Journal of Japanese Society of Oral Implantology
Online ISSN : 2187-9117
Print ISSN : 0914-6695
ISSN-L : 0914-6695
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Showing 1-14 articles out of 14 articles from the selected issue
Review
  • Jyoji TANAKA
    Type: Review
    2019 Volume 32 Issue 3 Pages 168-179
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    Facing a super-aged society, implant-supported overdentures (IOD) are attracting attention, which is advantageous to maintain potent therapeutic efficacy with only a small number of implants. However, it is difficult to provide details of all types of IODs at once, because the concept and design of IODs completely differ depending on the purpose of selecting IODs, number of implants, and attachments to be used. We herein describe the concept and precautions in designing IODs, after showing the usefulness of IOD applications.

    In general, IODs are categorized into the following : implant-supported, mucosa- implant-supported and mucosa-supported types. On the other hand, IODs are clinically divided into two major groups : anchoring rigid IOD and micromoving flexible IOD. This means that the concept of designing IODs varies greatly depending on whether bilateral balance, one of the important functions to stabilize the conditions of full dentures, is present or not. One of the points to bear in mind while performing implant surgery is not to place load on the implants during the non-weight-bearing period.

    We present an evaluation system to assess the level of requirements in design-changes to IODs, because the purposes of selecting IODs include the high usefulness of implant treatment when we consider the coming era where many people will be in need of nursing care. In addition, we present the application of an intraoral scanner and 3D printer, as well as the fabrication of copy dentures, which may bring a paradigm shift in prosthodontic dentistry. Further popularization of IODs is anticipated.

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Special Articles: Responsibilities to the super-aged society: For implant to sunggle up to the patients
  • Kenichi OKUDA, Kiyoshi KOYANO
    Type: Special Articles: Responsibilities to the super-aged society: For implant to sunggle up to the patients
    2019 Volume 32 Issue 3 Pages 180
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS
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  • Masahito YAMAMOTO, Kazuto KORESAWA, Yudai OGAWA, Hidetomo HIROUCHI, Sa ...
    Type: Special Articles: Responsibilities to the super-aged society: For implant to sunggle up to the patients
    2019 Volume 32 Issue 3 Pages 181-188
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    In the super-aging society of Japan, it is expected that the management period after dental implant treatment will increase and that the various situations of patients with implants will markedly change. We evaluated in terms of functional anatomy “matters in patients that should be understood” and “items in patients that should be checked” by dentists and dental hygienists during long-term management after treatment. Muscle strength decreases with age after the age of 45 because individual muscle fibers become thinner (the protein content decreases) and the number of muscle fibers decreases. This decrease in muscle strength of the elderly causes distortion of the body axis of the entire body. The head and neck are involved in the posture of the entire body, and so the possibility that age-related morphological changes in the body axis affect the head and jaw positions should be considered. The head position is determined and maintained mainly by muscle groups from the sides of the neck to its posterior portion. Many suboccipital muscles in the deep layer of the posterior portion of the neck connect the cervical vertebrae to the cranial base. Anterior tilting of the head position due to loss of cervical lordosis changes the normal positions of these muscles. Such age-related morphological and functional changes also occur in the temporomandibular joint and can affect the mandibular position. Therefore, in the super-aging society of Japan, it may be necessary to record age-related changes in not only the oral cavity but also the entire body.

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  • Keina NAGAHISA, Akira SAMUKAWA, Masataka ITODA
    Type: Special Articles: Responsibilities to the super-aged society: For implant to sunggle up to the patients
    2019 Volume 32 Issue 3 Pages 189-196
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    In Japan, which has become a super-aging society, the number of care recipients after diseases such as cerebral infarction is increasing. The field of life also changes as the patient's medical condition progresses. Many patients suffer from declines in their physical and mental functions after the onset of disease, and so it is necessary to carry out various rehabilitation programs for them to return home or return to society.

    In dentistry, positive and therapeutic responses as well as palliative and terminal measures are required in order to promote the health of patients and maintain and improve their quality of life. Recently, the number of elderly people presenting with implants in the mouth is increasing. To promote true health, it is essential to ensure that the remaining teeth and prosthetic devices cannot interfere with oral function. In addition, implant prostheses must contribute to the improvement of chewing function and oral hygiene must be maintained. For patients who have difficulty going to a hospital and cannot perform self-care, oral hygiene management by carers and oral function management by home dental care are required. However, home dental care such as home medical care and home oral care has not yet become sufficiently widespread. This paper describes 1)important points in implant treatment in a super-ageing society, and 2)considerations for patients after implant treatment, and the following three issues : 1)Who, when, and how to do maintenance? 2)How to convey information about the implant to the carers? 3)How should the patient be treated after implant treatment in the terminal phase?

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  • Kazunori IKEBE, Masahiro WADA, Tomoaki MAMENO, Jun MORITA
    Type: Special Articles: Responsibilities to the super-aged society: For implant to sunggle up to the patients
    2019 Volume 32 Issue 3 Pages 197-203
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    In Japan, despite the decrease in the total population, the elderly population is increasing, and this will continue for a long time. In 2040, the ratio of the elderly population to the working-age population is expected to be 2 to 3 and the social security costs to be 1.6 times higher than at present. Such an extremely low birthrate and aged society is an extremely fragile situation, both in human and financial resources.

    After dental implant treatment, patients' motor and cognitive function decline later in life. In the future, not only many teeth but also implants will be left in the oral cavity of old people who need nursing care. Most patients receive implant treatment in their fifties to early seventies. However, in the seventies, 40% have a possibility of diabetes and 40% of women develop osteoporosis. These rates increase with age, therefore the risk of implant loss increases. In the late eighties, one third of men and half of women are in need of nursing care mainly due to cerebrovascular disease and dementia, and the patients themselves may no longer be able to perform oral hygiene. On the other hand, the care-givers responsible for oral hygiene for the frail elderly are also mainly old family members.

    In order to minimize the burden in the future, dentists who provide implant treatment are required to face up to the inevitable reality of the future, and be prepared to manage implants for a lifetime.

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Special Articles: Technologies in Biomedical Engineering for Next-Generation Dentistry and Implantology
  • Takashi MIYAZAKI, Koichi IMAI
    Type: Special Articles: Technologies in Biomedical Engineering for Next-Generation Dentistry and Implantology
    2019 Volume 32 Issue 3 Pages 204
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS
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  • Yuji MATSUURA
    Type: Special Articles: Technologies in Biomedical Engineering for Next-Generation Dentistry and Implantology
    2019 Volume 32 Issue 3 Pages 205-209
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    Bio-molecules show strong optical absorption in the mid-infrared region of 2.5-25 micron wavelength and therefore, by analyzing the absorption spectrum (so-called “fingerprint spectrum”), a variety of non-invasive diagnoses will be possible. In this paper, firstly a blood-glucose measurement system based on Fourier-infrared spectrometry (FT-IR) is introduced. In this system, by using a flexible optical fiber, optical absorption spectra of lip mucosa that show relatively strong absorption of glucose are measured by touching the lips on a prism. By measurement using the human lips, it is shown that the system can measure blood glucose with a measurement error of less than 20%. Next, a blood glucose measurement system using quantum cascade lasers (QCLs) oscillated in the mid-infrared region is introduced for constructing a compact and low-cost system. By using the QCL-based system, it is shown that the differential absorption between two wavelengths that were chosen based on optical spectra taken by the FT-IR-based system exhibits a high correlation with blood glucose level.

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  • Yoshitomo HONDA, Tomonari TANAKA
    Type: Special Articles: Technologies in Biomedical Engineering for Next-Generation Dentistry and Implantology
    2019 Volume 32 Issue 3 Pages 210-216
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    Various stem cell-based therapies and regenerative medicine have started clinical trials. Nevertheless, such applications are still rare in dental practice. The complexity and issues of cell culture systems, such as huge cost, devices, laborious works, and time hamper the advancement of cell-based therapies. This paper reviews the infrastructure of cell culture systems and related issues. Additionally, we have recently developed novel bone regenerative materials using a botanical-based substance (catechin isolated from green tea) and aqueous chemical synthesis. The materials have advantages in terms of cost and environmental issues. We also introduce the function of fabricated epigallocatechin gallate-modified gelatin sponge for bone regenerative medicine.

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  • Atsushi MAHARA, Tetsuji YAMAOKA
    Type: Special Articles: Technologies in Biomedical Engineering for Next-Generation Dentistry and Implantology
    2019 Volume 32 Issue 3 Pages 217-221
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    Magnetic resonance imaging (MRI) is used in clinical sites as an imaging diagnostic technique for visualizing organ and blood vessel structures in a non-invasive manner. The method of visualizing blood vessels in MRI is called MR angiography. Recently, high-resolution MRA has been developed by increasing the magnetic strength and improving the cooled receiving coil. However, the MR signals from microblood vessels are extremely weak, and so it is essential not only to improve the hardware but also to develop contrast agents specific for the microvasculature in order to realize high-resolution imaging with a high S/N ratio.

    In our previous work, we developed fluorescein and Gd-chelate conjugated 8-arm polyethylene glycol as a polymeric contrast agent for visualizing a microvasculature. The contrast agent forms a self-assembled structure in a high concentration condition, and the structure collapses when diluted. This property enables the blood circulation time of the contrast agent to be increased, and we succeeded in visualizing a microvessel structure of approximately 100 μm in diameter, which could not be visualized by non-contrast MR imaging. In this article, we introduce the structural and physical properties of F-8-arm PEG-Gd, and discuss the MRA imaging results with and without contrast agents. The metabolism and toxicity of the agents are also mentioned. Based on these results and discussion, we explore the possibility of a new diagnostic method in the dental area based on the techniques for visualizing the microvasculature using polymeric contrast agents.

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Original Paper
  • Hajime SUZUKI, Koh TSUKAGOSHI, Akira TAKAHASHI, Nobuaki FURUYA, Hiroki ...
    Type: Original Paper
    2019 Volume 32 Issue 3 Pages 222-229
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    Purpose : When titanium (Ti) implants are inserted into bone, the adsorption of proteins at the implant-tissue interface is the first biological response to the implants. Thus, the adsorption behaviors of proteins on Ti must be studied. In this study, we investigated the adsorption of fibronectin on Ti with or without calcium (Ca) ion modification using the quartz crystal microbalance (QCM) technique.

    Method : A 27-MHz QCM apparatus was employed. The Ti sensor for the QCM measurement was treated with CaCl2 aqueous solution, and a Ti sensor with Ca ion modification (Ca-Ti) was obtained. Ti and Ca-Ti surfaces were characterized by atomic force microscopy, surface roughness measurements, contact angle against water, and X-ray photoelectron spectroscopy (XPS). The adsorption of human plasma fibronectin on the Ti or Ca-Ti sensor was monitored by the QCM technique. The decrease in the frequency was monitored until 60 min after fibronectin injection, and the amount of fibronectin adsorbed on each surface (⊿m) was calculated using the Sauerbrey's equation. By curve fitting for the ⊿F curve against the adsorption time, the apparent reaction rate, Kobs, was obtained.

    Results : There were no significant changes in the surface roughness and contact angles between Ti and Ca-Ti. Both sensors have hydrophilic surfaces. XPS measurements confirmed the presence of Ca on the Ca-Ti sensor. The Ca-Ti sensor exhibited a more rapid and significantly larger decrease in frequency than Ti did, according to the QCM analysis. The Ca-Ti sensor also exhibited a significantly greater amount of adsorbed fibronectin and larger Kobs values than those of Ti.

    Conclusion : Ca ion plays a significant role in fibronectin adsorption on Ti. The modification of Ca ion not only enhanced the adsorption of fibronectin on the Ti surface but also progressed the initial adsorption rate of fibronectin to Ti. The adsorption of fibronectin in living tissue conditions proceeds through Ca ion bridge adsorption.

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Case Reports
  • Yoshiaki ARAI, Hideyuki HOSHINA, Makiko TAKASHIMA, Atsushi KAWAMURA, Y ...
    Type: Case Reports
    2019 Volume 32 Issue 3 Pages 230-235
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    After mandibular bone segmental resection for tumor treatment, the mandible is usually reconstructed with autogenous bone, such fibula or iliac bone. However, in cases where reconstruction cannot be done with a plate alone due to defect size or diagnosis, age is a consideration. It is extremely difficult to cover the flap of such patients with a removable prosthesis. We report our experience with a case of edentulous jaw that was reconstructed with a plate alone after a mandibular unilateral resection for carcinoma with a good long-term function in an implant overlay denture.

    The patient was a 74-year-old woman who underwent primary reconstruction with a delto-pectoral (D-P) flap after hemimandibular segmental resection for the treatment of carcinoma of the lower gum. Two years later, she opted not to undergo secondary reconstruction with fibula or iliac bone because she wanted to run marathons as that was her hobby ; therefore, we used only a plate for the secondary reconstruction. She had been able to eat extremely soft food with complete dentures, but always complained of mucosal pain in the residual bone stump. Therefore, we placed one implant, an overlay denture, in the stump part of the existing alveolar ridge. After implantation of the overlay denture, her mucosal pain disappeared, and she was able to eat a wider range of foods. She maintained good masticatory function for 12 years, with no ulcer development in the flap on the reconstruction plate. Furthermore, the mucosa around the implant showed no sign of infection, and radiographs demonstrated no resorption of bone. Her oral health-related quality of life remained high.

    The implant placed in the stump part of the existing alveolar ridge was believed to help reduce the pressure of the flap on the reconstruction plate.

    Implantation of a lower jaw overlay denture that supported the flap on the reconstruction plate and alveolar ridge produced an excellent long-term outcome in this edentulous patient who underwent hemimandibular reconstruction.

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  • Kazuhiro KON, Makoto SHIOTA, Maho OZEKI, Tatsuya FUJIMORI, Shinji KURO ...
    Type: Case Reports
    2019 Volume 32 Issue 3 Pages 236-241
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    It is well known about blood spots occurring after surgical procedures. However, blood spots after implant operations were not well documented. In addition, occurrence of unexpected wide blood spots after implant operation could undermine the rapport between patient and clinician.

    In this paper, we report a case of broad blood spots after implant operation for maxillary implant over denture (IOD) treatment.

    A 73-year-old female patient visited our department because of mobility of the maxillary removable partial denture and difficulty with mastication. We planned IOD treatment by four implants with sprinted bar attachments. After implant placement surgery, we observed wide blood spots on postoperative day 7. On postoperative day 14, the blood spots were seen to be disappearing, and on postoperative day 35, almost all the blood spots had disappeared. Uneventful healing was observed before and after secondary surgery, and we delivered IOD treatment with bar attachments. Six years and nine months have passed since IOD treatment was delivered, and the patient has achieved a favorable clinical outcome.

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Survey, Statistics and Materials
  • Morio IMAI, Takashi KAMIO
    Type: Survey, Statistics and Materials
    2019 Volume 32 Issue 3 Pages 242-252
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    In recent years, as one of the measures for increasing the effectiveness of denture treatment, there has been great interest in using overdentures based on implants (implant overdentures ; IOD) for edentulous patients. There is a consensus on the recommended treatment for mandibular IOD, but there is less evidence for maxillary IOD treatment guidelines than for the mandible, especially from the viewpoint of denture treatment. In this article, we report cases of maxillary IOD using two implants with good functional recovery even 5 or more years after surgery from the viewpoint of denture treatment. Fifteen patients who underwent maxillary IOD treatment with two implants between April 2008 and April 2013 were studied. Evaluation was performed on 1) sex and age, 2) implantation site and number of implants, 3) type and size of implants, 4) type of attachment, 5) usage of old dentures for IOD, 6) shape of IOD, type of artificial teeth used and occlusal conditions, 7) denture fitness to mucosal surface and 8) patient's satisfaction. As a result, all 15 cases were done by “top-down treatment”. Old dentures were not used and complete dentures were newly made, although not all were roofless. Factors that contributed to obtaining good function while using only two implants were control of vertical movement by the implant and attachment, and good fit of the dentures, especially the dispersion of force to the palatal surface and the posterior denture sealing, thus reducing the force applied to the implant. It was suggested that in the treatment of IOD for maxillary edentulous patients, the prognosis is affected by the quality of the complete denture.

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  • Shinya HOMMA, Tomoki HIRANO, Mitsutaka YOSHIDA, Gentaro MORI, Takuya T ...
    Type: Survey, Statistics and Materials
    2019 Volume 32 Issue 3 Pages 253-259
    Published: September 30, 2019
    Released: November 20, 2019
    JOURNALS FREE ACCESS

    The students at Tokyo Dental College are required to take an oral implantology course in 4th grade before beginning their clinical training. The curriculum in the oral implantology course consists of basic training programs that are recommended by the Japanese Society of Oral Implantology and Lectures. We evaluated three reports : the “Evaluation of teaching effec tiveness”, “Investigating the issues of the education curriculum” and “Objective evaluation of comprehension level” in our oral implantology education. This survey was conducted in 2014, 2016 and 2018. The number of students surveyed was 438 (251 males and 187 females). We introduced a questionnaire to the students about the “Degree of achieving the target behavior” and the “Difficulty level and comprehension level of basic training”. Also, the surveyed students were post-tested for their knowledge of oral implantology. As a result of this survey, students' comprehension level of oral implantology improved in 2016 and 2018 by more than in 2014. The issues found in the education curriculum were “Poor comprehension of the compli cations of implant treatment” and “Need to improve computer simulation method”. Also, this survey suggested that the basic training recommended by the Japanese Society of Oral Implantology is needed to improve the comprehension level of oral implantology.

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