The surface treatments and various magnesium alloys are applied to improve the fast degradation rate and resulting negative effects of magnesium alloys. This study aimed to assess the effect of anodic oxidation treatment of magnesium-calcium (Mg-Ca) systems by creating artificial bone defects in the tibia of rats. The cylinder magnesium implants were fabricated using a Mg-xCa (x = 0, 1, 5 wt.%) binary alloy. Degradability and new bone formation were observed at two and six weeks using micro-CT. Histomorphometric parameters were evaluated with Goldner's trichrome staining. The degradation rate decreased depending on the amount of calcium added. The parameters related to bone formation revealed an increasing pattern depending on the addition of calcium, anodic oxidation, and time. The amount of absorbed magnesium to assess degradability of magnesium implants by the histomorphometric analysis revealed a high value in the untreated group at two and six weeks. Bone healing parameters increased depending on the amount of calcium added, anodic oxidation treatment, and region of interest (ROI-0.5 mm, 1.00 mm, 1.5 mm, and 2.0 mm). Biodegradable magnesium systems have the potential to replace bone screws and plates. Combination with calcium combined with anodization surface treatment can improve initial corrosion resistance and promote bone formation.

Regeneration of load-bearing tissues is crucial for ensuring the structural stability and biocompatibility of scaffolds. Hence, this study was aimed at developing a biomimetic dual-structured scaffold for bone tissue regeneration. A zirconia framework (outer wall) was fabricated by coating bioglass on a 3D-printed structure, and a cell-laden GelMA hydrogel (interior part) was embedded within the framework. The dual-structured scaffold was fabricated using 3D printing and coated with bioactive glass (BGS-7). The mechanical properties and biocompatibility of the construction were evaluated. The compressive strength of the constructed scaffold (similar to 100 MPa) was comparable to that of natural bone. The viability of the cells was enhanced following a sevenday culture period for the cell-laden GelMA with a 5 % concentration embedded on the bioactive glass-coated surface (G5). The results of ALP activity and ARS also demonstrate an increased tendency for osteoblast cell differentiation in the G5 group compared to other groups. Moreover, the combination of zirconia and GelMA hydrogel has the potential to enable the fabrication of scaffolds for load-bearing tissue engineering applications, while the bioglass coating can improve the bioactivity of the scaffold. Within the constraints of this experiment, the G5 group demonstrated enhanced outcomes in terms of osteoblast proliferation, and mineralization.

Inflammatory movable tissues in the maxillary anterior region are the result of excessive stimulation of the anterior alveolar ridge, as the maxillary denture habitually rotates anteriorly and upward during mastication. The pressure required for a functional impression makes it difficult to obtain the accurate anatomy of the inflamed mucosal tissues. An intraoral scanner can be used to record the movable tissues in an immobile state. However, for removable dentures, the oral scanner is limited by the difficulty in evaluating the denture borders or the posterior palatal seal area accurately. The fabrication of a complete denture by combining the use of an oral scanner to capture an anatomic impression without exerting pressure on the maxilla, including the movable tissues, and a traditional functional impression using the closed-mouth technique is described.

서론 골유착 임플란트는 단일 치아 상실부터 무치악 상태까 지 두루 수복할 수 있는 방법으로 임플란트 치료 초기의 성공요인이 골유착의 여부에 있었다면, 최근에는 골유착 성공률이 높아짐에 따라 임플란트의 성공여부를 판단하 는 새로운 변수가 대두되고 있다.이러한 변수에는 임플 란트 주변 연조직, 보철물, 환자의 주관적 평가 등이 포함 되며, 환자들은 기능적인 만족도 뿐만 아니라 심미에 대 한 기대가 있다.

Recently, computer-aided design and computer-aided manufacturing (CAD/CAM) environment have changed the clinician treatment method in the fabrication of prosthesis.The diagnostic wax-up by using digital technology simplifies the laboratory process and provides clinical efficiency and convenience.In this case, Digital diagnostic wax-up was superimposed on extra-oral photo to consider the patient's facial appearance and utilized to produce the final prosthesis.It can be more efficient and esthetic than a diagnostic wax-up that was made only on a model.The digital diagnostic wax-up that superimposed on extra-oral photo not only visualizes the predicted outcome of prosthodontic treatment but also improves satisfaction and facilitates the communication between patient and dentist.We report aesthetically and functionally satisfactory results that obtained after restoration.(

The purpose of this study is to evaluate the mechanical properties and clinical fitness of 3D-printed bioglass porcelain fused to metal (PFM) dental crowns. To evaluate the mechanical properties, tensile strength, Vickers microhardness, shear bond strength, and surface roughness tests of the SLM printed Co-Cr alloy was conducted. A right mandibular 1st molar tooth was prepared for a single dental crown (n = 10). For a three-unit metal crown and bridge, the right mandibular first premolar and first molar were prepared. Bioglass porcelain was fired to fabricate PFM dental restorations. A clinical gap was observed and measured during each of the four times porcelain was fired. A statistical analysis was conducted. The SLM technique showed the largest statistically significant tensile strength and a 0.2% yield strength value. The milling technique had the lowest statistically significant compressive strength value. The shear bond strength and surface roughness showed no statistically significant difference between the fabricated method. There was a statistically significant change in marginal discrepancy according to the porcelain firing step. The casting technique showed the greatest statistically significant margin discrepancy value. The SLM method showed better fitness than the traditional casting method and showed better mechanical properties as a dental material.

치과 임플란트학의 도약적인 발전에도 불구하고, 임플 란트 주위 질환과 관련하여

Zirconia was established as one of the chief vital ceramic materials for its superior mechanical permanency and biocompatibility, which make it a popular material for dental and orthopedic applications. This has inspired biomedical engineers to exploit zirconia-based bioceramics for dental restorations and repair of load-bearing bone defects caused by cancer, arthritis, and trauma. Additive manufacturing (AM) is being promoted as a possible technique for mimicking the complex architecture of human tissues, and advancements reported in the recent past make it a suitable choice for clinical applications. AM is a bottom-up approach that can offer a high resolution to 3D printed zirconia-based bioceramics for implants, prostheses, and scaffold manufacturing. Substantial research has been initiated worldwide on a large scale for reformatting and optimizing zirconia bioceramics for biomedical applications to maximize the clinical potential of AM. This book chapter provides a comprehensive summary of zirconia-based bioceramics using AM techniques for biomedical applications and highlights the challenges related to AM of zirconia.

Recently, digital technology and computer-aided design/computer-aided manufacturing (CAD/CAM) environment have changed the clinician treatment method in the fabrication of dentures.The denture manufacturing method with CAD/CAM technology simplifies the treatment and laboratory process to reduce the occurrence of errors and provides clinical efficiency and convenience.In this case, complete dentures were fabricated using stereolithography (SLA)-based 3D printing in patient with mandibular deviation.Recording base were produced in a digital model obtained with an intraoral scanner, and after recording a jaw relation in the occlusal rim, a definitive impression was obtained with polyvinyl siloxane impression material.In addition, facial scan data with occlusal rim was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work.Artificial teeth were arranged through a CAD program, and a gingival festooning was performed.The definitive dentures were printed by SLA-based 3D printer using a Food and Drug Administration (FDA)-approved liquid photocurable resin.The denture showed adequate retention, support and stability, and results were satisfied functionally and aesthetically.(

Abstract The purpose of this paper was to introduce a method for creating a digital virtual patient by combining cone-beam computed tomography (CBCT), intraoral scan, and facial scan with a high accuracy of integration. CBCT scan, facial scan, and intraoral scan were obtained from initial visit. The virtual patient was created using the integration of these imaging modalities. Once the virtual patient was generated, digital workflow could be applied to initial patient consultation, diagnosis, treatment planning, virtual tooth setup, virtual treatment simulation, and post-treatment evaluation. integration of digital technology allows clinicians to improve diagnosis and treatment outcome. in addition, it allows for favorable patient communication. This technique eliminates the traditional impression process and complicated laboratory procedures for evaluating patient's occlusion during smile and habitual resting position. Based on this protocol, it is possible to create a digital virtual patient using CBCT, intraoral scan, and facial scan with a high accuracy of integration. it would be helpful for precision diagnosis and accurate treatment as well as favorable communication with patient.

Recently with the advance in digital dentistry, the fabrication of dentures using computer-aided design and computer-aided manufacturing (CAD-CAM) is on the rise. The denture designed through a CAD software can be produced in a 3-di-mensional manufacturing process. This process includes a subtractive processing method such as milling and an additive processing method such as 3D printing and in which it can be applied efficiently in more complex structures. In this case, complete dentures were fabricated using Stereolithography (SLA)-based 3D printing to shorten the production time and interval of visits in patient with phys-ical disabilities due to cerebral infarction. For definitive impression, the existing interim denture was digitally replicated and used as an individual tray. The definitive impression obtained with polyvinyl siloxane impression material was includ-ing information about the inclination and length of the maxillary anterior teeth, vertical dimension, and centric relation. In addition, facial scan data with interim denture was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work. Artificial teeth were arranged through a CAD program, and a gingival festooning was performed. The definitive dentures were printed by SLA-based 3D printer using a FDA-approved liquid photocurable resin. The denture showed adequate reten-tion, support, and stability, and results were satisfied functionally and aesthetical-ly. (J Korean Acad Prosthodont 2022;60:202-10)

Treatment of ankylosed and submerged primary molars without permanent successors is challenging, as normal vertical dentoalveolar growth is compromised. Thus, grafting techniques and distraction osteogenesis are performed for ridge augmentation before implant restoration. However, these techniques are invasive with limited success. Another treatment for implant site development is noninvasive forced eruption. This case report describes long-term follow-up of alveolar ridge augmentation in the submerged mandibular primary second molars using subluxation and orthodontic forced eruption for implant site development. A 19-year old female had Class II molar relationships, upper anterior crowding with large overjet, missing four second premolars and submerged mandibular primary second molars with inadequate vertical development of alveolar bone. For the vertical alveolar bone alterations in the mandible, forced eruption with subluxation of ankylosed lower primary second molars was applied. Treatment outcome was evaluated over 5 years with stable occlusion, healthy periodontal tissues, and successful radiographic results.

A bone regeneration scaffold is typically designed as a platform to effectively heal a bone defect while preventing soft tissue infiltration. Despite the wide variety of scaffold materials currently available, such as collagen, critical problems in achieving bone regeneration remain, including a rapid absorption period and low tensile strength as well as high costs. Inspired by extracellular matrix protein and topographical cues, we developed a polycaprolactone-based scaffold for bone regeneration using a soluble eggshell membrane protein (SEP) coating and a nanotopography structure for enhancing the physical properties and bioactivity. The scaffold exhibited adequate flexibility and mechanical strength as a biomedical platform for bone regeneration. The highly aligned nanostructures and SEP coating were found to regulate and enhance cell morphology, adhesion, proliferation, and differentiation in vitro. In a calvaria bone defect mouse model, the scaffolds coated with SEP applied to the defect site promoted bone regeneration along the direction of the nanotopography in vivo. These findings demonstrate that bone-inspired nanostructures and SEP coatings have high potential to be applicable in the design and manipulation of scaffolds for bone regeneration.

During the design of membranes for guided tissue regeneration (GTR) to treat periodontal diseases, infection of the exposed membranes and postoperative complications can be prevented by increasing bacterial resistance. This study evaluated the antibacterial activity of PCL/ZnO membranes and their effect on cell viability via addition of antibacterial zinc oxide (ZnO) nanoparticles to a biocompatible and biodegradable material such as polycaprolactone (PCL). Neat PCL membranes and PCL/ZnO membranes containing 0.5 wt.% and 5 wt.% ZnO were produced, and divided into PCL (0% ZnO), LZ (0.5 wt.% ZnO), and HZ (5 wt.% ZnO) groups, respectively. The surface characteristics of the membranes including morphological features and changes in composition were analyzed. Adhesion of bacteria, including Streptococcus mutans and Porphyromonas gingi-valis, was analyzed using a crystal violet assay. The proliferation of MC3T3-E1 osteoblasts was evaluated using a WST-8 assay. Significant differences were analyzed using the Kruskal-Wallis test (P < 0.05). The results of groups were compared using the Mann-Whitney test (P < 0.017). ZnO nanoparticles were dispersed in the PCL matrix of PCL/ZnO membranes. Compared with neat PCL membranes, their ability to form crystals decreased and their amorphous structure increased. The adhesion of S. mutans and P. gingivalis in the LZ and HZ groups containing ZnO was significantly decreased compared with that of the neat PCL membranes (P < 0.05). No significant differences were observed in the proliferation of MC3T3-E1 cells between the PCL/ZnO membranes and the neat PCL membranes both on days 2 and 5 of culture (P > 0.05). This study has demonstrated that the PCL membranes carrying the ZnO nanoparticles inhibited bacterial adhesion without affecting the viability of osteoblasts, suggesting the potential application of ZnO in GTR to increase antibacterial activity of membranes.

The cover image is based on the Article Eggshell membrane as a bioactive agent in polymeric nanotopographic scaffolds for enhanced bone regeneration by Daun Kim et al., https://doi.org/10.1002/bit.27702.