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.

The fragility of pulp-less tooth has been well known. Besides the loss of time and money through the root canal treatment for a patient and a dentist. To solve this problem, we thought that it was worthwhile for pulp treatment to derive the partial pulp tissue using the derivation on stem cell differentiation. Recently the development of research on cell facial antigen of embryonic stem cell (ES cell) has been remarkable. Especially the Stage Specific Embryonic Antigen-1 (SSEA-1) stained the cell facial antigen of ES cell, Embryonal Carcinoma cell (EC cell) and Embryonic Germ cell (EG cell) on mouse, and on human cell SSEA-1 stains just only EG cell. But the Stage Specific Embryonic Antigen-4 (SSEA-4) stains all human ECIES and EG cell, and this SSEA-4 could not be observed in mouse cells. We stained these antigens on human and mouse pulp tissue cells. On human cells we could observe all ES,EC and ES antigens. Then this 2003 we tried to stain another antigen (Tumor Rejection Antigen-1-60: TRA-1-60) and TRA-1-81. we could stain these antigen on human pulp cells. But we could not bather the human pulp tissue under the definite condition. We must advance the immunohistochemical research under the definite condition using mouse cells. Moreover we need the establishment to distinguish the difference among the ES,EC and EG cells. If we can establish these difference, we will get the pulp tissue regeneration using the derivation on stem cell differentiation.

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.

歯周病はいまや生活習憤病の1つとして認識されているが、全身状態が歯周病の発症や進展におよぼす影響については報告が少ない。そこで今回は、実験的に骨吸収を惹起させる歯周病モデル(ラット)をもちいて、妊娠や授乳が歯周病の進行におよぼす影響について検討した。実験には62匹の雌ラットを用い、交配後3群に分けて各々カルシウム含有量の異なる飼料を与えた。実験開始後25日目に妊娠の有無によりさらに2郡に分けた。32日には右側下顎第一臼歯部の歯頚部に規格化されたゴム輪を挿入して、歯槽骨を吸収させた(実験側)。左側は、対照側とした。46日目にと殺して下顎骨を採取した。第一臼歯と第二臼歯の歯間隣接面部について、歯槽骨の骨密度および組織学的検索をおこなった。その結果、以下の知見が得られた。(1)対照側では、摂取する飼料のカルシウム含有量が少なくなるにつれて、骨密度の減少がみられた。妊娠群では、非妊娠群と比較してより減少の程度が大きかった。(2)実験側ではゴム輪の挿入による炎症性骨吸収がみられたが、対照側と同様に摂取する飼料のカルシウム含有量が少なくなるにつれて、骨密度の減少がみられた。妊娠群では、非妊娠群と比較してより減少の程度が大きかった。(3)組織学的所見より、妊娠群でも非妊娠群でも飼料中のカルシウム含有量の減少による骨粗鬆状態が観察された。しかし、カルシウム含有量の減少による影響については、対照側では歯槽骨の高さの変化が見られなかったのに対し、実験側では歯槽骨の高さの減少が明らかとなった。これらの知見より以下の示唆が得られた。(1)妊娠や授乳は、カルシウムが十分に摂取された状態では歯槽骨を減少させる直接のファクターとはならないが、摂取が不十分な状態ではリスクファクターになり得る。(2)歯槽骨吸収により全身のカルシウム需要が増大し、かつカルシウム摂取状態がよくない場合には、妊娠や授乳が歯槽骨を減少させるリスクファクターになり得る。

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.

全身状態(妊娠&授乳)および栄養摂取状態(Ca)の歯周組織に与える影響について検討した。試料として、ラットの下顎骨を用いた。全身状態については妊娠の有無の2群、Ca摂取状態については3群(充足、減少、欠乏)に分け、計6群間での画像解析および組織学的解析結果の比較を行った。 健康な歯周組織においては、骨塩量はCa摂取状態に依存して減少した。Ca摂取が減少または欠乏した状態では、非妊娠群と比較して妊娠群で有意に骨塩量が減少した。妊娠群のラットから生まれたこどもの下顎骨の骨塩量は、親のCa摂取状態を強く反映していた。組織所見では、Ca摂取が減少または欠乏した状態における、歯槽骨内面からの吸収による骨の非薄化が顕著であった。残存する歯槽骨の面積は、Ca摂取状態に依存していた。しかし、歯槽骨の高さの変化はみられなかった。 さらに、歯周組織に炎症を惹起させた状態での検討を加えた。歯肉溝にゴム輪を挿入することによって歯周炎を惹起した。骨塩量の変化は、健康な歯周組織と同様であった。組織所見ではゴム輪挿入による急激な歯槽骨吸収、著明な炎症性細胞浸潤をともなう軟組織の走行の乱れなどがみられた。その程度はCa摂取状態に依存し、妊娠&授乳により高度になる傾向がみられた。健康な歯周組織と比較して大きな相違は、Ca摂取状態に依存して歯槽骨の高さの減少がみられたことである。 以上の結果より、1)妊娠や授乳が、Caが十分に摂取された状態では歯槽骨を減少させる直接のfactorとはなり得ないが、Ca摂取が減少または欠乏した状態では、risk factorになり得る2)歯槽骨吸収により、全身のCa需要が増大し、かつCa摂取状態がよくない場合に、妊娠や授乳が歯槽骨を減少させるrisk factorになり得ることが示唆された。

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.