• The Journal of Advanced Prosthodontics
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• 제9권2호
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• pp.138-142
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• 2017

In restorative treatment using fixed dental prostheses, dentists should select appropriate restoration material among various types of dental materials. The strength, marginal fit, esthetics, wear resistance, biocompatibility, and cost are important factors in the choice of restoration materials. The present case showed a surface stain on a monolithic zirconia restoration that was due to wear between the monolithic zirconia restoration and the base metal alloy restoration. This phenomenon was confirmed by surface roughness measurement and electron probe micro-analysis.

• The Journal of Advanced Prosthodontics
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• 제13권3호
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• pp.144-151
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• 2021

PURPOSE. The purpose of this in vitro study was to investigate the wear resistance and surface roughness of three interim resin materials, which were subjected to chewing simulation. MATERIALS AND METHODS. Three interim resin materials were evaluated: (1) three-dimensional (3D) printed (digital light processing type), (2) computer-aided design and computer-aided manufacturing (CAD/CAM) milled, and (3) conventional polymethyl methacrylate interim resin materials. A total of 48 substrate specimens were prepared. The specimens were divided into two subgroups and subjected to 30,000 or 60,000 cycles of chewing simulation (n = 8). The wear volume loss and surface roughness of the materials were compared. Statistical analysis was performed using one-way analysis of variance and Tukey's post-hoc test (α=.05). RESULTS. The mean ± standard deviation values of wear volume loss (in mm³) against the metal abrader after 60,000 cycles were 0.10 ± 0.01 for the 3D printed resin, 0.21 ± 0.02 for the milled resin, and 0.44 ± 0.01 for the conventional resin. Statistically significant differences among volume losses were found in the order of 3D printed, milled, and conventional interim materials (P<.001). After 60,000 cycles of simulated chewing, the mean surface roughness (Ra; ㎛) values for 3D printed, milled, and conventional materials were 0.59 ± 0.06, 1.27 ± 0.49, and 1.64 ± 0.44, respectively. A significant difference was found in the Ra value between 3D printed and conventional materials (P=.01). CONCLUSION. The interim restorative materials for additive and subtractive manufacturing digital technologies exhibited less wear volume loss than the conventional interim resin. The 3D printed interim restorative material showed a smoother surface than the conventional interim material after simulated chewing.

• The Journal of Advanced Prosthodontics
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• 제11권4호
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• pp.232-238
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• 2019

PURPOSE. The aim of this study was to investigate simulated localized and generalized wear of indirect composite resins used for implant supported provisional restorations. MATERIALS AND METHODS. The study investigated ten indirect composite resins. Two kinds of wear were simulated by 400,000 cycles in a Leinfelder-Suzuki (Alabama) machine. Localized wear was simulated with a stainless-steel ball bearing antagonist and generalized with a flat-ended stainless-steel cylinder antagonist. The tests were carried out in water slurry of polymethyl methacrylate beads. Wear was measured using a Proscan 2100 noncontact profilometer in conjunction with Proscan and AnSur 3D software. RESULTS. Both localized and generalized wear were significantly different (P<.05) among the indirect composite resins. SR Nexco and Gradia Plus showed significantly less wear than the other indirect composite resins. The rank order of wear was same in both types of wear simulation. CONCLUSION. Indirect composite resins are recommended when a provisional implant-supported restoration is required to function in place over a long period. Although only some indirect composite resins showed similar wear resistance to CAD/CAM composite resins, the wear resistance of all the indirect composite resins was higher than that of bis-acryl base provisional and polymethyl methacrylate resins.

• 한국치위생학회지
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• 제22권4호
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• pp.225-230
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• 2022

Objectives: Patients with excessive tooth wear should first be diagnosed for the etiology of the tooth wear. Causes of tooth wear include bruxism, clenching, and taking medications for systemic diseases. After identifying the cause of tooth attrition, the final prosthesis should be restored with an appropriate vertical dimension. Methods: A 79-year-old man with worn out teeth desired a whole dental treatment. He was on medications for high blood pressure and asthma. The treatment proceeded with a consultation with a medical doctor. The medications for asthma evoked multiple teeth wear and a loss of the vertical dimension. After recovery of 3 mm of vertical dimension, 2 months of evaluation was followed by an interim prosthesis. Results: The increased vertical dimension caused no problem in function and esthetics, and the final restoration was performed with a full monolithic zirconia crown. Group function, adequate anterior guidance, and the occlusal plane were determined. Conclusions: After the final restoration, the patient was both esthetically and functionally satisfied, and a night guard splint was delivered to prevent prosthesis fracture. The patient was informed about the potential tooth wear associated with asthma drugs and educated to visit the clinic regularly.

• The Journal of Advanced Prosthodontics
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• 제11권1호
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• pp.7-15
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• 2019

PURPOSE. The aim of this study was to identify the effects of three aesthetic restorative materials on the wear between tooth and restoration by a pin-on-disk manner. MATERIALS AND METHODS. Six aesthetic restorative materials were used to prepare disk specimens for wear test, which were Lava Zirconia as zirconia group, Vintage MP and Cerabien ZR as veneering porcelain group, Gradia Direct microhybrid composite containing prepolymerized fillers, Filtek Z250 microhybrid composite containing zirconia glass and colloidal silica particles, and Filtek Z350 nanocomposite as composite resin group. Vertical loss of the worn cusp, change of the surface roughness of the restoration materials, and the surface topography were investigated after wear test under 9.8-N contact load. RESULTS. The porcelain groups (Vintage MP and Cerabien ZR) caused the largest vertical loss of teeth when compared with those of the composite resin and zirconia groups, and Filtek Z250 microhybrid composite results in the second-largest vertical loss of teeth. The surface of Filtek Z350 nanocomposite was deeply worn out, but visible wear on the surface of the zirconia and Gradia Direct microhybrid composite was not observed. When the zirconia surface was roughened by sand-blasting, vertical loss of teeth considerably increased when compared with that in the case of fine polished zirconia. CONCLUSION. It was identified that microhybrid composite resin containing a prepolymerized filler and zirconia with reduced surface roughness by polishing were the most desirable restorative materials among the tested materials to prevent the two-body wear between aesthetic restorative material and tooth.

• The Journal of Advanced Prosthodontics
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• 제13권5호
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• pp.281-291
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• 2021

PURPOSE. To evaluate the wear of computer-aided design/computer-aided manufacturing (CAD-CAM) dental ceramic materials opposed by enamel as a function of increased chewing forces. MATERIALS AND METHODS. The enamel cusps of healthy human third molar teeth (n = 40) opposed by materials from CAD-CAM dental ceramic groups (n = 10), including Vita Enamic^® (ENA), a polymer-infiltrated ceramic network (PICN); GC Cerasmart^® (CERA), a resin nanoceramic; Celtra^® Duo (DUO), a zirconia-reinforced lithium silicate (ZLS) ceramic; and IPS e.max ZirCAD (ZIR), a polycrystalline zirconia, were exposed to chewing simulation (1,200,000 cycles; 120 N load; 1 Hz frequency; 0.7 mm lateral and 2 mm vertical motion). The wear of both enamel cusps and materials was quantified using a 3D laser scanner, and the wear mechanisms were evaluated by scanning electron microscopy (SEM). The results were analysed using Welch ANOVA and Kruskal Wallis test (α = .05). RESULTS. ZIR showed lower volume loss (0.02 ± 0.01 mm³) than ENA, CERA and DUO (P = .001, P = .018 and P = .005, respectively). The wear of cusp/DUO [0.59 mm³ (0.50-1.63 mm³)] was higher than cusp/CERA [0.17 mm³ (0.04-0.41 mm³)] (P = .007). ZIR showed completely different wear mechanism in SEM. CONCLUSION. Composite structured materials such as PICN and ZLS ceramic exhibit more abrasive effect on opposing enamel due to their loss against wear, compared to uniform structured zirconia. The resin nano-ceramic causes the lowest enamel wear thanks to its flexible nano-ceramic microstructure. While zirconia appears to be an enamel-friendly material in wear volume loss, it can cause microstructural defects of enamel.

• The Journal of Advanced Prosthodontics
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• 제2권2호
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• pp.46-49
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• 2010

BACKGROUND. Though implant dentistry is very successful and predictable in treatment of patients with destroyed dentition, there are some cases with limitations to implant therapy. In these cases, alternative treatment modality should be considered. CASE DESCRIPTION. A patient with destroyed dentition was rehabilitated with a lateral rotational path removable partial denture. According to the diagnosis, we determined to raise vertical dimension for esthetic and functional restoration. The final restoration was performed after four months of provisional period. CLINICAL IMPLICATION. The edentulous patients with compromised esthetics and functions can be successfully treated with a rotational path removable partial denture through adequate treatment planning and precise laboratory procedure.

• 구강생물연구
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• 제42권4호
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• pp.262-268
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• 2018

In a situation where a vertical dimension has to be increased, the normal occlusion, function and aesthetics should be restored after taking into consideration the neuromuscular system and temporomandibular join. In order to do this, the provisional prosthesis should be made according to the patient's information. Moreover, the period of adjustment should be made through the provisional prosthesis modification, if necessary. The patient is then transferred to the final prosthesis to obtain results that are satisfactory. In the modern-day world, provisional prosthesis are replicated using three dimensional scanning and computer aided design/computer aided manufacturing (CAD/CAM) then made into final prosthesis. The adaptability of stomatognathic system can be judged by the PMMA provisional restoration. Functional and aesthetical aspect can be obtained. The adjustment period can be shortened by an intraoral correction and proper wear between provisional restorations. By using the CAD/CAM technology that transfers the information right into the final prosthesis.

• 대한심미치과학회지
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• 제24권2호
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• pp.101-121
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• 2015

지르코니아 폴리크리스탈은 (Y-TZP) 다른 치과용 세라믹에 비해 기계적 강도와 파절저항성이 우수하다. 지르코니아 기반 세라믹은 캐드캠 시스템을 바탕으로 고정식 수복물 제작에 성공적으로 소개되어 왔다. 이는 고정식 수복물을 위한 금속 구조물의 임상적 대안으로 제시되었다. 지르코니아 수복물의 가장 흔한 합병증은 상부 도재의 파절이다. 다른 옵션은 고도로 반투명한 지르코니아를 전부지르코니아 고정식 수복물로 사용하는 것이다. 본 논문에서는 전부지르코니아 수복물의 장점, 지르코니아 수복물의 임상적용, 지대치 삭제, 대합치 마모, 지르코니아와 레진시멘트와의 접착, 그리고 기공소와의 의사소통에 관하여 보고하였다.

• 구강회복응용과학지
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• 제33권2호
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• pp.154-162
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• 2017

노인 환자 구강의 생리적 변화 중 하나인 생리적 치아 마모는 일반적으로 치료를 필요로 하지 않으나 교합 부조화, 저작기능의 저하, 치수 노출 등 구강 내 문제 발생 시 보철 수복을 필요로 한다. 마모된 치열을 지닌 환자의 보철 수복 시 우선적으로 고려되는 사항들 중 하나가 바로 수직고경에 대한 고려이다. 이에 정확한 진단 및 분석과 예지성 있는 치료계획을 위한 악간관계에 대한 올바른 판단이 요구되며, 노인 환자의 치과 치료를 감안한 단계별 치료접근을 필요로 한다. 본 증례는 93세 남자 환자로 전반적인 치아 마모 및 기존 고정성 보철물의 동요도를 보이고 있었다. 진단 및 평가 후 수직교합 고경을 유지한 상악 구강회복술을 시행하였으며, 기능 및 형태적으로 만족할만한 결과를 보여 보고하는 바이다.