Purpose: This study assessed the influence of cross-sectional shape of the margin, contour, and positioning of palatal connectors on oral sensation.
Methods: The study population comprised six healthy dentulous individuals with an average age of 26 years. Ten types of connectors were fabricated in the form of light-cured resin baseplates; four types had different cross-sectional shapes of the margins, two had different contours of the upper surface (i.e., the surface facing the oral cavity), and four varied in their placement position. The subjects’ feelings when the different types of connectors were placed in their oral cavities were assessed using a questionnaire. The results were analyzed and weighted using the sigma score method, which is a tool used in the field of psychology.
Results: The results suggested that the subjects experienced greater comfort with connectors having a knife-edge-shaped margin (P<0.05). Moreover, greater discomfort was reported with bilateral oblique positioning of the connector, while less discomfort was reported with bilateral symmetrical positioning (P< 0.05).
Conclusion: We suggest that to achieve maximum oral comfort, palatal connectors should be constructed such that their thickness gradually increases from the margin toward the top, and they should be placed in a bilaterally symmetrical position.

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Purpose: To clarify the effects of deviated mandibular positions on the center of sole pressure in terms of fluctuations and positional changes.
Methods: Of 100 subjects at Osaka University Graduate School of Dentistry, 30 faculty members and students who exhibited no mandibular deviation (i.e., who had a median menton angle and an SNB angle within one standard deviation of the mean) were selected. Using a machine capable of assessing the distribution of sole pressure, the center of sole pressure and the degree of fluctuations in the center of sole pressure corresponding to the mandibular positions, were measured at deviated mandibular positions. The mandible was moved 3 mm in the left, right, or anterior directions and maximally in the posterior direction. The data were analyzed statistically using a paired t test with a significance level of P=0.05.
Results: No tendencies were observed between the positional changes in the center of sole pressure and the mandible moving from the intercuspal position. Whereas the degree of fluctuation increased significantly, irrespective of the direction of change, for the subjects in whom the position of the center of sole pressure did not change, or changed in the same direction as the deviated mandibular position, it did not increase for subjects in whom the position of the center of sole pressure changed in the direction opposite to that of the deviated mandibular position.
Conclusion: The results of this study suggest the possibility that deviated mandibular positions do not affect the positional changes in the center of sole pressure, but do affect the fluctuations in relation to the direction of positional changes.

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Purpose: The purpose of this study was to select silicone materials as markers on CT (computed tomography) images and to evaluate with edentulous mandibles wearing mandibular complete dentures. The study also aims to evaluate the influence of different mandible positions during CT examination on the resulting CT image.
Methods: Three different silicone impression materials and three different maxillomandibular registration materials were selected as markers. The CT number of the silicone specimens was measured. Nine dried edentulous mandibles used for the examination were categorized into three types; spiral CT was used to acquire images of each edentulous mandible wearing complete dentures with the markers. The following five measurements were taken: jawbone height, jawbone width, residual mucous membrane, distance from the impression material to mandibular plane, and angle of inclination of the mandibular crest. The measurements were performed using DICOM software.
Results: The CT number of Fit Checker was the highest of the silicone impression materials, while the CT number of Memoreg 2 was the highest of the maxillomandibular registration materials. There were significant differences for all measurement items between each other angles in the anterior, premolar, and molar area for the three bone types (P<0.05).
Conclusion: The impression material and maxillomandibular registration material with the highest CT numbers were selected as markers for CT and the five measurement items were quantified. Attention must be paid to positioning of the mandible because the CT image changes according to its position during the CT examination.

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Purpose: The purpose of this study was to classify condylar dynamics to understand stomatognathic disorders and design effective treatments for functional occlusal disorders by considering comprehensive mandibular function. This assessment of categorizing of condylar movement in combination with frequency analyses will contribute to the diagnosis and treatment of functional occlusal disorders.
Methods: Lateral-border movements with/without tooth contact were recorded from a reference condylar position in 102 patients (30 males and 72 females; mean age, 41.5±15.9 years) by using the CADIAX^®III (GAMMA, Klosterneuburg, Austria). After superimposing the two types of movement on both sagittal and horizontal planes, a trace of lateral movement with tooth contact was compared in terms of direction with the trace of the lateral movement without tooth contact. The area in the sagittal view was then classified into the following four categories: no-shift, upward shift, downward shift, and rearward shift. We obtained 10 grinding shift (GS) patterns by combining the four area categories of each condylar movement.
Results: The data set of condylar movements—a total of 204 sides of the 102 patients—permitted us to classify the pattern of each subject into 1 of the 10 GS patterns.
Conclusion: Since the GS patterns provided an active image of mandibular behavior during grinding movement, this newly developed classification is expected to improve the diagnosis of stomatognathic disorders.

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Purpose: Medical materials in clinical settings could function as risk factors that cause allergic symptoms. This issue is particularly relevant to dental professionals because they are exposed to various allergens. The objective of the present study is to conduct an allergy survey among dental professionals and clarify the actual prevalence and other parameters of allergies.
Methods: An anonymous questionnaire was distributed to employees and dental students working at the University of Tokushima Dental Hospital (currently, the Department of Dentistry, Tokushima University Hospital).
Results: Valid responses were obtained from 294 individuals (145 males and 149 females). The average age of the respondents was 34.0 years. Of the respondents, 61.2% had experienced some subjective symptoms associated with allergy. The most common allergic symptom was allergic rhinitis (40.1%), and 20.4% of the respondents perceived themselves to be allergic to medical gloves.
Conclusion: The study results indicated that the prevalence of subjective allergic symptoms was higher among dental professionals than among the general public or other healthcare professionals. This suggests that dental professionals work in an environment where they are likely to be sensitized to different allergens.

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Purpose: The purpose of this study was to investigate the effects of the insertion of unilateral extension base removable partial dentures (RPDs) on the elution of umami components during mastication in Kennedy Class II cases.
Methods: Rishiri kelp cut into 25 mm×25 mm pieces was selected as the test food. Eight patients with unilateral molar teeth defects were instructed to masticate samples for 50 strokes each, on the edentate side with RPDs, on the edentate side without RPDs, and on the dentate side. The amount of glutamic acid extracted from the samples was determined by spectrometry; the difference between the amounts of glutamic acid in the original and chewed samples was regarded as the amount intraorally eluted. The ratios of the amounts of glutamic acid eluted intraorally to that present in the original samples were compared among the groups.
Results: Bonferroni-adjusted Wilcoxon matched-pairs signed-rank tests revealed a significant difference between the ratios of the amount of glutamic acid eluted intraorally from samples chewed on the edentate side with RPDs and that from samples chewed on the edentate side without RPDs and between the ratios of the amount of glutamic acid eluted intraorally from samples chewed on the dentate side and that from samples chewed on the edentate side without RPDs (P<0.017). There was no significant difference between the ratios of the amount of glutamic acid eluted intraorally from samples chewed on the edentate side with RPDs and that from samples chewed on the dentate side (P=0.48).
Conclusion: Our results suggested that the insertion of unilateral extension base RPDs were useful for the elution of umami components during mastication.

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Purpose: This study evaluated the effect of the method of keeper fabrication on the attractive force of the magnetic attachment.
Methods: The attractive forces of the keepers of a Hyper Slim 3513 magnetic attachment system (Neomax Material Co. Ltd., Osaka, Japan) and Physio magnetic attachment system 35 (Nissin Co. Ltd., Kyoto, Japan) were measured. Specimens were prepared by the cast-bonding (n=5) and direct-bonding (n=5) techniques. The attractive force was measured using a digital force gauge (FGC-1, Nidec-Shimpo Corporation, Kyoto, Japan). The attractive force was statistically analyzed by the t-test at a significance level of α=0.05.
Results: The direct-bonding technique yielded a keeper with significantly greater attractive force than that of the keeper obtained by the cast-bonding technique (P<0.05).
Conclusion: Measurement of the attractive force of magnetic attachments fabricated by two different techniques revealed that the magnetic attachment fabricated by direct bonding possessed a significantly greater attractive force than that fabricated by cast bonding. Our results and those of previous studies suggest that the flatness and smoothness of the keeper surface may influence the attractive force of the magnetic attachment.

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Purpose: Porcelain-fused-to-gold copings prepared by the electroforming technique were introduced as an alternative to conventional metal/ceramic crowns. However, there are few clinical studies that have evaluated this technique. The purpose of this study was to prospectively evaluate the clinical performance of Auro Galvano Crowns (AGCs).
Methods: One hundred and twenty-seven AGCs were used to treat patients at the Tsurumi University Dental Hospital from October 2002 to December 2003. All the crowns were evaluated using the modified California Dental Association (CDA) quality assessment system at baseline and at all follow-up appointments.
Results: A total of 122, 119, and 72 crowns were examined at the 1-, 2-, and 3-year follow-ups, respectively. During the observation period, four crowns were removed because of partial fracture of the veneered porcelain in premolar and posterior teeth. No chips were detected during this observation period. All of the crowns examined were rated as satisfactory according to the modified CDA quality assessment system. During this period, the cumulative survival rate was 96.1%.
Conclusion: Within the limitations of this clinical study, AGCs luted with adhesive resin cement functioned satisfactorily with a relatively low fracture rate compared to porcelain-fused-to-metal (PFM) and all-ceramic crowns. Since the observation period was short, long-term observation will be necessary in order to further evaluate these crowns.

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Patient: The authors present the case of a 61-year-old woman who requested implant treatment for her completely edentulous maxilla because of difficulty in masticating with a removable complete denture. A treatment plan that involved the immediate loading of implants in the completely edentulous maxilla by using flapless surgery was developed. Soft tissue was punched out, and 10 implants were placed. To avoid sinus bone grafting, tilted implants were placed in front of the wall of the maxillary sinus and in the region of maxillary tuberosity. An immediate provisional restoration was placed on the same day.
Results: All the implants achieved good primary stability. Since an immediate provisional restoration was placed on the same day as the implantation, the patient was able to recover immediate jaw function. After surgery, she experienced no postoperative pain and did not need to take any anti-inflammatory and analgesic medications.
Discussion: Immediate loading of implants made it possible to reduce the treatment period, achieve immediate jaw function, and decrease surgery time. Thus, this treatment was obviously advantageous for the patient. Flapless implant surgery also contributed to minimizing surgical invasion, reducing the treatment period, and decreasing surgery time.
Conclusion: This report presents a case in which the implants were successfully loaded immediately into a patient’s completely edentulous jaw by using flapless surgery.

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Patients: A 9-year-old Japanese female patient with an unremarkable medical history was initially examined for the chief complaint of slight pain and discomfort in a traumatized maxillary central incisor. Four years after endodontic treatment, the patient complained of dark discoloration of the tooth. Among the treatments/restorations indicated, the patient and her parent consequently selected and approved of a porcelain laminate veneer restoration because of its advantage of minimal tooth reduction. The maxillary diastema was gradually closed after insertion of a porcelain laminate veneer, and 9 years of follow-up have revealed that the prosthodontic treatment successfully restored the tooth.
Discussion: Many methods have been introduced as aesthetic solutions to discoloration. Although the patient was satisfied with the prosthodontic approach from a functional as well as an aesthetic point of view, direct composite restorations might be an alternative for younger patients in mixed dentition.
Conclusion: The treatment in a growing individual should be carefully planned and performed, considering the development of permanent dentition.

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