Objective: The position of the denture base outline is an important factor that affects the retention and stability of complete dentures. However, positioning of the outline of lower complete dentures in particular varies among different practitioners.
We conducted a series of studies, of which this is the first report. In this study, we used a traction device to determine the effect of the position of the denture base outline on retention of lower complete dentures. Here, we describe changes in retentivity for different amounts of retromolar pad area coverage by the denture base.
Methods: The distal border of the experimental trial plate was trimmed in a phased manner to reduce the amount of coverage. The distal border was positioned at the distal end dome of the retromolar pad, at posterior border of the retromolar pad, at its 2/3 coverage, at its center, and at its anterior border. During this process, traction was applied to the experimental trial plate with a digital force gauge while it was inserted in the mouth, and the pulling force required to separate the denture base from the alveolar ridge was measured. The measured values obtained were used to compare the effect on retention of the positioning of the distal border of the denture base outline. At the same time, we also measured the dimensions of the retromolar pad area, and attempted to quantify the positioning of the denture base outline.
Results: Measured values declined as the position of the distal border of the denture base was shifted proximally from the distal end dome of the retromolar pad. The values were highest when the border of the denture base was positioned on the distal end dome of the retromolar pad, and it was significantly higher than when it was positioned at the anterior border of the retromolar pad(p<0.01).
Conclusions: To obtain a stable border seal in the retromolar pad area, the distal denture border should be positioned so as to cover at least 2/3 of the retromolar pad(approximately 7 mm posterior from the anterior border of the retromolar pad), and if possible, should be extended to the distal end dome of the retromolar pad (approximately 15 mm posterior from the anterior border of the retromolar pad).

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“Osteoporosis" is featured as decrease of the density of bone, which disease tends to increase the risk of fracture. In Japan, the number of patients suffering from osteoporosis is presumed as many as approximately 11,000,000 persons. The number of them suffering from the disease of osteoporosis which have been proved to be due to tumble or fracture for long-term care is as many as approximately 12 %.
So long as these accidents such as fracture, etc. havenʼt occurred, however, most of patients may be unaware of the subjective symptom thereof. In fact, they will not consult a general practitioner in most cases. The rate of medical check they have consulted a general practitioner of osteoporosis was only approximately 5 %, among which cases approximately 20 % of them had been subjected to medical care.
Therefore, we consider that if it is possible to easily make the medical check of those patients consulting dentists for alveolar bone density, therby urging the patients to visit their dentists jauntily to be examined of the degree of osteoporosis, it will positively be able to contribute to decreasing the number of such debilitated patients as lying down on the bed caused of fracture from the viewpoint of social problem.
The “Alveolar Bone Density Measurement"(Bone Right^® , Dental Graphic Inc.)used in the clinical dental check this time functions to make an alveolar bone density measurement in a high level of precision with ease handling in low cost in such a way as properly adjusting the degree of shading of the image of a dental X-ray photograph and indicating it in a histogram.
The objective samples for the measurements of alveolar bone mineral density （Hereinafter to be referred to as “al-BMD”）made this time were taken out of those 99 women ranging from 40 to 65 years old who havenʼt ever been diagnosed to be the symptom of osteoporosis.
As the result, it has been found that the density of bone decreases proportionally as the age becomes older.
Notwithstanding that those patients of 85 or under in terms of al-BMD who had not been diagnosed to be “osteoporosis" were objective for this medical check, the result of the medical check indicated that the ratio increased up to 2%, 7%, and 14% for 40 to 49 years old, 50 to 59 years old, and 60 to 69 years old respectively.
As the result, it corroborated of the low rate of those patients to be diagnosed of osteoporosis with many patients potential of osteoporosis.
We also obtained such data that though those patients to be objective for our study were interested in the result of al-BMD, in fact they did not visit an orthopedics.

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Porcelain laminate veneer restoration method is to restore the tooth color and form attached with porcelain shell. There are many researches for color matching; however, there is no cement research for attachment due to the color change and condition of cement after restored.
The purpose of this experiment is to examine and find the way of color change after laminate veneer restored. Porcelain fused-to-metal crown( VINTGE Hallo : Shofu) A1B, A2B and A3B are used as Crown Porcelain, A3B, A4B, B4B, C3B, D4B are used as Abutment Porcelain in this experiment. Dual cure resin cement( ResiCem: Shofu) was used as in this study. We used three types of color cement( transparent, ivory and opaque), and two conditions( air and water) were control point. After adhesion thickness of cement was 50μm
First examination was evaluate, the influence of the thickness specimen on the color.Second examination was the color and chronological change for resin cement. Final examination was influence of the color of resin on the laminate veneer restoration color between veneer porcelain( 0.6mm thickness) and abutment( 3.0mm thickness).
The followings are the conclusions from this experiment:
1.The color is effected by the thickness of specimen.
2.When the thickness of cement is 1mm, b* has been increased, 7 more days after restored. When the thickness of cement is 50μm , the color is not changed.
3.Two types of cements with color difference 3 have no significant color difference after restored.
4.Since the difference of the color is significant decreased with water between adhesive testing specimens, the color can be predictable before setting.

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In preparation of complete denture fabrication, it is an important work for dental technicians to precisely recreate the original maxillomandibular relation assessed through dentist's examination and diagnosing by mounting and produce a prosthesis that allows its application only with a little occlusal adjustment. However, it is known that mounting with dental plaster, an easily expanding material might cause a lifting of anterior guide pin. In this study, we investigated whether the lifting of anterior guide pin produces some discrepancy in the upper and lower jaw relation on the articulator or not. Furthermore, a plaster model experiment was made to reduce such lifting of guide pin. The results showed that lifting of the anterior guide pin was produced by setting expansion and hygroscopic setting expansion of dental plaster used for mounting (MT plaster). The plaster model experiment to examine the upper and lower relation on the articulator showed that there was some significant discrepancy in the upper and lower relation on the articulator, of which mechanism was markedly different from that in the original maxillomandibular relation. Here, we described that the work of mounting so as to inhibit the expansion of mounting plaster was a key step to recreate the original maxillomandibular relation of oral cavity and the reason why the step was thought most important for dental technicians.

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In the case of lacking the posterior occlusal support, decrease of peripheral neural input from periodontal ligament and occlusal vertical dimension due to loss of teeth cause shift of mandibular position( deviation of temporomandibular joint and increase of muscle tonus) and disharmony among masticatory muscles, perioral muscles and tongue most likely induces dysfunction of stomatognathic system.
Therefore, treatment should focus on setting of mandibular position and mandibular lateral movement path.
In order to restructure functional occlusion system on the patient with symptom mentioned above, the mouth volume was restored by placing a treatment denture in the upper and lower jaws, mandibular position was stabilized, and lateral movement was provided centering on canine teeth of both sides in addition to rehabilitation. As consequence of the treatment, disturbance of mastication and sleep which were the patient's chief complaint have improved, then the partial metal base denture was placed in the upper and lower jaws after six months.

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Recently, we have seen remarkable progress in implant therapy with respect to its technique, hardware, and diagnostic approach. The progress has made safe and reliable implant fixation available to treat injuries and/or dislocations that have previously been considered difficult to treat via hardware fixation. For example, immediate implant placement method and maxillary sinus lift surgery are considered effective in treating complex injuries. Moreover, recent improvement in the implant surface is allowing rapid osseous union.In addition, a remarkable advancement of the diagnostic equipment, such as CT, is making implant fixation available to treat high-risk injuries. Nonetheless, we cannot deny the possibility of osteointegration to be lost after the weight-bearing period. There is currently no procedure that can be considered effective in fixing the loss of osteointegration.In this study, patients were administered physical stimulation in order to treat the loss of osteointegration and/or mal-osteointegration with Periotest（Gulden.Modautal, Hesse）, which resulted in in a reliable promotion of osteointegration.

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Recently our concern has been focused on increasing risks of various allergies including pollen diseases and atopic dermatitis. Dental metal allergies, as well, are known to be caused by especially nickel chrome or cobalt chrome from metal compositions within crowns, bridges and denture metals inducing various diseases in the oral cavity ¹⁾.
In this occasion our report will refer to treatment processes of a patient who developed allergies after insertion of a maxillary single denture using cobalt chrome base, and we would like to discuss over future solutions and measures.
Symptoms:Concave and convex irregular bloating and reddening in the process of white keratinization were observed in the palatal mucosa where the Co-Cr metal base was in contact.
Clinical progress:Patch testing revealed positive reactions to cobalt chloride and zinc chloride, and so a resin based denture was made for this patient.
Results:Symptoms were improved with the resin based denture.
Discussion:Materials for appliances should be clarified through patch test verification.

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Recent advances in the structure and surface characteristics of implants have led to effective application for prosthetic replacement of missing teeth. In present-day clinical practice, implants are being placed immediately after tooth extraction or at a relatively early stage to reduce the treatment duration and establish occlusion as soon as possible.
When immediate placement of an implant is planned, it is necessary to predict the morphological changes in alveolar bone and gingiva following tooth extraction in order to insert the implant in the most appropriate site. However, as the number of missing teeth increases it becomes more difficult to predict changes following tooth extraction.
Here, we discuss the pattern of bone resorption and suitable implant position after tooth extraction in patients with an edentulous maxilla in whom occlusal reconstruction was carried out using implants.

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Life related disease( LRD) may be correlated with dental diseases which are malocclusion as well as dental caries and marginal periodontitis. Accordingly, control of LRD is likely to be a key factor to control dental diseases, and dentist should pay attention to patientʼs life. Furthermore, it would be nearly impossible maintain oral health without long-term follow up by dentist and/or hygienist.Hence, detail explanation of dental treatment process as well as treatment result should be required for rapport between patient and dentist. Rapport between patients and dentist is quite important, and it must be comprisable by familiar communication. Therefore, dentist and its stuff should take technique to make ʻfamiliar communicationʼ with patients. However, little is discussed about communication approach as item of dental clinic. We applied ʻcommunication style inventoryʼ which was utilized in business coaching area to take ʻfamiliar communicationʼ with patients. Additionally, we introduced how to make ʻheart to heart communicationʼ between dentist and patient, and its efficacy in clinical cases is discussed in this article.

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Recent widespread recognition of cosmetic dentistry, including all-ceramic restorations （inlays, crowns, bridges and veneers）and tooth whitening, not only among dental specialists but also among the general public, has led to a surge in the number of patients seeking these treatments. This in turn has given rise to the misconceptionamong some patients that cosmetic dentistry is simply limited to placing a white restoration over an existing tooth.
Even in cases requiring an esthetic restoration in a localized area, performing an accurate full-mouth assessment—and, sometimes, explaining the need for orthodontic or occlusal intervention—is just as important as the restorative treatment.
Cosmetic restoration of a single tooth, for instance, should not end with the placement of the crown, veneer, inlay, or bridge but also may require proper soft tissue management to ensure stability in the patientʼs oral environment.
Ideal cosmetic dentistry therefore involves not only esthetic considerations but also measures to improve the oral environment, including periodontal plastic surgery and　orthodontic treatment, with a greater emphasis on ease of brushing and functional aspects.
The present study describes the cosmetic treatment in a patient which included soft tissue management and ridge augmentation (improvement of oral environment) to achieve an esthetic smile line. Despite limited treatment options due to the patientʼs unwillingness to undergo orthodontic therapy, the outcome was favorable and the patient was satisfied.

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In conventional medicine and life science the most important concept for human life is not only the energy metabolism of mitochondria, but also the environmental energy system and the biomechanical energy system of animals themselves. However, this energy concept continues to be completely over-looked. Introducing not only energy metabolism of mitochondria but also environmental energy, as well as the animals own biomechanical energy of behavior into medicine, the author has established a new concept of Stomato-facial and Neuro-cranial Medicine. From the standpoint of this new concept of medicine introducing environmental energy, the author has developed the new system of gompholic artificial dental root, having root supportive fibrous articulation instead of dental implants, which join with the jawbone via the ankylotic system. Basic studies of artificial roots were reported in the initial section of Part 1. The different concepts between gompholic artificial roots and dental implants are presented in this paper. It has taken 20 years from the development of artificial roots to the completion of clinical artificial root therapeutics. The operative artificial root therapeutics, which persues the better occlusal condition of a patient s masticatory organ is quite different from operational therapy of common diseases. Stomato-facial and masticatory apparatus are the most important organs for maintaining life activity as well as social life for humans. From this aspect it is necessary to establish clinical artificial root therapeutic methods. Practically, in operative artificial root therapeutics, the development of safe, easy and sure methods are the most important. For this purpose, the shapes of artificial roots have been decided considering the organ specificity of mammalian human teeth namely sphening (tearing) as well as tribosing (mashing) substances with mass through mastication, undulated cylinder type short and thick titanium artificial roots as well as operative apparatus respective to artificial roots have been developed. Quite safe and easy methods for implanting artificial roots, with very little bleeding during the operative procedure, have also been developed. After 15 minutes post operatively, the surface of the artificial root and gingival as well as periroot mesenchymal tissue in the operative socket wound completely agglutinates. Therefore, eating is possible 30 minutes after the operation. The implant devices in dentistry and orthopedics, which are now in vogue, are the ankylotic joint system of rigid vs. rigid, namely bone vs. titanium implant adhesion, which had been denied scientifically from the standpoint of geostatics because of collapse under repeated loading. Therefore, in the modern world, except in medicine, the ankylotic joint system has never been tried from standpoint of geostatics in engineering, mechanics, technology, and architecture. In today's medicine, for the sake of lack of concepts of not only energy but also biomechanics, no one has noticed the mistaken concept of the ankylotic joint system of implants. Therefore, not only the concepts of energy as well as biomechanics but also the concepts of the gompholic joint system have to be immediately introduced. After that, medicine can finally reach today's level in science and technology.

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In this study, the author discussed the necessity of a facebow on the articulator which can reproduce forward movement of human jaw and conducted a geometrical analysis of compensating curve. Being against the use of a facebow, the author mathematically defined compensating curve which have not been determined accurately. Once centric occlusion obtained, the position of the jaw set in the articulator is exclusively related to the movement of the jaw and maintains the movement that are ideatical to those of the jaw by the use of check-bite. Therefore, the positions of the articulator joints( center of the calibration plate and anterios guide table) does not have to correspond to that of the condyle head. There is no need to use a facebow. On the other hand, since the inclination of the movement path of the articulator is determined when the occlusion plane of the articulator is positioned, the occlusion plane of the occlusion rim should correspond to that of the articulator. In other words, it is more logical to use the occlusion plane table for setting.
In addition, with the length of the occlusion rim being a chord, compensating curve is　on the circumference of the circle containing difference between the movement path of forward and backward ends of the occlusion rim on the occlusal plane table.

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