From the viewpoint of labor of the manual labor by the sterile supply duties of the cut device for the dental treatment and infection accident prevention by the puncture, assort a device automatically, and read a shape and a mark, and distinguish it; high-precision, developed application with operability, the durability. As a result, algorithm of the image processing with the minute image of the optical camera was applicable. And a robot arm and the actuator control that retension extracts the device which we recognized from a new shape and distinction, the image data of the color change when we evaluate the wear degree of the device, furthermore, the construction of the moving automatic assortment system to carry was enabled to a cart for the assortment sectioned for each type of the device.

The cause of dentin hypersensitivity and its regression have not been elucidated yet. We established a quantitative measurement system of dentin permeability to analyze the time-based effect for hypersensitivity.In this study, we improved the dentin permeability measurement system and analyzed the process in which the inhibitory effect changes with time after performing the surface analysis and micromorphological analysis.As a result, new devices made it possible to measure the hydraulic conductance accurately, and was clarified the mechanism of the suppressing effect of the permeability by calcium phosphate-based material and the effect of the ingredient addition from the outside.The particle size distribution, the significance of crystal formation, the amount of internal crystals and the changes of structure were also clarified. These findings were expected to become base evidence for developing a safe and highly effective dentin hypersensitivity inhibitor.

Pure titanium has excellent biocompatibility and shows reduced possibility of metal allergy. Pure titanium is very excellent as a metallic material for dental prosthesis. However, the machining of pure titanium is very difficult due to its low conductivity and high chemical reactivity. The purpose of this research is to develop a polishing fluid-impregnated mounted wheel enables dry polishing of dental pure titanium. Dry polishing of pure titanium has been considered to be very difficult so far. Therefore, polyethylene glycol (PEG) was impregnated into the vitrified bond. A vitrified-bonded polishing fluid-impregnated mounted wheel having a lubricating action and a cooling action was developed and subjected to dry polishing. As a result, the surface roughness reached the target value (Arithmetic mean surface roughness Ra=0.2μm) under some experimental conditions. Therefore, it was possible to clarify the effectiveness of PEG impregnation on vitrified-bonded mounted wheel.

In this study, we focus on the finding that cells grow on new inspired titanium membranes developed for tissue regeneration. A new cell culture method different from the conventional passage method that the cells are migrated and attached on the other media. We established a technology of cell culture amplification method in which cells could move between membranes. A osteoblast-like cell of MC3T3 was cultured on a porous titanium membrane having 20 μm pore size and through-hole structure with proximate span of 50 μm formed on a thin pure titanium sheet of 20 μm. Observation using GFP and analysis using immunostaining revealed the engraftment and proliferation of cells comparable to collagen - coated culture dishes even on pure titanium film. We will use this material to regenerate alveolar bone tissue.

The dental peri-implantitis is caused by adhesion of dental biofilm to the open surface of pure titanium. The purpose of this study is to establish a highly durable DLC film on the surface of the implant on the surface around the gingival margin, and innovative dental implant that is compatible with alveolar bone attachment and deterrence of biofilm adhesion such as dual-phase surface conditions of the biocompatible and anti-biofilm. As a result of depositing GCIB-DLC on the surface of pure titanium sample, it was confirmed that an adhesion strength of the DLC to the pure titanium surface is significantly high in comparison with a standard DLC coat. It could be applied to biofilm adhesion preventing type implants. In addition, GCIB-DLC showed an inhibitory effect on biofilm adhesion. We are going to examine biocompatibility and the safety by the animal test.

The cause of regression of hypersensitivity has not been elucidated yet. We established a quantitative measurement system of dentin permeability to analyze the time-based effect for hypersensitivity.The process was analyzed through the morphological analysis and the measurement of dentin permeability after the improvement of equipment. As a result, new device made it possible to measure the hydraulic conductance and was clarified the differences in the permeability suppression mechanism of different materials. The particle size distribution, the significance of crystal formation, the amount of internal crystals and the changes of structure were also clarified. These findings were expected to become base evidence for developing safe and effective therapeutic agents of dentinal hyperesthesia.

In this study, we have represented a novel design to achieve a CGM (continuous glucose monitoring) system incorporated for the bone regenerative therapy what the electronic device of blood sugar sensor can be assembled to the thin titanium mesh for bone augmentation surgery. This method has a feasibility of the implantable CGM that the ready-made CGM telemetry device can be placed in gingival tissue and operated to measure the blood sugar rate for a long period under the gums. A flexible electronic substrate with exclusive durability and biocompatibility has become to achieve this technology. We have completed producing a precision micro-porous plate (titanium membrane) with pure titanium. This is not only provided as a barrier membrane for GBR and GTR surgery but used for the substrate for CGM telemetry device. The titanium membrane has also blood flow permeability to prevent inhibiting the blood circulation in the living tissue to stably indwelling embedded electronic circuitry.

It is one of the big aims of dentistry to regenerate a tooth substance (dentin), which is lost by dental caries. We demonstrated that LIPUS exposure to dental pulp cells induces the expression of BMP-2, which is known to be a powerful osteogenic growth factor. Moreover, the expression of osteopontin, an osteogenic differentiation marker, was enhanced by LIPUS, where extracellular ATP released from cell acts on purinergic receptors on dental pulp cells. These findings suggest that LIPUS exposure can be an effective and non-invasive endodontic therapy for dentin regeneration.

This research project was aimed to develop the new strategy of alveolar bone regeneration by a combination of dental stem cells and guided bone regeneration technique using a newly developed titanium (Ti) mesh membrane. Our in vitro studies revealed the molecular mechanisms of proliferation and differentiation of dental stem cells regulated by Wnt signaling. Dental folllicule cells (DFC) are able to differentiate into cement blast and alveolar bone cells. Canonical and non-canonical Wnt signaling performed the complementary role on DFC, that canonical Wnt3a signaling induced the osteoblastogenesis of DFC and non-canonical Wnt5a signaling negative developed these processes. Our newly developed Ti-mesh exhibited the proliferative effects on DFCs by a topographical effect. Furthermore, our animal studies indicated that a combination of graft and Ti-mesh induced the superior bone regeneration on standardized bone defect model made in beagle dogs.

This research project was aimed to develop the new strategy for periodontal regeneration by combining both technologies of honeycomb microfilm (HF) and conditioning of the extracellular microenvironment for periodontal stem cells. As the result of studies, we indicated that: 1) a biodegradable polymer HF is suitable for the carrier of periodontal ligament cell sheet, 2) autocrine secretion of prostaglandin E2 is essential for the differentiation of periodontal cells stimulated with Ca2+ ion and mechanical stress, and 3) nano-hydroxyapatite could upregulated BMP-2 expression independent of ion release. Furthermore, OCP/ gelatin composite inlay increased angiogenesis as well as bone regeneration in the rat calvaria defect model. Our research results well established the foundations of new concept scaffold technology that can stimulate both cell proliferation and differentiation.

The cause for regression of hypersensitivity has not yet been fully elucidated. We have established a method to measure quantitatively dentin permeability, and to analyze the time-based effect of hypersensitivity. The gradual relief of hypersensitivity with time was analyzed by morphological analysis of the dentin slices and measurement of their permeability. Crystal deposition in orifices of dentinal tubules was evident. Even small particle size crystallites not completely obturating dentinal tubules, have a major effect on reduction of permeability. The concentration of hydroxyethyl methacrylate affects the permeability of resin-based material for hypersensitivity. The structure and volume of the internal crystal varies depending on the stock solution in calcium phosphate-based material.

This study was aimed to develop the new fabrication method that can fabricate an ideal surface structure on implant fixture to control the microscopic surface topography suitable for osseointegration and bone regeneration. For this purpose, we used “micro-dimple imprint method" by applying honeycomb films. We fabricated the regularly arrayed micro-dimple structure on the mirror-like finished surface of Type 1 Ti plate masked with honeycomb film by wet-etching. After the etching, we obtained the regularly arrayed dimples on Ti surface with identical diameter and pitch as a honeycomb mesh structure of the mask. Human periodontal ligament (hPDL) or STRO-1^+dental follicle (STRO-1^+DF) cells were seeded and culture on the honeycomb-fabricated and control Ti. hPDL/ STRO-1^+DF cells showed stimulated proliferation and a unique forms on the fabricated Ti, that is completely different from the uniformed pattern of cell behavior on control Ti surface, suggesting that our newly developed micro-dimple imprint method is useful for the processing of implant fixture surface and fabrication the surface topography at a μm order.

In order to improve the physical property of the current model of the barrier membrane, the new style of the barrier membrane has implemented by using microfabrication technology to create high-density form of 20 μm pored pure titanium membrane. It has a significant advantage on the toughness and durability to stabilized a tissue regeneration space to contribute establish to reproduce the target tissue, and also on the prevention of a contamination by oral microorganisms. The new titanium membrane is relatively saved a thickness that eliminated a tissue regeneration volume to be compromised the space in comparison with the one of the current models of barrier membrane. membrane. On the culture test by using human periodontal ligament-derived cells, the new titanium membrane showed excellent properties supporting cell attachment, migration and proliferation to be promising the periodontal tissue regeneration successfully. Its usefulness has been confirmed in the animal test using beagle dogs.

Abstract. A radio frequency identification (RFID)transponder covering the 13. 56 MHz band was adapted to be resized and sealed with biocompatible materials so that it could be placed in the periodontal tissue on the periodontal tissue regeneration therapy. We have found an arrayed pierce processing to thin titanium sheet with a micron order (Micro-pierce)as an appropriate barrier membrane and scaffold for the periodontal tissue regeneration. The biocompatible effect of the titanium mesh sheet was exclusive predominated. The new product of the micro-pierce titanium sheet is applicable to implanted electric devices to measure biological markers on using the periodontal tissue regeneration therapy.

本研究では歯周病により失われた歯周組織の再生のため、細胞オーダーの高精細微小ハニカム構造を有するハニカムフィルムによる培養細胞グラフトを構築する.今年度はその実用性を高め臨床応用へ近づくために、ハニカムフィルムの特性である均一なマイクロサイズの小孔のサイズおよびその材質の違いによる、歯根膜由来細胞培養の様相の変化を観察、歯周組織再生にふさわしい培養細胞グラフト形成の条件を検討した。まずハニカム孔径について検討したところ、孔径5μmでは細胞はフィルムの立体構造内に進入することなく、専らフィルム上にて進展し、若干の重層化を伴い所々で小細胞塊(スフェロイド)が認められた。一方、孔径10および15μmでは細胞群がフィルムの内外に進展して増殖、重層化するとともに、ネスト状に組織化した。次にハニカムフィルム素材の違いについて検討したところ、まず生分解性ポリマーであるポリカプロラクトンでは、細胞増殖の初期においてハニカムフィルムのピラー構造に偽足を伸ばし進展したのに対し、非吸収性のポリスチレンを素材では細胞体は著しい樹状形態を伴いながら細胞体を線維状に進展させその長さは時には100μmに達していた。また双方の素材上にて細胞は旺盛に増殖した後、2週間後においてポリスチレン製ハニカムフィルム上では硬組織代謝マーカーであるOsteopontinおよびOsteocalcinの発現が明らかに更新した。これらの素材の違いはポリマー材の微小堅さと化学的安定性に有ると見られるが、特に素材表面の化学的安定性が歯根膜由来細胞の増殖および分化に優位に作用したものと見られ、ハニカムフィルムの持つ特有のトポグラフィーとそのポアサイズおよび素材の物理的、化学的物性が培養細胞のprolifelationとdifferentiationに対して明らかな影響を与える事が示唆された。

被曝を伴うエックス線透視診査は幼児や妊婦への適用が困難でその際は充分な診査を施せない. 被爆の無い超音波断層画像診査は口腔内にプローブを適用できず利用は困難である. 一方, 歯槽骨を被覆する歯肉や歯槽粘膜は, その部位や外形に応じて健常時の組織厚さが概ね規則的であり, これを大きく逸脱する厚さは炎症性病変などの存在を示唆する. そこで単素子による小型超音波探触子を口腔内に導入し, Aモード信号(エコー)から組織厚さを算出, 歯周組織内の炎症性病変を検知する方法, およびエコーをリアルタイムに可聴域音声に変換, 術者が超音波信号を音声で体感するシステムを開発した. そのため本研究の趣旨を説明し協力を得た慢性辺縁性歯周炎患者10名を対象とした. 感染対策を施した高周波探触子(20MHz : V208RM)をパルサーレシーバー(Model 5077PR)にて駆動し, これを歯肉に接触した際に得られた音響波形信号をオシロスコープ(DS4372)にて表示した. 信号はIEEE488(GPIB)インターフェースを経由してパーソナルコンピュータに伝送した. 音響波形のデータ処理を行う解析プログラムをLabVIEW7 Expressにて作製した. エコー波形の潜時を300〜5000Hzの音声周波数, 波形の強度を音量として変換し, オーディオ出力とした. 本研究の結果、健常な歯肉より得られたシグナルは, 直下にある歯槽骨面に由来する明瞭なエコーが検知された. 一方, 辺縁歯槽骨の吸収が認められた部位では明瞭なエコーは検知されなかった. 以上の検知信号の変動は音響変化として聴覚でとらえることが可能であった. 以上の結果から、浅い深度範囲を高解像に検知する高周波超音波を用いることで, 歯周疾患に由来する組織変化の検知が可能となった. 超音波計測でエコーを直接観察する手法は, 断層画像が得られない口腔内での苦肉の策ではあるが, 一方でエコーを音声に変換して捉える"聴診器"のようなシステムは, 高価なアレイ型探触子を使用しないため, むしろ安価で安全な生体検索法としての利用価値があると思われる.

INTRODUCTION: In recent years, automatic identification procedure (Auto-ID) has become very popular in many service industry, merchandise and distribution logistic, finance, transport and medical system. Auto-ID exists to provide information about people, animal, goods and procedure in transit. One of the technically optimal solutions of Auto-ID, using a silicon chip, has been provided as a technology of radio frequency identification (RFID). The most common form of electronic data-carrying-device in everyday life is a smart card based upon a contact field (phone card, bank card) on the data communication between host system and chip in housing of the card. Now an integrated design of contactless data transfer between the device and its reader is more flexible. In the ideal case, the power required to operate the electronic microchip in the card would also be transferred from the reader using contactless technology. This contactless system used for the transfer of power and data is called RFID. METHODS: Ten extracted human third molar teeth free from dental caries were used to encapsulate RFID transponders. Fifteen cylindrical transponders (o. d. 3 mm, length 13 mm) using a medium wave frequency (125 kHz Emfreccia ONMETALTM, Mitsubishi Materials, JAPAN) were tested. The endodontic cavity, including the coronal chamber and root canal of each tooth, was prepared to fit the cylindrical core of the RFID from the coronal side of the tooth. Volume expansion of cavity in the tooth and decrease of the dentin thickness might result in significant reduction of facility as a radio frequency shield. Dentin thickness of 3mm was preserved to allow functioning as a barrier for radio frequency between the transponder and the reader. Three acrylic cylinders (ψ10×22 mm) were used as controls in which co-axial holes (diameter: 3mm, depth: 13mm) were drilled to fit for the transponders. A reader (EmfrecciaTM, Mitsubishi Materials) that communicated with the transponder enclosed in dentin was located on the extension line of the tooth axis, because these tags had sharp directionality for communication with the reader along the cylindrical shaft direction. The tooth was held with a plastic clamp attached to a carriage in longitudinal axis direction. The maximum communication range was measured with establishment of the data transfer by a utility program for IBM-PC compatible via RS-232-C serial interface. RESULTS: The mean communication distance of unencapsulated RFID transponders was 18.6±1.7mm (n=15), while the mean ranges in RFID transponders encapsulated with acrylic materials (control) or teeth were 18.1±1.6 mm (n=45) and 17.8±1.7mm (n=150), respectively. The percentages of the range compared with the unencapsulated were 97.3±1.6% and 94.6±1.9%, respectively. No statistical significant difference under these conditions could be observed. The actual decrease of communication distance under dentin encapsulated conditions was very small (5.4%). DISCUSION: The RFID tag, holding ID information attached to the wristband, has already been carried out for a swift identification of inpatients. But continuous wearing of a wristband may induce physical and mental stress in some patients. The method embedding the RFID in the tooth might disengage the patients from the stress by the wristband. However, the contrivance to exclude psychological pressure on recipient in using the embedded RFID, such as placing the detector close to the embedded position in the human body, should be elaborated. Embedded ID into oral cavity could be apply to a mobile phone in combination with a RFID reader. This engineering system is called 'stealth identification' that utilizes communication equipment such as a mobile phone. In most of the voice communications, the distance between the face and the handset is relatively small. When the handset equips RFID reader, the identification can be established by detecting the RFID during the phone usage. It would be difficult to detect existence of the RFID transponder in the oral cavity. Furthermore, it seems almost impossible to distinguish voice communication from the identification process using the RFID in a tooth by the third party. The invisible method is relatively safe to hide the existence of imbedded RFID from malicious purpose. This contributes to the protection of individual privacy. The patient has little physical and mental restrain. CONCLUTION: The insulation effect of the tooth had small enough to allow for the penetration of the signal of the medium frequency band.

People haven't liked the dental treatment and tried to avoid going to a dental clinic. The main reason of this avoidance was the peripheral nervous pain during dental treatment. Then the dental treatment machine, for example air-turbine and electric handpiece, caused the cutting noise and vibration which were conducted to brain tissue through the cranium. We thought these stimulation caused depression and mental pain of the patients. To clear of the mental change, we observed the brain waves of mind operation. On the otherhand, we have many old patients who had heart disease and lung disease. So in this study, we measured the heart beats by SpO2 and air-pad sensor, respiratory rate by air-pad sensor and blood pressure by fina-press. And to observe the change of stress and pain, we measured the change of respiration by GSR. To analyze the recorded data, we used LabVIEW. Under the Helsinki declaration, we had twelve volunteers who understood the object of this study. As the experimental stimulator, we used an ultrasonic scaler (full, 70% and 50% power). To certificate of the change of patient, we recorded the video picture by USB camera. The results of this study, 1,The pain and stress caused by the scaling lead the change of peak interval length, like R-R length. 2,Air-pad sensor was able to record the body conditions as like as the previous established recorders. These results supported the possibility which the air-pad sensor could find the change of patient's mind operation and body condition. So we thought this air-pad sensor could detect the sign of body condition and protect the aggravation during the dental treatment.

本研究の目的は齲蝕等の病変および補綴学的要求により、歯科学的術式によって歯の歯髄が除去された状態、すなわち失活歯の内部に生ずる歯髄腔内に、微小な無線通信媒体を設置し、これに内蔵したセンサーによって生体内情報を計測する基本的手法を確立することである。今年度は動物(犬)を用い、実際に歯内に無線通信媒体(RFID)を埋設し、埋設した装置と実際の通信が可能であるかどうかを検証した上、その耐久性と生体に対する安全性を評価し、さらにこれらの手法を実際の生体計測に利用するための具体例を提示した。まず、生体内に設置した無線ICタグ通信媒体との通信を想定し、制御を実施するために用いる電波として、硬組織および軟組織を同時に透過しうる短波領域を用いた。この帯域をカバーするRFIDチップ(ISO/IEC15693 chip 13.56MHz : SRF55V10S, Infineon Technologies)をもとに無線ICタグを顕微鏡下にて製作した。ビーグル犬の右側犬歯を抜髄、根管充填を実施したのち、試作ICタグを根管内に埋設した。リーダー(FPRH100, 500mW, Feig, Weilburg, Germany)と試作ICタグとの通信距離は口腔内への設置前で30mm、設置後はおよそ25mmであり、短波領域では、軟組織、硬組織を通じて生体が著明なバリアーとはならなかったことが示された。一方で、埋設された通信媒体は一両日後には機能を停止した。口腔内にRFID等の無線通信媒体を設置する手法は確立したと思われるが、これを長期にわたって運用するには埋設する無線通信媒体に高度の耐久性を備える必要があると思われる。 口腔内に設置した無線通信媒体を用いた生体計測として、温度、pH、圧力等を利用することが挙げられる。本研究では、歯周外科治療の歯周組織の治癒および組織再生を促すための術後におけるリハビリテーションを効果的に行うために、これら無線ICタグを生体内に設置する方法が有意義であると考え、実際に生体にレーザー照射による物理的刺激を加えた際の生体反応をシミュレーションし、生体内に設置した計測システムの利用法を模索した。その結果、生体に可視短波長領域(緑色)レーザー照射実施すると、抗アポトーシス効果が生ずることが明らかとなった。すなわち、歯周治療における組織の細胞死を抑止する手法としてのレーザー照射が有用であり、その際、歯周組織生体に対するレーザー光の照射量を正確に計測する方法およびその後の組織反応を経時的に把握するため、無線通信媒体を歯周組織内に設置する手法が有用であると思われた。

Acoustic sensing methods using ultrasound devices for the functional monitoring and morphological inspection of biological tissues are recently receiving widespread through medical field. Ultrasound being non-ionizing nature, are relatively safe have capabilities for the non-invasive and non-destructive monitoring of the structural and functional states of patients. In the biological tissues in which the acoustic wave sent from ultrasonic probe is propagated, the echo is generated in the boundary in the organization in which the sound velocity differs. The ultrasonic tomography detects the echo got from the layer which differs as acoustic medium in the tissues. In this study, we designed the detection system to obtain acoustic properties from human periodontal tissues for inspecting functional and structural conditions. The acoustic investigation by the ultrasonic wave for oral tissue was carried out for the volunteer. High frequency, ultrasound source (20MHz) was applied to the mandible frontal skin over the alveolar portion, or to the surface of gingival using the acoustic probe via delay line. The delay line of the probe with the connection to the target tissue transmitted the echo which was obtained from the live tissue to the receiver, while the sound was transmitted to the tissue. The diameter of the attached portion to the skin on the acoustic probe was 2mm. The transmitted sound beam to the periodontal tissue generated the echoes on the boundary between the layers of different tissues. The echo waveforms from the periodontal tissues were measured on the oscilloscope and was added 50 times repeatedly, then averaged. An intensive sharp spike which was generated at the surface of alveolar bone obtained on the frontal labial mucosa, and on the gingival surface having healthy periodontal tissue. On the other hand, no intensive spike was not obtained from the inflamed periodontal gingival. A group of the small spike wave were obtained simultaneously on the gingival tissues which had lose the processes of alveolar bone then have been cured and recovered from periodontitis. These spikes were seemed to indicate the boundary points between the layers in the healthy soft tissue free from periodontal desease. We could detected the distinguished signal signed the healthy periodontal tissue from the echo waveforms from epidermis of periodontal tissues without a two-dimensional inspection system which was required very expensive ultrasound equipments.

Optical and acoustic sensing methods for the functional monitoring and morphological inspection of biological tissues are recently receiving widespread attention. Light and sound being non-ionizing nature, are relatively safe have capabilities for the non-invasive and non-destructive monitoring of the structural and functional states of patients. The CDI method possesses high sensitivity and directional selectivity in detecting the coherence retaining and the least scattering photons from tissues. In the biological tissues in which the acoustic wave sent from ultrasonic probe is propagated, the echo is generated in the boundary in the organization in which the sound velocity differs. The ultrasonic tomography detects the echo got from the layer which differs as acoustic medium in the tissues. In this study, we designed the measurement system to obtain optical and acoustic tomographic images for human teeth and periodontal tissues with submillimeter resolution. Ten human extracted teeth were used for the optical detection. Continuous wave, single frequency, semiconductor laser(532nm) were used as the light source. The diameter of the incident beam was 200 μ m. The transmitted beam from opposite side of the tooth was superposed on the reference beam and impinged on a photodiode generating an intermediate frequency at 20MHz. The tooth was mounted on a translational-rotational stepper and the scanning was performed in the T-R mode similar to that of the conventional computed tomography. The image reconstruction was done using the filtered back projection. Laser CT images of teeth were compared to the microscopic cross sections and assessed. The internal structure of teeth, pulp cavities and canals were reflected in the horizontal images, and also the site of the transparent dentine could be located. The acoustic investigation by the ultrasonic wave for oral tissue was carried out for the volunteer. High frequency, ultrasound source (20 MHz) was applied to the mandible frontal skin over the alveolar portion using the acoustic probe via delay line. The delay line with the connection to the irradiation mouth of the probe transmitted the echo which was obtained from the live tissue to the receiver, while the sound was transmitted to the tissue. The diameter of the attached portion to the skin on the acoustic probe was 2mm. The transmitted sound beam to the periodontal tissue generated the echoes on the boundary between different tissues. The probe was mounted on a translational-rotational(T-R) arms which was controlled automatically by programmatic sequencer. The rotational stepper gradually moved and located the probe to scan horizontally on facial skin. The pneumatic translational cylinder made the probe move toward the skin, and it was made to contact the tip of prove to the akin in the constant force. The echo waveforms were measured on the oscilloscope. An intensive sharp spike which was generated on the labial surface of the alveolar bone which was located in the place which was more deep than the epidermis and gingival tissue was observed, while the comparative small spikes which was produced on the soft tissue and mucosa which were near for the epidermis were observed in great numbers. Acoustic data with a Two-dimensional resolution in the range from epidermis to alveolar bone could be constructed from such echo waveforms which were horizontally arranged in the order on the computer display.

本研究では口腔内気相の調査について検知される一酸化炭素濃度が歯周疾患の病態と相関を得られるか否かを検討するため大規模なスクリーニング調査を実施した。スクリーニングは2002年4月、宮城県仙台市の中高一貫教育の女子校における中学1年から高校3年までの6学年にわたる女子生徒1206人を対象として実施した。口腔内気相の調査にあたっては可能な限り口腔内の雰囲気のみを抽出できるようCO濃度計測装置に加え、ストローにより口腔内の雰囲気を選択的に採取する独自の吸引装置を製作した。歯周組織診査はCPIにて6歯を診査、これらの合計をCPI合計値とした。CPI合計値1〜6を示した比較的軽度の歯肉炎を示した被験者(1070)の口腔内気相におけるCO濃度は平均0.256ppmであり、一方CPI合計値7〜15を示した中度ないし高度の歯肉炎を示した被験者(136)ではこれが平均0.276ppmであったけれども、統計的な有意差は認められなかった。すなわち歯肉炎の進行により口腔内気相におけるCO濃度が上昇する可能性は示唆されるものの、これを確定するには至らなかった。これは装置がスクリーニング用途の比較的簡易に計測するシステムであり、1ppm以下の極めて微量のCO濃度を計測することが困難であったためと思われる。また、大気および空気汚染に由来する歯周疾患以外の外来要因から曝露するCO濃度影響を考慮するため、被験者全員にアンケート調査を実施した結果、タバコと煙を避ける習慣をもつ被験者(843)では、CO濃度が平均0.24ppmであったのに対し、普段の生活でタバコの煙にさらされる機会が比較的生じやすいと思われる被験者(349)では0.29ppmと、間接喫煙の影響を受けている可能性が示され、このシステムの環境評価における有用性は示されたと思われる。

従来から低出力レーザー照射により骨芽細胞あるいは歯根膜細胞の増殖や石灰化が促進することが知られている。本研究はこのような低出力レーザーのヒト細胞への作用効率を最大限に高めて歯髄細胞や歯周組織構成細胞を賦活化して、保存あるいは再生療法に応用しようというものである。まず出力3mWの赤外光(830nm)ならびに可視光(670nm)レーザーをヒト口腔上皮由来KB細胞に照射し炎症性サイトカイン産生に及ぼす影響を検討した。その結果、いずれの波長のレーザーも1.8Jの照射でKB細胞からのspontaneousなIL-8産生を有意に抑制することが明らかとなった。これは低出力レーザー照射が歯肉上皮細胞からのケモカイン産生の抑制を介して抗炎症的に働くことを示唆するものと考えられた。しかし、3mWの出力では旋光抽出条件や照射時間を変えても、歯肉線維芽細胞(HFG)や歯根膜細胞(PDL)機能に影響を与えることはできなかった。そこで我々の予備研究から、可視〜赤色光領域に比べて生体組織による吸収・散乱が大きい短波長領域のレーザーを用いることとした。すなわち、波長532nm、出力150mWのレーザーを用いて、12.6Jの照射をHGFに行ったところ、陽性対照としたIL-1刺激の場合に比べて5分の照射時間で有意に高いGM-CSF産生を生じることが明らかとなった。さらに、この照射条件では未照射群に比べて細胞のviabilityに低下は認められなかった。今回の結果より、歯肉上皮細胞に対しては低出力レーザーがケモカインの産生抑制を介して抗炎症的に働くこと、HGFなどの深部歯周組織を構成する細胞については、従来の報告よりも低出力の短波長域レーザーの照射により効率的に細胞機能を制御できることが明らかとなった。

Dentine perception is evoked by the transfer of internal fluid in the dentine microtubule according to the hydrodynamics theory, therefore, the technique which measures the deterrence of the transfer of dentinal tubule internal fluid seems to be useful in order to objectively evaluate the hypersensitive dentine control material. Ten extracted human third molar teeth were used in this study. The dentine slices at the crown part of 1 and 1.5mm thickness were prepared in tooth axis vertical surface. These slices were fixed in the 10% neutral formalin solution. The dentine microtubule were opened to wash in the experiment by 3O% hydrogen peroxide water. From both slice sides where the dentine microtubule in the tooth crown and tooth pulp side opened, these dentine slices were held with the O-ring by the transparent acrylic tube. 1% sodium hydroxide solution in the acrylic tube in the tooth pulp side with the 0.02% luminol was filled. 1% potassium ferricyanide solution including the 0.3% hydrogen peroxide water which similarly removed the fine particle in the acrylic tube in the tooth crown side by the Millipore Corp. filter of ostia size of 0.2 μm was satisfied. The photodiode (s6204 : Hamamatsu Photonics Co.)which contained preamplifier and thermoelectric cooling device by having approximately 30mm distances in the neighborhood of the sample was installed. The equipment with sample was installed in the black box which almost perfectly cuts off the outside light. The light emission of luminol chemiluminescence evoked by the active oxygen of hydrogen peroxide water is generated by the mixture of the reagents filled in the acrylic tube of both sides through dentine microtubules. The luminous phenomenon was detected in the photodiode. The optical output from the photodiode was recorded through the AD converter in personal computer after observing by the oscilloscope. In the condition that the reagent just contacted both dentine slice sides, there was a slight light emission of the transience. The light emission was observed time-dependent, when 10〜500mmHg air pressure was applied for the acrylic tube that the potassium ferricyanide and hydrogen peroxide solution was filled. These light emission quantity had the correlation which was positive with the pressure in the same sample, though there is the fluctuation in proportion to individual sample, and the light emission quantity changed. At the light emission quantity in using slice samples of the 1.0mm thickness which was excellent in the permeability in the dentine, the light emission quantity tended to generally increase in comparison with 1.5mm samples. In the condition without opening of dentine microtubule by 30% hydrogen peroxide water, the dentine sample could not demonstrate the light emission even in any loading of reagent. It is a system that dentine hypersentive simulator using the chemiluminescence visualizes the transfer of the internal fluid in dentine microtubule and that it can be supersensitized, and that it can be observed. It is possible to show the degree of the opening of the dentine microtubule in fluctuation situation of the light emission quantity. This system seems to be very much the usefulness as the tool which can straightforwardly evaluate the effect of the control material for dentine hypersensitive disease.

The purpose of this study was to rapidly degrade and remove organisms in a gas atmosphere in a high frequency plasma state. 1) Photoresist was applied to wafers, and plasma treatment was performed with oxygen gas. The film thickness of the resist was measured using a film thickness scale. The film thickness more markedly decreased for wafers vertically placed in the quartz rack than for those horizontally placed, at a higher output, and using opposed electrodes than coaxial electrodes as a discharge method. 2 ) Specimens to which bacterial spores were applied were plasma-treated by the opposed electrode method and cultured in Triptocase medium. The sporicidal effects were more marked using a longer treatment time, higher output , and a higher heater temperature. All 10 plasma-treated specimens for ten min (heater temperature, 60ーC) to which 10^4 B. Stearothemophilus was applied were negative for culture. All non-plasma-treated specimens (heater temperature, 60℃, 100℃, and 140℃) were positive for culture. 3 ) The mechanism of hydrogen peroxide/low temperature plasma sterilization system (ST system : STERRAD*100R, Johnson ＆ Johnson) was evaluated. A biological indicator (BI, Johnson ＆ Johnson) and a power source were placed in the chamber. The power supply was deliberately terminated 25 minutes before the treatment completion time indicated by the display panel to skip the plasma treatment process. All 10 cultured BI specimens were negative. These results suggest that sterilization has been already completed before the plasma treatment process , and sterilization primarily depends not on plasma but on the pharmaceutical effects of hydrogen peroxide in the ST system. Our apparatus allows sterilization only with plasma without the pharmaceutical effects of hydrogen peroxide.

Optical sensing methods for the functional monitoring of biological tissues are recently receiving widespread attention. One of the emerging application of optical methods is its potential use in imaging. Light being non-ionizing nature, is relatively safe has capabilities for the non-invasive and non-destructive monitoring of the structural and functional states of patients. One of the proposed technique for spectroscopic optical imaging of biological tissues is referred to as the coherent detection imaging (CDI) method that is based on optical heterodyne detection [1,2]. The CDI method possesses high sensitivity and directional selectivity in detecting the coherence retaining and the least scattering photons from tissues. In this study, we used this measurement system to obtain optical tomographic images of extracted human teeth with submillimeter resolution. Ten human extracted teeth were used in this study. Continuous wave, single frequency, semiconductor laser (532nm) were used as the light sources. The output of the laser was split into signal and reference beams. They were frequency shifted by a pair of acousto-optic modulators to 80 MHz and 100 MHz, respectively. The diameter of the incident beam was 200μm. The transmitted beam from opposite side of the tooth was superposed on the reference beam and impinged on a photodiode generating an intermediate frequency at 20MHz. The measurement system has a dynamic range of 〜90dB. The tooth was mounted on a translational-rotational (T-R) stepper and the scanning was performed in the T-R mode similar to that of the conventional computed tomography. Approximately 20 min was required for each image acquisition. The image reconstruction was done using the filtered back projection (FBP). After the optical measurement, thin sections (500μm thickness, approx.) of the root, at the measurement plane were made. Laser CT images of teeth were compared to the microscopic cross sections and assessed. The internal structure of teeth, pulp cavities and canals were reflected in the horizontal images, and also the site of the transparent dentine could be located. Dentine is a highly scattering tissue, and the incident light is heavily dispersed and attenuated. It seems to be difficult that such as X-ray imaging. We had earlier demonstrated that the CDI has the capability to selectively detect the least forward scattered light transmitted from dentine slabs (J Dent Res 74 : IADR abstract 423, 1995). This component of the emergent light was used to reconstruct the tomographic images in the present study. Our results indicate that the CT images obtained by CDI is reliable to detect the internal structure of the tooth. Relative low light attenuation is observed in the pulp cavity, canals and transparent dentine. The light sources with other shorter wavelengths could provide more information on the monitoring of teeth functions such as the circulation in the pulp. The CDI method has an advantage as a remote detection method. There is a possibility to arrange detectors outside of the oral cavity. The CDI method is reliable to visualize the internal structure of the tooth. This method may also be applicable to the detection of the circulation in the pulp.

レーザーを用いた光CT画像計測は、これまでのエックス線による透視法に比べ生体に対し極めて安全でしかも生体の色を反映する透視像が得られることから、より生命の本質に近い代謝活動をリアルタイムで検知できる手法として期待されている。歯は、その独特の分光特性によって入射光により様々な色彩や紋様を示す組織として歯学のみならず光学的にも興味深い対象である。けれども歯は生体組織の中で光の透過性に比較的秀でた組織であるとはいえ強い光散乱作用を有する。本課題担当者らの過去の知見により、歯に対する入射光に対し見かけ上の透過光はそのほとんどが散乱成分であり、その直進透過成分は極めて限られていることが知られている。光ヘテロダイン検出法が備える優れた空間指向性および高感度光検知能力は、これら見かけ上の透過光に含まれる直進透過光成分のみを選択的に検出することにより、高い空間分解能を有するコヒーレント検出画像計測(CDI)法による光断層像の生成を実現する。今回、光断層撮影法の臨床応用を目指し、単一周波数発振のHe-Neレーザー(632.8nm)およびNd-YAG レーザー(第二高調波、532nm)光源とするCDI法により、根管形成を施した歯の内部構造を検索し、実際の根管形状との比較を行った。単根歯7本について、根尖より5mmにおける歯軸に対する垂直面をスキャンした。試料はT-Rステージに固定され、並進および回転操作の制御を受けながら、測定点にレーザー光(約1mW)が照射された。並進ステップ間隔250μm、回転は6度刻みで繰り返し、60の投影データを採得したのち、これらをfiltered back projection法により解析し、断層画像として再構成した。根管形成前および#40、80、120各ステップにて断層画像を取得した後、試料を計測面において薄切して標本とし、得られた断層画像との比較を行った。得られた断層像は内部の空洞が光の減衰値の小さい部分として表示され、それらは各ステップにおける形成サイズと有意に相同した(r=0.57、p<0.01)。以上の知見によりCDI法は歯について0.5mm角pixel以下の解像度を有する光断層像を生成し得ることが示された。

The purpose of this study was to design a device which determines the root canal contamination by analyzing the color of the reflected light from the canal wall. 1.The spectrum analysis was made with the reflected light from the enlarged canal wall and the dirty one. The spectrum pattern with the enlarged canal wall was similar to that obtained with the light source, while that with the dirty one showed a tendency of the increased light intensity at wavelengths longer than 600nm. 2.The reflected light intensities at 560nm and 650nm were measured on the enlarged canal wall and the dirty one. There was a difference of the ratio of the light intensities at these wavelengths between the enlarged and the dirty. 3.A trial device for determining the root canal contamination was made, and its clinical applicability was examined. The light source was a white light, and an optical probe which illuminated and collected the reflected light laterally to its long axis was used. The device simultaneously measured the light intensities at 560nm and 650nm using 2 photo-diodes and compared them at the same time, and expressed the color of the reflected light from the sample by the polarity and amplitude of the output signal. The polarity of the output was the same between those obtained with a blue color board, a white color board, and a clean tooth surface. While, a red color board and a dirty tooth surface produced the opposite polarity to that obtained with the clean tooth surface. A large output signal amplitude was obtained when the tooth surface was dyed red. The results obtained in this study indicated that the trial device could develop as a root canal contamination detector. The detection system could improve with the modification of the system such as the selection of wavelengths of the light, use of a laser light, the alteration of the signal processing, and dying the tooth.

Air of the dental operating room is contaminated with airborne particles, produced during the dental operation, such as dentine tip, saliva, blood, bacteria and virus. Suction and removal of these particles through the extra-oral or intra-oral aspirator is a crusial procedure to prepare sound and comfortable environment of patients and dental staffs. Various kinds of dental aspirators have appeared on our market, but little is known about the characteristics of the aspirators. At the moment each producer introduced its own standard. The results were as follows. 1. Electrical and mechanical properties Wind velocity of the extra-oral vacuum aspirator (EOVA) was 3.2-3.70 m^3/min. This velocity corresponded to 10200 times that of the ejector, and was 22 times that of the intra-oral vacuum aspirator (IOVA). Suction noise of the EOVA was measured using a noise meter. Among the aspirators examined the conventional type showed large difference between A mode and C mode, Namely this means the noise of a conventional aspirator distributed in the low frequency range. On the whole, most of the new type aspirators showed no difference in these values. Peak current at the closure of the EOVA was 7.1-19.7 A in the new types, and was 1.4-2.0 times current at the stable phase, though peak current was 30-37 A in the conventional type. 2. The total evaluation of the aspirator in the clinical practice The effect of the aspirator was examined. The number of particles per a definite volume of air was adopted as the marker of the particles produced during the tooth preparation. As the result, there were 7.7 times increase in the '0.3mum particle', 53 times increase in the '0.5mum particle', 151 times increase in the '1mum particle', 127 times increase in the '2mum particle', 28 times increase in the '5mum particle', respectively, as compared with the number of particles before the preparation. In the case of using both of EOVA and IONA,particles more than 0.5mum' has decreased to the level of the number of the particle before the preparation. The EOVA showed higher effectiveness on sucking '5mum particle' than the IOVA.

The autoclave has been widely used in dentistry as an effective method to sterilize instruments and materials. Corrosion of carbon steel instruments and the decomposed bacterial substances remaining on the surface of the instruments have been the problem with the autoclave. The purpose of this study was to investigate the characteristics of an oxygen plasma reactor as the dental sterilizer. The plasma reactor used was type PR-31 (YAMATO Sci.Co.Ltd) . High frequency electric field of 13.56MHz was applied to the glass cham ber by capacitance coupling. Oxygen flow in the chamber was 50ml/min to 100ml/min. Internal temperature of a glass tube (outer diameter : 2.00mm, internal diameter : 0.95mm) inserted into the pla sma was measured by the iron-constantan thermocouple(diameter : 0.08mm) . The temperature increased in accordance with the out put power and duration of the application of the plasma Metal plates (5*20*0.5mm) were u sed as the test specimens. Whole saliva (circa 10000 to 1000000CFU) was place d on the specimen and dried for 30min. The effect was estimated by the cult ured specimens in the brain heart infusion broth. When the plasma treatment of 300W (10min) was applied, all of the 25 specimens resulted in negative culture. New carbon steel burs were treated by plasma, or autoclave sterilization or dry heat sterilization. Obsevation of the surfaces of these burs under a scanning electron microscope revealed that plasma treatment produced the cleannest surface. In conclusion, the oxygen plasma treatment has possibility to be used as a dental sterilizer.

In order to construct an optimal detection system for the transmitted light, light transmittance characteristics of the human extracted teeth and the human peripheral blood were investigated between 400 and 800 nm using a spectrophotometer. A tungsten incandescent light and a CdS-CdSe photoconductive cell were used as the light source and the photodetector, respectively. The spectrum analysis showed that the light of its wavelength shorter than 600 nm was more absorbable by the blood than the longer wavelength. Transmitted light photoplethsmography (TLP) was applied to vital human upper central incisors of healthy volunteers. Three different light sources (the tungsten light, a LED with its peak at 565 nm (LED565) and a LED with its peak at 695 nm (LED695)) were used as the light source. The light illuminated the palatal surface of the tooth crown and the transmitted light was collected form the labial side. The Cds-CdSe photoconductive cell was used as the photodetector. Pulse waves were observed on most of the examined teeth with the LED565, however, it was difficult to recognise the pulse wave with the tungsten light and the LED695 The results indicated the LED565 was suitable for the pulpal TLP. Then, the detectable area of the root pulp blood flow by our method was assessed. Human extracted upper central incisors were used to determine the transmitted area of the light. An LED (intensity peak 565 nm) and an optical fiber (o.d.2.2 mm) were placed in contact with the palatal and the labial surface of the teeth approximately 2 mm from the enamel-cement junction, respectively. The transmitted light throught the teeth was guided to the CdS-CdSe photoconductive cell (peak sensitivity 560nm) via the optical fiber. The results indicated that our method can detect the root pulp blood flow as far as app.2 mm from the enamel-cement junction.