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Low-level laser irradiation has been reported to enhance wound healing. Activation of gingival fibroblasts (GF) has a potential for early wound healing in periodontal treatment. The present study aimed to investigate the direct effect of low-level Er:YAG laser irradiation on gingival fibroblasts proliferation in order to clarify the laser effect on healing.Cultured human gingival fibroblasts (hGF) were exposed to low-power, pulsed Er:YAG laser irradiation with different energy densities ranging from 1.68 to 5.0 J/cm(2). The cultures were analyzed by means of trypan blue staining and counted under a light microscope. The effect of Er:YAG laser on hGF was also evaluated using a transmission electron microscope (TEM).Cultures irradiated with Er:YAG laser presented faster cell growth when compared with untreated controls. This difference was statistically significant. Transmission electron microscopy revealed rough endoplasmic reticulum, prominent Golgi complexes, and mitochondria after laser irradiation.Our results showed that the low-level Er:YAG laser irradiation stimulates the proliferation of cultured gingival fibroblasts. The optimal stimulative energy density was found to be 3.37 J/cm(2). This result suggests that Er:YAG laser irradiation may be of therapeutic benefit for wound healing.

【目的】手術部・ICUへの下足立ち入り(一足制)の導入による空気清浄度の変化を検討する。【方法】一足制導入前後の一定期間,(1)0.5μm以上の塵埃数・feet-3,(2)空中浮遊細菌コロニー数・m-3,(3)寒天培地上の落下細菌数を測定した。【結果】非稼働中手術室の平均塵埃数は一足制の導入による有意な変化はなかった(P=0.485)が,稼働中手術室では若干の悪化傾向を示した(P=0.141)。ICUではNASAクラス分類の度数分布は改善した(P 0.25)。【考察】手術室・ICU共に塵埃数,空中浮遊菌数共に一足制導入後もNASA基準や日本医療福祉設備協会規定を十分に満たしていた。【結語】適切な空調を備えた清潔区の一足制は空気清浄度に影響しないと判断したが,追跡調査が必要である。

This article reviews the current and potential applications of laser technology in nonsurgical therapy for the treatment of periodontal diseases. Based on its various characteristics, such as ablation or vaporization, hemostasis, and sterilization effect, laser treatment may serve as an adjunct or alternative to conventional, mechanical periodontal therapy. The Carbon dioxide (CO2) and the Neodymiumdoped:Yttrium-Aluminum-Garnet (Nd:YAG) lasers were previously approved for soft tissue treatment in periodontics (1, 2, 4), because of their superior ability of soft tissue ablation, accompanied by strong hemostatic and bactericidal effects (6, 37, 143, 170, 218). However, when these lasers are applied to dental hard tissues the result is major thermal damage, especially at a high-energy output, rendering them unsuitable for hard tissue treatment (56, 214). Recently, the Erbium-doped:Yttrium-AluminumGarnet (Er:YAG) laser was developed in dentistry (71, 85, 87). As it is capable of ablation in both soft and hard tissues, the Er:YAG laser can be used for periodontal hard tissue treatment such as root surface debridement, as well as soft tissue management (78). The use of lasers within the periodontal pocket has become a topic of much interest and is a promising field in periodontal therapy. This article deals with recent advances in nonsurgical laser therapy for periodontal disease, and will briefly describe the advantages and disadvantages of various laser types.

The aim of this study was to analyze the early healing process of bone tissue irradiated by Er:YAG laser and compare it with that treated by mechanical drilling and CO(2) laser.Er:YAG laser has a great potential for cutting hard tissues as it is capable of ablation with less thermal damage.Twenty-four male Wistar rats were used for this study. The calvarial bone of rats was exposed and straight grooves were prepared by Er:YAG laser, mechanical bur and continuous wave CO(2) laser. Four rats each were sacrificed at six time points: 10 min, 6 and 24 h and 3, 7, and 14 days post-surgery. Sections were prepared for light and transmission electron microscopic (TEM) observations.Compared to mechanical bur and CO(2) groups, the inflammatory cell infiltration adjacent to the irradiated bone surface, fibroblastic reaction, and revascularization were more pronounced in the Er:YAG laser-irradiated tissues. A cell-rich granulation tissue with fibroblasts and osteoblasts was predominant in 7-day specimens of Er:YAG laser group. Histopathological analysis of 14-day specimens in the Er:YAG group also revealed significantly greater new bone formation, compared with the mechanical bur and CO(2) laser groups.Initial bone healing following Er:YAG laser irradiation occurred faster than that after mechanical bur and CO(2) laser. Er:YAG laser treatment may be advantageous for wound healing of bone tissue, presumably by providing a favorable surface for cell attachment.

高機能患者シミュレータの日本における使用の現状と, 導入の予定・期待を調査した. 全国80大学医学部麻酔科への郵送によるアンケート調査の結果, 78%の施設から回答が得られた. シミュレータの使用対象は医学生が主で, 次いで研修医であった. 平均の使用時間は3.7時間/週であった. シミュレータの維持管理のための専門の人員を確保している施設はまったくなかった. シミュレータ施設の運営にあたって, 経済的な問題および人員の確保の問題を考慮する必要がある. 今後, 国際的なシミュレータ・コミュニティーと連携した情報交換の場を日本国内において確保する必要がある.

Background and Objectives The aim of the present study was to investigate the in vivo effects of an Er:YAG laser (ERL), an ultrasonic system and scaling and root planing (SRP) on the biocompatibility of periodontally diseased root surfaces in cultures of human periodontal ligament fibroblasts (PDL). Study Design/Materials and Methods Forty single rooted teeth, considered for extraction due to severe periodontal destruction, have been randomly assigned to the following groups: (1) ERL at 160 mJ/pulse and 10 Hz, or (2) Vector® ultrasonic system (VUS), or (3) SRP using hand instruments, or (4) untreated control (C). Immediately after instrumentation, all test and control teeth were extracted and root specimens (4 mm2) were prepared from all mesial and distal surfaces (n = 80). Following the prescribed treatments, the root specimens were incubated with human PDL fibroblast cultures. Adherent cells were stained with methylene blue and counted using a reflected light microscope and the cell density per mm2 was calculated. Additionally, the cell morphology was investigated using SEM (n = 8 teeth). Results Cell counts within each group yielded the following means and standard deviations (cells/mm2): ERL, 111 ± 27; VUS, 75 ± 25; SRP, 41 ± 17; control, 25 ± 11. Analysis of variance (ANOVA) revealed significant differences in the number of attached cells between the test and control groups (P

The Er:YAG laser has been effectively applied for periodontal soft-tissue management. The purpose of this study was to evaluate the effectiveness of high pulse rate Er:YAG laser in removal of gingival melanin pigmentation. Five patients participated in this study. An Er:YAG laser was irradiated for removal of melanin pigmentation under surgical microscope monitoring. The irradiation was performed at 27–54 mJ/pulse and 20–30 Hz under water spray in an oblique contact mode. The clinical parameters were evaluated at immediately after, 1, 2 and 4 weeks, 3 and 6 months after. The visual analog scale (VAS) was used to evaluate the pain level experienced by each patient. The ablation of the hyperpigmented epithelial tissue was easily achieved without prominent bleeding complications. The use of water spray provided a clear operation field. The surgical microscope monitoring was of great advantage for complete removal of remaining melanin pigmentation. The patients perceived slight to moderate pain such as irritation or contact pain until 4–5 days after treatment. At 2 weeks, the gingiva appeared completely normal appearance. In some cases, slight recurrence was observed after 6 months. These results indicate the removal of gingival melanin pigmentation can be performed safely and effectively by high pulse rate Er:YAG laser irradiation.

This aim of this study was to evaluate the clinical effectiveness of Er:YAG laser at a high pulse rate (ER-D1: HOYA continuum, Japan) for scaling of subgingival calculus and root planning. Sixty-one patients with calculus deposition were treated with the Er:YAG laser (panel setting 30–108 mJ/pulse, 30 Hz) using contact tips and the results were then subjected to clinical analysis. Clinical assessments of calculus index, pain, redness, swelling, discomfort, roughness of root surface, efficiency of scaling, PlI, PD, BOP and mobility were made prior to and at 1, 4 weeks and 3 months after treatment. Fifteen of the sixty-one patients were treated during the flap operation. The Er:YAG laser high-pulse-rate irradiation was capable of ablating the calculus on the root surface precisely and effectively. The roughness of root surface after debridement was evaluated to be adequately plane for 41 cases and still rough for 20 cases. BOP and PD were significantly improved throughout the 3-month examination of this study. No negative side effects or influences were observed on the healing of periodontal tissue following Er:YAG laser irradiation during this clinical study. In conclusion, the Er:YAG laser high-pulse-rate irradiation would be a safe and effective, alternative method for root surface treatment in both nonsurgical and surgical periodontal therapy.

The purpose of this study was to examine the morphological changes and temperature increases of the titanium after Er:YAG laser irradiation, and also to investigate the effect of this laser on debridement of contaminated healing abutments.Mechanical instruments have been used for the cleaning of implant abutment surfaces, however, most of them are not appropriate for the application to titanium surface. Recently, the Er:YAG laser has been expected to have a promising ability for the debridement of implant surface.Experiments were composed of three parts. At first, ten titanium round plates were exposed to the Er:YAG laser irradiation at 30-200 mJ/pulse and the surface changes were observed by stereomicroscope and scanning electron microscope. Secondly, the surface temperature changes of 60 titanium plates during and after Er:YAG laser irradiation at 30 and 50 mJ/pulse were measured by thermographic equipment. At last, calculus on the surface of six contaminated healing abutments was removed by Er:YAG laser or ultrasonic scaler, and the treated surfaces were examined by stereomicroscope.Under 50 mJ/pulse, distinct morphological changes were not observed and the elevation of surface temperature was minimal, especially in the use of water-cooling. The Er:YAG laser at 30 mJ/pulse and 30 Hz with water spray was capable of effectively removing plaque and calculus on the implant abutments without injuring their surfaces.This study indicates that the Er:YAG laser can be a novel technical modality for the debridement of implant abutment surface.

Background and Objectives To investigate the morphology of cementum and root dentin after Er:YAG laser irradiation with and without water coolant, compared to that after CO2 laser irradiation and an untreated surface. Study Design/Materials and Methods Ten extracted healthy human teeth were used. Er:YAG and CO2 lasers were applied with energy outputs of 0.4 W, with and without coolant and 0.5 W, without coolant, respectively. Scanning electron microscopy (SEM) analysis was performed at high and ultra-high magnifications. Results The surface of cementum was micro-irregular with numerous projections while that of dentin appeared scaly after Er:YAG laser irradiation. Unlike after CO2 laser treatment, no major melting or cracking was observed with Er:YAG laser treatment. The use of water spray produced fine micro-irregularities without attached debris. Ultra-high magnification revealed similar microparticles-composed aspects for both cementum and dentin. However, the more porous structure of the surface was observed after Er:YAG laser irradiation without water spray. Conclusions Cementum and root dentin presented distinct micro-roughness after Er:YAG laser irradiation, possibly due to structural differences in the original tissue. However, under ultra-high magnifications, both cementum and dentin presented similar characteristics of the irradiated surface. In addition, the use of water spray during laser irradiation minimized thermal effects and resulted in a cleaner and less porous surface. Lasers Surg. Med. 31:79–85, 2002. © 2002 Wiley-Liss, Inc.

The present study examines the dental root after Er:YAG laser irradiation, compared with CO2 lased and non-treated surfaces, using Fourier Transformed Infrared (FTIR) spectroscopy. Freshly extracted human teeth were irradiated by Er:YAG laser at an energy output of 40 mJ/pulse, 10 Hz (0.4 watts), with or without water coolant, and by CO2 laser at an energy output of 0.5 watts in continuous wave mode without coolant. The surfaces were chalky and smooth after irradiation by Er:YAG laser with water coolant, were charred and irregular after irradiation by Er:YAG laser without water coolant, and were completely carbonized after CO2 laser irradiation. The FTIR profiles from samples of the surfaces that were irradiated by Er:YAG laser with water coolant were similar to those from non-treated samples, except for a slight decrease on the OH and amide bands, which are mainly related to organic components. This decrease was observed to be extreme after CO2 laser irradiation and moderate after Er:YAG laser irradiation without coolant. The formation of new bands showing toxic substances was observed to a large extent after CO2 laser irradiation and to a smaller extent after Er:YAG laser irradiation without water coolant. In contrast, no such bands were detected after Er:YAG laser irradiation with water coolant. The present results show that these laser treatments selectively ablated more organic components than inorganic components and that Er:YAG laser irradiation with water coolant did not cause major compositional changes or chemically deleterious changes in either root cementum or dentin.

As a fluid in close proximity to periodontal tissue, the Gingival Crevicular Fluid (GCF) is the principal target in the search for biomarkers of periodontal disease, because its protein composition may reflect disease pathophysiology. For the identification of novel GCF biomarkers of periodontal disease, GCF samples from five patients with severe periodontal disease were analyzed by liquid chromatography-mass spectrometry/mass spectrometry. Two hundred twenty-five proteins were identified as possible candidates for GCF biomarkers. Of these marker candidates, we focused on a protein not well studied in periodontal disease, i.e., moesin, a member of the ezrin– radixin–moesin family. Western blotting analysis revealed that moesin expression in GCF was higher in patients with severe periodontal disease than in controls. We further examined moesin protein expression levels in human gingival fibroblasts (HGFs) following stimulation with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Moesin expression in HGFs was found to be increased by LPS treatment in a dose-dependent manner. Our findings suggest that moesin may be involved in progression of periodontal disease and is a potential biomarker of periodontal disease.

The purpose of the present study was to evaluate the effectiveness of Er:YAG laser scaling and the morphological and histological changes of the laser-scaled root surface in comparison with the effectiveness and root surface changes produced by conventional ultrasonic scaling. Fifty-three periodontally involved human extracted teeth with a band of subgingival calculus were used. The teeth were divided randomly into 2 groups for laser scaling and ultrasonic scaling. Laser irradiation was performed at an energy output of 40 mJ/pulse and 10 pulses/s under water spray, with the probe tip contacted obliquely to the root surface. Ultrasonic scaling was performed at a clinically standard power setting. The time required for scaling, the scaled area and the temperature changes were determined using both methods of treatment. The features of the scaled surfaces were examined by histological and scanning electron microscope (s.e.m.) observations. The Er:YAG laser provided subgingival calculus removal on a level equivalent to that provided by the ultrasonic scaler, without major thermal elevation. Macroscopically, the laser-treated root surface was somewhat rougher than or similar to the ultrasonically scaled root. However, the efficiency of the laser scaling was lower than that of the ultrasonic scaling. In addition, histological examination revealed a thin deeply stained zone on the lased root surface, and s.e.m. analysis revealed a characteristic microroughness on the lased surface. The laser scaling provided a level of calculus removal that was similar to that provided by the ultrasonic scaling. However, the Er:YAG laser produced superficial, structural and thermal microchanges on the root cementum.

A six-degree-of-freedom model and a twelve-degree-of freedom model incorporating a rider's vibrational characteristics have been developed. The models include a mechanical model of the rider's body which consists of a leaning motion of the upper body and a lateral movement of the lower body. Damping properties and natural frequencies of weave and wobble modes were calculated using these models. Conclusions are drawn about effects of the rider's vibrational characteristics on the stability of motorcycles during straight running from the calculations in the six degree of freedom model. Implications for accurate modeling of motorcycle stability are derived from differences between the calculations in the twelve-degree-of-freedom model and running experiments.

A basic motorcycle dynamics model having four degrees of freedom was experimentally confirmed in this study. The frequency response functions, damping properties, and natural frequencies of weave and wobble modes which are vibrational modes of straight-running stability, were calculated using this model. Conclusions were drawn about effectiveness of the model from comparing of calculations and running experiments. (1) The four-degree-of-freedom model is effective for predicting steering response of the motorcycle during normal running conditions. (2) The weave mode calculations compare favorably with experiments in damped natural frequency, and agree approximately with experiments in damping ratio. (3) The calculated and experimental values of wobble mode are not necessarily the same with each test vehicle in damped natural frequency, and may differ in damping ratio.

Effective ablation of dental hard tissues by means of the erbium-doped:yttrium-aluminum garnet (Er:YAG) laser has been reported recently, and its application to caries removal and cavity preparation has been expected. However, few studies have investigated the capability of the Er:YAG laser to treat caries. In the present study, the effectiveness of caries removal by using an Er:YAG laser in vitro was compared with that of conventional mechanical treatment. Thirty-one extracted human teeth with root caries were used. Half of the caries in each tooth was treated with the Er:YAG laser, and the other was removed with a conventional bur or was left untreated as a control. Laser treatment was performed by means of a combination of contact and non-contact irradiation modes with cooling water spray, with a new fiber delivery and contact probe system. Conventional bur treatment was conducted by means of a low-speed micromotor. Measurements of the time required for caries removal, histopathological observations of decalcified serial sections, scanning electron microscope (SEM) observations, and hardness measurements of the treated cavity-floor dentin were performed for each treatment. Due to the careful irradiation technique, a longer treatment time was required for the complete removal of carious dentin by the Er:YAG laser. However, the Er:YAG laser ablated carious dentin effectively with minimal thermal damage to the surrounding intact dentin, and removed infected and softened carious dentin to the same degree as the bur treatment. In addition, a lower degree of vibration was noted with the Er:YAG laser treatment. The SEM examination revealed characteristic micro-irregularities of the lased dentin surface. Our results show that the Er:YAG laser system is promising as a new technical modality for caries treatment.

Six five-degree-of freedom models and a ten degree-of-freedom model incorporating frame rigidity of motorcycles have been developed. The models include torsional rigidity of the main frame and rear swing arm in the rolling direction ; torsional rigidity of the front fork in the steering direction ; and lateral bending rigidity of the main frame, front fork and rear swing arm. Computational results using the models, including damping properties and natural frequencies of weave and wobble modes, are presented, discussed and compared with experimental results. Conclusions are drawn about effects of frame rigidity on the stability of motorcycles during straight running from the calculations in the five degree-of-freedom models. Implications for accurate modeling of motorcycle stability are derived from differences between the calculations in the ten-degree-of-freedom model and running experiments.

Multiple endocrine neoplasia type 1 (MEN1) is an autosotnal dominant familial cancer syndrome. The responsible gene MEN1 has recently been isolated, and its germline mutations have been identified in affected individuals in the United States, Canada and Europe. We screened for MEN1 mutations by direct nucleotide sequencing of all protein‐coding regions, and identified five distinct germline mutations in five among six Japanese kindreds with familial MEN1 or familial hyperparathyroidism. The mutations were dispersed across the gene. These findings suggest that, because of the absence of an obvious founder effect, the entire MEN1 gene region should be examined for germline mutations in the probands of MEN1 and related syndromes in Japanese families.

The purpose of this study was to examine morphological and histopathological changes of the cervical enamel and root dentin of the treated cavity after root caries ablation using an Er: YAG laser. The prepared surfce using the Er: YAG laser was compared with that of conventional mechanical treatment. Ten extracted human teeth with root caries were used. Half of the carious lesion in each tooth was ablated with the Er: YAG laser, and the other was removed with a steel bur mounted on a low-speed micromotor. Er: YAG laser treatment was carefully performed under water spray using a combination of contact and non-contact irradiation modes. SEM and histopathological observations were performed for each treatment. The Er: YAG laser was able to ablate root carious lesion effectively without major thermal damage to the surrounding dental hard tisssues. However, the treated cavity margin tended to be irregular and unclear. Due to the careful irradiation technique, the irregularity of the cavity floor was relatively small and the residual structural change of the lased dentin was generally minimal except for the scarce highly-damaged area. The super ficial layer of the lased dentin showed deep staining with hematoxylin in the histological observation and typical microirregularities in the SEM examination. On the lased enamel, however, large microcraks and microirregularities were noted in the SEM evaluation.In order to perform effective caries removal and cavity preparation using the Er: YAG laser, further studies are required on the irradiation conditions and techniques, and on the conditioning of the lased surface for adhesive restorations. Especially, structural changes and finishing of the marginal enamel of the lased cavity should be investigated more minutely.(J. Jpn. Soc. Laser Dent. 8: 31-37, 1997, Reprint requests to Dr. AOKI)

The rule of the surgical treatment of insulinoma is its perfect resection, but the localization of insulinoma is very important to select the operative procedure. We experienced recently an insulinoma that was detected by preoperative procedure and enucleated successfully with intraoperative ultrasonography (US) and CUSA (Cavitron. Ultrasonic Surgical Aspirator). A 28-year-old female had a cold sweat and numbness in the hands sometimes from the summer of 1991. In May, 1993, she was admitted to the hospital because of cold sweat and numbness in the whole body. An intraparenchymal insulinoma of the pancreas head was detected by abdominal US, CT, and angiography. The tumor was enucleated safely by using intraoperative US and CUSA at a low amplitude. There has been no evidence of recurrence in postoperative examinations.

BACKGROUND AND OBJECTIVE Antimicrobial photodynamic therapy (a-PDT) using a combination of red-colored laser/light-emitting diode (LED) and blue dye has been employed for periodontal therapy and the antimicrobial effect seems promising. Blue light, which has favorable wavelength properties, would be more effective as a light source for a-PDT because blue light itself possesses an antimicrobial effect. This study aimed to investigate the effect of a-PDT using a novel combination of high-power blue LED and red-dye agent on Porphyromonas gingivalis in vitro. MATERIAL AND METHODS Porphyromonas gingivalis ATCC 33277 suspension was irradiated with blue LED (BL) (425-470 nm) or red LED (RL) (625-635 nm) at 30-90 J/cm(2) , or was mixed with erythrosine (ER), phloxine B (PB) or rose bengal (RB) with or without BL irradiation (30 J/cm(2) ). RL (30 J/cm(2) ) in combination with toluidine blue was employed as positive control. All the suspensions of P. gingivalis were serially diluted, plated and incubated anaerobically, and the numbers of colony-forming units (CFUs) were counted on day 7. RESULTS BL irradiation at 60 and 90 J/cm(2) demonstrated a significant reduction in the numbers of CFUs. ER, PB and RB solutions at 160 μg/mL showed almost no or only a minimal reduction in the numbers of CFUs. BL at 30 J/cm(2) combined with ER, PB or RB at 160 μg/mL resulted in a log reduction of 0.9, 1.0 and 7.1, respectively, in the numbers of CFUs; 30 J/cm(2) BL with RB at 1.6, 16 and 160 μg/mL demonstrated a log reduction of 6.3, 8.0 and 5.5, respectively; and a log reduction of 5.2 was obtained after 30 J/cm(2) RL with 16 μg/mL TB. CONCLUSION Within the limits of this study, BL was found to have an antimicrobial/growth-inhibiting effect on P. gingivalis, and a-PDT using a combination of BL and RB shows promise as a new technical modality for bacterial elimination in periodontal therapy.

Clinical application of the Er: YAG Laser for dental caries and periodontal treatment has been developed. In clinical use, the effect of mis-irradiation of the Er: YAG Laser on the surrounding tissues should be considered. The purpose of this study was to examine the effect of the Er: YAG Laser on soft tissues supposing the side effect of mis-irradiation. The Er: YAG Laser was irradiated against the tongue of rat under following various conditions; the energy level: 50, 150, 300mJ/pulse, pulsing time: 1 and 10 pulses, irradiation distance: 0, 5, 10 and 20mm, and irradiated field: wet or dry. Wounds on tongue were observed macroscopically at 0, 1, 3, 7 and 14 days after laser irradiation. Some specimens were also examined by SEM. The following results were obtained: contact irradiations caused limited damages to tongue regardless of water irrigation; however, the depth of wounds depended upon the pulsing time and power level of the laser, while, non-contact irradiation showed a little or no effect against tongue. Moreover, the use of water irrigation decreased their damages effectively. With respect to wound healing, all cases were shown as normal process. Clinically, most of mis-irradiations are supposed to happen with non-contact irradiation under water spray. These results indicate that the Er: YAG Laser application for intraoral usage would be safe for the surrounding soft tissues within the usual power setting in dental treatment.(J. Jpn. Soc. Laser Dent. 7: 46-57, 1996 Reprint requests to Dr OHNO)

The purpose of this study was to evaluate the effects of Er: YAG laser irradiation on human extracted root surfaces in vitro, and to compare with Nd: YAG and CO2 laser irradiation. Twelve 5mm×5mm human root slices were prepared for this study. Two areas with 2mm×3mm were marked at both sides to the tooth axis in each slice. One area was irradiated with water cooling and the other without cooling. Three slices were randomly assigned to each of the following 4 different treatment groups: 1) Er: YAG laser treatment; 2) CO2 laser treatment; 3) Nd: YAG laser treatment; 4) Nd: YAG laser treatment to the root surface coated with black stain. Non-lased surfaces served as controls. The pulsed Er: YAG and Nd: YAG laser irradiations were performed for 10 seconds with an energy level of 50mJ at 10pps in the contact mode, holding the 0.6mm contact handpiece at 45 degree angulation to the root surface. The CW CO2 laser was irradiated with an energy level of 0.5W in the non-contact focus mode. After laser irradiation, the specimens were examined with stereoscope and scanning electron microscope. Root surfaces irradiated by Er: YAG laser featured scaly like appearances. Surfaces received CO2 laser irradiation without water cooling exhibited distinct carbonization and many cracks. With the Nd: YAG laser irradiation, charing, melting and lava-like appearance were observed when the laser was irradiated to the black stained surface without water cooling. The results of this study showed that three kinds of laser application to root surfaces resulted completely different morphological changes. We should consider the characteristics of laser and their effects to root surface, using any laser for periodontal treatment such as scaling, root conditioning, and killing of periodontopathic bacteria.(J. Jpn. Soc. Laser Dent, 7: 58-66, 1996 Reprint requests to Dr. ANDO)

High Resolution Solid State 13 C NMR Spectroscopy of Polypropylene with Very High Syndiospecificity

This case report describes a 68-year-old man with Cushing's syndrome due to adrenocorticotropic hormone (ACTH)-independent bilateral adrenocortical macronodular hyperplasia (AIMAH). He was referred to our hospital for evaluation of bilateral enlargement of the adrenal glands found incidentally by computed tomography (CT). He had a ten-year history of hypertension. Although he was normokalemic and did not show Cushingoid features, the diagnosis of ACTH-independent Cushing's syndrome was established by endocrinological examinations. His plasma cortisol showed no diurnal rhythm and was unsuppressible by high-dose (8 mg/day) dexamethasone. Plasma ACTH was undetectable and did not respond to corticotropin-releasing hormone. Excised adrenal glands were markedly enlarged (right 28 g and left 64 g). Macroscopic appearance of the glands showed multiple yellowish nodules typical for AIMAH; microscopic findings were also compatible with AIMAH. The present case indicates that patients with AIMAH sometimes do not show typical Cushingoid features and therefore AIMAH can be found incidentally from ultrasound or CT examination of the abdomen.

This study was undertaken to provide a light microscopic and ultrastructural basis to compare the early healing events at Er:YAG and CO2-lased bone tissue. Twenty-four male Wistar rats were used in this study. After anesthetizing, the calvarial bone was irradiated by Er:YAG laser in a contact mode at an energy output of 100 mJ/pulse and 10 pps with water coolant and by CO2 laser with an energy output of 4 W. The rats were then sacrificed at 10 min, 6 and 24 h and 3, 7 and 14 days after irradiation. The histopathological study of healing following Er:YAG laser irradiation suggested that this mode of treatment had a beneficial effect on initial bony wound healing. It was found that proliferation of fibroblasts and osteoblasts were more prominent in this group and, thus, were revascularization and the formation of osteoid tissue. On the contrary, large amounts of necrotic tissue, char and carbonized tissue with polymorphonuclear leukocytes (PMNs) were the major histological features in the CO2 laser specimens. We conclude that Er:YAG laser irradiation did not adversely affect the bone healing process and would be applicable for bone surgery.

The purpose of this study was to examine histologically the healing process of the bone defect created by Er:YAG laser irradiation in the long-term, in comparison with that created by conventional rotating bur. Two straight groove-like defects were prepared on the rat calvaria by Er:YAG laser or rotating bur. After operation, SEM analysis of the lased surface and histological observation of the healing process were performed. The results showed that the Er:YAG laser was capable of ablating bone tissue with the same effectiveness as the bur treatment, without causing severe thermal damage.The bone defect created by Er:YAG laser irradiation was repaired by new bone uneventfully within 2 months, almost equal to that of the bur treatment. These results suggest that the Er:YAG laser can be clinically applicable to periodontal bone surgery.

The purpose of this study was to evaluate the effectiveness and safety of periodontal minor soft tissue surgery with the Er/YAG laser at a high pulse rate of 30 Hz and the subsequent clinical wound healing. Sixty-one patients were subjected to gingivectomy, removal of gingival melanin pigmentation, or frenectomy using the Er/YAG laser. Clinical parameters were evaluated before, immediately after, at 1 week and 4 weeks after surgery. The Er/YAG laser was capable of cutting or ablating gingival soft tissue easily and effectively with less or no bleeding as well as less pain. The healing process was uneventful without any complications or side effects. The results of this study suggest that the Er/YAG laser at 30 Hz could be used safely and effectively for minor periodontal soft tissue management without causing major thermal damage as well as the delay of wound healing.

Periodontal disease is a bacterial infection that destroys the gingiva and surrounding tissues of the oral cavity. Gingival crevicular fluid (GCF) is extracted from the gingival sulcus and pocket. Analysis of biochemical markers in GCF, which predict the progression of periodontal disease, may facilitate disease diagnosis. However, no useful GCF biochemical markers with high sensitivity for detecting periodontal disease have been identified. Thus, the search for biochemical markers of periodontal disease is of continued interest in experimental and clinical periodontal disease research. Using tandem mass tag (TMT) labeling, we analyzed GCF samples from healthy subjects and patients with periodontal disease, and identified a total of 619 GCF proteins based on proteomic analysis. Of these, we focused on two proteins, matrix metalloproteinase (MMP)-9 and neutrophil gelatinase-associated lipocalin (LCN2), which are involved in the progression of periodontal disease. Western blot analysis revealed that the levels of MMP-9 and LCN2 were significantly higher in patients with periodontal disease than in healthy subjects. In addition, ELISA also detected significantly higher levels of LCN2 in patients with periodontal disease than in healthy subjects. Thus, LC-MS/MS analyses of GCF using TMT labeling led to the identification of LCN2, which may be a promising GCF biomarker for the detection of periodontal disease.

In periodontal therapy, the use of low-level diode lasers has recently been considered to improve wound healing of the gingival tissue. However, its effects on human gingival epithelial cells (HGECs) remain unknown. The aim of the present study was to examine whether high-frequency low-level diode laser irradiation stimulates key cell responses in wound healing, proliferation and migration, in primary cultured HGECs in vitro. HGECs were derived from seven independent gingival tissue specimens. Cultured HGECs were exposed to a single session of high-frequency (30 kHz) low-level diode laser irradiation with various irradiation time periods (fluence 5.7-56.7 J/cm(2)). After 20-24 h, cell proliferation was evaluated by WST-8 assay and [(3)H]thymidine incorporation assay, and cell migration was monitored by in vitro wound healing assay. Further, phosphorylation of the mitogen-activated protein kinase (MAPK) pathways after irradiation was investigated by Western blotting. The high-frequency low-level irradiation significantly increased cell proliferation and [(3)H]thymidine incorporation at various irradiation time periods. Migration of the irradiated cells was significantly accelerated compared with the nonirradiated control. Further, the low-level diode laser irradiation induced phosphorylation of MAPK/extracellular signal-regulated protein kinase (ERK) at 5, 15, 60, and 120 min after irradiation. Stress-activated protein kinases/c-Jun N-terminal kinase and p38 MAPK remained un-phosphorylated. The results show that high-frequency low-level diode laser irradiation promotes HGEC proliferation and migration in association with the activation of MAPK/ERK, suggesting that laser irradiation may accelerate gingival wound healing.

Blue light has been employed or investigated in both the medical and dental fields. Many studies have so far been reported a bactericidal effect of blue light emitting diodes (LED). However, it is still unclear whether exposure to blue LED kills or inhibits the growth of bacteria. We therefore investigated the effect of blue LED irradiation on the growth of Porphyromonas gingivalis compared with the effects of red LED.P. gingivalis cell suspensions were irradiated with blue or red LED (135 J/cm2) anaerobically, incubated for various lengths of time, and then the total RNAs were isolated. The RNA degradation and gene expression levels of stress-related proteins in blue or red LED-irradiated samples were examined using the RNA integrity number (RIN) and RT-PCR, respectively. Quantitative RT-PCR was done to investigate the gene expression profiles associated with chromosome replication and cell division.Exposure to blue LED delayed the growth of P. gingivalis, while red LED did not. The RIN value indicated no RNA degradation in either the blue or red LED-irradiated samples. In addition, the gene expression levels of stress-related molecules remained either constant or increased 15 minutes after the blue LED irradiation compared to that before irradiation, thus suggesting that blue LED may not kill P. gingivalis cells. However, the blue LED irradiation did lead to a remarkably decreased expression of genes associated with chromosomal DNA replication and cell division after 5 minutes; exposure to the red LED did not.The inhibition of the growth of P. gingivalis by blue LED may therefore be induced not by a bactericidal effect, but instead due to a bacteriostatic effect mediated by the suppression of the genes associated with chromosomal DNA replication and cell division at the transcriptional level.

Er:YAG laser (ErL) irradiation has been reported to be effective for treating peri-implant disease. The present study seeks to evaluate morphological and elemental changes induced on microstructured surfaces of dental endosseous implants by high-pulse-repetition-rate ErL irradiation and to determine the optimal irradiation conditions for debriding contaminated microstructured surfaces. In experiment 1, dual acid-etched microstructured implants were irradiated by ErL (pulse energy, 30-50 mJ/pulse; repetition rate, 30 Hz) with and without water spray and for used and unused contact tips. Experiment 2 compared the ErL treatment with conventional mechanical treatments (metal/plastic curettes and ultrasonic scalers). In experiment 3, five commercially available microstructures were irradiated by ErL light (pulse energy, 30-50 mJ/pulse; pulse repetition rate, 30 Hz) while spraying water. In experiment 4, contaminated microstructured surfaces of three failed implants were debrided by ErL irradiation. After the experiments, all treated surfaces were assessed by stereomicroscopy, scanning electron microscopy (SEM), and/or energy-dispersive X-ray spectroscopy (EDS). The stereomicroscopy, SEM, and EDS results demonstrate that, unlike mechanical treatments, ErL irradiation at 30 mJ/pulse and 30 Hz with water spray induced no color or morphological changes to the microstructures except for the anodized implant surface, which was easily damaged. The optimized irradiation parameters effectively removed calcified deposits from contaminated titanium microstructures without causing substantial thermal damage. ErL irradiation at pulse energies below 30 mJ/pulse (10.6 J/cm(2)/pulse) and 30 Hz with water spray in near-contact mode seems to cause no damage and to be effective for debriding microstructured surfaces (except for anodized microstructures).

エチレンープロピレンー1-ブテン共重合体の13C NMRスペクトルでは異なる共重合連鎖に起因した複雑な分裂ピークが観測される. その分裂ピークを帰属するために, 13C INEPT法により炭素原子団を区別するとともに, 13C 2次元INADEQUATEスペクトルの解析から骨格炭素のつながりを明らかにした. さらにγ効果法による化学シフト計算からピークの分裂幅および分裂様式を予測した. その結果, INEPT法では判別不可能であった主鎖メチレン炭素と1-ブテン側鎖メチレン炭素のピークが重なり合う領域において, 2D-INADEQUATEスペクトルの解析により, 各々の炭素原子に起因したピークを分離帰属した. また化学シフト計算からテトラッド以上の共重合連鎖の差に起因した分裂ピークを帰属した. さらに1-ブテンの側鎖コンホメーション確率を計算することにより側鎖の優位コンホメーションの評価を行った.

Two-dimensional (2D) heteronuclear 1 H- 13 C, homonuclear 1 H, and spin-lock relay NMR experiments have been used to provide 13 C NMR chemical shift assignments of stereosequences in PVC. However, relative areas of methylene tetrad peaks based on the assignments given by these 2D NMR experiments do not agree with the relative areas predicted by Bernoullian propagation statistics. Tetrad and pentad assignments are proposed on the basis of the carbon-carbon connectivities revealed by the 2D-INADEQUATE (two-dimensional incredible natural abundance double quantum transfer experiment) spectrum

Recently, the Er:YAG and CO(2) lasers have been applied in periodontal therapy. However, the characteristics of laser-irradiated root cementum have not been fully analyzed. The aim of this study was to precisely analyze the alterations of root cementum treated with the Er:YAG and the CO(2) lasers, using non-decalcified thin histological sections. Eleven cementum plates were prepared from extracted human teeth. Pulsed Er:YAG laser contact irradiation was performed in a line at 40 mJ/pulse (14.2 J/cm(2)/pulse) and 25 Hz (1.0 W) under water spray. Continuous CO(2) laser irradiation was performed in non-contact mode at 1.0 W, and ultrasonic instrumentation was performed as a control. The treated samples were subjected to stereomicroscopy, scanning electron microscopy (SEM), light microscopy and SEM energy dispersive X-ray spectroscopy (SEM-EDS). The Er:YAG laser-treated cementum showed minimal alteration with a whitish, slightly ablated surface, whereas CO(2) laser treatment resulted in distinct carbonization. SEM analysis revealed characteristic micro-irregularities of the Er:YAG-lased surface and the melted, resolidified appearance surrounded by major and microcracks of the CO(2)-lased surface. Histological analysis revealed minimal thermal alteration and structural degradation of the Er:YAG laser-irradiated cementum with an affected layer of approximately 20-μm thickness, which partially consisted of two distinct affected layers. The CO(2)-lased cementum revealed multiple affected layers showing different structures/staining with approximately 140 μm thickness. Er:YAG laser irradiation used with water cooling resulted in minimal cementum ablation and thermal changes with a characteristic microstructure of the superficial layer. In contrast, CO(2) laser irradiation produced severely affected distinct multiple layers accompanied by melting and carbonization.

歯科臨床医10名の協力を得て, 保険診療上I型で歯周治療を行った患者20名, II型で行った患者20名について調査を行った。患者群は, 年齢, 男女比, 病型, メンテナンス期間共にほぼ同じ構成を示すように配慮した。本調査用に作成した診査用紙およびX線写真から, オレリーのプラークコントロールレコード, 歯周ポケットの深さの変化 (各歯の最深部), 動揺度の変化, プロービング時の出血部位数の変化, 歯周治療開始前の歯槽骨吸収の程度 (口腔内を6分割し, 各分画において骨吸収度の程度を評価する) について検討し, さらに, I型とII型に分ける際の術者の選択基準を加味したところ, I型ではやや重症の患者を治療し, II型ではこれより軽症の患者を治療する傾向が見られたが, 同程度の治療効果が得られた。以上のことから保険診療上のI型の歯周治療は有用であり, 今後一般臨床医の間にも普及することが望まれる。