Chiba, Japan
Chiba, Japan

Tokyo Dental College is a private university in the city of Mihama-ku, Chiba, Japan. The predecessor of the school was founded in 1890, and it was chartered as a university in 1946. Wikipedia.

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Taguchi T.,Tokyo Dental College
The International journal of oral & maxillofacial implants | Year: 2011

The purpose of the present study was to determine whether intravenous sedation during dental implant surgery contributed to stabilization of hemodynamics. Two hundred fifty-five consecutive patients treated with dental implants were randomly assigned to receive either intravenous sedation with local anesthesia (sedation group, n = 123) or local anesthesia only (nonsedation group, n = 132). Midazolam and propofol were used synergistically as sedative agents. Systolic blood pressure, diastolic blood pressure, and pulse rate were measured every 2.5 minutes during dental implant surgery. On the basis of these data, the coefficient of variation, percentage of change, maximum values, and incidences of a larger increase were analyzed and expressed as cardiovascular changes. A comparison of percentages of change, maximum values, and incidences of a greater increase showed that systolic and/or diastolic blood pressure were significantly higher in the nonsedation group than in the sedation group. The combination of midazolam and propofol sedation prevented excessive increases in blood pressure. The circulatory suppression induced by the intravenous sedation regimen not only reduced mental stress arising from the state of sedation but also exerted a pharmacologic effect. The application of this intravenous sedation regimen stabilized hemodynamics and contributed to the safety of the patient in dental implant surgery. The application of intravenous sedation had a beneficial effect for hemodynamic changes during dental implant surgery.

The aim of this retrospective study was to determine factors that might cause complications in use of temporary anchorage devices (TADs) for orthodontic anchorage. We investigated 904 TADs in 455 patients. Clinical diagnoses requiring orthodontic treatment were malocclusion, jaw deformity, various syndromes, cleft lip and palate and impacted teeth. All patients underwent surgery at Tokyo Dental College Chiba Hospital between November 2000 and June 2009. Three kinds of titanium screw of different diameter and length were used: self-drilling mini-screws (Dual Top Autoscrew® and OSAS®), pre-drilling micro-screws (K1 system®) and palatal screws (PIAS®). Mini-plates fixed with 2 or 3 screws (SAS system®) were also used for skeletal anchorage. Patients were aged between 8 and 68 years (25.7±9.8 years). A total of 460 screw-type and 444 plate-type TADs were used. These comprised the following: mini-plates, 444; self-drilling mini-screws, 225; pre-drilling micro-screws, 83; and palatal screws, 152. Each type of implant had a high success rate of over about 90%. Failure rates were as follows: micro-screws, 7%; mini-screws, 6%; palatal implants, 11%; and mini-plates, 6%. Inflammation rate occurring in soft tissue surrounding TADs was follows: plate-type, 7.6%; mini-screws, 1.3%; micro-screws, 0%; and palatal implants, 2.5%. Inflammation frequencies depended on degree of mucosal penetration. Granulation rate in soft tissue surrounding TADs occurred as follows: micro-screws, 5.7%; self-drilling mini-screws, 0%; palatal screws, 0.6%; plate-type, 0.9%. Both plate- and screwtype orthodontic implants showed excellent clinical performance.

Komiya Ito A.,Tokyo Dental College
The Bulletin of Tokyo Dental College | Year: 2010

Periodontopathic bacteria such as Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Campylobacter rectus and Treponema denticola play an important role in the initiation and progression of periodontitis. The aim of this investigation was to evaluate the relationship between periodontal clinical parameters and the subgingival profile of periodontopathic bacteria. Twenty-six periodontitis patients (23-62 years of age; mean age, 40.2±13.2) with no systemic disease agreed to participate in the study. Periodontal clinical parameters, including probing depth (PD) and bleeding on probing (BOP) were recorded. Subgingival plaque samples were obtained from deep (PD≥4 mm) and shallow (PD≤3 mm) pockets in each patient for detection of P. gingivalis, A. actinomycetemcomitans, T. forsythia, C. rectus and T. denticola by polymerase chain reaction technique. The relationship between the periodontal pathogens and clinical parameters was determined with the Fisher exact test, and a statistically significant association was found between detection of P. gingivalis, T. forsythia, C. rectus and T. denticola and PD or BOP. T. denticola was the most prevalent pathogen in both shallow PD and deep PD sites. No statistically significant association was found between detection of A. actinomycetemcomitans and the clinical parameters examined. A statistically significant association was found between detection of the red complex bacteria and the clinical parameters. These results suggest that the red complex pathogens and C. rectus play an important role in the initiation and progression of periodontitis.

Sugihara N.,Tokyo Dental College
The Bulletin of Tokyo Dental College | Year: 2010

The purpose of this study was to determine the risk factors for root surface caries in the elderly and to evaluate the factors associated with gingival recession, one of the main risk factors for root surface caries. A total of 153 elderly people (35 men, 118 women) aged between 60 and 94 years (73.5+/-7.5 years) were surveyed. All participants were relatively healthy elderly who did not need special care in their daily lives. The survey was conducted in Chiba prefecture, Japan, and oral examinations and a questionnaire with face-to-face interviews were also carried out. Correlation analysis revealed that number of present teeth (p<0.001), gingival recession (p<0.001), bleeding on probing (p<0.001) and presence or absence of dentures (p<0.05) were significantly correlated with number of root surface caries. Stepwise multiple linear regression analysis for root surface caries revealed that the risk factors for increasing numbers of teeth with root surface caries were number of teeth with gingival recession (p<0.0001), bleeding on probing (p=0.0017) and self-reported dry mouth (p=0.0454). Sex (p<0.05), number of present teeth (p<0.001), bleeding on probing (p<0.01), the presence or absence of systemic disease (p<0.01), dentures (p<0.01), drinking alcohol (p<0.01) and smoking (p<0.01) were significantly correlated with amount of gingival recession by correlation analysis. Moreover, the risk factors for increasing number of teeth with gingival recession were living in an institution (p=0.0244), number of present teeth (p<0.0001) and smoking (p=0.0037), as determined by stepwise multiple linear regression analysis for gingival recession.

Various bone matrix proteins are produced during the process of osteogenesis. Many previous studies suggested that the topography of an implant surface might affect the expression of osteoblast-mediated cytokines. However, these earlier studies were performed using in vitro cell culture. This study investigated the influence of the surface topography of a titanium implant placed under the periosteum on the gene expression of bone morphogenic markers in rat. Six custom-made implants with a rough upper surface and 6 custom-made implants with a smooth machined upper surface were placed subcrestally with the upper surface facing up in the femurs of 6 adult male rats. Five rats were sacrificed 7 days after the implant placement, and the periosteum above the embedded implant was obtained and analyzed by quantitative real-time RT-PCR for the target genes: alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteocalcin (OCN). The other rat was sacrificed at day 7, and both implants and the surrounding tissue were embedded in paraffin. For light microscopic observations, paraffin sections were stained with toluidine blue. Gene expression of ALP, BSP and OCN at the rough surface implant was significantly higher than that at the smooth machined surface implant. At day 7, both types of implant were covered with soft tissue, but a lower number of cells stained with toluidine blue was observed on the machined surface compared with on the rough surface. It is considered that rough surfaces may stimulate osteoblasts, and that ALP activity is increased indirectly. Furthermore, the two other markers were also increased by the rough surface in vivo, and different distributions of cellular and extracellular components on the upper surface of the implants were observed at day 7. These results suggest that a rough surface implant under the periosteum promotes higher gene expression of ALP, BSP and OCN in rat.

Dens invaginatus is a morphological abnormality of the tooth in which the coronal tooth enamel and dentin fold inwards towards the pulp cavity. Dens invaginatus type III (Oehlers: 1957) is characterized by infolding of the enamel and dentin as far as the root apex. This report describes a case of surgical and non-surgical endodontic therapy for a maxillary lateral incisor with type III dens invaginatus, necrotic pulp, and an associated large periradicular lesion. The patient was a 16-year-old man. Periapical radiographs suggested the presence of an untreated area of invagination. Cone beam computed tomography (CBCT) was then used for three-dimensional observation of the morphological details of this area. The CBCT scans revealed invagination and its relationship with the pulp chamber. A dental operating microscope was used to access two primary root canals and the area of invagination. The root canals were then localized, negotiated, enlarged, and filled with calcium hydroxide. Two months later, the canal and invagination were obturated with core-based gutta-percha (FlexPoint Neo: FP core-carrier technique) and restored. Cone beam computed tomography and microscopic techniques allow even complicated cases of dens invaginatus to be diagnosed and treated using non-surgical root canal management.

Onodera K.,Tokyo Dental College
The Bulletin of Tokyo Dental College | Year: 2011

The purpose of the present study was to determine the relationship between cross-sectional design and fracture load using a static load bearing test in yttria-stabilized tetragonal zirconia polycrystal ceramic frameworks on a molar fixed partial denture. The test framework was designed as a 3-unit bridge with two abutment teeth at the second premolar and second molar of the mandible. The cross-sectional area of the connector was 9.0, 7.0, or 5.0mm(2). In terms of shape, the cross-section was either circular or oval, with a height/width ratio of 1:1, 3:4, or 2:3. For each of the 9 combinations of cross-sectional area and shape, 5 frameworks were prepared (45 in total). Frameworks were cemented to a metallic test model with adhesive resin cement. After fracture load was measured, the percentage of fracture sites was determined and the fracture surfaces observed. In terms of cross-sectional area, there was a statistically significant difference in fracture load between 9.0, 7.0, and 5.0mm(2). No significant difference in fracture load was observed between any two shapes of connector (p>0.05). The fracture load of all frameworks with a cross-sectional area of 9.0 or 7.0mm(2) was over 880 N, which was recognized as parafunctional occlusal force. Fracture occurred at the distal connector in 82.2% of all frameworks on average. Fracture load decreased as cross-sectional area of the connector became smaller. The cross-sectional shape used in the present study was less influential on fracture load. It appears to be clinical possible to apply a connector with a cross-sectional area of 7.0mm(2). Fracture often occurred at the distal connector between the pontic and the abutment, corresponding to the second molar.

Shimazaki J.,Tokyo Dental College
Journal of Cataract and Refractive Surgery | Year: 2010

Safe and efficient exposure of Descemet membrane is the key to success in deep anterior lamellar keratoplasty. Although widely used, the big-bubble technique has the drawback of difficulty in maintaining appropriate needle insertion depth in the corneal stroma, resulting in injected air sometimes escaping to the peripheral cornea without separation of Descemet membrane. We describe a variation of the big-bubble technique in which air is injected into the anterior chamber before it is injected into the stroma. By observing the reflection created on the surface of the air, a needle can be inserted deep into the stroma without puncturing Descemet membrane. This allows safe and efficient separation of Descemet membrane. Moreover, air in the anterior chamber can be used as an indicator of successful Descemet membrane separation as air is shifted to the periphery with creation of the big bubble. Financial Disclosure: The author has no financial or proprietary interest in any material or method mentioned. © 2010 ASCRS and ESCRS.

Chiyoda T.,Tokyo Dental College
The journal of obstetrics and gynaecology research | Year: 2011

Epithelioid sarcoma of the vulva is an extremely rare and aggressive tumor. This tumor most commonly occurs on the labia majora in women of reproductive age. The molecular pathogenesis remains largely unknown. Only 20 cases of vulvar epithelioid sarcoma have been reported to date and more than half have had poor outcomes. We report a successfully treated case of vulvar epithelioid sarcoma in a 33-year-old woman. We performed a radical vulvectomy with flap reconstruction. Three years after surgery, the patient remains well, showing no evidence of recurrence. Early tissue diagnosis of vulvar epithelioid sarcoma is essential because this tumor can be clinically misdiagnosed as a benign lesion. Gynecologists should be aware of this rare tumor variant and carefully plan the treatment. © 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology.

News Article | February 15, 2017

Anesthesia Progress – Everyone wants less pain during dental surgery, but it can be challenging for dentists to choose the best drug option for each patient. Dentists have several general anesthesia alternatives and finding the right option can result in less patient anxiety and better overall outcomes. Researchers from the Tokyo Dental College in Tokyo, Japan wanted to find out which anesthetic was the better choice in a dental office: propofol or sevoflurane. In an article published in the current issue of the journal Anesthesia Progress, the researchers compared the recovery and satisfaction of 20 patients who had severe anxiety about the dental surgery. All patients were healthy, and none had been given general anesthesia for prior dental treatment. At two different appointments, each patient was anesthetized with either propofol or sevoflurane alone. Patients were given the same drug to eliminate any movement and a breathing tube was used. The single-drug anesthetic had never been studied; patients were always given opioids or nitrous oxide to keep them anesthetized throughout the procedure, making it difficult to pinpoint the effects of the primary painkilling drugs themselves. The researchers found no differences between the two drugs in terms of recovery. Although patients came out of anesthesia more quickly with sevoflurane than with propofol, all patients were discharged at a similar time. A few patients had nausea while recovering from sevoflurane, but none reported complications 24 hours later. All patients were able to eat their first meal and drink fluids at a similar time, and no patients experienced nausea or vomiting once leaving the dentists’ office. However, patients revealed a clear preference for propofol after being anesthetized with each drug. They said they had more discomfort and fatigue after taking sevoflurane. Some also said they disliked the smell of sevoflurane. Even though some patients reported more pain during injection of propofol, 80 percent of patients in the study said they would choose propofol for future surgeries. The researchers concluded that propofol is the anesthetic of choice for dental patients with severe anxiety about surgery, but these patients may continue to need general anesthesia in future surgeries. When patient satisfaction is the highest priority, the researchers suggest that dentists may want to give propofol during in-office surgery. Full text of the article “Recovery Profile and Patient Satisfaction After Ambulatory Anesthesia for Dental Treatment—A Crossover Comparison Between Propofol and Sevoflurane,” Anesthesia Progress, Vol. 63, No. 4, 2016, is now available at About Anesthesia Progress Anesthesia Progress is the official publication of the American Dental Society of Anesthesiology (ADSA). The quarterly journal is dedicated to providing a better understanding of the advances being made in the science of pain and anxiety control in dentistry. The journal invites submissions of review articles, reports on clinical techniques, case reports, and conference summaries. To learn more about the ADSA, visit

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