This paper reports the comparison of impression design between the following two techniques: an open-mouth impression technique with a provider centric approach, which is a mandibular complete denture impression technique involving border molding for separate blocks with the use of a compound; and an impression technique with a patient centric approach, which involves impression molding in a closed-mouth position during which the patient himself/herself is allowed to perform functional jaw movement for the attachment by suction of a mandibular complete denture. The results for comparison and observation revealed that there are characteristic differences relative to individual parts in the mouth. Based on such characteristics, it is suggested that the impression technique with a provider centric approach is focused on the support of a mandibular denture and thus is intended to extend a denture base while keeping the supporting tissue free from functional problems, and that the impression technique with a patient centric approach involves the attachment by suction of a mandibular complete denture to residual ridges and thus is intended to sufficiently fill a defect space with a denture.

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The perception of stress by an individual activates the CNS with two major consequences: the neuroendocrine system responds via the HPA axis and the autonomic nervous system responds, causing sympathetic nerve termini to locally release catecholamines. Each of these processes have a potential cost to the body when allostasis is either called upon too often or is inefficiently managed,and that cost is referred to as "allostatic load". We investigated the effects of biting on restraints stress-induced high blood pressure and core temperature as an allostatic load accumulation, and chemical mediators in the serum for further define. Biting of a wooden stick during restraint resulted in a significant reduction of blood pressure at 30, 45, 60 and 75 min, and significant inhibition in core temperature at 30, 60, 120, and 180 min compare with restraint-only rats and these differences are visible in the comparison of infrared thermal images of the restraint-only and restraint with biting rats after 60 min. Biochemical analysis revealed that plasma interleukin(IL)-1β, IL-6, and leptin were significantly suppressed by biting and thyroid stimulating hormone was significantly increased by biting. These results suggest a possible anti-stress effect of biting and an important role of para-functional masticatory activity in coping with stressful events.

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Tooth guidance was studied in 5,146 Japanese subjects, aged 10 to over 60 years, with complete dentitions. Casts mounted on an SAM articulator with face bow-transfer offered the possibility to measure the guidance inclination on both sides of the dentitions. The functional points F1 and F2,which represent the starting point and end point of the tooth guidance, were recorded by a 3D digitizer on maxillary teeth from central incisor to second molar. The inclination of the line connecting F1 to F2 with reference to the axis orbital plane was calculated for each tooth. The inclination of the occlusal plane connecting the F1 points of all teeth from central incisor to first molar, central incisor to first premolar, and second premolar to second molar was also calculated. The values were compared in different age groups and different occlusion groups; Angle Class Ⅰ,Ⅱ, and Ⅲrelationships. The average occlusal guidance sequentially decreased from anterior to posterior. Occlusal guidance indicated that inclinations of canine and first premolar gradually decreased with age, while those of molars were increased. The occlusal plane measurements showed that although the anterior occlusal plane was relatively stable with age, the posterior occlusal plane continuously and gradually flattened. The results confirmed the concept of sequential guidance with canine dominance, although the inclinations of guidance between neighboring teeth decreased with age.

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In routine practice, implant treatment has been applied in various cases. It is beyond discussion that implant treatment under accurate examination and diagnosis is a remedy that both patients and dentists can attain satisfaction. In implant treatment for cases required tooth extraction, implant placement into the alveolar bone with excellent bone quality and sufficient bone volume after healing of the extraction socket allows for reducing operator's stresses. However, actually, a variety of problems including alveolar bone resorption, movement of the adjacent tooth, occlusal changes,and lack of esthetics due to the lengthened healing time may occur. Thus, implant placement immediately after tooth extraction may resolve these problems. However, immediate implant includes many problems to be resolved; securement of sufficient bone volume, achievement of primary stability, and the presence or absence of damages due to inflammation. As a method, the affected tooth is orthodontically extruded for strategic vertical augmentation of the surround alveolar bone and soft tissue, perhaps improving the predictability of implant placement immediately after tooth extraction. In the present case, the implant was placed immediately after tooth extraction following orthodontic extrusion, thus obtaining good results.

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Keeping oral environment clean and controlling occlusal force are necessary to lengthen the life of implant restorations. To enable this，having regular maintenance of them is essential. We have developed and operated a system which balance technologies with human factors. By utilizing it，we have achieved high patients recall rates and it has brought good influence on keeping good conditions of implant restorations and oral environments of patients. Hence，maintenance systems that balance technologies with human factors are considered to be effective.

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Recently, less invasive treatment has been focused based on the patient driven concept in implant treatment. A narrow diameter implant is one of the alternatives to reduce the pain of patients, and it enables to avoid bone augmentation and to shorten treatment period, and makes treatment procedure easy. However, narrow diameter implants have been used in limited case by its physical properties, and its application for full mouth reconstruction is considered to be difficult. Furthermore, it is also difficult to achieve good esthetic outcome in prosthetic treatment by using them. Therefore, in cases where bone width is narrow, regular diameter implants is frequently used with bone augmentation,which is invasive and increase the treatment period and costs. On the other hand, it has been reported that narrow diameter implants showed similar clinical outcome compared with regular diameter implants recently. In this case, we used narrow diameter implants to full mouth reconstruction of no opposing tooth occlusion without bone augmentation to reduce patient tolerance, and had a good clinical outcome. We concluded that the use of narrow diameter implant appears to be predictable if understanding of the properties of narrow implant and careful and appropriate planning are provided. In addition,CT image and three dimensional bone model is useful for application of narrow diameter implant.

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Currently, there are several bone augmentation techniques which are widely used for patients with atrophied alveolar bones in order to gain the quantity of bone required to apply dental implants. Although effective, a major disadvantage of such techniques is that they inevitably involve a considerable amount of stress for both the patient and doctors performing the procedure. As an alternative, there has been a recent trend for doctors to apply short implant placements which are significantly less invasive than using bone augmentation techniques. However, in the case of patients with larger defects such as full edentulous jaws, short implant application requires the placing of a larger number of implants than in procedures which use standard length implants for the prosthetic to be biomechanically sound. Until a few years ago, the fabrication process for such prosthetics demanded a high level of skill on part of the technician due to the greater amount of soldering being required for a prosthetic superstructure large enough to accommodate the required number of implants. Furthermore, the greater use of costly rare metals means a significantly increased financial burden for patients. In light of the above, the Procera' Implant Bridge system has several advantages. The most significant of which is that it guarantees less deformation of finished prosthetics than those manufactured with conventional casting techniques. The system greatly simplifies the manufacturing process by enabling individual prosthetics to be milled from titanium blocks using computer-aided design (CAD) and computer-aided manufacturing (CAM) systems. This means that prosthetics can be produced at lower cost yet with higher degrees of consistency and precision. Additionally, prosthetics made using the CAD/CAM systems have a highly durable single-piece structure with abutments already integrated into the frame. In this article, I will suggest the application of short implant placements and the Procera' Implant Bridge system as an option for full edentulous patients by means of offering specific examples of cases which resulted in high aesthetic outcomes and precise fitting of the dental prosthetic. The following are the most significant characteristics of the procedure: 1. Reduction of the amount of stress involved for both dental clinicians and patients. 2. Simplification of the manufacturing process which leads to cost-reduction. In view of these results, I posit that in the near future, this method will become one of the standard options for applying dental implants for full edentulous patients.

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CAD/CAM systems are evolving much faster than clinicians imagine. These systems are in the middle of evolution, but are widely applied in the clinical setting and, in particular, are indispensable to the aesthetics of the front teeth, today. In the years spanning their introduction to the present day, CAD/CAM systems have seen much improvement and a wide range of materials for them are now available. At the same time, the author's opinion about CAD/CAM has changed. In this paper, the author would like to present his current views of CAD/CAM.

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Although the intercuspal position has generally been used as the reference jaw position in which final prostheses are inserted, this is merely based on the understanding that the intercuspal position is always functionally and morphologically normal. Kawamura described 3 factors, which are the masticatory muscles, temporomandibular joint, and teeth, and the nerves innervating the masticatory muscles, as the functional occlusal system, and explained the importance of the harmonized functioning of these factors. The intercuspal position is the most stable jaw position in which the maxillo-mandibular teeth are occluded with a maximal contact area, and the positional relationship between the condyle in the mandibular fossa and the articular disc is stable, and must be harmonized with the neuro-muscular organization. Furthermore,it is more desirable that the deviation from the centric position be slight. However, when tooth inclination, movement, and defects develop due to dental caries, severe tooth abrasion, and periodontal disease, its normal intercuspal position gradually collapses and becomes unstable,causing muscular hypertension. Furthermore, when clinicians perform symptomatic treatment-like prosthetic treatment, believing that the mandibular position is in the process of collapse, functional abnormalities in the stomatognathic system and of the entire body may occur. Therefore, observing long-term occlusal conditions using provisional restoration based on a diagnostic wax-up in the centric position, final prostheses should be inserted after confirming that there is no problem regarding the achieved mandibular position. Furthermore, it is considered that evaluation of the validity of occlusal treatment from its long-term clinical course becomes important.

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We, as Dental technicians, produce prosthodontal crowns and bridges that meet the expected requirements. Although their key features slighly differ, we have to admit that the focus is put on the aesthetic elements. However, the durability of the aesthetic, other requirements of the recovery of function and the shape we need to give in order to improve the client's occlusion are the most important aspects concerned. This describes the point to keep in mind abnormal cases of, in particular, tooth (abutment teeth and implants) position as of the design of the first molar occlusal pattern.

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In recent years, the prevention of periodontal disease and caries has been focused PMTC, which is one of methods of preventing from periodontal disease and caries, has been already supplied to patients in many dental offices. However, it is difficult for patients to maintain the motivation to keep their teeth clean for a long time. Consequently, they often drop out of their PMTC program. In our office, particular PMTC program has been provided to each patient in order to maintain their motivation. This article reviews some PMTC programs with some cases in our office.

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An approaching method for a patient diagnosed as having extensive moderate chronic periodontitis, who had difficulty of continuous dental office visit, was studied. According to Oral Health of Health and Welfare Trend Survey Report 1999, 77.0% of patients between 25 to 34 years old group received cavity treatment, which was the top of all dental therapies for the group. On the other hand, periodontal disease therapy covered only 3.7%, and oral examination / coaching covered only 6.8% of the group. For the age group which marked the highest score at“Having experience of therapy cessation /Changed dental office”within the report, it must be important to let them possess accurate understanding of their oral health situation and of the need for therapy, and to make a system easy for them to resume dental therapy even after cessation. This presentation case showed some improvement of gingival fibrosis over two years through maintaining patient motivation for long by effective coaching at initial therapy, and also through periodontal initial therapy around the same time as discontinuation of smoking.

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[in Japanese]

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