Utilization of Tenting Pole Abutments for the Reconstruction of Severely Resorbed Alveolar Bone: Technical Considerations and Case Series Reports.

INTRODUCTION: Although various surgical techniques have been utilized in the reconstruction of severely resorbed alveolar bone, its regeneration is still regarded as a major challenge. Most of the surgical techniques used in advanced ridge augmentation have the disadvantages of prolonging the patient's edentulous healing and increasing the need for surgical revisits because simultaneous implant placement is not allowed. This report presents a new and simplified method for advanced ridge augmentation, which utilizes a vertical tenting device. CASE PRESENTATION: The first case presented the reconstruction of the mandibular posterior region with severely resorbed alveolar bone due to peri-implantitis using tenting pole abutment for ridge augmentation. The second and third cases presented three-dimensional ridge augmentations in severely resorbed ridges due to periodontitis. The last case presented horizontal ridge augmentation using a vertical tenting device. All cases were performed under local anesthesia. Implants were simultaneously placed in the bone defect area. A vertical tensioning device was then connected to the implant platform to minimize the collapse of the bone graft during the bone regeneration period due to the contraction of the soft tissue matrix. A sticky bone graft was transplanted onto the exposed surface of the implant and on top of the vertical tensioning device. After covering with an absorbable barrier membrane, the soft tissues were sutured without tension. CONCLUSIONS: In all cases, prosthetic restorations were provided to patients after a bone grafting period of 5-6 months, leading to a rapid restoration of masticatory function. Results tracked for up to 6 years revealed observed stable reconstruction of the alveolar bone. The use of a vertical tenting device can prevent the collapse of biomaterials in the augmented ridge during the healing period, leading to predictable outcomes when achieving three-dimensional ridge augmentation.

Marginal fit of three different nanocomposite inlays fabricated with computer-aided design/computer-aided manufacturing (CAD/CAM) technology: a comparative study.

BACKGROUND: This study aimed to compare and evaluate the marginal fit of nanocomposite computer-aided design/computer-aided manufacturing (CAD/CAM) inlays. Three types of nanocomposite CAD/CAM blocks (HASEM, VITA Enamic, and Lava Ultimate) were used as materials. METHODS: Class II disto-occlusal inlay restorations were prepared on a typodont mandibular right first molar using diamond rotary instruments. The inlays were fabricated using CAD/CAM technology and evaluated using the silicone replica technique to measure marginal gaps at five locations on each inlay. The data were analyzed by two-way analysis of variance and Tukey post hoc tests ( α=0.05). RESULTS: There were no significant differences in the marginal gaps based on the type of nanocomposite CAD/CAM inlay used (p=0.209). However, there was a significant difference in the marginal gaps between the measurement regions. The gingival region consistently exhibited a larger marginal gap than the axial and occlusal regions (p<0.001). CONCLUSION: Within the limitations of this in vitro study, the measurement location significantly influenced the marginal fit of class II disto-occlusal inlay restorations. However, there were no significant differences in the marginal gaps among the different types of CAD/CAM blocks. Furthermore, the overall mean marginal fits of the class II disto-occlusal inlay restorations made with the three types of nanocomposite CAD/CAM blocks were within the clinically acceptable range.

Spontaneous Transition of Spherical Coacervate to Vesicle-Like Compartment.

Numerous biological systems contain vesicle-like biomolecular compartments without membranes, which contribute to diverse functions including gene regulation, stress response, signaling, and skin barrier formation. Coacervation, as a form of liquid-liquid phase separation (LLPS), is recognized as a representative precursor to the formation and assembly of membrane-less vesicle-like structures, although their formation mechanism remains unclear. In this study, a coacervation-driven membrane-less vesicle-like structure is constructed using two proteins, GG1234 (an anionic intrinsically disordered protein) and bhBMP-2 (a bioengineered human bone morphogenetic protein 2). GG1234 formed both simple coacervates by itself and complex coacervates with the relatively cationic bhBMP-2 under acidic conditions. Upon addition of dissolved bhBMP-2 to the simple coacervates of GG1234, a phase transition from spherical simple coacervates to vesicular condensates occurred via the interactions between GG1234 and bhBMP-2 on the surface of the highly viscoelastic GG1234 simple coacervates. Furthermore, the shell structure in the outer region of the GG1234/bhBMP-2 vesicular condensates exhibited gel-like properties, leading to the formation of multiphasic vesicle-like compartments. A potential mechanism is proposed for the formation of the membrane-less GG1234/bhBMP-2 vesicle-like compartments. This study provides a dynamic process underlying the formation of biomolecular multiphasic condensates, thereby enhancing the understanding of these biomolecular structures.

Comparative Histomorphometric Analysis of Bone Regeneration According to Bone Graft Type.

PURPOSE: To use histomorphometric analysis to evaluate bone reconstruction in rabbit calvaria with autogenous bone, anorganic bovine bone, undecalcified human tooth bone (UdTB), and decalcified human tooth bone (dTB) grafts. MATERIALS AND METHODS: Extracted human teeth were crushed, and tooth bone with and without decalcification was prepared. Bony defects were made in 10 rabbit calvaria and allocated to one of the following four groups: group 1, in which UdTB was grafted; group 2, in which dTB was grafted; group 3, in which anorganic bovine bone was grafted; group 4, in which autogenous bone was grafted. The rabbits were sacrificed at 2 or 8 weeks postoperatively, and histomorphometric comparison was performed. RESULTS: Histologically, new bone formation was observed at the defect margin and around all graft materials. The dTB group revealed significantly greater new bone areas at 2 and 8 weeks compared to the UdTB group and the anorganic bovine bone group (P < .05). The dTB group revealed no significant difference in the new bone area at 2 weeks but revealed significantly less new bone area at 8 weeks compared to the autogenous bone group (P < .05). The dTB group also revealed significantly less graft material area compared to the anorganic bovine bone group at 8 weeks (P < .05). The autogenous bone group revealed significantly less graft material area and significantly greater bone marrow area compared to other groups at 8 weeks (P < .05). CONCLUSIONS: Grafting with dTB resulted in better bone regeneration than UdTB and anorganic bovine bone grafting at 8 weeks and addresses the potential disadvantages of autogenous bone grafting.

Effects of Surface Treatment Method Forming New Nano/Micro Hierarchical Structures on Attachment and Proliferation of Osteoblast-like Cells.

Titanium (Ti) and Ti-based alloys are commonly used in dental implants, and surface modifications of dental implants are important for achieving osseointegration (i.e., direct connection between the implant surface and bone). This study investigated the effect of an eco-friendly etching solution-a hydrogen peroxide-sodium bicarbonate mixture-on the surface properties and contact angles of osteoblast adhesion and proliferation on Ti surfaces. Disk-shaped Ti specimens were prepared using different surface treatments (machining, sandblasting, and sandblasting/acid-etching), and they were immersed in the etching solution and ultrasonically cleaned. Surface characterization was performed using scanning electron microscopy, digital microscopy, contact angle analysis, and X-ray photoelectron spectroscopy. MG-63 osteoblasts were cultured on the specimens, and their adhesion to the specimen surface and proliferation were examined using staining and the MTT assay, respectively. Additional etching with the etching solution caused the formation of nano/micro hierarchical structures, increased surface roughness, and enhanced hydrophilicity. Osteoblast adhesion and proliferation were found to improve on the modified surfaces. The eco-friendly etching method has the potential to enhance the biological properties of Ti implant surfaces and thereby improve dental implant performance.

Adaptive behavior in stroke survivors: A concept analysis.

PURPOSE: This study aims to explore a clear and evidence-based definition of adaptive behavior in stroke survivors and establish the antecedents, attributes, consequences, and empirical referents of the concept. METHODS: The concept analysis was performed using the Walker and Avant methods as a framework. Data from 90 publications were collected using various databases (PubMed, EMBASE, CINAHL, RISS, and KISS) and applied in the analysis. RESULTS: Adaptive behavior in stroke survivors was defined according to four attributes: realizing change, taking an optimistic view, restructuring daily activities to suit oneself, and carrying out one's own daily life. The conceptual structure of their adaptive behavior comprised stroke onset, functional changes, and emotional liability as antecedents and autonomy, family equilibrium, and quality of life as consequences. CONCLUSIONS: Clarifying the concept of adaptive behavior in stroke survivors provides an understanding of the underlying attributes of this concept. Furthermore, it will facilitate the development of scales to measure the concept and the application of a theory-based intervention program that can improve adaptive behavior.

Simplified Free Gingival Graft Around Implants Using Medical Grade Tissue Cyanoacrylate: A Case Series Report.

The free gingival graft (FGG) procedure using suturing techniques has been widely utilized to effectively increase the amount of attached keratinized gingiva. However, conventional suturing procedures are time-consuming and technique-sensitive. Simplified FGG procedure around teeth and dental implants using medical grade tissue adhesive (cyanoacrylate) is known to overcome drawbacks of traditional suture techniques. However, the clinical application of cyanoacrylate as a means of stabilizing the graft has not been a common practice. The aim of this report demonstrates simplified FGG procedures around dental implants using cyanoacrylate with follow-up results.

A useful method of using the healing abutments for interocclusal records in implant overdenture: a case report.

To determine the vertical dimension and centric relation during the construction of implant overdentures, the record base and wax rim may need to be adjusted. The conventional method has several drawbacks, as it requires repeated tightening and loosening of the impression coping. Here, we report a useful and novel method for interocclusal records using the healing abutments in implant overdentures. Our case demonstrates that this method is easier and simpler and prevents gingival collapse.

Comparison of immunohistochemical analysis on sinus augmentation using demineralized tooth graft and bovine bone.

OBJECTIVES: The purpose of this animal research was to compare bone regeneration in augmented rabbit maxillary sinuses treated with demineralized particulate human-tooth graft and anorganic bovine bone by immunohistochemical analysis. MATERIALS AND METHODS: Piezoelectric bilateral sinus augmentation was performed in eight adult rabbits. In the control group, anorganic bovine was grafted in the maxillary sinus following elevation of the sinus membrane. In the experimental group, demineralized human particulate tooth bone was grafted in the sinus. Bone regeneration in augmented sinuses was evaluated by immunohistochemical analysis using various markers of osteoprogenitor cells. RESULTS: The number of bromodeoxyuridine-labeled cells was significantly higher in the experimental group than in the control group at eight weeks. The immunoreactivity of proliferating-cell nuclear antigen was increased slightly in the experimental group relative to the control group at eight weeks. Other bone markers were expressed equally in the two groups. CONCLUSION: In the rabbit maxillary sinus, higher osteoinduction was correlated with demineralized human particulate tooth bone grafting than with anorganic bovine grafting.

Comparative finite element analysis of mandibular posterior single zirconia and titanium implants: a 3-dimensional finite element analysis.

PURPOSE: Zirconia has exceptional biocompatibility and good mechanical properties in clinical situations. However, finite element analysis (FEA) studies on the biomechanical stability of two-piece zirconia implant systems are limited. Therefore, the aim of this study was to compare the biomechanical properties of the two-piece zirconia and titanium implants using FEA. MATERIALS AND METHODS: Two groups of finite element (FE) models, the zirconia (Zircon) and titanium (Titan) models, were generated for the exam. Oblique (175 N) and vertical (175 N) loads were applied to the FE model generated for FEA simulation, and the stress levels and distributions were investigated. RESULTS: In oblique loading, von Mises stress values were the highest in the abutment of the Zircon model. The von Mises stress values of the Titan model for the abutment screw and implant fixture were slightly higher than those of the Zircon model. Minimum principal stress in the cortical bone was higher in the Titan model than Zircon model under oblique and vertical loading. Under both vertical and oblique loads, stress concentrations in the implant components and bone occurred in the same area. Because the material itself has high stiffness and elastic modulus, the Zircon model exhibited a higher von Mises stress value in the abutments than the Titan model, but at a level lower than the fracture strength of the material. CONCLUSION: Owing to the good esthetics and stress controllability of the Zircon model, it can be considered for clinical use.

Korean Translation and Psychometric Evaluation of Korean Version EORTC QLQ-BRECON23.

The purpose of this study was to evaluate the psychometric properties of the Korean version of the European Organization for Research and Treatment of Cancer Quality of Life-QLQ-BRECON23 in women diagnosed and treated for breast cancer undergoing all types of breast reconstruction. METHODS: A total of 148 Korean women who underwent breast reconstruction were recruited from the breast cancer center to participate in the study. After performing forward and backward translation of the original English version of the questionnaire into Korean, its validity (construct, known-group validity, concurrent) and reliability were assessed. A structural equation model (SEM) was used to assess construct validity. RESULTS: The mean age of the patients was 52 years, and 89.8% underwent implant-based reconstruction. Construct validity using confirmatory factor analysis showed a good fit, and the effect size was small-to-medium regarding known-group validity. Concurrent validity was confirmed by the significant correlation between the QLQ-BRECON23 and the QLQ-BR23. The reliability of the QLQ-BRECON23 symptom and function scales ranged from 0.61 to 0.87. CONCLUSION: The Korean QLQ-BRECON23 can be applied to assess quality of life and its related factors, and also to internationally compare the level of quality of life in breast cancer patients undergoing breast reconstruction.

Structure-Activity Relationships of 6- and 8-Gingerol Analogs as Anti-Biofilm Agents.

Pseudomonas aeruginosa is a causative agent of chronic infections in immunocompromised patients. Disruption of quorum sensing circuits is an attractive strategy for treating diseases associated with P. aeruginosa infection. In this study, we designed and synthesized a series of gingerol analogs targeting LasR, a master regulator of quorum sensing networks in P. aeruginosa. Structure-activity relationship studies showed that a hydrogen-bonding interaction in the head section, stereochemistry and rotational rigidity in the middle section, and optimal alkyl chain length in the tail section are important factors for the enhancement of LasR-binding affinity and for the inhibition of biofilm formation. The most potent compound 41, an analog of (R)-8-gingerol with restricted rotation, showed stronger LasR-binding affinity and inhibition of biofilm formation than the known LasR antagonist (S)-6-gingerol. This new LasR antagonist can be used as an early lead compound for the development of anti-biofilm agents to treat P. aeruginosa infections.

Synthesis and evaluation of antitumor activity of novel 2-[Nmethyl-N-(4-methyl-1,3-benzothiazol-2-yl)aminomethyl]-5,8-diacyloxy-1,4-naphthoquinones.

A series of nine new compounds bridged by acyl groups at the 5,8-dihydroxyl group of DHNQ were synthesized and their cytotoxic activity against L1210 and P388 cancer cells was examined. Their antitumor action in mice bearing S-180 cells in the peritoneal cavity was also assessed. Increasing the size of the acyl group (compounds 7-9) up to propyl increased the antitumor activity (T/C value), whereas the cytotoxicity of these compounds was comparable against L1210 (lymphocytic leukemia) and P388 (lymphoid neoplasm) cancer cells. Further increasing in the chain length (compounds 11-15) decreased the potency. Thus, acyl group chains of three carbon atoms is optimal for antitumor activity. The most potent compound of this series was 2-[N-methyl-N-(4-methyl-1,3-benzothiazol-2-yl)aminomethyl]-5,8-dipropylcarbonyloxy-1,4-naphthoquinone (compound 9) with a T/C (%) value of 354.

Pulmonary edema during pregnancy: unilateral presentation is not rare.

Information regarding pulmonary edema in obstetric patients is limited, especially its natural history as most cases are from tertiary care centers. The incidence, etiology, and course of pulmonary edema in all obstetric patients at a primary-secondary care center was studied prospectively among 29,621 obstetric cases in the past 3.5 years. Pulmonary edema developed in 18 cases (0.06%) of all obstetric patients that were associated with pre-eclampsia-eclampsia and tocolysis with beta-mimetics. The onset of pulmonary edema was 1-8 days postpartum in 12 patients, 1 day antepartum in 3 patients, and 26-32 gestational weeks in 3 patients. The cause was mainly cardiogenic, and the mean time taken for resolution was 2.2 days. Unilateral pulmonary edema occurred in 4 patients and there was delayed resolution compared with bilateral pulmonary edema because of delayed treatment. Pulmonary edema associated with pregnancy developed in 0.06% of cases, mainly during the peripartum, and resolved rapidly. Unilateral pulmonary edema was not uncommon.