Geriatric oral health care encounters significant challenges with the increase in the proportion of older individuals. Age-related changes in the dentition, muscles, and joints result in a decline in objective masticatory function, subjective restoration requirements, and acceptability among the elderly population, with individual variations influenced by systemic health. Considering functional requirements, the adaptability of stomatognathic and systemic health conditions, health economics and other factors, the authors believe that it should not be limited to the conventional "one-to-one" strategy for replacing missing teeth in geriatric prosthodontics. There is an urgent need for a precise and adaptable restoration strategy that is more suitable for older individuals. The proposal of a new concept of functional tooth loss updates the minimal restoration standards for elderly patients and establishes the theory of age-friendly functional restoration. Based on the restoration strategy of functional tooth loss, this paper proposes a new concept termed "age-friendly functional restoration of the stomatognathic system", which integrates treatment considerations including endodontics, periodontology, mucosa, muscles, temporomandibular joint, and systemic health. Efforts should be made in four areas as follows. Firstly, the "assessment of accessible function" should be enhanced by considering the interrelationship between stomatognathic and systemic health. Secondly, the "evaluation of appropriate function" is supposed to be optimised in view of subjective needs and objective evaluation of the stomatognathic system. Moreover, the "formulation of treatment plans" needs to be accomplished with the aid of assistive technologies, such as artificial intelligence, to accurately exert appropriate functional restoration. Lastly, the "management and maintenance of health" is likely to be strengthened through follow-ups, propaganda and education, and preventive healthcare, so as to improve quality of life and ultimately achieve healthy ageing among older individuals.
Humans ; Tooth Loss/therapy* ; Aged ; Stomatognathic System ; Oral Health ; Dental Care for Aged ; Dental Restoration, Permanent/methods*

The current low quality of fixed restoration margins is highly correlated with the high incidence of margin-related complications. It is also related to the unclear spatiotemporal geometric position relationship among the consensus definitions of the gingival margin (G), preparation margin (P), and restoration margin (R). This paper discusses the existing problem of the existing term "gingival margin" as a surface anatomical landmark; proposes the term "free gingival margin line" that conforms to geometry and measurement and has importance as a surface anatomical landmark; and clarifies the participants that exist in the marginal area. These participants include the P, R, and G; cementation (adhesive) layer; and gingival sulcus. Moreover, this paper discusses the various iatrogenic damages induced by entering the gingival sulcus via the P, R, and cementing (adhesive) layer. Through the discussion of the design deficiencies of the subgingival and biologically oriented preparation technique, the physiological and clinical importance of the concept of gingival sulcus/gingival sulcus fluid + supercrestal tissue attachment (biological width) = first periodontal protective barrier was analyzed. The value of preserving the physiological role of the gingival sulcus is emphasized. Furthermore, the newly defined RPG distance represents the distance between the successive P or R line and free G line and can be measured in the clinical procedure of tooth preparation. The optimal solution is 0-200 µm, that is, RPG200: the P and R are located on the free G line and the distance between these margins is less than 200 µm. This distance not only has the aesthetic effect of invisibility to the naked eye, it also has a minimal effect on the G and gingival sulcus and is convenient for doctors and patients to clean. Furthermore, in accordance with the positional relationship between the three margins and cementation (adhesive) layer, a new classification of marginal positions is proposed. This classification overcomes the problems of incomplete inclusion objects and uncontrolled risk factors in the previous classification. It also has the advantages of strong practicability, good efficiency of main control geometric quantity, and clear risk control points. The new design scheme and classification of the margi-nal position of RPG200 proposed in this paper provide a new understanding for margin design and complication prevention in the future.
Humans ; Gingiva/anatomy & histology* ; Cementation ; Dental Restoration, Permanent/methods*

Achieving precise restoration of tooth function and personalized restoration of natural tooth esthetics has always been a significant challenge in direct restorative dentistry. The traditional direct restorative techniques are limited by the subjective operations of dentists, resulting in high technical sensitivity, long operation time, and unpredictable restoration results, making it difficult to meet patients' personalized demands for restoration outcomes. An innovative flowable resin injection technique was introduced in this study. By combining digital design with personalized restoration guides, this technique achieves precise and personalized tooth restoration, thus revolutionizing the traditio-nal paradigm of direct tooth restoration. Specifically, this technique is guided by the patient's subjective aesthetic needs. It utilizes digital technology to pre-design the restoration result and creates a personalized restoration guide. During clinical operation, the dentist needs to only precisely inject the flowable resin into the guide, allowing for rapid completion of the restoration, thereby significantly reducing the operation time and improving the precision and predictability of the restoration. The perfect combination of digital design and flowable resin injection not only significantly improves the precision and predictability of direct tooth restoration but also remarkably shortens the clinical operation time and reduces the requirements for the dentist's technical level, making it widely applicable to the restoration of various tooth defects. Thus, it improves patient satisfaction and reduces the workload of dentists. This innovative restoration technique is expected to become a new productive force in future clinical direct adhesive restorations.
Humans ; Dental Restoration, Permanent/methods* ; Esthetics, Dental ; Composite Resins ; Computer-Aided Design ; Injections

OBJECTIVES: This study aims to evaluate the differences in shear bond strength, marginal adaptation, and nano-microleakage after aging among snowplow, layered filling, and lining techniques applied to the resin-bonded restoration of defective primary teeth. METHODS: In this study, 51 freshly extracted, crown-intact primary anterior teeth and 30 primary molars were collected. The experimental groups were as follows: layered filling group, lining group, and snowplow group. Experiments were performed to compare the differences in shear bond strength, marginal integrity, and silver ion nano-microleakage after aging among these groups. RESULTS: The median shear bond strength of the layered filling group, lining group, and snowplow group were 2.45, 5.72, and 9.43 MPa, respectively. The values for lining group and snowplow group were significantly higher than that for layered filling group (P<0.05). No statistically significant difference was found between lining group and snowplow group (P>0.05). The median overall margin integrity of the layered filling group, lining group, and snowplow group were 55.38%, 48.25%, and 65.63%, respectively. The difference among the three groups was not statistically significant (P>0.05). The median percentages of silver ion nano-microleakage in the layered filling group, lining group, and snowplow group were 11.71%, 9.47%, and 11.55%, respectively. The difference among the three groups was not statistically significant (P>0.05). CONCLUSIONS Applying the snowplow technique to restore defective primary teeth can improve the bond strength and margin integrity and reduce nano-microleakage.
Tooth, Deciduous ; Humans ; Dental Restoration, Permanent/methods* ; Dental Leakage ; Shear Strength ; Dental Bonding/methods* ; Molar ; Composite Resins ; Silver

This report presents a case of a 9-year-old child with a complicated crown-root fracture of the maxillary central incisor, accompanied with a root fracture. The treatment strategy was minimally invasive, focusing on vital pulp preservation, root fracture recovery, and crown restoration. The fractured crown was reattached using resin short posts to enhance retention, resulting in aesthetic and functional restoration of the anterior teeth. A 2-year follow-up revealed favorable clinical and radiographic outcomes.
Humans ; Child ; Tooth Fractures/therapy* ; Tooth Root/injuries* ; Incisor/injuries* ; Tooth Crown/injuries* ; Post and Core Technique ; Dental Restoration, Permanent/methods* ; Maxilla

Immediate implant-supported fixed restoration in edentulous jaws demonstrates a success rate comparable to that of conventional implant restoration. However, this approach still presents a certain degree of technique sensitivity. In the field of immediate implant-supported fixed restoration in dentistry, a repeatable and stable jaw relation is the prerequisite for the design and fabrication of prostheses. It also reduces chairside denture placement and occlusal adjustment time and lowers the risk of occlusion-related complications. For patients with terminal dentition, the precise transfer of jaw relation following full-arch implantation serves as the fundamental basis for implant-supported occlusal reconstruction and functional restoration. This process is also a key research focus and challenge in the area of implant-supported occlusal rehabilitation. This review summarizes the procedures and methods for determining and transferring jaw relation in immediate implant-supported fixed restoration. It aims to serve as a basis for clinical decision making in implant-supported fixed restorations for terminal dentition patients.
Humans ; Dental Prosthesis, Implant-Supported ; Clinical Decision-Making ; Immediate Dental Implant Loading ; Jaw, Edentulous/surgery*

With the increasing demand for dental aesthetic outcomes, techniques for composite resin restoration intended for anterior teeth have been widely applied due to their minimally invasive and superior esthetic performance. Despite promising short-term outcomes, the long-term prognosis of anterior resin restorations remains challenging. Frequently reported complications include restoration fractures and decoloration. Material selection, operative procedures, and patient-related factors can affect the long-term outcomes of restorations. This review aims to systematically analyze the long-term clinical performance of resin restorations in anterior teeth. The key factors influencing treatment efficacy are also investigated. The findings are expected to provide a basis for optimizing clinical strategies in procedures for anterior composite resin restoration.
Humans ; Composite Resins ; Dental Restoration, Permanent/methods* ; Prognosis ; Esthetics, Dental ; Treatment Outcome ; Time Factors

Prosthesis loosening is the leading cause of postoperative revision in unicompartmental knee arthroplasty (UKA). The deviation of medial and lateral translational installation of the prosthesis during surgery is a common clinical phenomenon and an important factor in increasing the risk of prosthesis loosening. This study established a UKA finite element model and a bone-prosthesis fixation interface micromotion prediction model. The predicted medial contact force and joint motion of the knee joint from a patient-specific lower extremity musculoskeletal multibody dynamics model of UKA were used as boundary conditions. The effects of 9 femoral component medial and lateral translational installation deviations on the Von Mises stress of the proximal tibia, the contact stress, and the micro-motion of the bone prosthesis fixation interface were quantitatively studied. It was found that compared with the neutral position (a/A of 0.492), the lateral translational deviation of the femoral component significantly increased the tibial Von Mises stress and the bone-prosthesis fixation interface contact stress. The maximum Von Mises stress and the maximum contact stress of the fixation interface increased by 14.08% and 143.15%, respectively, when a/A was 0.361. The medial translational deviation of the femoral component significantly increased the bone-prosthesis fixation interface micro-motion. The maximum value of micromotion under the conditions of femoral neutral and medial translation deviation was in the range of 20-50 μm, which is suitable for osseointegration. Therefore, based on considerations such as the micromotion range suitable for osseointegration reported in the literature, the risk of reducing prosthesis loosening, and factors that may induce pain, it is recommended that clinicians control the mounting position of the femoral component during surgery within the safe range of 0-4 mm medial translation deviation.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Finite Element Analysis ; Biomechanical Phenomena ; Knee Prosthesis ; Tibia/surgery* ; Femur/surgery* ; Stress, Mechanical ; Prosthesis Failure ; Knee Joint/surgery* ; Prosthesis Design

Tesla blood pumps demonstrate a reduced propensity for hemolysis and thrombosis compared with vane blood pumps. Considering the restricted driving force within the secondary flow channel of vane blood pumps, along with the low hydraulic efficiency of conventional Tesla blood pumps and their internal flow characteristics that significantly contribute to hemolysis and thrombosis, this study introduces a set of vanes atop the rotor of the Tesla blood pump. This forms a dual-fluid domain rotor, and an axial dual-outlet volute shell structure is adopted to realize the separation of the fluid domains. Through numerical simulations of the new structure, a comparative analysis was conducted in this study on the internal flow characteristics of double-outlet and single-outlet volute shells, and symmetric and asymmetric cross-sections of the same rotor. The results indicate that the flow field distribution is more uniform under the double-outlet volute shell structure, and overall energy dissipation is decreased. After implementing the double-outlet design, in the asymmetric cross-section, compared with the symmetric cross-section, the fluid velocity gradient and turbulent kinetic energy at the tongue of the septum are reduced, and the fluid velocity gradient at the convergence of the diffuser tube outlets are also decreased. The maximum scalar stress is lower, and the decline in head and efficiency is mitigated. Moreover, compared with the single-outlet volute shell, the hemolysis index in the asymmetric cross-section is reduced. In summary, this paper proposes a novel dual-outlet centrifugal disk blood pumps, which can provide a reference for the structural design and performance optimization of magnetically levitated centrifugal blood pumps.
Heart-Assist Devices ; Humans ; Equipment Design ; Hemolysis ; Computer Simulation

The orientation of the acetabular cup in hip joint anteroposterior radiograph is a key factor in evaluating the postoperative outcomes of total hip arthroplasty (THA). Currently, measurement of the acetabular cup anteversion angle primarily relies on manual drawing of auxiliary lines by orthopedic surgeons and calculations using scientific calculators. This study proposes an automated computer-aided measurement method for the acetabular cup anteversion angle based on hip joint anteroposterior radiograph. The proposed method segments hip prosthesis images using an improved Otsu algorithm, identifies feature points at the acetabular cup opening by combining circle-fitting theory and the cup's geometric characteristics, and fits an ellipse to the cup opening to calculate the anteversion angle. A total of 104 hip joint anteroposterior radiographs, including 71 right-sided and 81 left-sided prostheses, were analyzed. Two orthopedic surgeons independently measured the postoperative anteversion angles, and the results were compared with computer-generated measurements for correlation analysis. Spearman and Pearson correlation analyses demonstrated significant correlations between the proposed method and manual measurements for both the right group ( r = 0.795, P < 0.01) and the left group ( r = 0.859, P < 0.01). This method provides a reliable reference for orthopedic surgeons to assess postoperative prognosis.
Humans ; Acetabulum/anatomy & histology* ; Arthroplasty, Replacement, Hip/methods* ; Algorithms ; Hip Prosthesis ; Hip Joint/diagnostic imaging* ; Radiography ; Image Processing, Computer-Assisted/methods*