The Journal of Osaka University Dental School最新文献

In this study, our induction methods of endotracheal anesthesia was evaluated with reference to electrocardiogram, hemodynamic status and arterial blood gas analysis on 153 patients. From the beginning of induction, electrocardiogram was recorded continuously to the completion of intubation. The blood pressure and heart rate were also measured. Arterial blood samples were taken at 40 seconds of apneic period after the mask was removed from the patient's face (CONT group), at 40 seconds of apnea with intratracheal spray (LIDO group), and after intubation following intratracheal spray (INT group). In the electrocardiographic survey, arrhythmias during intubation were rare (1/113, 0.9%). PaCO2 values in INT group showed a significant elevation (+ 14.0 mmHg; p < 0.01) compared to these in CONT group. As a result of careful and gentle induction techniques, the incidence of arrhythmias during intubation was very low. However, an elevation of PaCO2 was not avoidable, even in smooth and successful intubation. In conclusion, the importance of more adequate ventilation coupled with skillful intubation in a shorter period to avoid hypercapnia and arrhythmias is appreciated again in the endotracheal anesthesia for the maxillofacial surgical patients with anatomical airway problems.

An accurate, quantitative method of measuring external nasal forms was described to evaluate the results of rhinoplasty, in which facial plaster models were measured with a highly accurate contact-type three-dimensional coordinate measurement apparatus. Furthermore, two original programs to identify facial landmarks objectively and to measure the curved surface of the external nasal form in order to evaluate cleft lip nasal deformities were described. These provided accurate and objective data for the facial landmarks and the curvature of nasal alae.

Two kinds of hard type self-cured denture reline materials were polymerized using three different techniques: (1) on a surface of glass plate, (2) under water, (3) under water with some hardening agent. Hardness of specimens were measured longitudinally during three weeks periods of storage in water at 37 degrees C. Results of our study indicated that the specimen cured with the special hardening agent showed the higher hardness than those cured only in water. Most of the hardness changes took place during first three days of the experiment period.

Amputation neuroma occurred in three cases among 111 cases of oral cancer patients after radical neck dissection. All of three cases appeared as a small nodule at superior neck around the carotid artery with accompanying tenderness. The lesions were located in continuity with the proximal end of nerve at excision. Although the incidence of amputation neuroma is low, critical examination is required to distinguish this from recurrent tumor after cancer surgery.

It has been shown that composite incorporating the antibacterial agent Triclosan (Irgasan DP 300, which is sparingly soluble in water, inhibited in vitro plaque formation by Streptococcus mutans, although the release of the agent was much less than the minimum inhibitory concentration for the bacterium. In this study, the inhibitory effect of the composite incorporating 1% Triclosan against growth and adherence of S. mutans was investigated. S. mutans was inoculated on the surface of a specimen made of control or Triclosan-incorporated composite and the number of bacteria was compared after 3, 6, 12 and 24 hr of incubation. The adherence of S. mutans to the control and experimental composite, with or without saliva treatment, was also examined by scanning electron microscopy. The composite incorporating Triclosan demonstrated significant inhibition of growth of S. mutans after 6, 12 and 24 hr of incubation. Adherence of S. mutans to the Triclosan-incorporated composite was less compared with control for both non-treated and saliva-treated specimens. It is concluded that the antiplaque effect of composite incorporating Triclosan depends upon its ability to inhibit bacterial growth and adherence, and Triclosan-incorporated composite is able to exhibit the antibacterial activity even after being treated with saliva.

The purpose of this study was to evaluate the effect of heat application after light curing on some physical properties of composite resin for dental inlay. Specimens each were additionally dry heat-cured at various temperatures for 15 min after initial light curing, and other specimens were not heat-cured as a control. Fracture toughness, bending strength, bending elastic modulus, coefficient of thermal expansion, hygroscopic expansion, microhardness, water absorption and solubility were determined. Fracture toughness, bending strength and bending elastic modulus were significantly higher when heated at 80-120 degrees C than the control. The coefficient of thermal expansion, hygroscopic expansion, microhardness and solubility were significantly improved than those of the control when heated, while water absorption was not significantly altered by dry heat-curing. These results indicate that the physical properties of composite resin, except water absorption, were improved significantly when heated after initial cure.

Leukoplakia is a commonly occurring precancerous lesion. The following case report describes a patient who had multiple leukoplakia in this mouth. He had three sites of leukoplakia, the left hard palate, the gum of the right maxilla and the gum of the left mandible, all of which underwent malignant transformation during the period of 11-years after diagnosis.

In previous research, we found that the Salvia Miltiorrhiza Bunge (SMB), a traditional Chinese medicinal herb, accelerates orthodontic tooth movement. In the present study, to characterize the actions of SMB on bone remodeling, we investigated the effect of SMB on DNA synthesis and alkaline phosphatase activity of murine osteoblast like cell-clone, MC3T3-E1 cells in vitro. Treatment of the cells with SMB for 72 hours caused significant increase in ALPase activity. It was found that SMB increased ALPase activity in a dose-dependent manner, and up to maximum at the concentration of 5.0 mg/ml. At that concentration, ALPase activity was about 135% greater than that of control. SMB at 5.0 mg/ml significantly stimulated ALPase activity of the cells in multilayer on day 8 or calcification stage on day 16, but inhibited it in the sparse stage on day 2 or subconfluency stage on day 4. SMB had no effect on DNA synthesis in any stage of culture. ALPase activity significantly increased at 48 hours and was up to 300% greater than that of control activity at 96 hours. These findings suggest that SMB directly stimulates ALPase activity of MC3T3-E1 cells in multilayer stage or calcification stage without any effect on proliferation. Locally administrated SMB may affect the differentiation of osteoblasts in vivo.

The object of this study was to analyze two measuring methods for determining the amount of generalized wear of dental materials. Using a recently developed three-body wear testing machine, generalized wear defect was produced on the surface of various dental materials. Although the generalized wear was defined as the depth of the enamel exposed at the cavity margin for both methods, this depth was measured with two different devices. One is an image-analyzer and the other was a profilometer. From the results of this study, it was confirmed that measurement by means of profilometer gave almost the same wear values with those by image-analyzer. In addition, the measurement by profilometer seemed to be more precise and not very much sophisticated.

With an increasing number of elderly people retaining natural dentition, the number of exposed root surfaces and root surface caries is increasing. A total of 100 people, aged from 38 to 86, were examined for exposed root surfaces and root surface caries. Denture wearers and non-denture wearers were examined. The following results were obtained; 1. The percentages of exposed root surfaces were significantly higher (P < 0.05) in the 60's and 70's age groups. Root surface caries showed a tendency to increase until people were in their 60's. 2. Denture wearers had more exposed root surfaces (P < 0.05) and were more likely to have root surface caries than non-denture wearers. Denture wearers showed a tendency to have more severe grades of root surface caries than non-denture wearers. 3. Concerning denture wearers, there were not significant differences in the percentages of exposed root surfaces of buccal and proximal surfaces facing edentulous space. However, proximal surfaces facing edentulous space were more prone to root surface caries than buccal surfaces (P < 0.05).