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Patient: A 62-year-old man complained of discomfort during insertion of lower removable partial denture (RPD). Existing denture was highly objectionable to tongue and intolerable to wear due to volume and contour of its lingual aspect. The treatment plan included fabrication of an interim denture and altering its shape until it did not lead to discomfort, followed by fabrication of a final denture. Consequently, RPD using sublingual bar was found to be the most comfortable to wear and was fabricated as final denture. The patient was ready to insert the final denture and restoration of masticatory function was accomplished., Discussion: In cases with unfavorable anatomic conditions such as a lack of mouth-floor depth, lingual plate should be applied as first choice, and when it is not well tolerated by the patient, sublingual bar should be applied., Conclusion: Sublingual bar is suggested to be one of the least objectionable major connectors.

Patient: A 50-year-old female who wore a cast-clasp-supported removable partial denture (RPD) complained of speech disturbance, because the clasps disturbed her tongue movement during speech. She wished to receive dental implant treatment, but it was difficult to solve the esthetic problem by the planned implant-supported fixed partial denture. Therefore, the RPD (overdenture) supported by magnetic attachments was inserted to recover the speech disturbance., Discussion: The treatment outcome of this patient was evaluated with a self-administered questionnaire. The results suggested that the RPD with magnetic attachments improved the patient's pronunciation, esthetics and quality of life., Conclusion: It was suggested that the magnetic attachment overdenture effectively solved the speech disturbance.

In the treatment of removable dentures including mucosa born, it is essential to secure the occlusion based on adequate consideration of deformation of mucous membrane. This means that it is necessary to clarify the plastic deformation of underlying soft tissues after denture insertion. With the objective of assessing the influence of the difference in the supporting pressure of the underlying soft tissues, the longitudinal changes of the tissue surface after insertion of denture were observed. The non-pressure areas with special conditions were established between the basal surface of the dentures and the surface of the underlying soft tissues. Removable free end dentures with cylindrical non-pressure cavity (3 mm in diameter and 2 mm in depth) in the basal surface were prepared for 20 subjects having a missing of lower posterior region. Such three non-pressure cavities were positioned in the following locations: in a mesio-distal location corresponding to the distal region of the first molar, at the alveolar crest, at a location halfway between the alveolar crest and the buccal denture border, and a location halfway between the alveolar crest and the lingual denture border. Impressions were taken from the subjects' jaws after the fixed numbers of days following initiation of denture wearing. Contours of the non-pressure areas were measured in 100 jaw models. Results. 1. Swelling of the mucous membrane of the non-pressure area 1) Subjects are classified into the following 5 types on the bases of longitudinal changes in the swelling height of the mucous membrane in the non-pressure area. Type S-1: Marked increase in swelling height observed within the first 3 days after insertion of dentures, but practically no change in swelling height until the 30th post installation day. Type S-2: Marked increase in swelling height observed within the first 3 days after insertion of dentures, and swelling height increased continuously until the 30th post installation day. Type S-3: Marked increase in swelling height observed within the first 3 days after insertion of dentures, but swelling height decreased continuously until the 30th post-installation day. Type G: Increase in swelling height comparatively small within the first 3 days after insertion of dentures, but swelling height increased until the 30th post-installation day. Type N: No increase in swelling height observed until the 30th post-installation day. 2) Swelling height and frequency in each location according to type.(ABSTRACT TRUNCATED AT 400 WORDS)

It was examined, in this study, whether the tannin-fluoride preparation (HY preparation), which might have a caries reductive, plaque inhibiting and astringent action, could reduce the incidence of gingival inflammation around abutment teeth for removable partial dentures. Zinc oxide eugenol cement mixed with HY preparation filled in the cavity prepared in the resin base facing the abutment tooth. Crevicular fluid (Periotron unit: GCF), gingival index (GI), plaque index (PII), probing depth and caries activity around the abutment tooth were measured during 12 months. The following results were obtained: 1. GCF decreased at 1 month later and showed low values at 2, 3, 6 and 12 months. 2. The percentage of low GI value showed an increasing tendency during the experimental period. 3. There was slight variation in PII and probing depth during the experimental period. 4. Caries activity showed a decreasing tendency. These results indicate that the tannin-fluoride preparation reduces not only caries activity but also gingival inflammation around abutment tooth.

The purpose of this study was to simulate the process of bone resorption under removable denture bases. Two dimensional finite element models were prepared for the frontal section of a maxillary complete denture with its supporting mucosa and bone in the first molar region. Simulations were performed with the optimization program which could proportionally move the nodal points according to the stress level difference between the actual and the reference stress level. By exerting loads on occlusal table of the model, the bone resorption progressed in the similar manner to reported clinical observations. The location and magnitude of the resorption were highly related to the location and direction of the loads.

Excess denture movement during function may cause to jeopardize the resorption of the residual ridges and the mechanical trauma on the abutments in the partially dentate mouth. A removable partial denture (R.P.D.'s) should be so constructed that the artificial teeth on the denture base will be stabilized in their spatial position by way of the compensatory support due to the remaining abutments and the residual ridges. In this pilot study, the ordinary denture movement, that is the denture dynamics in function of the free end saddle R.P.D.'s was measured in the test denture assembly. The denture dynamics was assessed in two ways: The displacement sensors revealed the vertical and the horizontal movement of the denture base during function. They were based on the field magnetic effect and with good lineality. Tiny accerelometer was attached to the denture base to detect the accerelation during function. Ordinary mastication was not interefered by both methods. The Author has already reported the palpation test for diagnosing the denture dynamics of the free end saddles in clinics. This method was discussed objectively against the accerelometry on fifty patients. Two methods have revealed the good coincidence with each other to detect the dynamics of the free end saddles.