
Conclusion: Less invasive and more aesthetic dental treatment was carried out to a case of diastema with laminate veneers and osseointegrated implant prosthesis following MTM as a preprosthetic treatment.

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Patient: A 69-year-old male patient with left maxillary defect and dysphagia by surgical operation for adenoid cystic carcinoma. Swallowing rehabilitation was performed primarily for weaning from tube feeding using training of swallowing function and placement of swallowing obturator prosthesis. Masticatory rehabilitation was performed secondly, using maxillary jaw denture and mandibular complete denture. Functional assessment and feeding instruction were performed by videoendoscopy and video. uorography.
Discussion: Rehabilitation of swallowing and masticatory function was performed safely and smoothly by gradual rehabilitation with objective functional assessment.
Conclusion: Oral rehabilitation for an edentulous patient with maxillary defect and dysphagia was performed successfully using prosthesis and training of swallowing and masticatory function.

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Patient: A 55-year-old male patient had undergone marginal mandibulectomy and reconstruction by rectus abdominis flap for carcinoma of the right buccal mucosa. After the surgical operation, dento-maxillary prostheses were inserted in the maxilla and mandible. Then, a lip plumper prosthesis was added to restore lip support.
Discussion: For 5 years after the insertion, since the prostheses have provided good retention and stability, chewing, swallowing, and esthetics were improved as well as QOL of the patient. However, 5 years after the surgical operation, the flap proliferated and hypertrophied, so that the prostheses resulted in flap biting. Therefore the patient received defatting and the prostheses were refabricated. Collaborative rehabilitation efforts between oral surgeons and prosthodontists through pre- and post-operation are important for improvement of patients' QOL after surgery.
Conclusion: Rehabilitation using dento-maxillary prostheses to a patient with reconstruction by rectus abdominis flap contributed to functional and esthetic improvement.

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Patient: A 58-year-old female with the chief complaints of trismus and pain around the left temporomandibular joint. The mandibular position was deviated backward and tooth contact was not found in the anterior region. As a result, the mandibular position was unstable. Therefore it was stabilized by splint therapy, followed by behavioral and cognitive therapies, and the occlusion was reconstructed thereafter.
Discussion: It was thought that recovery of occlusal contact in the whole jaw, including the anterior region, and adequate setting of anterior guidance resulted in stability of the mandibular position, and guidance for parafunction prevented a relapse of the symptoms.
Conclusion: In this case, as a result of stabilization of the mandibular position by an occlusal splint followed by behavioral and cognitive therapies and occlusal reconstruction, a favorable prognosis was obtained.

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