A case of removable partial denture restoration using implant supported surveyed crown in a maxillary edentulous patient / 대한치과보철학회지

When planning oral rehabilitation for maxillary edentulous patients, fixed prosthetic restoration using implants, complete denture restoration or overdentures using implants can be considered as treatment methods. In the case of complete denture restoration, it does not require additional surgery and is relatively economical. In the case of implant-supported fixed prostheses, the functional part is generally superior to that of complete denture restoration, but there are cases in which implant placement is clinically difficult. Recently in consideration of the patient’s needs and the condition of the remaining alveolar bone, after partial implant placement, a method of restoring with a removable partial denture using implant-supported surveyed crown is also being attempted. This case is a case of performing a removable partial denture restoration using implant-supported surveyed crown in the anterior maxilla, and showing satisfactory esthetic and functional results.

Oral rehabilitation of excessive tooth wear patient usingzirconia fixed prosthesis with increased vertical dimension / 대한치과보철학회지

From the point of view of oral rehabilitation, the treatment of extensive tooth wear requires a prosthetic approach. Physiological tooth wear is considered as a normal processand generally does not require treatment, but excessive tooth wear causes problems like inadequate occlusion and esthetics. Changes of occlusal vertical dimension should bemade through accurate diagnosis and analysis. Also, the patient’s adaptation to the changed occlusal vertical dimension should be assessed over time. This case was a60-year-old male patient who complained of a decrease in chewing function and esthetics due to severe tooth wear. Full-mouth rehabilitation was performed with a tooth supportedfixed prosthesis. An occlusal stabilization splint and provisional restoration were used to evaluate the adaptation to increased occlusal vertical dimension and induce astable centric relation position. After that, monolithic zirconia prosthesis was delivered. We report this as a satisfactory functional recovery and esthetics. (J Korean AcadProsthodont 2020;58:121-9)

Full mouth rehabilitation of a patient with severe periodontitis using immediate loading after computer aided flapless implant surgery

Oral rehabilitation of a patient having severe periodontitis with alveolar bone resorption and periodontal inflammation presents a challenge to clinicians. However, if appropriate implant placement according to the bone shape is selected, unnecessary bone grafting or soft tissue surgery can be minimized. In recent years, using cone beam CT and software, it has become possible to operate the planned position with the surgical guide made with 3D printing technology. This case was a 70 years old female patient who required total extraction of teeth due to severe periodontitis and performed a full-mouth rehabilitation with an implant-supported fixed prosthesis. During the surgery, the implant was placed in a flapless manner through a surgical guide. Immediate loading of the temporary prosthesis made by CAD/CAM method before surgery was done. Since then, we have produced customized abutments and zirconia prostheses, and have reported satisfactory aesthetic and functional recovery.

Maxillary full-arch fixed dental prosthesis of the elderly patient with worn dentition

Tooth wear, one of the physiological changes in the elderly patient's mouth, generally does not require treatment, but requires prosthodontic restoration when occlusal disharmony, poor masticatory function, pulp exposure occurs. One of the primary considerations in prosthodontic restoration for tooth wear is vertical dimension. It is necessary to make an accurate diagnosis and analysis, correct judgement of the interdental relationship for predictive treatment plan. A step-by-step approach considering dental care for aged is also required. In this case, a 93-year-old male patient presented with worn dentition and mobility of existing fixed dental prosthesis. After diagnosis and evaluation, maxillary rehabilitation without any change in the occlusal vertical dimension was performed and this shows satisfactory results both functionally and morphologically.

Effect of light-curing, pressure, oxygen inhibition, and heat on shear bond strength between bis-acryl provisional restoration and bis-acryl repair materials

PURPOSE: This study aimed to discover a way to increase the bond strength between bis-acryl resins, using a comparison of the shear bond strengths attained from bis-acryl resins treated with light curing, pressure, oxygen inhibition, and heat. MATERIALS AND METHODS: Self-cured bis-acryl resin was used as both a base material and as a repair material. Seventy specimens were distributed into seven groups according to treatment methods: pressure - stored in a pressure cooker at 0.2 Mpa; oxygen inhibition- applied an oxygen inhibitor around the repaired material,; heat treatment - performed heat treatment in a dry oven at 60degrees C, 100degrees C, or 140degrees C. The shear bond strength was measured with a universal testing machine, and the shear bond strength (MPa) was calculated from the peak load of failure. A comparison of the bond strength between the repaired specimens was conducted using one-way ANOVA and Tukey multiple comparison tests (alpha=.05). RESULTS: There were no statistically significant differences in the shear bond strength between the control group and the light curing, pressure, and oxygen inhibition groups. However, the heat treatment groups showed statistically higher bond strengths than the groups treated without heat, and the groups treated at a higher temperature resulted in higher bond strengths. Statistically significant differences were seen between groups after different degrees of heat treatment, except in groups heated at 100degrees C and 140degrees C. CONCLUSION: Strong bonding can be achieved between a bis-acryl base and bis-acryl repair material after heat treatment.

A study on the in-vitro wear of the natural tooth structure by opposing zirconia or dental porcelain

PURPOSE: This study was conducted to evaluate clinical validity of a zirconia full-coverage crown by comparing zirconia's wear capacity over antagonistic teeth with that of feldspathic dental porcelain. MATERIALS AND METHODS: The subject groups were divided into three groups: the polished feldspathic dental porcelain group (Group 1), the polished zirconia group (Group 2), and the polished zirconia with glazing group (Group 3). Twenty specimens were prepared from each group. Each procedure such as plasticity, condensation, and glazing was conducted according to the manufacturer's manual. A wear test was conducted with 240,000 chewing cycles using a dual-axis chewing simulator. The degree of wear of the antagonistic teeth was calculated by measuring the volume loss using a three-dimensional profiling system and ANSUR 3D software. The statistical significance of the measured degree of wear was tested with a significant level of 5% using one-way ANOVA and the Tukey test. RESULTS: The degrees of wear of the antagonistic teeth were 0.119 +/- 0.059 mm3 in Group 1, 0.078 +/- 0.063 mm3 in Group 3, and 0.031 +/- 0.033 mm3 in Group 2. Statistical significance was found between Group 1 and Groups 2 and between Group 2 and 3, whereas no statistical significance was found between Group 1 and Group 3. CONCLUSION: Despite the limitations of this study on the evaluation of antagonistic teeth wear, the degree of antagonistic tooth wear was less in zirconia than feldspathic dental porcelain, representing that the zirconia may be more beneficial in terms of antagonistic tooth wear.