Titanium of 30, 40, and 50% porosity has been developed to create a firm bond between the dental implant and bone. We examined its cytocompatibility with osteoblast-like cells by evaluating cell viability and alkaline phosphatase (ALP) activity in vitro. Cell viability after 1 day of culture was lower with the three types of porous titanium than with polished titanium. After 14 days of culture, the three porous titanium samples showed a level of cell viability similar to that of polished titanium. However, cell viability decreased with increasing porosity. The highest level of ALP activity was found on 30% porosity titanium after 7 and 14 days of culture. Cells penetrated the 50% porosity titanium. The results suggest that porous titanium promotes osteoblast proliferation and differentiation.

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Although basic neuropathy research often uses either axotomy or crush models, cases of clinical neuropathy are overwhelmingly caused by ischemic injuries, such as infections and thrombi. Therefore, the nerve damage observed with the axotomy and crush models will generally be greater than the pathophysiology seen in the majority of clinical cases. In order to create neuroparalysis that more closely resembles clinical pathophysiology, we attempted to create an ischemic facial nerve paralysis model using the selective embolization technique. The paralysis created by this model lasted for approximately three days and disappeared completely in about one week. Edema and degeneration were observed in approximately 7% of the entire nerve fiber, suggesting that neuropathy was very slight. In order to determine whether the neuropathy affected the neurotransmitters in this model, we monitored the expression of calcitonin gene-related peptide (CGRP) mRNA in the facial nuclei. Its expression was up-regulated on the operative side. These findings suggest the possibility that the ischemic neuroparalysis model might be a useful animal model for basic research that creates pathophysiologic conditions much closer to clinical cases.

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We explored the possibility of local inflammation as the mechanism responsible for the chronic constriction injury (CCI) model. Local inflammation induces the release of several algogenic substances and causes pain. It is thought that nitric oxide (NO), a free radical, causes pain. We administered a free radical scavenger to a CCI model and analyzed the reactions of neuropathic pain through behavioral and histological studies. We divided the experimental model into group A, in which edaravone was administered at 15mg/kg/day, group B, in which it was administered at 5mg/kg/day, and group S, in which saline was administered. All substances were applied for a period of six days. We then used the Plantar test^[○!R] and a Dynamic Plantar Aesthesiometer^[○!R] to evaluate the degree of neuropathic pain. The Histological investigation of the occurrence of local changes was done using H-E staining. Evaluation of neuropathic pain using the behavior test showed no improvement in any of the groups. However, H-E staining showed no difference in the degree of increase in cell components. We found that the free radical scavenger did not inhibit neuropathic pain.

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We examined the influence of aquaporin 5 (AQP 5) on the paracellular transport of submandibular gland acini in Wistar rats focusing on elucidation of both AQP 5 and the junctional protein localization. In the control gland, although immunocytochemistry revealed expression of AQP 5 along the luminal membrane, it was not detected on the lateral membrane in the acinar cells. However, both E-cadherin and β-catenin were detected on the lateral membrane. In the gland stimulated by pilocarpine, localization of AQP 5 was similar to that in the control gland. In addition, there was positive staining of the lateral membrane. However, β-catenin disappeared on the luminal membrane. This is because water-rich fluid is secreted in the lumen of the acinar cells where AQP 5 is abundant, and because the tight junction is permeable. It is reasonable to speculate that both intracellular and paracellular transport play important roles concomitantly in water secretion. These results indicate that AQP 5 facilitates fluid secretion via the paracellular pathway in submandibular gland acini, and that the luminal membrane of gland acinar cells is the rate-limiting barrier to water movement.

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We attempted to clarify the effect of the water temperature used for mixing impression materials on blood circulation by analyzing the changes in blood pressure in healthy adults during impression taking of the maxilla. The subjects were 21 healthy adults who had no history of cardiovascular disease. Blood pressure was measured using a noninvasive continuous sphygmomanometer during impression taking, which was done with alginate and a stock net tray. The alginate was mixed either with water at room temperature water (24-26℃) or with cold water (4℃). Although there was variation among the subjects, all showed an elevation in blood pressure during impression taking. Also, the mixing temperature significantly affected the blood pressure during impression taking, with the lower temperature inducing a greater elevation in blood pressure. We concluded that the mixing temperature of the water significantly elevated blood pressure. The lower temperature induced a greater elevation in blood pressure. This was true regardless of whether the cold water was used for the first impression or the second.

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Twenty-four subjects were classified into two groups. Group I was 18 patients with missing teeth. Six were missing an anterior maxillary tooth, 5 had maxillary complete dentures, 5 were missing mandibular molars and two were edentulous. Group II was 6 patients who had malocclusion. One had an open bite and 5 had mandibular protrusion. Assessment of articulation was based on the 100 Japanese monosyllable articulation test. Sound analysis was performed with a sound spectrograph to reveal any vocal changes caused by dental disorders. The articulation score for Group I was 71.4-96.0% (average 89.0%), while for Group II it was 88.4-97.0% (average 93.0%). Of the 24 subjects, 18 had a score of 80% or greater. Twelve subjects in Group I (66.6%) misarticulated /d/ and /n/, 9 subjects (50.0%) misarticulated /dz/, 8 subjects (44.4%) misarticulated /t/, 6 subjects (33.3%) misarticulated /ts/ and /r/. The alveolar sounds /d/, /n/ and /t/ sounded more like the bilabial sounds /b/, /m/ and /p/. The sibilant sound /d/ sounded like /r/. Four subjects in Group II misarticulated /d/, and 3 misarticulated /s/, /dz/ and /d〓/. The alveolar /d/ and sibilant sound /s/ sounded like /r/ and /∫/ respectively. The sound spectrogram showed the same trend in seven out of eight subjects with loss of teeth and malocclusion. During the articulation of /s/, /ts/, /t∫/ and /n/, formant 2 was increased above the baseline, increasing the difference between formant 1 and 2. The tongue moved forward in a compensatory effort to overcome the dental abnomalities. We concluded that ordinary conversation is unaffected by dental disorders.

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We have previously reported that some clinical isolates of Prevotella intermedia (P. intermedia) produced large amounts of extracellular viscous material that consisted mainly of neutral sugars, and that the capacity to produce exoplysaccharide (EPS) might allow this organism to live as a matrix-encased microbial community, rendering it highly resistant to unfavorable environmental conditions. In this study, we investigated how these clinical isolates (P. intermedia strains OD 1-2 and OD 1-16) change their productivity of EPS under ethanol and salt stress, which are known activators of biofilm formation. When trypticase soy broth (TSB) was supplemented with 3% ethanol (v/v), viscosities of spent culture media from OD 1-2 were significantly increased, although they were slightly decreased from OD 1-16. Supplementation of TSB with 1% (w/v) NaCI significantly enhanced the viscous material production on both OD 1-2 and OD 1-16. These results may suggest that P. intermedia has the capacity to augment its viscous material productivity under a stressed condition and that the response against ethanol stress is not identical among strains.

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It has recently been clarified that various hormones and cytokines derived from adipose tissues are essential for the maintenance of biological homeostasis, and that adipose tissues are the heaviest endocrine organ in the body. We induced obesity in mice and investigated how traditional Chinese herbs effected their condition. The herbs improved obesity by reducing body and organ weights. Cellular hypertrophy created by enlarged fatty droplets was noted in visceral and subcutaneous white and brown adipocytes in the control (c) group with the high-fat diet group compared with the group given the normal diet (N). In contrast, the body and organ weights were decreased in the group treated with the Chinese herbs (CH) compared with the C group. This was evidenced by a reduction in adipocyte hypertrophy. These findings suggest that the traditional Chinese herbs modified fat metabolism in the obese mice.

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We evaluated the retentive force characteristics of electroformed telescope crowns by analyzing the retentive force-displacement curve during vertical dislodgement using a tensile testing machine. The inner crown was made of gold alloy with 0, 2, 4 or 6 degrees of taper between the axial surface and the principal axis of the abutment tooth. Five outer crowns were made by electroforming on the same inner crown, and tensile tests were done five times on each sample. We measured the displacement before (DBP) and after (DAP) the peak retentive force, and calculated the retentive energy before (EBP) and after (EAP) the peak. All measurements were performed with and without the interposition of artificial saliva. We found that the retentive force was augmented significantly by the interposition of artificial saliva. The retentive force of the electroformed telescope crown was significantly greater with 2 degrees of taper than with 6 degrees. DBP and EBP were both significantly greater at 0 degrees than at 2, 4, or 6 degrees. In addition, DAP of the 2 degree crown was significantly greater than the other values. EAP of the 0 and 2 degree crowns was significantly greater than that of the 4 and 6 degree crowns. The peak retentive force, DBP, DAP and EBP of the 2 degree crowns were comparable to magnetic attachments. We concluded that the 2 degree electroformed telescope crown could be used as an effective retainer for the protection of abutment teeth.

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We investigated how distal tipping of the mandibular first molar affects the direction of eruption of the second molar. Eight female monkeys with mixed dentition were used in this study. An extraoral force of 300g per side was applied distally to the tip of the mandibular first molars. Tantalum implants were placed in the mandible to allow accurate superimposition of serial cephalograms and to document changes in the mandibular bone following force application. The lateral cephalograms taken during the active treatment of 180 days were used to analyze tooth movement. From the cephalometric findings we concluded that first molars of the experimental animals tipped distally, and the second molars tipped mesially before eruption. However, although the second molars began to tip distally as they began to erupt, they ultimately moved distally and tipped mesially.

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We measured the viscoelastic properties of implants placed in bone augmented by guided bone regeneration (GBR). Moreover, the viscoelastic properties of implants in bone augmented by GBR (GBR group) were compared with those of IMZ implants with either an element made of pure titanium (Ti group) or an intramobile element made of polyoxymethylene (IME group). The viscoelastic properties of the implants were measured by an automatic mobility diagnostic system that we developed. Statistical analysis was performed using the Kruskal-Wallis test for comparison between groups at a significance level of 0.05. When a significant difference was found, the Dunn test was applied for after-the-fact comparison. There were significant differences among the three groups for all parameters (viscosity c_1, viscosity c_2 and elasticity k) by the Kruskal-Wallis test. The three parameters were greatest for the GBR group, and the values were lower for the Ti and IME groups in that order. Moreover, even when only the internal element in the same implant was changed, there was a tendency for the Ti group to have greater values than the IME group. We concluded that implants where GBR has been used show good viscoelastic properties.

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We treated 29 patients who had Angle Class II division 1 malocclusion using the functional regulator. Cephalograms taken before and after treatment were traced and analyzed. Five esthetic indices were used to evaluate soft tissue profile changes in the patients. Most of the indices tended to normal values and soft tissue profile of the patients improved after the functional treatment. However, individual changes differed and second stage treatment was still required for some patients.

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We investigated how the position of the mandibular incisors relates to an acceptable soft tissue profile in Japanese adults. The E-line was used to evaluate esthetics. In addition, the 108 subjects were divided into four groups, and the Holdaway ratio was determined for each group. We found that all the subjects had a positive distance from the pogonion to the NB line of between 0.1mm and 4.2mm. The positions of the mandibular incisors could be moved by modifying the distance from the pogonion to the NB line. We determined that an acceptable Holdaway ratio in Japanese adults was 2:1 in the subjects who had 3mm positive distance from the pogonion to the NB line, and 3:1 in the subjects who had 2mm of distance. These results suggest that about 6mm is a desirable figure for the distance from the mandibular central incisor (L1) to the NB line as the final treatment target in Japanese adults.

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We studied the causative factors and prodromal symptoms of facial nerve palsy by questionnaires given to 219 patients who were seen between 1978 and 1982 at Hyogo College of Medicine and between 1996 and 2004 at Chibune Hospital and Osaka Dental University. Each patient was asked to select his or her most likely causative factors (physiological or psychological) of facial palsy and the most dominant symptom from a list. The two most prominent causative factors reported for facial nerve palsy could roughly be divided into the two categories of physiological (65.3%) and psychological (16.9%). These results did not differ greatly between Bell's palsy (BP) and Hunt syndrome (HS). Prodromal symptoms were also of two forms: those specific to viral infection, such as facial pain and vertigo, and those thought caused by disturbances in the autonomic nervous system (ANS), such as stiffness in the shoulders and headaches. While disturbances in the ANS seem to be the major cause of BP, viral infections seemed predominant as the cause of HS. These results were based on the assumption that damage to the facial nerve in BP is predominantly caused by strangulation in the fallopian canal resulting from local disturbance in the ANS. Therefore, the disruption of the blood flow, which was directly caused by the viral infection, was more important than neuritis,. We discussed the relationship of stress, reactivation of the neural virus, and disturbances in blood flow in the fallopian canal.

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The aging society in Japan has resulted in a marked increase in the number of elderly patients seeking dental treatment. In the present study, we investigated successive changes in the average age of insertion of prosthesis, and examined the influence of aging. The investigation focused on inlays which are thought to be the preceding stage of all prostheses, crowns, bridges, partial dentures, and complete dentures, that were placed in patients at Osaka Dental University Hospital between June 1997, and May 2005. In addition, we examined the average age of insertion of these prostheses. The result showed a significant increase in the average age of inlays, crowns, and partial dentures throughout the investigation period, but no significant change was observed in bridges and complete dentures. This is considered to be due to the different reasons for renewing each prosthesis. A decrease in the number of missing teeth was observed despite a minor difference among different prostheses. Based on these results, we predict there will be an increase in the number of bridges and partial dentures in the future, and a decrease in the number of complete dentures.

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