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Biomedical subjects

T Suetsugu

Publications and source records attributed to T Suetsugu.

66 records · Page 4Linked to original sources
PubMed1978

A biomathematical study on implant design and stress distribution.

Three types of implant were simulated by the two-dimensional finite element method using the mechanical properties of human mandible and implant material as input data. Type 1 was a blade implant, type 2 was blade implant with subperiosteal wings in buccolingual direction, and type 3 was subperiosteal implant with no blade. The effect of bucco-lingual subperiosteal wings in decreasing the stress concentration around the neck portion of the blade implant was investigated under three kinds of occlusal force. In conclusion, the greatest stress concentration was observed at the cortical bone around the neck portion of T-1 blade implant. It was effective in decreasing the stress concentration at this neck portion to change the implant design from T-1 to T-2 or T-3.

Blade Implantation↗
PubMed1977

Mechanical behavior of tooth, periodontal membrane, and mandibular bone by the finite element method.

Simulation of the human tooth, periodontal membrane, and mandibular bone was attempted basing on the anatomical form and dimension, and the experimental data of each component were examined by the two-dimensional finite element method. Following problems were investigated: (1) Which of two factors, elastic modulus or Poisson's rate, in periodontal membrane played an important role for supporting the tooth, and (2) Characteristics of tooth and alveolar bone displacement, and stress distribution in periodontal membrane and mandibular bone were investigated under a definite condition. It is clarified that Poisson's ratio plays a much important role than the elastic modulus and this method is more suitable for simulating the model equivalent to human body and for examining the internal stress and it's displacement than the strain gauge and photoelastic method.

Dental Stress Analysis↗
PubMedDate not supplied

Histopathologic observation of seven removed endosseous dental implants.

Seven failed endosseous dental implants that were removed from humans were examined histologically. Results suggest that the hollow-basket portion or the vent should be located as far from the gingiva as possible, and that an adequate healing period is needed for implant placement following tooth extraction. In addition, findings also suggest that the hollow-basket implant is not suitable for a healing socket, that periodic inspection is necessary for two-stage implants to evaluate adaptation of the embedded junction between the abutment and implant in the gingiva, and that there is risk of coating separation from hydroxyapatite-coated implants and possibilities of coating resorption.

Adult↗
PubMedDate not supplied

Histologic study of failed hollow implants.

Nine hollow dental implants that were removed from patients were examined histologically to determine whether there was a common mechanism of failure with this implant design. When a hollow implant showed saucerized bone loss at the neck portion radiologically, the hollow portion was divided histologically into soft tissue and bone tissue. In advanced cases, stratified flattened epithelium that had invaded the hollow and the dead space at the top was observed. The condition of bone tissue located in the bottom of the basket can be adversely affected by an unfavorable crown-root ratio. The presence of an empty basket may cause fracture of the basket portion. The hollow portion can foster the growth of pathogenic bacteria. The hollow-type implant may not be suitable for immediate placement because surrounding soft tissues can invade the basket immediately.

Aged↗
PubMedDate not supplied

Review of failed implant cases.

Five Failed implant cases were presented and gained the following; 1) The use of computed tomography is recommended for treatment planning such as to ascertain the three-dimensional position of the mandibular canal, maxillary sinus and nasal floor, and also to decide the diameter, length and inclination of the implant placement. 2) The implant should be located for enough from mental foramen, mandibular canal, maxillary sinus and nasal floor. 3) The use of surgical stent is recommended for accurate drilling of the implant site. 4) Adequate number of implants and strategic arrangement of implants are required to equally distribute stress. 5) An implant abutment which is connected to natural teeth will be affected by the difference of micromobility of the natural teeth and the trouble of abutment of prosthesis.

Aged↗
PubMedDate not supplied

Effect of altered canine guidance on condylar movement during laterotrusion.

PURPOSE: The purpose of this study was to investigate the effect of an altered inclination of the canine guidance on the pattern of the condylar movements during laterotrusion. MATERIALS AND METHODS: The inclination of the canine guidance was steepened approximately 10 degrees by attaching a metal overlay to the lingual surface of the maxillary working-side canine. The laterotrusive movements of 20 young adults were measured using a three-dimensional mandibular movement analyzing system before and after alteration of the canine guidance. The difference between anterior, lateral, and inferior components of the working- and nonworking-side condylar movements, the Bennett angle, and the sagittal inclination of the nonworking-side condylar path before and after steepening of the canine guidance was evaluated by a paired t test. RESULTS: After the canine guidance was steepened, the working-side condyle moved even more anteriorly and inferiorly. In contrast, little change was found in the direction and the amount of the nonworking-side condylar movement. CONCLUSION: The results of this study suggest that there is a relationship between the steepness of canine guidance and the pattern of the working-side condylar movement. but not between the steepness of the canine guidance and the pattern of the nonworking-side condylar movement.

Adult↗