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PURPOSE@#This analysis aimed to evaluate the intaglio surface trueness, antagonist’s wear volume loss, and fracture resistance of full-contour crowns of (Y, Nb)-stabilized fully-sintered zirconia (FSZ), 4 mol% or 5 mol% yttria-stabilized partially sintered zirconia (4YZ or 5YZ) with high-speed sintering. @*MATERIALS AND METHODS@#A total of 42 zirconia crowns were separated into three groups: FSZ, 4YZ, and 5YZ (n = 14). The intaglio surface trueness of the crowns was evaluated at the inner surface, occlusal, margin, and axial areas and reported as root-mean-square, positive and negative average deviation. Half of the specimens were aged for 120,000 cycles in the chewing simulator, and the wear volume loss of antagonist was measured. Before and after chewing, the fracture load was measured for each group. The trueness values were analyzed with Welch's ANOVA, and the wear volume loss with the Kruskal-Wallis tests. Effect of the zirconia type and aging on fracture resistance of crowns was tested using two-way ANOVA. @*RESULTS@#The intaglio surface trueness measured at four different areas of the crown was less than 50 µm, regardless of the type of zirconia. No significant P in wear volume loss of antagonists were detected among the groups (P > .05). Both the type of zirconia and aging showed statistically significant effects on fracture resistance (P < .05). @*CONCLUSION@#The full-contour crowns of FSZ as well as 4YZ or 5YZ with high-speed sintering were clinically acceptable, in terms of intaglio surface trueness, antagonist’s wear volume loss, and fracture resistance after simulated mastication.
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Crohn’s disease is usually diagnosed according to intestinal symptoms, but extra-intestinal manifestations are important in approximately one-third of cases. Although several extra-intestinal symptoms associated with various organs have been reported, renal involvement is uncommon in patients with Crohn’s disease. Tubulointerstitial nephritis in a patient with Crohn’s disease is usually caused by infection, sarcoidosis, or medications. However, primary tubulointerstitial nephritis caused by Crohn’s disease alone is extremely rare. A 19-year-old male patient was referred to our hospital because of an increase in serum creatinine level. He underwent a kidney biopsy with renal insufficiency. Renal histological findings revealed granulomatous tubulointerstitial nephritis. Thereafter, a colonoscopy was performed with suspicion of Crohn’s disease. Ultimately, he was diagnosed with granulomatous tubulointerstitial nephritis based on Crohn’s disease. The patient had improved gastrointestinal symptoms after the last treatment. This case report presents a rare case of primary tubulointerstitial nephritis caused by Crohn’s disease.
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An all-on-4 restoration allows edentulous patients to use a fixed prosthesis with a minimum number of implants. These implant-supported fixed complete dentures have traditionally been fabricated as screw-retained or cementretained prostheses. However, it is difficult to passively fit the long-span full-arch prosthesis using the screw-retained type restoration, and predictable retrievability is not obtained with the cement-retained type. This case report describes a prosthesis fabricated using a combination of the two retention types. The screwmentable method allows the implant-supported fixed complete denture to achieve a passive fit at the connection with retrievability. In addition, a framework with an optimized size was designed by using digital dental technology.
ABSTRACT
Installation of dental implants at optimal angles and positions is critical in longterm stable implant-supported restorations. Surgery and prosthodontic procedures should be performed accurately as the treatment is planned. In this clinical case, Computer aided design and manufacturing technology was used not only to establish a precise surgical plan, but also to fabricate both provisional and definitive fixed prostheses. A surgical guide was designed to install the implants at proper positions for the definitive prostheses. The patient’s esthetic information, which was necessary for the new provisional and definitive fixed prostheses, was obtained from the existing temporary dentures. Finally, the complete mouth fixed implant-supported rehabilitation using monolithic zirconia provided the patient with functionally and esthetically satisfactory prostheses.
ABSTRACT
With the development of digital dentistry, it is being applied in various ways of dental treatment. This case report presents the definitive prosthesis designed in advance with a re-established vertical dimension and the digital technology, which determined the amount of tooth preparation, in order to preserve as much tooth structure as possible in a patient with pathological wear of the posterior teeth and loss of vertical dimension. For accurate tooth preparation, the guides of the occlusal and axial surfaces were digitally and additively manufactured. Then, aesthetics and anterior guidance were established at the provisional stage. The information of the provisional restoration was delivered to the definitive stage by double scanning. The digital technology, including the virtual planning and the guided tooth removal, produced the definitive restorations satisfactory to both the patient and clinician.
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PURPOSE@#. This in vitro study aimed to evaluate the surface characteristics of a full veneer crown fabricated chairside (CS) from a (Y, Nb)-TZP zirconia block in response to conventional zirconia grinding and polishing. @*MATERIALS AND METHODS@#. Zirconia crowns (n = 40) were first prepared and divided into two groups of materials: Labside (LS) and CS, after which each specimen went through a five-step grinding and polishing procedure. Following each surface treatment, surface characteristics were analyzed using confocal laser microscopy (CLSM), average surface roughness (Ra) values were processed from the profile data through Gaussian filtering, and X-ray diffraction pattern analysis was performed to evaluate the monoclinic (M) phase content. Then, a representative specimen was selected for field-emission scanning electron microscopy (FE-SEM), followed by a final analysis of the roughness and X-ray diffraction of the specimens using the independent t-test and repeated measures analysis of variance (RM-ANOVA). @*RESULTS@#. In every group, polishing significantly reduced the Ra values (P < .001).There was no significant difference in Ra between the polished state CS and LS.Furthermore, CLSM and FE-SEM investigations revealed that even though grain exposure was visible in CS specimens throughout the as-delivered and ground states, the exposure was reduced after polishing. Moreover, while no phase transformation was visible in the LS, phase transformation was visible in CS after every surface treatment, with the M phase content of the CS group showing a significant reduction after polishing (P < .001). CONCLUSION. Within the limits of this study, clinically acceptable level of surface finishing of (Y, Nb)-TZP can be achieved after conventional zirconia polishing sequence.
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PURPOSE@#. This in-vitro analysis aimed to compare the intaglio trueness, the antagonist’s wear volume loss, and fracture load of various single-unit zirconia prostheses fabricated by different manufacturing techniques. @*MATERIALS AND METHODS@#. Zirconia crowns were prepared into four different groups (n = 14 per group) according to the manufacturing techniques and generations of the materials. The intaglio surface trueness (root-mean-square estimates, RMS) of the crown was measured at the marginal, axial, occlusal, and inner surface areas. Half of the specimens were artificially aged in the chewing simulator with 120,000 cycles, and the antagonist’s volume loss after aging was calculated. The fracture load for each crown group was measured before and after hydrothermal aging. The intaglio trueness was evaluated with Welch’s ANOVA and the antagonist’s volume loss was assessed by the Kruskal-Wallis tests. The effects of manufacturing and aging on the fracture resistance of the tested zirconia crowns were determined by two-way ANOVA. @*RESULTS@#. The trueness analysis of the crown intaglio surfaces showed surface deviation (RMS) within 50 µm, regardless of the manufacturing methods (P = .053). After simulated mastication, no significant differences in the volume loss of the antagonists were observed among the zirconia groups (P = .946). The manufacturing methods and simulated chewing had statistically significant effects on the fracture resistance (P < .001). @*CONCLUSION@#. The intaglio surface trueness, fracture resistance, and antagonist’s wear volume of the additively manufactured 3Y-TZP crown were clinically acceptable, as compared with those of the 4Y- or 5Y-PSZ crowns produced by subtractive milling.
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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 oneway analysis of variance and Tukey’s post-hoc test (α=.05). @*RESULTS@#The mean ± standard deviation values of wear volume loss (in mm 3 ) 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; µm) 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.
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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 oneway analysis of variance and Tukey’s post-hoc test (α=.05). @*RESULTS@#The mean ± standard deviation values of wear volume loss (in mm 3 ) 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; µm) 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.
ABSTRACT
A three-dimensional (3D) intraoral scanner, which is one of the major developments in digital dentistry, is widely used in fixed prosthodontics. The application of intraoral scanner is now increasing in removable prosthodontics. Sclerotic change induced by scleroderma causes the limitation of mouth opening and multiple loss of the teeth. Conventional prosthodontic procedures are challenging for patients with this disease. This study showed a case of digital approach to the removable prosthodontic treatment of a patient who had the scleroderma and the consequent microstomia. At the provisional stage, the optical impression of patient’s oral structures was digitally obtained. Using a 3D printer, the provisional dentures were fabricated. After extraction of hopeless tooth, the definitive digital impression was taken and the metal frameworks were fabricated, based on the data acquired from the impression. The definitive removable partial dentures were completed and delivered to the patient, who was satisfied with the prostheses.
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Dental implants should be placed at ideal sites for implant-supported restorations. For a patient with insufficient residual ridge, mouth preparation including surgical intervention can be indicated to establish a soft and hard tissue environment favorable for a definitive prosthesis. Prosthodontic design based on computer-guided surgery and computer-aided design-computer-aided manufacturing (CAD-CAM) provides a visual blueprint allowing a clinician to assess the necessity of such a surgical intervention beforehand. In this case, a definitive restoration was planned and made via a CAD-CAM system according to the patient’s oral status before treatment, simulated surgical interventions and serial provisional restorations. Based on the planning, a guided template was made and the implants were installed with bone augmentation using the template. Customized abutments, the first and the second provisional restorations were designed and fabricated by CAD-CAM. The definitive restorations were digitally made following the shape of the second provisional prostheses, which were confirmed in the patient’s mouth. The patient was satisfied with the masticatory, phonetic and aesthetic functions of these definitive prostheses.
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With the evolution of the computer-aided design/computer-aided manufacturing (CAD/CAM) technology, the intraoral scanners are playing an increasingly important role, as they are the first step towards a completely digital workflow. The CAD/CAM double scanning technique has been used to transfer the information from provisional restorations to definitive restorations. In this case, a 67-year-old male with esthetically compromised anterior teeth, generalized severe attrition of teeth, and reduced vertical dimension was treated with full mouth rehabilitation including a re-establishment of the lost vertical dimension of occlusion assisted by the crown lengthening procedure. The provisional restorations were fabricated using an intraoral scanner and the CAD/CAM double scanning technique. After the period of adaption, the definitive monolithic zirconia restorations were delivered. The CAD/CAM double scanning technique successfully transferred the occlusal and morphological characteristics, obtained from the provisional restorations, to the definitive restorations.
Subject(s)
Aged , Humans , Male , Crown Lengthening , Dentition , Mouth Rehabilitation , Mouth , Tooth , Tooth Wear , Vertical DimensionABSTRACT
Computer aided design and manufacturing and implant surgery using a guide template improve restoration-driven implant treatment procedures. This case utilized those digital technologies to make definitive prostheses for a patient. According to the work flow of digital dentistry, cone beam computed tomography established the treatment plan, which was followed to make the guide template for implant placement. The template guided the implants to be installed as planned. The customized abutments and surveyed fixed restorations were digitally designed and made. The metal framework of the removable partial denture was cast from resin pattern using an additive manufacturing technique, and the artificial resin teeth were replaced with the zirconia onlays for occlusal stability. These full mouth rehabilitation procedures provided functionally and aesthetically satisfactory results for the patient.
Subject(s)
Humans , Computer-Aided Design , Cone-Beam Computed Tomography , Dentistry , Denture, Partial, Removable , Inlays , Mouth Rehabilitation , Mouth , Prostheses and Implants , Tooth , WorkflowABSTRACT
BACKGROUND: A balanced nutrient intake is important for patients with diabetes. Even if individuals have the same number of residual natural teeth, there are large differences in the masticatory performance between edentulous sites restored with a fixed dental prosthesis, including dental implants, and those restored with a removable dental prosthesis. This study assessed whether the prevalence and control of diabetes differed based on the use of removable dental prostheses through an analysis of nationally representative data. METHODS: Overall, 8,155 individuals (3,525 men and 4,630 women) aged ≥ 50 years were included in this study and were classified into the following 3 groups: group 1, did not use any removable dental prostheses (NF); group 2, used removable partial dentures (RPD); and group 3, used removable complete dentures on at least 1 jaw (CD). The characterization of diabetic patients and glycemic control were analyzed and compared among groups. To determine the relationship between diabetes and the use of dental prostheses, multivariable logistic regression analysis was performed (P < 0.05). RESULTS: The adjusted odds ratios and 95% confidence intervals for diabetes in men participants in groups NF, RPD, and CD were 1 (reference), 1.165 (0.878–1.544), and 1.491 (1.034–2.151), respectively, after adjusting for confounding factors. Diabetes and glycemic control were significantly associated with the use of removable dental prostheses among men. CONCLUSION: The use of removable dental prostheses is a potential risk indicator for uncontrolled diabetes in Korean men adults, suggesting the need for a comprehensive approach to minimize the complications of diabetes mellitus.
Subject(s)
Adult , Humans , Male , Dental Implants , Dental Prosthesis , Denture, Complete , Denture, Partial, Removable , Dentures , Diabetes Complications , Diabetes Mellitus , Jaw , Logistic Models , Odds Ratio , Oral Health , Prevalence , ToothABSTRACT
This study reported the treatment of a patient with excessive worn dentition and limited maxillo-mandibular space for restoration, utilizing the computer-aided design and computer-aided manufacturing (CAD/CAM) technology. After the thorough examination of the patient's occlusal vertical dimension (OVD), full mouth rehabilitation was planned with increase of the OVD. The patient was satisfied with the provisional restorations establishing the increased OVD. The horizontal and vertical data of the patient's jaw relation that the provisional restorations contained were transferred to the definitive metal ceramic fixed prostheses by double scanning and three-dimensional printing. After the fixed restorations were cemented to the abutments, electronic surveying and three-dimensional printing were used to fabricate metal frameworks for the patient's removable partial dentures. The mandibular definitive removable prostheses were delivered to the patient's mouth and the full mouth rehabilitation procedures were completed. The digital technologies used for this case produced fixed and removable restorations satisfactory in masticatory, phonetic and aesthetic functions to both the patient and the dental clinician.
Subject(s)
Humans , Ceramics , Computer-Aided Design , Dentition , Denture, Partial, Removable , Jaw , Mouth Rehabilitation , Mouth , Printing, Three-Dimensional , Prostheses and Implants , Tooth Wear , Vertical DimensionABSTRACT
An accurate implant placement with ideal location is significant for long-term success of the implant. An exact evaluation of nearby anatomic structures such as quality of residual bone, an inferior alveolar bone and a maxillary sinus is required. For a prosthetic-driven treatment, planned surgery, precise prosthesis and communication with the patient are significant requisites especially for full-mouth rehabilitation. In this case, the patient with severe alveolar bone resorption had a CT guided surgery supported by CT data and the data from scanning diagnostic wax-up. Afterward, edentulous area was restored by full mouth implant-supported prosthesis by using monolithic zirconia and CAD/CAM technique. This paper reports the outcome of the procedure which was remarkable both esthetically and functionally.
Subject(s)
Humans , Bone Resorption , Maxillary Sinus , Mouth Rehabilitation , Mouth , Prostheses and Implants , RehabilitationABSTRACT
PURPOSE: The purpose of this study was to investigate the effects of the insertion depth of an immediately loaded implant on the stress distribution of the surrounding bone and the micromovement of the implant using the three-dimensional finite element analysis. MATERIALS AND METHODS: A total of five bone models were constructed such that the implant platform was positioned at the levels of 0.00 mm, 0.25 mm, 0.50 mm, 0.75 mm, and 1.00 mm depth from the crest of the cortical bone. A frictional coefficient of 0.3 and the insertion torque of 35 Ncm were simulated on the interface between the implant and surrounding bone. A static load of 178 N was applied to the provisional prosthesis with a vertical load in the axial direction and an oblique load at 30°with respect to the central axis of the implant, then a finite element analysis was performed. RESULTS: The implant insertion depth significantly affected the stress distribution on the surrounding bone. The largest micromovement value of the implant was 39.34 µm. The oblique load contributed significantly to the stress distribution and micromovement in comparison to the vertical load. CONCLUSION: Increasing the implant insertion depth was advantageous in dispersing the concentrated stress in the cortical bone and did not significantly affect the micromovement associated with early osseointegration failure.
Subject(s)
Dental Implants , Finite Element Analysis , Friction , Immediate Dental Implant Loading , Maxilla , Osseointegration , Prostheses and Implants , TorqueABSTRACT
PURPOSE: This study was performed to evaluate the osteogenic potential of 3mol% yttria-stabilized tetragonal zirconia polycrystals (3Y-TZP) and niobium oxide containing Y-TZPs with specific ratios, new (Y,Nb)-TZPs, namely YN4533 and YN4533/Al20 discs. MATERIALS AND METHODS: 3Y-TZP, YN4533 and YN4533/Al20 discs (15 mm diameter and 1 mm thickness) were prepared and their average surface roughness (Ra) and surface topography were analyzed using 3-D confocal laser microscope (CLSM) and scanning electron microscope (SEM). Mouse pre-osteoblast MC3T3-E1 cells were seeded onto all zirconia discs and evaluated with regard to cell attachment and morphology by (CLSM), cell proliferation by PicoGreen assay, and cell differentiation by Reverse-Transcription PCR and Quantitative Real-Time PCR, and alkaline phosphatase (Alp) staining. RESULTS: The cellular morphology of MC3T3-E1 pre-osteoblasts was more stretched on a smooth surface than on a rough surface, regardless of the material. Cellular proliferation was higher on smooth surfaces, but there were no significant differences between 3Y-TZP, YN4533, and YN4533/Al20. Osteoblast differentiation patterns on YN4533 and YN4533/Al20 were similar to or slightly higher than seen in 3Y-TZP. Although there were no significant differences in bone marker gene expression (alkaline phosphatase and osteocalcin), Alp staining indicated better osteoblast differentiation on YN4533 and YN4533/Al20 compared to 3Y-TZP. CONCLUSION: Based on these results, niobium oxide containing Y-TZPs have comparable osteogenic potential to 3Y-TZP and are expected to be suitable alternative ceramics dental implant materials to titanium for aesthetically important areas.
Subject(s)
Animals , Mice , Alkaline Phosphatase , Cell Differentiation , Cell Proliferation , Ceramics , Dental Implants , Gene Expression , Niobium , Osteoblasts , Polymerase Chain Reaction , Real-Time Polymerase Chain Reaction , TitaniumABSTRACT
PURPOSE: The aim of this study was to design an intraoral environment simulator and to assess the accuracy of two intraoral scanners using the simulator. MATERIALS AND METHODS: A box-shaped intraoral environment simulator was designed to simulate two specific intraoral environments. The cast was scanned 10 times by Identica Blue (MEDIT, Seoul, South Korea), TRIOS (3Shape, Copenhagen, Denmark), and CS3500 (Carestream Dental, Georgia, USA) scanners in the two simulated groups. The distances between the left and right canines (D3), first molars (D6), second molars (D7), and the left canine and left second molar (D37) were measured. The distance data were analyzed by the Kruskal-Wallis test. RESULTS: The differences in intraoral environments were not statistically significant (P>.05). Between intraoral scanners, statistically significant differences (P < .05) were revealed by the Kruskal-Wallis test with regard to D3 and D6. CONCLUSION: No difference due to the intraoral environment was revealed. The simulator will contribute to the higher accuracy of intraoral scanners in the future.
Subject(s)
Georgia , Molar , SeoulABSTRACT
Approximately 10–15% of pheochromocytomas are malignant. There are insufficient histologic criteria for the diagnosis of malignant pheochromocytoma. Thus, the term malignant pheochromocytoma is restricted to tumors with local invasion or distant metastases. We experienced a case of malignant pheochromocytoma recurred with spinal metastasis 4 years after the surgery for huge benign pheochromocytoma. A 68-year-old female was admitted for trunk and back pain. The patient had a history of surgery 4 years ago for a 10.0×9.5×7.5 cm sized benign pheochromocytoma at the left adrenal gland. A thoracolumbar magnetic resonance imaging showed a tumor in the 7th thoracic vertebral body and a 24-hour urinary norepinephrine increased, suggesting metastatic recurrence of malignant pheochromocytoma. After metastasectomy in the 7th thoracic vertebral body, urine catecholamine was normalized and pain also disappeared. However, a metastatic lesion was found in the paraaortic area on a follow-up abdominal computed tomography scan and an additional metastasectomy was performed. The pathology confirmed the diagnosis of metastatic pheochromocytoma in the paraaortic lymph nodes. She is supposed to be treated with adjuvant iodine 131-meta-iodobenzylguanidine therapy. In our experience, a close follow-up should be considered in patients who had a huge benign pheochromocytoma due to the possibility of malignant metastases.