Fluorinated hydroxyapatite conditions a favorable osteo-immune microenvironment via triggering metabolic shift from glycolysis to oxidative phosphorylation.

BACKGROUND: Biological-derived hydroxyapatite is widely used as a bone substitute for addressing bone defects, but its limited osteoconductive properties necessitate further improvement. The osteo-immunomodulatory properties hold crucial promise in maintaining bone homeostasis, and precise modulation of macrophage polarization is essential in this process. Metabolism serves as a guiding force for immunity, and fluoride modification represents a promising strategy for modulating the osteoimmunological environment by regulating immunometabolism. In this context, we synthesized fluorinated porcine hydroxyapatite (FPHA), and has demonstrated its enhanced biological properties and osteogenic capacity. However, it remains unknown whether and how FPHA affects the immune microenvironment of the bone defects. METHODS: FPHA was synthesized and its composition and structural properties were confirmed. Macrophages were cultured with FPHA extract to investigate the effects of FPHA on their polarization and the related osteo-immune microenvironment. Furthermore, total RNA of these macrophages was extracted, and RNA-seq analysis was performed to explore the underlying mechanisms associated with the observed changes in macrophages. The metabolic states were evaluated with a Seahorse analyzer. Additionally, immunohistochemical staining was performed to evaluate the macrophages response after implantation of the novel bone substitutes in critical size calvarial defects in SD rats. RESULTS: The incorporation of fluoride ions in FPHA was validated. FPHA promoted macrophage proliferation and enhanced the expression of M2 markers while suppressing the expression of M1 markers. Additionally, FPHA inhibited the expression of inflammatory factors and upregulated the expression of osteogenic factors, thereby enhancing the osteogenic differentiation capacity of the rBMSCs. RNA-seq analysis suggested that the polarization-regulating function of FPHA may be related to changes in cellular metabolism. Further experiments confirmed that FPHA enhanced mitochondrial function and promoted the metabolic shift of macrophages from glycolysis to oxidative phosphorylation. Moreover, in vivo experiments validated the above results in the calvarial defect model in SD rats. CONCLUSION: In summary, our study reveals that FPHA induces a metabolic shift in macrophages from glycolysis to oxidative phosphorylation. This shift leads to an increased tendency toward M2 polarization in macrophages, consequently creating a favorable osteo-immune microenvironment. These findings provide valuable insights into the impact of incorporating an appropriate concentration of fluoride on immunometabolism and macrophage mitochondrial function, which have important implications for the development of fluoride-modified immunometabolism-based bone regenerative biomaterials and the clinical application of FPHA or other fluoride-containing materials.

Prediction of primary stability via the force feedback of an autonomous dental implant robot.

STATEMENT OF PROBLEM: While the high osteotomy and implant placement accuracy via robotic implant surgery has been verified, whether the force feedback in the osteotomy process can be used to determine appropriate primary implant stability remains unknown. PURPOSE: The purpose of this in vitro study was to explore the relationship between the force feedback and the primary stability of implants placed by using an autonomous dental implant robot. MATERIAL AND METHODS: Five groups (n=7) of wooden and polyurethane foam blocks were used to execute an implant surgery by using an autonomous implant robot. Tapered bone-level titanium dental implant replicas were placed in the blocks. The Young modulus, the maximal vertical and lateral drilling resistances, the position accuracy, and the insertion torque of implants were recorded. Simple linear regression, principal component analysis, and multiple linear regression were used. The osteotomy strategy for the implant site was adjusted according to the maximal vertical resistance of the pilot drill to achieve appropriate insertion torque. The correlation, Gompertz growth curve fitting of the insertion torque, and Young modulus were determined. The effect of the drilling resistances on the insertion torque was analyzed using 2-way ANOVA, simple linear regression, and the principal component analysis. RESULTS: The vertical resistance of the Ø2.2-mm pilot drill, the Ø3.5-mm twist drill, and the Ø4.1-mm profile drill had a strong simple linear correlation with the insertion torque of the implants, and the lateral resistance had a moderate linear correlation with the insertion torque. The contributions of these 6 variables to the implant torque, among which the vertical resistance of the twist drill and the pilot drill ranked first and second, were comparable. Adjustments to the strategy of site preparation according to the vertical resistance of the pilot drill achieved appropriate insertion torque (P<.001). CONCLUSIONS: The force feedback of the autonomous dental implant robot was significantly correlated with the insertion torque of implants, which may fit an interpretable mathematical model, allowing dental implants to be placed with predictable primary stability.

Balance between the CMC/ACP Nanocomplex and Blood Assimilation Orchestrates Immunomodulation of the Biomineralized Collagen Matrix.

Calcium phosphate-based biomineralized biomaterials have broad application prospects. However, the immune response and foreign body reactions elicited by biomineralized materials have drawn substantial attention recently, contrary to the immune microenvironment optimization concept. Therefore, it is important to clarify the immunomodulation properties of biomineralized materials. Herein, we prepared the biomineralized collagen matrix (BCM) and screened the key immunomodulation factor carboxymethyl chitosan/amorphous calcium phosphate (CMC/ACP) nanocomplex. The immunomodulation effect of the BCM was investigated in vitro and in vivo. The BCM triggered evident inflammatory responses and cascade foreign body reactions by releasing the CMC/ACP nanocomplex, which activated the potential TLR4-MAPK/NF-κB pathway, compromising the collagen matrix biocompatibility. By contrast, blocking the CMC/ACP nanocomplex release via the blood assimilation process of the BCM mitigated the inflammation and foreign body reactions, enhancing biocompatibility. Hence, the immunomodulation of the BCM was orchestrated by the balance between the CMC/ACP nanocomplex and the blood assimilation process. Controlling the release of the CMC/ACP nanocomplex to accord the biological effects of ACP with the temporal regenerative demands is key to developing advanced biomineralized materials.

Tailoring the multiscale mechanics of tunable decellularized extracellular matrix (dECM) for wound healing through immunomodulation.

With the discovery of the pivotal role of macrophages in tissue regeneration through shaping the tissue immune microenvironment, various immunomodulatory strategies have been proposed to modify traditional biomaterials. Decellularized extracellular matrix (dECM) has been extensively used in the clinical treatment of tissue injury due to its favorable biocompatibility and similarity to the native tissue environment. However, most reported decellularization protocols may cause damage to the native structure of dECM, which undermines its inherent advantages and potential clinical applications. Here, we introduce a mechanically tunable dECM prepared by optimizing the freeze-thaw cycles. We demonstrated that the alteration in micromechanical properties of dECM resulting from the cyclic freeze-thaw process contributes to distinct macrophage-mediated host immune responses to the materials, which are recently recognized to play a pivotal role in determining the outcome of tissue regeneration. Our sequencing data further revealed that the immunomodulatory effect of dECM was induced via the mechnotrasduction pathways in macrophages. Next, we tested the dECM in a rat skin injury model and found an enhanced micromechanical property of dECM achieved with three freeze-thaw cycles significantly promoted the M2 polarization of macrophages, leading to superior wound healing. These findings suggest that the immunomodulatory property of dECM can be efficiently manipulated by tailoring its inherent micromechanical properties during the decellularization process. Therefore, our mechanics-immunomodulation-based strategy provides new insights into the development of advanced biomaterials for wound healing.

Optimizing the biodegradability and osteogenesis of biogenic collagen membrane via fluoride-modified polymer-induced liquid precursor process.

Biogenic collagen membranes (BCM) have been widely used in guided bone regeneration (GBR) owing to their biodegradability during tissue integration. However, their relatively high degradation rate and lack of pro-osteogenic properties limit their clinical outcomes. It is of great importance to endow BCM with tailored degradation as well as pro-osteogenic properties. In this study, a fluoride-modified polymer-induced liquid precursor (PILP) based biomineralization strategy was used to convert the collagen membrane from an organic phase to an apatite-based inorganic phase, thus achieving enhanced anti-degradation performance as well as osteogenesis. As a result, three phases of collagen membranes were prepared. The original BCM in the organic phase induced the mildest inflammatory response and was mostly degraded after 4 weeks. The organic-inorganic mixture phase of the collagen membrane evoked a prominent inflammatory response owing to the fluoride-containing amorphous calcium phosphate (F-ACP) nanoparticles, resulting in active angiogenesis and fibrous encapsulation, whereas the inorganic phase induced a mild inflammatory response and degraded the least owing to the transition of F-ACP particles into calcium phosphate with high crystallinity. Effective control of ACP is key to building novel apatite-based barrier membranes. The current results may pave the way for the development of advanced apatite-based membranes with enhanced barrier performances.

Placement accuracy and primary stability of implants in the esthetic zone using dynamic and static computer-assisted navigation: A retrospective case-control study.

STATEMENT OF PROBLEM: Both the placement accuracy and primary stability of implants are important to implant therapy in the esthetic zone. The effect of dynamic and static computer-assisted navigation on the primary stability of implants in the esthetic zone remains uncertain. PURPOSE: The purpose of this case-control study was to investigate the effect of dynamic and static computer-assisted navigation on the placement accuracy and primary stability of implants in the esthetic zone. MATERIAL AND METHODS: Partially edentulous participants who received at least 1 implant in the anterior maxilla using either fully guided static or dynamic computer-assisted implant surgery (s-CAIS, d-CAIS) from January 2020 to February 2022 were screened. Participant demographic information, timing of implant placement, primary stability represented by the insertion torque value (ITV) in Ncm, and implant survival were collected from the treatment record. Bone quality at the implant sites was determined according to the Lekholm and Zarb classification. The accuracy of implant placement represented by the linear (platform: Dpl, mm; apex: Dap, mm) and angular deviations (axis: Dan, degree) between the planned and placed implants was evaluated based on the preoperative surgical plan and postoperative cone beam computed tomography (CBCT) data. A statistical analysis of the data was completed by using the chi-square, Fisher exact, Student t, and Mann-Whitney U tests (α=.05). RESULTS: A total of 32 study participants (38 implants) were included. The groups of s-CAIS (16 participants, 18 implants) and d-CAIS (16 participants, 20 implants) were statistically comparable in sex (P=.072), age (P=.548), bone quality (P=.671), and timing of implant placement (P=.719). All implants survived during an average follow-up period of 13 months. The d-CAIS group showed close linear deviations (Dpl 1.07 ±0.57 mm, Dap 1.26 ±0.53 mm) but lower angular deviation (Dan 2.14 ±1.20 degrees) and primary stability (ITV 25.25 ±7.52 Ncm) than the s-CAIS group (Dpl 0.92 ±0.46 mm, Dap 1.31 ±0.43 mm, Dan 3.31 ±1.61 degrees, ITV 30.56 ±11.23 Ncm, PDpl=.613, PDap=.743, PDan=.016, PITV=.028). CONCLUSIONS: Comparable linear positioning accuracy and higher angular deviation were found for implants placed in the esthetic zone by using s-CAIS than when using d-CAIS. Higher primary stability of implants may be achieved by using s-CAIS, as s-CAIS seemed to have higher osteotomy accuracy than d-CAIS.

Effect of Scan Pattern on the Accuracy of Complete-Arch Digital Implant Impressions with Two Intraoral Scanners.

PURPOSE: To evaluate the effect of six scan patterns on the accuracy and speed of digital impressions with two different intraoral scanners for complete-arch implant rehabilitation. MATERIALS AND METHODS: A master model containing six parallelly placed implant analogs was fabricated, and six scan bodies were connected to the analogs. Reference scan was obtained with a laboratory scanner. Test scans were obtained by intraoral scanning with six scan patterns using 3Shape TRIOS 3 and Carestream CS 3600 intraoral scanners. Scanning time was recorded. Trueness and precision were assessed with an inspection software. Two-way analysis of variance (ANOVA) was performed to examine the effect of scan pattern, scanner, and their interaction on accuracy and scanning time. Differences between the six scan patterns with each scanner were tested by one-way ANOVA. Differences between the two scanners were evaluated by t test. The level of significance was set at α = .05. RESULTS: For trueness, the effects of scanner, scan pattern, and their interaction were significantly different in both linear and angular discrepancy. For precision, the scanner and scan pattern each had a significant effect on linear discrepancy independently, while their interaction did not. Only the effects of scanners were significantly different in angular discrepancy. For each of the two scanners, significant differences were detected in accuracy and speed between the patterns. CONCLUSION: Scan pattern significantly influenced the accuracy and speed of digital impressions for complete-arch implant rehabilitation.

Optimizing the bio-degradability and biocompatibility of a biogenic collagen membrane through cross-linking and zinc-doped hydroxyapatite.

Biogenic collagen membranes have been widely used as soft tissue barriers in guided bone regeneration (GBR) and guided tissue regeneration (GTR). Nevertheless, their clinical performance remains unsatisfactory because of their low mechanical strength and fast degradation rate in vivo. Although cross-linking with chemical agents is effective and reliable for prolonging the degradation time of collagen membranes, some adverse effects including potential cytotoxicity and undesirable tissue integration have been observed during this process. As a fundamental nutritional trace element, zinc plays an active role in promoting the growth of cells and regulating the degradation of the collagen matrix. Herein, a biogenic collagen membrane was cross-linked with glutaraldehyde-alendronate to prolong its degradation time. The physiochemical and biological properties were enhanced by the incorporation of zinc-doped nanohydroxyapatite (nZnHA), with the native structure of collagen preserved. Specifically, the cross-linking combined with the incorporation of 1% and 2% nZnHA seemed to endow the membrane with the most appropriate biocompatibility and tissue integration capability among the cross-linked membranes, as well as offering a degradation period of six weeks in a rat subcutaneous model. Thus, improving the clinical performance of biogenic collagen membranes by cross-linking together with the incorporation of nZnHA is a promising strategy for the improvement of biogenic collagen membranes. STATEMENT OF SIGNIFICANCE: The significance of this research includes.

Triptolide: pharmacological spectrum, biosynthesis, chemical synthesis and derivatives.

Triptolide, an abietane-type diterpenoid isolated from Tripterygium wilfordii Hook. F., has significant pharmacological activity. Research results show that triptolide has obvious inhibitory effects on many solid tumors. Therefore, triptolide has become one of the lead compounds candidates for being the next "blockbuster" drug, and multiple triptolide derivatives have entered clinical research. An increasing number of researchers have developed triptolide synthesis methods to meet the clinical need. To provide new ideas for researchers in different disciplines and connect different disciplines with researchers aiming to solve scientific problems more efficiently, this article reviews the research progress made with analyzes of triptolide pharmacological activity, biosynthetic pathways, and chemical synthesis pathways and reported in toxicological and clinical studies of derivatives over the past 20 years, which have laid the foundation for subsequent researchers to study triptolide in many ways.

Memory B Cell as an Indicator of Peri-implantitis Status: A Pilot Study.

PURPOSE: Gingiva-resident memory B cells found recently in healthy periodontal tissue may play important roles in maintaining homeostasis against bacterial plaque. Whether resident memory B cells exist in healthy peri-implant tissue and how they respond in peri-implantitis lesions are of interest. The aim of this study was to preliminarily investigate whether memory B cell activities are related to inflamed or healthy peri-implant status. MATERIALS AND METHODS: Patients with peri-implantitis or healed implants were recruited. The gingiva samples were collected and divided into inflamed (n = 4), treated (n = 4), and healed (n = 3) groups, followed by a flow cytometry analysis staining with CD3, CD19, CD27, CD38, and RANKL. The biopsy samples were also cryo-embedded for immunofluorescent double staining of CD19 and CD27. RESULTS: CD27+ CD38+ ASC comprised 83.3% ± 3.3% of the total B cells in the inflamed group, and this proportion in the treated group was reduced to 44.5% ± 13.4%. The proportion of CD27+ CD3+ T cells was found to be unchanged between the inflamed and treated groups. Immunofluorescent staining indicated that CD19+ CD27+ population infiltrated peri-implant connective tissue. RANKL was expressed by almost all B cells and a portion of T cells in the inflamed group, while the proportions of RANKL+ B and T cells were significantly reduced in the treated group. Barely any memory B cells were detected in the healed group. CONCLUSION: Memory B cells were markedly activated in peri-implantitis and responded to the suprastructure removal treatment. The lack of gingiva-resident memory B cells in the clinically healed implants serves as a hint for the weakness of peri-implant tissue against bacterial plaque.

Mechanism of Cyclic Tensile Stress in Osteogenic Differentiation of Human Periodontal Ligament Stem Cells.

Human periodontal ligament stem cells (hPDLSCs) can undergo osteogenic differentiation under induction conditions. Cyclic tensile stress (CTS) can stimulate stem cell osteogenic differentiation. The present study explored the mechanism of CTS in hPDLSC osteogenic differentiation. The hPDLSCs of the 4th passage were selected. hPDLSCs were subjected to CTS with deformation of 10% elongation at 0.5 Hz for 1, 4, 8, 12 and 24 h. ALP activity and staining, ARS staining and detection of expressions of osteogenesis-related genes (RUNX2, OPN, Sp7 and OCN) were used to assess hPDLSC osteogenic differentiation ability. microRNA (miR)-129-5p and BMP2 expression and p-Smad1/5 level were detected under CTS stimulation. The binding relationship between miR-129-5p and BMP2 was predicted and verified. The osteogenic differentiation ability of CTS-treated hPDLSCs was evaluated after intervention of miR-129-5p and BMP2. CTS induced hPDLSC osteogenic differentiation, as manifested by increased ALP activities, osteogenesis-related gene expressions and mineralized nodules, together with positive ALP staining. CTS inhibited miR-129-5p expression, and promoted BMP2 expression and p-Smad1/5 level in hPDLSCs. miR-129-5p targeted BMP2. Overexpressed miR-129-5p or silenced BMP2 prevented hPDLSC osteogenic differentiation ability. We demonstrated that CTS inhibited miR-129-5p expression, and then activated the BMP2/Smad pathway, thereby showing stimulative effects on hPDLSC osteogenic differentiation.

Implementation of a Phase Synchronization Scheme Based on Pulsed Signal at Carrier Frequency for Bistatic SAR.

Phase synchronization is one of the key technical challenges and prerequisites for the bistatic synthetic aperture radar (SAR) system, which can form a single-pass interferometry system to perform topographic mapping. In this paper, an advanced phase synchronization scheme based on a pulsed signal at carrier frequency is proposed for a bistatic SAR system and it is verified by a ground validation system. In the proposed phase synchronization scheme, the pulsed signal at carrier frequency is used for phase synchronization link, and it is exchanged by virtue of a time slot between radar signals. The feasibility of the scheme is proven by theoretical analysis of various factors affecting the performance of phase synchronization, and the reliability of the scheme is verified by the test results of the ground validation system.

Self-Assembled FRET Nanoprobe with Metal-Organic Framework As a Scaffold for Ratiometric Detection of Hypochlorous Acid.

Metal-organic framework (MOF) has been extensively explored in a number of fields due to its diverse properties. In this work, we demonstrated the potential of MOF in the establishment of a self-assembled fluorescence resonance energy transfer (FRET) system for developing ratiometric fluorescent nanoprobe. For this purpose, zeolitic imidazolate framework-8 (ZIF-8) was selected as a MOF model to entrap carbon dot (CD) and curcumin (CCM) during its self-assembly, which produces CD/CCM@ZIF-8. Benefiting from the confinement effect of ZIF-8, the loaded CD and CCM can be brought in close proximity for energy transfer to occur. Under optimal conditions, a high FRET efficiency of 68.7% can be obtained. Importantly, compared with traditional FRET systems, the fabrication process of CD/CCM@ZIF-8 is much more simple and straightforward, which does not involve the elaborate design and complicated synthesis of molecular linkers. However, in the presence of hypochlorous acid (HClO), the FRET process from CD to CCM will be disrupted, rendering CD/CCM@ZIF-8 to display a ratiometric response to HClO. This finding led to a method for ratiometric fluorescent detection of HClO with a detection limit of 67 nM and excellent selectivity over other reactive oxygen species. We believe that this study can give a new insight into the rational design and application of FRET-based nanoprobes.

Downregulation of Linc-RNA activator of myogenesis lncRNA participates in FGF2-mediated proliferation of human periodontal ligament stem cells.

BACKGROUND: Accelerated proliferation of human periodontal ligament stem cells (PDLSCs) is present in periodontitis. It is known that fibroblast growth factor 2 (FGF2) regulates the proliferation of PDLSCs, while the function of FGF2 in myogenic cell differentiation is mediated by Linc-RNA Activator of Myogenesis (Linc-RAM) lncRNA. Therefore, Linc-RAM lncRNA may also participate in periodontitis. METHODS: This study included 28 patients with periodontitis (patient group) and 22 patients without periodontitis but received orthodontic treatment (control group) in the stomatological hospital of Sun Yat-Sen university. Gingival biopsies were obtained from participants. RT-qPCR, cell transfection, cell proliferation assay and western blot were carrying out to analyze the samples. RESULTS: We found that FGF2 mRNA was upregulated, while Linc-RAM was downregulated in PDLSCs derived from periodontitis-affected teeth than in healthy teeth. FGF2 mRNA and Linc-RAM were inversely correlated in both types of PDLSCs. FGF2 overexpression led to inhibited Linc-RAM expression in PDLSCs derived from periodontitis-affected teeth and promoted the proliferation of PDLSCs. Linc-RAM overexpression failed to significantly affect FGF2 expression but attenuated the enhancing effects of FGF2 overexpression on the proliferation of PDLSCs. CONCLUSIONS: Therefore, downregulation of Linc-RAM lncRNA may participate in FGF-2 mediated- proliferation of human PDLSCs.

Prevention of hematoma on the floor of the mouth during dental implant surgery in the anterior mandible / 口腔疾病防治

Objective@# To explore the cause and preventive measures of floor-of-mouth hematoma after dental implant placement. @*Methods@#The prevention of hematoma of the floor of the mouth in a case of lower anterior teeth implant placement was analyzed, and the literature was reviewed.@*Results@# Four mandibular vascular canals were found on the lingual side of the anterior mandible before dental surgery in the reported case. Two of them were quite thick (1.4 mm and 1.0 mm, respectively) and were located adjacent to the crest of the alveolar bone and superior to the mental spine. These two thick endosseous branches from the sublingual artery were dissected and ligated , and there was no obvious hematoma in the patients immediately after the operation and at the postoperative 3 d review. The results of the literature review show that the incidence of endosseous branches from the lingual vascular canal of the mandible is 90%-100%. The distribution of the vessels on the lingual side of the mandible is highly variable and adjacent to the lingual cortical plate. Accidental injury of the lingual cortical plate during implant surgery would probably lead to bleeding or hematoma on the floor of the mouth. @*Conclusion @#Mastering the anatomy of blood vessels on the floor of the mouth, elaboratively examining preoperative three-dimensional radiographic imaging, and cautiously exploring the lower jaw bone morphology after flap elevation are preventive measures to avoid damage to the arterial supply on the lingual side of the anterior lower jaw and to prevent complications of hematoma in the floor of the mouth.

Recombinant Klotho Protects Human Periodontal Ligament Stem Cells by Regulating Mitochondrial Function and the Antioxidant System during H2O2-Induced Oxidative Stress.

Human periodontal ligament stem cells (hPDLSCs) are a favourable source for tissue engineering, but oxidative stress conditions during cell culture and transplantation could affect stem cell viability and stemness, leading to failed regeneration. The aim of this study was to evaluate the antioxidant and protective effects of Klotho, an antiageing protein, against cell damage and the loss of osteogenesis in hPDLSCs in H2O2-induced oxidative environments. H2O2 was used as an exogenous reactive oxygen species (ROS) to induce oxidative stress. Recombinant human Klotho protein was administered before H2O2 treatment. Multitechniques were used to assess antioxidant activity, cell damage, and osteogenic ability of hPDLSCs in oxidative stress and the effects of Klotho on hPDLSCs. Mitochondrial function was analyzed by an electron microscopy scan of cellular structure, mitochondrial DNA copy number, and cellular oxygen consumption rate (OCR). Furthermore, we explored the pathway by which Klotho may function to regulate the antioxidant system. We found that pretreatment with recombinant human Klotho protein could enhance SOD activity and reduce intracellular oxidative stress levels. Klotho reduced H2O2-induced cellular damage and eventually maintained the osteogenic differentiation potential of hPDLSCs. Notably, Klotho promoted mitochondrial function and activated antioxidants by negatively regulating the PI3K/AKT/FoxO1 pathway. The findings suggest that Klotho protein enhanced the antioxidative ability of hPDLSCs and protected stem cell viability and stemness from H2O2-induced oxidative stress by restoring mitochondrial functions and the antioxidant system.

Clinical and Radiologic Outcomes of Submerged and Nonsubmerged Bone-Level Implants with Internal Hexagonal Connections in Immediate Implantation: A 5-Year Retrospective Study.

PURPOSE: To evaluate the 5-year clinical and radiologic outcome of immediate implantation using submerged and nonsubmerged techniques with bone-level implants and internal hexagonal connections and the effects of potential influencing factors. MATERIALS AND METHODS: A total of 114 bone-level implants (XiVE S plus) with internal hexagonal connections inserted into 72 patients were included. Patients were followed up for 5 years. A t-test was used to statistically evaluate the marginal bone loss between the submerged and nonsubmerged groups. The cumulative survival rate (CSR) was calculated according to the life table method and illustrated with Kaplan-Meier survival curves. Comparisons of the CSR between healing protocols, guided bone regeneration, implants with different sites, lengths, and diameters were performed using log-rank tests. RESULTS: The 5-year cumulative implant survival rates with submerged and nonsubmerged healing were 94% and 96%, respectively. No statistically significant differences in terms of marginal bone loss, healing protocol, application of guided bone regeneration, implant site, or length were observed. CONCLUSIONS: High CSRs and good marginal bone levels were achieved 5 years after immediate implantation of bone-level implants with internal hexagonal connections using both the submerged and nonsubmerged techniques. Factors such as implant length, site, and application of guided bone regeneration did not have an impact on the long-term success of the implants.

Ultraviolet irradiation enhanced bioactivity and biological response of mesenchymal stem cells on micro-arc oxidized titanium surfaces.

This present study investigated the effect of ultraviolet (UV) irradiation on bioactivity of micro-arc oxidized (MAO) titanium surface in vitro by cell culture medium immersion test and interactions with rat-derived mesenchymal stem cells (MSCs). UV-irradiated MAO surface exhibited no obvious changes in surface roughness, morphology, and phase composition when compared with MAO-only surface. However, in cell culture medium immersion test, markedly more bone-like apatite was formed on UV-modified samples than on MAO sample. Rat bone marrow- and adipose tissue-derived MSCs cultured on UV-modified samples displayed accelerated attachment, significant higher levels of alkaline phosphatase (ALP) activity, and up-regulated osteogenesis-related mRNA expression than MAO sample. XPS results provided direct evidence that the amount of basic hydroxyl groups increased with UV irradiation time, which could be one of the key mechanisms underlying their improved bioactivity.

Effects of fluoridation of porcine hydroxyapatite on osteoblastic activity of human MG63 cells.

Biological hydroxyapatite, derived from animal bones, is the most widely used bone substitute in orthopedic and dental treatments. Fluorine is the trace element involved in bone remodeling and has been confirmed to promote osteogenesis when administered at the appropriate dose. To take advantage of this knowledge, fluorinated porcine hydroxyapatite (FPHA) incorporating increasing levels of fluoride was derived from cancellous porcine bone through straightforward chemical and thermal treatments. Physiochemical characteristics, including crystalline phases, functional groups and dissolution behavior, were investigated on this novel FPHA. Human osteoblast-like MG63 cells were cultured on the FPHA to examine cell attachment, cytoskeleton, proliferation and osteoblastic differentiation for in vitro cellular evaluation. Results suggest that fluoride ions released from the FPHA play a significant role in stimulating osteoblastic activity in vitro, and appropriate level of fluoridation (1.5 to 3.1 atomic percents of fluorine) for the FPHA could be selected with high potential for use as a bone substitute.

Self-reported questionnaire for surveillance of periodontitis in Chinese patients from a prosthodontic clinic: a validation study.

BACKGROUND AND PURPOSE: Periodontal maintenance is critical for the long-term success of prosthodontic treatment. This study investigates the validity of questionnaires/models in monitoring periodontitis for Chinese prosthodontic patients. METHODS: In total, 114 patients completed the questionnaire. The chi-squared test and classification and regression trees were used to screen for predictive items. Predictive models developed by Yamamoto et al. and Dietrich et al. were validated using ROC curves and calibration plots. RESULTS: Univariate and multivariate analysis revealed that demographic features (age, gender, smoking history, education history and number of remaining teeth), symptoms(tooth mobility without injury, painful gums), dental recommendations ("need periodontal or gum treatment?") and treatment history (scaling and root planing) were predictive of periodontitis. The AUC values of the Yamamoto model and Dietrich's model-a and model-b were 0.67, 0.89, and 0.89 for moderate/severe periodontitis and 0.78, 0.93, and 0.93 for severe periodontitis, respectively. The calibration plot showed that Dietrich's model-a and model-b accurately predicted the actual probability of moderate/severe and severe periodontitis, respectively. CONCLUSION: Questionnaires may be an efficient approach to monitor periodontal health in China. Dietrich's models, with age, smoking and self-reported mobility as predictors, can be used to monitor periodontal health for Chinese prosthodontic patients.