It is very important to obtain a well fitting denture base when making a full denture for the edentulous patient. The denture base is stable in the mouth when it has a tight marginal seal. It is therefore important that we dentists possess the knowledge and technique for taking good impressions.
In order to accomplish a good marginal seal, the margin of the denture base must have a functional form and be in harmony with movements of the perioral muscles. The most important thing is that we are able to take the correct functional impression when these muscles are properly functioning.
I feel that it is poissible to easily obtain a correct functional impression if a treatment provisional denture is fabricated and adjusted with the appropriate vertical dimension of occlusion, proper positioning of the artifcial teeth, and correct occlusal contact during lateral excursions.

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Among the various methods (including the method using Lucia's jig) for guiding the mandible to centric relation, locating centric relation with a leaf gauge has been assumed to be the optimum way.
In this paper, the virtue of the Lusia's jig which has been improved by D_R Lusia in 1985 is discussed in comparison with the old one. The improvement was to add a ledge on the upper part of the lingual side of the jig to where the incisal edge of the lower incisor contacted and in which the surface of the ledge was made in parallel to the occlusal plane.
One of demerits of the old Lucia's jig was that the patient was apt to bite anteriorly due to lack of vertical stop for the lower incisor, causing the condyles to displace anteriorly. On the contrary, another demerit of it was that, in some cases, the incisal edge of the lower incisor was apt to slide along the lingual surface of the jig in supero-posterior direction and then the mandible was forced to retrude and the condyles were pressed backwards.
In the improved version of Lucia's jig, the above mensioned demerits were cancelled by placing a vertical stop (a ledge) . In addition, an merit was added that the incisal edge of the lower incisor can move freely back and forth or left and right in small area on the surface of the ledge.
The method of locating centric relation with a leaf gauge has the same demerits as the old Lucia's anterior jig had. Therefore, it is concluded that the method using an improved Lucia's jig is superior than the method using a leaf gauge.

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Marginal openings before and after cementation has been measured on freshly extracted teeth. This study measured marginal openings after cementation on natural teeth in a many teeth treatment case for examining the compensating effect of periodontal ligament in oral cavity.
1. Maximum marginal opening after temporary cementation was 0.26 mm in maximum.
2. Maximum marginal opening after final cementation was 0.16 mm in maximum, that is, 0.08 mm larger than the value on extracted teeth and 0.10 mm smaller than the value after temporary cementation.
3. Decrease of maximum marginal openings from“after temporary”to“after final”cementations can be attributed to the effect of the remount procedure performed between the temporary and final cementations.

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The titanium is superior in strength and resistance against corrosion, and the stimulation toxicity for a tissue is little. Positive introduction is planned in the field of endodontics ultra elasticity and shape memory are special. On this account, in the field of tooth treatment, the nature of the nickel enhanced titanium alloy is utilized. If conforms to it with flexibility in root canals. Possibilty of reduce technique troubles, especially in curve root canals where difficult operations were needed formerly. hecently, it becomes possible to do effectively treatments. At This time, this study was examined and discussed conformity in the extracted root canales which compared with useing titanium files and stainless files. As a result, in carve canal, a meaningfull difference was recognized and NT file system was an effective appliance for gulf canal.

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Mathematical equations to calculate the amount of disocclusion on an articulator from adjustment values of the condylar guidance and anterior guide table and also cusp angles on the casts, were derived, based on the mathematical model of mandibular movement. The equations derived can be used for analysing relations between the amounts of disocclusion, cusp angles on the casts and adjustment values on an articulator.

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The disease referred to as temporomandibular disorder that we encounter in clinical dentistry includes joint noises, pain in the joint, and disruption of joint movements during opening and closing of the mouth. However, the symptoms do not stop here, but may also include the associated muscle groups and autonomic nervous system, as well as nonspecific psychosomatic complaints. This is a disease that has chief complaints such as clicking, pain in the masseter muscles, discomfort, problems with opening and deviation of the mandible, feelings of fatigue in the head, neck, shoulders and back, and disruption of mandibular movement. Consequently, temporomandibular disorder patients may complain of symptoms associated with premature contacts in centric occlusion, cuspal interferences during lateral excursion, a decrease in the intermaxillary distance, and rapid changes in the vertical dimension of occlusion.
Recent treatments for temporomandibular disorder have included splint therapy, pharmacological treatments, and sometimes even surgical intervention. In addition, orthodontic and prosthetic treatments have been carried out as a technique for occlusal rehabilitation of the repositioned mandible after conservative treatment using a splint. However, because temporomandibular disorder is fundamentally a multifactorial disease, a treatment protocol has yet to be established.
I would like to report here the good results I obtained using the sliding plate, which is employed in the orthodontic treatment of some young patients for correcting and activating inappropriate muscle function associated with occlusion.

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Effective cusp angle which is defined as “the angle made by the average slope of a cusp with the horizontal reference plane measured buccolingually along the cusp path of the opposing tooth”, was measured on occlusal surfaces of the “cusp fossa design dental model” made by Dr. Peter K. Thomas. The cusp angles were measured on the left and right working and nonworking sides of the model's maxilla and mandible. The cusps of the first and second molars were cut perpendicularly along each cusp path of the opposing tooth, the horizontal reference plane was drawn on each section and the photo of the section was taken and each cusp angle was measured on the section using a graduator. The measurement was done by two dentists and an engineer. The results were analaysed statistically.
The average cusp angles of the first molar on the left and right sides of the model's maxilla and mandible were 15.8° and 22.5° on working and nonworking sides, respectively. The corresponding data measured on the second molar were 15.0° and 22.5°. The standard deviations of each measurement were less than 4.0°.
The above averaged values were compared with the standard values which were determined by means of computerized analysis theoretically and experimentally by Hobo and Takayama. The differences between the both were less than 1° on working side and less than 3° on nonworking side.
The significance of the measurement along the cusp path of the opposing tooth, systematic errors due to the difference of the horizontal reference plane, human errors during measurement, laboratory workmanship errors in the dental model and statistical difference between the effective cusp angles of the model's maxilla and mandible on nonworking side, were discussed.

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Deep caries, an existing faulty restoration, or a collapse of edentulous alveolar ridge may not only affect the amount of coronal support but may also leave large deformities to the fixed prosthesis.
Therefore, to repair of lost oral structures and prevention of unacceptable esthetic deformities, surgical crown lengthening or edentulous ridge augmentation were performed.
In this paper, we present a case which underwent a 2-step surgical procedure, consisting of a crown lengthening with apically positioned flap and a edentulous ridge augmentation with subepithelial connective tissue graft to removal of subgingival root caries, to improve asymmetrical or unesthetic gingival topography, and to correct the form of ridge.
In consequence of these periodontal reconstructive surgery, we attained the establishment of more idealized ridges prior to placing fixed bridge in the maxillary anterior portion.

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A large number of devices are frequently used in daily clinical practice as retainers for partial dentures, including clasps, telescopes and various attachments. However, in cases where there are few remaining teeth and the biological conditions associated with the oral cavity are bad, we have all had problems with the selection of retainers and the preservation of anchor teeth. In recent years magnetic attachments have been used for clinical cases like this. It is said that the retention of magnetic attachments does not deteriorate over time, and that this retainer minimizes harmful rotational and lateral forces on the anchor teeth.
I would like to report a case with one remaining tooth where I attempted to restore function using an over denture with magnetic attachments.

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Various compornents and surgical-prosthetic method for osseointegrated implant have been developed as for using single-tooth restorations in implant prosthesis. The present case was observed for edenturous ridge of the 1st premolar on the upper left side which conditioned the narrow intercoronal distance and the lack of the quantity of buccal alveoear bone.
For these problems, we performed guided bone regeneration (GBR) procedure using by autogenous bone graft and edentulous ridge augmentation using by subepithelial connective tissue graft. The purpose of this report is to point the reproduction of the aesthetical emargence profile for single-tooth restoration using by Screw-Vent^® implant.

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