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PURPOSE@#. This in vitro study aimed to compare the accuracy of the conventional facebow system and the newly developed POP (PNUD (Pusan National University Dental School) Occlusal Plane) bow system for occlusal plane transfer in asymmetric ear position. @*MATERIALS AND METHODS@#. Two dentists participated in this study, one was categorized as Experimenter 1 and the other as Experimenter 2 based on their clinical experience with the facebow (1F, 2F) and POP bow (1P, 2P) systems. The vertical height difference between the two ears of the phantom model was set to 3 mm. Experimenter 1 and Experimenter 2performed the facebow and POP bow systems on the phantom model 10 times each, and the transfer accuracy was analyzed. The accuracy was evaluated by measuring the angle between the reference virtual plane (RVP) of the phantom model and the experimental virtual plane (EVP) of the upper mounting plate through digital superimposition. All data were statistically analyzed using a paired t-test (P .05). @*CONCLUSION@#. In cases of asymmetric ear position, the POP bow system may transfer occlusal plane information more accurately than the facebow system in the frontal view, regardless of clinical experience.
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PURPOSE@#. This study aims to clinically compare the fitness and trueness of zirconia crowns fabricated by different combinations of open CAD-CAM systems. @*MATERIALS AND METHODS@#. Total of 40 patients were enrolled in this study, and 9 different zirconia crowns were prepared per patient. Each crown was made through the cross-application of 3 different design software (EZIS VR, 3Shape Dental System, Exocad) with 3 different processing devices (Aegis HM, Trione Z, Motion 2). The marginal gap, absolute marginal discrepancy, internal gap(axial, line angle, occlusal) by a silicone replica technique were measured to compare the fit of the crown. The scanned inner and outer surfaces of the crowns were compared to CAD data using 3D metrology software to evaluate trueness. @*RESULTS@#. There were significant differences in the marginal gap, absolute marginal discrepancy, axial and line angle internal gap among the groups (P .05). @*CONCLUSION@#. All 9 groups showed clinically acceptable level of marginal gaps ranging from 74.26 to 112.20 μm in terms of fit comparison. In the comparison of trueness, no significant difference within each group was spotted. Within the limitation of this study, open CAD-CAM systems used in this study can be assembled properly to fabricate zirconia crown. [J Adv Prosthodont 2023;15:155-70]
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Pathological wear across the entire dentition causes problems such as collapsed occlusal plane, reduced vertical dimension, anterior premature contact, inadequate anterior guidance, and tooth migration, thereby induce symptoms such as temporomandibular joint disorder, reduced masticatory efficiency, and tooth hypersensitivity. For the treatment of patients with excessive wear, evaluation of vertical dimension should be preceded along with analysis of the cause. The patient in this case was a 45-year-old female with a history of orthognathic surgery. Through clinical examination, radiographic examination, and model analysis, overall tooth wear, interdental spacing in the anterior maxillary region, retruded condylar position, and insufficient interocclusal space for prosthetic restoration were confirmed. Full mouth rehabilitation with increased vertical dimension was planned, the patient’s adaptation to the new vertical dimension was evaluated with a removable occlusal splint and temporary prosthesis, and cross-mounting was performed based on the temporary restoration to fabricate the definitive zirconia prosthesis, maintaining the adjusted vertical dimension. It showed satisfactory functional and esthetic results through stable restoration of the occlusal relationship.
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In order to manufacture functional and esthetic prostheses, it is essential to accurately transmit information about the patient’s occlusal plane. In particular, in the case of a completely edentulous patient, the occlusal plane is very important to correctly support the soft tissue, to achieve aesthetic harmony with the facial appearance, and to properly pronounce it, and to form a balanced occlusal relationship for stable mastication. In the conventional method, various facebow systems were used to transmit patient’s information from the clinic to the laboratory, but there were several limitations in the process of transferring them to CAD. To simplify this process, a prefabricated POP (PNUD Occlusal Plane) Bow system was recently developed. In this case, a CAD-CAM (Computer-aided design-computer-aided manufacturing) treatment dentures reflecting the patient’s occlusal plane information was manufactured using the POP Bow system during the treatment of a completely edentulous patient, and aesthetic and functional satisfaction was obtained.
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Among many contributing factors of implant failure, excessive loading and inflammation contribute mainly to increasing implant failure rate. Especially, poor oral hygiene around implants is one of the most common reasons for implant failure. When implant prosthesis fails to function, the clinician should re-diagnose and plan treatment using the remaining implants. Additional implantation may be needed to make a new type of prosthesis or either implant-assisted RPD and implant overdenture treatment may be performed using the remaining implants.In this article, a patient whose fixed implant prosthesis in the maxilla had failed of poor oral hygiene maintenance was reported to be recovered with removable implant overdenture by using remaining implant abutments and a milled bar with additional retentive elements. Through this treatment, the clinical results were satisfactory in terms of esthetics, masticatory function recovery and oral hygiene management.
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Excessive crown height space increases can cause crestal bone loss and screw loosening after prosthesis is placed. Milled bar and implant overdenture can be used as a treatment method for partially edentulous patients who have severe alveolar bone loss and excessive crown height space. Milled bar can provide primary splinting effect and stability between implants. Also, milled bar with additional retention device such as Advanced Dental Device-Treatment Of Choice (ADD-TOC) and magnet can provide additional retention force for implant overdenture. In this case, the patient has a partially edentulous mandible that has severe alveolar bone loss and multiple number of teeth loss after excision due to leiomyosarcoma. Because of the long-term loss of mandibular molars, the opposing teeth were extruded. Maxillary left molars were corrected to the occlusal plane through molar intrusion, and mandibular left molar region were treated with implant overdenture, using milled bar with ADD-TOC and magnet after implant placement. The clinical result was satisfactory on the aspect of esthetic and masticatory function.
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One of the treatment options for edentulous state patients with residual ridge resorption is implant overdenture using milled bar and attachment. It not only provides improved retention and stability but can also reduce the coverage of palatal surface. In addition, when a small number of implants are used, milled bar has the effect of being splinted between implant fixtures, which makes it mechanically advantageous under functions such as mastication. The patient in this case was a maxillary edentulous state patient with a considerable amount of residual alveolar bone resorption after removing the existing failed implants. Three implants were planted on both sides and an implant overdenture was fabricated using milled bar and ADD-TOC attachment.
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The use of implants could improve the support, retention, and stability of removable prosthetic restoration for fully edentulous patients with severe alveolar bone resorption. When the prosthesis is manufactured without accurate diagnosis and evaluation, this may lead to unfavorable treatment result. The patient in this case had the treatment of implant overdentures at a private dental clinic, but visited the hospital for retreatment due to soft tissue pain and decreasing retention of existing dentures. The vertical dimension was raised compared to the existing dentures, and overdentures were manufactured using milled bars and additional attachments. The clinical results were satisfactory in the aspect of improved oral hygiene maintenance, function and esthetics.
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Excessive teeth wear can lead to reduced chewing efficiency, occlusal plane collapse, and facial changes. Full mouth rehabilitation with a change in vertical dimension may cause pain in the temporomandibular joint, masticatory muscle and teeth, so an accurate diagnosis and treatment plan is required. In this case, a 69-year-old man had excessive teeth wear with a loss of posterior support. We evaluated the degree of adaptation to the increased vertical dimension with the removable occlusal splint and provisional restoration. We report this case because the treatment result has been functionally and aesthetically satisfactory by providing stable anterior guidance, proper posterior teeth disclusion, and even contact of all teeth in centric occlusion.
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Surgeries performed for patients with coronavirus disease 2019 (COVID-19) place the medical staff at very high risk of infection. We suggest recommendations for appropriate operation preparation, anesthetic management, and infection control for COVID-19 patients in operating rooms.Current Concepts: Surgeries must be performed in an airborne infection isolation room, such as a negative-pressure operating room. It is recommended that scheduled surgeries for COVID-19 patients be postponed to an acceptable extent, with the exception of emergency cases. Moreover, the number of medical staff participating in the surgery should be minimized. Medical staffs should practice proper hand hygiene and wear an appropriate level of personal protective equipment depending on the infection risk. While performing surgery and inducing anesthesia in COVID-19 patients, endotracheal intubation should be performed by trained anesthesiologists with a video laryngoscope, preferably using high-efficiency viral filters, which can prevent contamination in the anesthesia machine. Use of disposable equipment or COVID-19 patient-specific devices is recommended to prevent the spread of infection, but instruments that require sharing among multiple patients must be thoroughly cleaned and disinfected before their use for the next patient.Discussion and Conclusion: Medical staff performing surgeries for COVID-19 patients are at very high risk of infection. Therefore, the use of appropriate personal protective equipment, high-efficiency viral filters in breathing circuits during anesthesia, and disinfection of contaminated equipment after the operation are mandatory.
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Excessive teeth wear can lead to reduced chewing efficiency, occlusal plane collapse, and facial changes. Full mouth rehabilitation with a change in vertical dimension may cause pain in the temporomandibular joint, masticatory muscle and teeth, so an accurate diagnosis and treatment plan is required. In this case, a 69-year-old man had excessive teeth wear with a loss of posterior support. We evaluated the degree of adaptation to the increased vertical dimension with the removable occlusal splint and provisional restoration. We report this case because the treatment result has been functionally and aesthetically satisfactory by providing stable anterior guidance, proper posterior teeth disclusion, and even contact of all teeth in centric occlusion.
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Surgeries performed for patients with coronavirus disease 2019 (COVID-19) place the medical staff at very high risk of infection. We suggest recommendations for appropriate operation preparation, anesthetic management, and infection control for COVID-19 patients in operating rooms.Current Concepts: Surgeries must be performed in an airborne infection isolation room, such as a negative-pressure operating room. It is recommended that scheduled surgeries for COVID-19 patients be postponed to an acceptable extent, with the exception of emergency cases. Moreover, the number of medical staff participating in the surgery should be minimized. Medical staffs should practice proper hand hygiene and wear an appropriate level of personal protective equipment depending on the infection risk. While performing surgery and inducing anesthesia in COVID-19 patients, endotracheal intubation should be performed by trained anesthesiologists with a video laryngoscope, preferably using high-efficiency viral filters, which can prevent contamination in the anesthesia machine. Use of disposable equipment or COVID-19 patient-specific devices is recommended to prevent the spread of infection, but instruments that require sharing among multiple patients must be thoroughly cleaned and disinfected before their use for the next patient.Discussion and Conclusion: Medical staff performing surgeries for COVID-19 patients are at very high risk of infection. Therefore, the use of appropriate personal protective equipment, high-efficiency viral filters in breathing circuits during anesthesia, and disinfection of contaminated equipment after the operation are mandatory.
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Fixed implant prostheses or removable partial dentures are common treatment for partially dentulous patients. Recently, an implant-assisted removable partial denture (IARPD) has been introduced and is widely used. In the case of removable partial dentures using implant attachment and surveyed fixed prostheses, the consideration about parallelism of insertion path between implants and surveyed fixed prostheses is an important factor for success of IARPDs. In this case, she complained of discomfort while using the mandibular removable partial denture. Thus, an IARPD using implant surveyed fixed prostheses was fabricated.Thereafter, more implants were placed by a digital guide surgery to have the same insertion path as the existing surveyed fixed prostheses. Locator attachments were installed to the left and right premolar implants, and the left molar was able to obtain support of the removable partial denture with healing abutment. The clinical results were satisfactory on the aspect of aesthetic and masticatory function.
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For patients with unstable mandibular movements and centric relation of the mandible due to long-term use of ill-fitting dentures, the successful fabrication of new dentures is challenging. Before fabrication new dentures, registration of centric relation is the critical point in such cases. In this case, treatment dentures with a flat occlusal table were used to stabilize mandibular movements and to register centric relation. In order to reflect the patient's jaw relation and vertical dimension obtained through the treatment dentures to the final denture, the treatment dentures were digitally duplicated, and impressions and jaw relations were obtained using the duplicated therapeutic dentures. The clinical results were satisfactory on the aspect of aesthetic and masticatory functioned.
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were satisfactory on the aspect of esthetic and masticatory function. (J Korean Acad Prosthodont 2020;58:137-44)
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Failure of fixed implant supported prosthesis is caused by biomechanical factors such as excessive occlusal stress and biological factors such as bacterial infections andinflammation. Implants with severe bone resorption that have worsened without being resolved due to implant complications should be removed and then new treatmentsshould be planned, taking into account remaining teeth, remaining implants, and residual alveolar. The patient of this case removed some of fixed implant prosthesis of mandible.The condition of the remaining alveolar bone was reassessed for further implant replacement and a few implants were placed. Then implant assisted removable partialdenture (IAPRD) treatment is performed using implant surveyed bridge as abutment. Through this treatment, the clinical results were satisfactory on aspect of masticatoryfunction recovery and oral hygiene management. (J Korean Acad Prosthodont 2020;58:161-8)
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Traditionally, gingival retraction has been performed to obtain customized abutment impressions with subgingival margins of the implant supported prosthesis. However, gingivalretraction may have side effects such as gingival recession and bleed, leading to an inaccurate impression. In order to prevent these problems, in this case, the new techniquehas been introduced; a customized abutment which is designed for superimposition is used. Before the connection of the abutment to the implant fixture, pre-scannedshape data are stored, and then the optical impression without gingival retraction is obtained after connecting to the fixture. The suprastructure is fabricated by superimposingthe two data. This technique showed the clinical efficacy of fabricating the implant supported prosthesis with subgingival margin, which satisfied the aesthetics, convenience,and clinically acceptable marginal and internal fit. (J Korean Acad Prosthodont 2020;58:169-75)
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Background@#Surgeries in patients with coronavirus disease 2019 (COVID-19) put medical staff at a high risk of infection. We report the anesthetic management and infection control of a mechanically ventilated COVID-19 patient who underwent exploratory laparotomy for suspected duodenal ulcer perforation.Case: A 73-year-old man, mechanically ventilated for confirmed COVID-19, showed clinical and radiographic signs of a perforated duodenal ulcer, and he was transferred under sedation and intubation to a negative-pressure operating room. The operating and assistant staff wore personal protective equipment. High-efficiency particulate absorbing (HEPA) filters were inserted into the expiratory circuits of the anesthesia machine and portable ventilator. No participating staff contracted COVID-19, although the patient later died due to pneumonia. @*Conclusions@#This report can contribute to establishing clinical guidelines for the surgical management and operation room setting of COVID-19 patients.
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Background@#The analgesic effect of perineural opioid in clinical practice are still controversial. This randomized controlled trial compared analgesic effect of ropivacaine with fentanyl or ropivacaine alone for continuous femoral nerve block following unilateral total knee arthroplasty. @*Methods@#Fourty patients of ASA PS Ⅰ or Ⅱ receiving total knee arthroplasty with spinal anesthesia were enlisted and randomly allocated into two groups. Group R; bolus injection of 0.375% ropivacaine, 30 ml and an infusion of 0.2% ropivacaine at 8 ml/h (n = 20). Group RF; 0.375% ropivacaine, 29 ml added with 50 μg of fentanyl as a bolus and an infusion of 0.2% ropivacaine mixed with 1 μg/ml of fentanyl at 8 ml/h (n = 20). Local anesthetic infusion via a femoral nerve catheter was started at the end of operation and continued for 48 h. Intravenous patient-controlled analgesia with hydromorphone (0.15 mg/ml, 0-1-10) were used for adjuvant analgesics. Position of catheter tip and contrast distribution, visual analog scale of pain, hydromorphone consumption, side effects were recorded for 48 h after operation. Patient satisfaction for the pain control received were noted. @*Results@#The pain visual analogue scale, incidences of side effects and satisfaction were not different between the two groups (P > 0.05), but the hydromorphone usage at 48 h after operation were lower in the Group RF than in the Group R (P = 0.047). @*Conclusions@#The analgesic effect of ropivacaine with fentanyl for continuous femoral nerve block after knee replacement arthroplasty was not superior to that of the ropivacaine alone.
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Implant-Assisted Removable Partial Dentures (IARPDs) treatment is being performed in a fully edentulous patient using implant surveyed prosthesis as an abutment. Implant-supported prosthesis as an abutment of IARPDs is classified into screw-retained and cement-retained type according to the retention type, and each has advantages and disadvantages. The EZ crown system (Samwon DMP, Yangsan, Korea) has a cylinder combined with abutment, and the nickel-titanium spring in this cylinder provides a constant force on the zirconia ball to obtain retention in EZ crown system. In this patient, the natural abutment teeth of the mandibular overdenture was hopeless. We planned implant assisted removable partial denture using anterior implant surveyed prosthesis considering functional and esthetical rehabilitation, cost and patient's needs. When fabricating IARPDs using implant as abutment, we could compensate for the shortcomings of existing implant-supported prosthesis retention type and made the design of removable partial denture easy due to using EZ crown system.