Osseointegration Potential Assessment of Bone Graft Materials Loaded with Mesenchymal Stem Cells in Peri-Implant Bone Defects.

Many studies have been exploring the use of bone graft materials (BGMs) and mesenchymal stem cells in bone defect reconstruction. However, the regeneration potential of Algipore (highly purified hydroxyapatite) and Biphasic (hydroxyapatite/beta-tricalcium phosphate) BGMs combined with bone marrow-derived mesenchymal stem cells (BMSCs) remains unclear. Therefore, we evaluated their osseointegration capacities in reconstructing peri-implant bone defects. The cellular characteristics of BMSCs and the material properties of Algipore and Biphasic were assessed in vitro. Four experimental groups-Algipore, Biphasic, Algipore+BMSCs, and Biphasic+BMSCs-were designed in a rabbit tibia peri-implant defect model. Implant stability parameters were measured. After 4 and 8 weeks of healing, all samples were evaluated using micro-CT, histological, and histomorphometric analysis. In the energy-dispersive X-ray spectroscopy experiment, the Ca/P ratio was higher for Algipore (1.67) than for Biphasic (1.44). The ISQ values continuously increased, and the PTV values gradually decreased for all groups during the healing period. Both Algipore and Biphasic BGM promoted new bone regeneration. Higher implant stability and bone volume density were observed when Algipore and Biphasic BGMs were combined with BMSCs. Biphasic BGM exhibited a faster degradation rate than Algipore BGM. Notably, after eight weeks of healing, Algipore with BSMCs showed more bone-implant contact than Biphasic alone (p < 0.05). Both Algipore and Biphasic are efficient in reconstructing peri-implant bone defects. In addition, Algipore BGM incorporation with BSMCs displayed the best performance in enhancing implant stability and osseointegration potential.

Stability of peri-implantitis surgical reconstructive therapy-a (> 2 years) follow-up of a randomized clinical trial.

OBJECTIVES: This follow-up study aimed to report the 24- and 30-month outcomes of a cohort previously enrolled in a randomized clinical trial on surgical reconstructive treatment of peri-implantitis. METHODS: Twenty-four patients were diagnosed with peri-implantitis and treated with surgical reconstructive therapy with or without the adjunctive use of Er:YAG laser. Within-group and between-group comparisons were tested with mixed model with repeated measures. RESULTS: Regarding peri-implant pocket depth (PPD) reduction (control vs. laser test group) between 6 months (- 1.85 vs. - 2.65 mm) and 30 months (- 1.84 vs. - 3.04 mm), the laser group showed statistically significant changes but not the control group. In terms of radiographic marginal bone loss (RMBL) at 6 months (- 1.1 vs. - 1.46 mm) to 24 months (- 1.96 vs. - 2.82 mm), both groups showed statistical difference compared to baseline. The six explanted implants all were featured by severe peri-implantitis and mostly with no or limited keratinized tissue (< 2 mm) at baseline and membrane exposure after surgery. Among the 15 retained cases, eight cases achieved more than 50% peri-implant bone level gain. CONCLUSIONS: Within the limitation and follow-up time frame of this trial, the outcome of the surgical reconstructive therapy sustained or improved in most of the cases. However, 25% of the implants with severe peri-implantitis failed 2 years after the surgical reconstructive therapy. The use of Er:YAG laser favors PPD reduction in the longer term up to 30 months. CLINICAL RELEVANCE: Longer-term follow-up on reconstructive therapy of peri-implantitis revealed sustained or improved stability in certain cases, but the survival of implants with severe peri-implantitis has its limitation, especially when there is limited keratinized tissue (< 2 mm or no KT). TRIAL REGISTRATION: Clinical Trials Registration Number: NCT03127228 and HUM00160290.

Surfactin reduces particulate matter-induced VCAM-1-dependent monocyte adhesion in human gingival fibroblasts by increasing Nrf2-dependent HO-1 expression.

BACKGROUND AND OBJECTIVES: The mechanisms of particulate matter (PM) toxicity involve the generation of ROS and upregulation of proinflammatory molecules. Nrf2 is a multifunctional cytoprotective transcription factor that regulates the expression of various antioxidant, anti-inflammatory, and detoxifying molecules, such as HO-1. As surfactin has potential to induce Nrf2 activation and HO-1 expression, this study aimed to investigate the anti-inflammatory effects of surfactin on PM-exposed human gingival fibroblasts (HGFs) and signaling pathways engaged by surfactin. MATERIALS AND METHODS: Human gingival fibroblasts were challenged by PM with or without surfactin pretreatment. The expression of Nrf2, HO-1, VCAM-1, and other molecules was determined by western blot, real-time PCR, or ELISA. Human monocytic THP-1 cells labeled with fluorescent reagent were added to HGFs, and the cell adhesion was assessed. ROS generation and NADPH oxidase activity were also measured. The involvement of Nrf2/HO-1 and ROS signaling pathways was investigated by treating HGFs with specific pathway interventions, genetically or pharmacologically. One dose of surfactin was given to mice before PM treatment to explore its in vivo effect on VCAM-1 expression in gingival tissues. RESULTS: Particulate matter led to VCAM-1-dependent monocyte adhesion in HGFs, which was regulated by PKCα/NADPH oxidase/ROS/STAT1/IL-6 pathway. Surfactin could attenuate monocyte adhesion by disrupting this VCAM-1-dependent pathway. Additionally, surfactin promoted Nrf2-dependent HO-1 expression in HGFs, mitigating VCAM-1 expression. PM-treated mice exhibited the lower expression of IL-6 and VCAM-1 in gingival tissues if they previously received surfactin. CONCLUSION: Surfactin exerts anti-inflammatory effects against PM-induced inflammatory responses in HGFs by inhibiting VCAM-1-dependent pathway and inducing Nrf2/HO-1 axis.

Innovation Glass-Ceramic Spray Deposition Technology Improving the Adhesive Performance for Zirconium-Based Dental Restorations.

Glass-ceramic spray deposition (GCSD) is a novel technique for coating lithium disilicate (LD) glass-ceramics onto zirconia through simple tempering steps. GCSD has been proven to improve the bonding of zirconia to resin cement, but the effect of etching time on GCSD and the long-term durability of the bond achieved remain unknown. The effects of air abrasion with aluminum particles (ABB) and air abrasion (GAB) or etching with 5.0% hydrogen fluoride (HF) for 20, 60, 90, and 120 s (G20, G60, G90, and G120) on the resin cement−zirconia bond were studied. LD was included as a control (LDG). The microstructure, sub-micron roughness, wettability, and phase changes of samples were analyzed. After resin cement was bonded to zirconia, half of the samples were subjected to thermocycling (5000 cycles at 5−55 °C). The bond strengths of the samples were determined in shear bond strength (SBS) tests (n = 10 per group). An LD structure can be formed on zirconia after GCSD and proper etching processes, which result in high roughness and a hydrophilic nature. GCSD and HF etching significantly improved SBS, with G90 and G120 samples with pre- or post-thermocycling exhibiting SBS values comparable to those of LDG (p > 0.760). The surface characteristics of the LD layer are influenced by the etching time and affect the SBS of the bond of zirconia to resin cement. HF etching for 90−120 s after GCSD results in zirconia with SBS and bond durability comparable to LD.

The Treatment Efficiency and Microbiota Analysis of Sapindus mukorossi Seed Oil on the Ligature-Induced Periodontitis Rat Model.

Periodontitis is a common oral disease mainly caused by bacterial infection and inflammation of the gingiva. In the prevention or treatment of periodontitis, anti-bacterial agents are used to inhibit pathogen growth, despite increasing levels of bacterial resistance. Sapindus mukorossi Gaertn (SM) seed oil has proven anti-bacterial and anti-inflammation properties. However, the possibility of using this plant to prevent or treat periodontitis has not been reported previously. The aim of this study was to evaluate the effects of SM oil on experimental periodontitis in rats by using micro-CT and microbiota analysis. The distance between cementoenamel junction (CEJ) and alveolar bone crest (ABC) on the sagittal micro-CT slide showed that total bone loss (TBL) was significantly lower in CEJ-ABC distances between SM oil and SM oil-free groups on Day 14. Histology data also showed less alveolar bone resorption, a result consistent result with micro-CT imaging. The microbiota analyzed at phylum and class levels were compared between the SM oil and SM oil-free groups on Day 7 and Day 14. At the phylum level, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were the dominant bacterium. Firmicutes in box plot analysis was significantly less in the SM oil group than in the SM oil-free group on Day 7. At the class level, Bacteroidia, Gammaproteobacteria, Bacilli, Clostridia, and Erysipelotrichia were the dominant bacteria. The bacteria composition proportion of Bacilli, Clostridiay, and Erysipelotrichia could be seen in the SM oil group significantly less than in t SM oil-free group on Day 7. Overall, the present results show that topical application of SM oil can reduce bone resorption and change bacteria composition in the ligature-induced periodontitis model. According to these results, it is reasonable to suggest SM oil as a potential material for preventing oral disease.

Effect of Different Bone Grafting Materials and Mesenchymal Stem Cells on Bone Regeneration: A Micro-Computed Tomography and Histomorphometric Study in a Rabbit Calvarial Defect Model.

This study evaluated the new bone formation potential of micro-macro biphasic calcium phosphate (MBCP) and Bio-Oss grafting materials with and without dental pulp-derived mesenchymal stem cells (DPSCs) and bone marrow-derived mesenchymal stem cells (BMSCs) in a rabbit calvarial bone defect model. The surface structure of the grafting materials was evaluated using a scanning electron microscope (SEM). The multipotent differentiation characteristics of the DPSCs and BMSCs were assessed. Four circular bone defects were created in the calvarium of 24 rabbits and randomly allocated to eight experimental groups: empty control, MBCP, MBCP+DPSCs, MBCP+BMSCs, Bio-Oss+DPSCs, Bio-Oss+BMSCs, and autogenous bone. A three-dimensional analysis of the new bone formation was performed using micro-computed tomography (micro-CT) and a histological study after 2, 4, and 8 weeks of healing. Homogenously porous structures were observed in both grafting materials. The BMSCs revealed higher osteogenic differentiation capacities, whereas the DPSCs exhibited higher colony-forming units. The micro-CT and histological analysis findings for the new bone formation were consistent. In general, the empty control showed the lowest bone regeneration capacity throughout the experimental period. By contrast, the percentage of new bone formation was the highest in the autogenous bone group after 2 (39.4% ± 4.7%) and 4 weeks (49.7% ± 1.5%) of healing (p < 0.05). MBCP and Bio-Oss could provide osteoconductive support and prevent the collapse of the defect space for new bone formation. In addition, more osteoblastic cells lining the surface of the newly formed bone and bone grafting materials were observed after incorporating the DPSCs and BMSCs. After 8 weeks of healing, the autogenous bone group (54.9% ± 6.1%) showed a higher percentage of new bone formation than the empty control (35.3% ± 0.5%), MBCP (38.3% ± 6.0%), MBCP+DPSC (39.8% ± 5.7%), Bio-Oss (41.3% ± 3.5%), and Bio-Oss+DPSC (42.1% ± 2.7%) groups. Nevertheless, the percentage of new bone formation did not significantly differ between the MBCP+BMSC (47.2% ± 8.3%) and Bio-Oss+BMSC (51.2% ± 9.9%) groups and the autogenous bone group. Our study results demonstrated that autogenous bone is the gold standard. Both the DPSCs and BMSCs enhanced the osteoconductive capacities of MBCP and Bio-Oss. In addition, the efficiency of the BMSCs combined with MBCP and Bio-Oss was comparable to that of the autogenous bone after 8 weeks of healing. These findings provide effective strategies for the improvement of biomaterials and MSC-based bone tissue regeneration.

Modified surgical drilling protocols influence osseointegration performance and predict value of implant stability parameters during implant healing process.

OBJECTIVE: The aim of this study was to evaluate the effects of three different surgical drilling protocols on changes of implant stability parameters and osseointegration performance during the healing period in rabbit femoral condyles. MATERIAL AND METHODS: Thirty New Zealand white rabbits were used in this study. Three experimental groups according to different surgical drilling protocols (undersized, standard and oversized preparation) were designed. Measurements of implant stability parameters were performed immediately after implant insertion and then at 1, 2, 4, and 8 weeks after the operation. After the animals were sacrificed, the bone blocks with implant were prepared for histological evaluation and histomorphometric analysis. RESULTS: The results demonstrated that the ISQ values of each group increased gradually through the whole healing period, while the damping factor showed the opposite tendency. The histomorphometric analysis revealed that BIC (bone-implant contact) values gradually increased with time until 8 weeks of healing at each group. In addition, the undersized group has the highest initial BIC (25.16% ± 7.25%) and the lowest values were found in oversized group (9.13% ± 5.89%). Moreover, a higher correlation (R2 = 0. 9817) between ISQ and BIC values in oversized group and moderate correlations between DF and BIC values in undersized group (R2 = 0.823) were demonstrated. CONCLUSIONS: The undersized drilling protocol group presented the highest implant stability and BIC values in the whole healing period, while the similar tendency of results was found between standard and oversized drilling protocol groups. CLINICAL RELEVANCE: These results suggested that undersized drilling protocol is mechanically and biologically beneficial in low-density bone. The modifications of surgical drilling protocols would influence the predictive value of implant stability parameters for osseointegration performance.

The association between fecal hemoglobin concentration and oral potentially malignant disorders.

OBJECTIVES: The present study was to investigate the association between fecal hemoglobin (f-Hb) concentration and oral cancer and its precursor, oral potentially malignant disorders (OPMD). METHODS: We used a population-based longitudinal cohort study data based on both Taiwanese nationwide oral and colorectal cancer screening programs implemented between 2004 and 2009. The total of 235,234 smokers and/or betel-quid chewers aged 50 to 69 years free of oral cancer and OPMD at entry were followed up over time to quantify the association between baseline f-Hb concentration on newly diagnosed oral cancer and OPMD. RESULTS: The risk of OPMD increased with baseline f-Hb in a dose manner, yielding a statistically significant elevated risk of developing OPMD in parallel with the incremental concentration of f-Hb (adjusted hazard ratios = 0.99, 1,11, 1,07, 1,57, and 1,63 for f-Hb categories of 1-9, 10-19, 20-49, 50-89, and ≥90 µg Hb/g, respectively, as compared with the reference group (low and undetectable f-Hb concentrations)) However, there was lacking of a statistical significance for the corresponding association regarding the risk of oral cancer, which is possibly due to sparse cases given a shorter follow-up time. CONCLUSION: We discovered that f-Hb concentration was positively related to the risk of OPMD. f-Hb can be used as a biomarker for early detection of OPMD.

Comparing the Osteogenic Potentials and Bone Regeneration Capacities of Bone Marrow and Dental Pulp Mesenchymal Stem Cells in a Rabbit Calvarial Bone Defect Model.

The bone regeneration efficiency of bone marrow mesenchymal stem cells (BMSCs) and dental pulp mesenchymal stem cells (DPSCs) combined with xenografts in the craniofacial region remains unclear. Accordingly, this study commenced by comparing the cell morphology, cell proliferation, trilineage differentiation, mineral synthesis, and osteogenic gene expression of BMSCs and DPSCs in vitro. Four experimental groups (empty control, Bio-Oss only, Bio-Oss+BMSCs, and Bio-Oss+DPSCs) were then designed and implanted in rabbit calvarial defects. The BMSCs and DPSCs showed a similar morphology, proliferative ability, surface marker profile, and trilineage-differentiation potential in vitro. However, the BMSCs exhibited a higher mineral deposition and expression levels of osteogenic marker genes, including alkaline phosphatase (ALP), runt related transcription factor 2 (RUNX2), and osteocalcin (OCN). In the in vivo studies, the bone volume density in both MSC groups was significantly greater than that in the empty control or Bio-Oss only group. Moreover, the new bone formation and Collagen I / osteoprotegerin protein expressions of the scaffold+MSC groups were higher than those of the Bio-Oss only group. Finally, the Bio-Oss+BMSC and Bio-Oss+DPSC groups had a similar bone mineral density, new bone formation, and osteogenesis-related protein expression. Overall, the DPSCs seeded on Bio-Oss matched the bone regeneration efficacy of BMSCs in vivo and hence appear to be a promising strategy for craniofacial defect repair in future clinical applications.

Enhancement of natural killer cell cytotoxicity by using static magnetic field to increase their viability.

Natural killer (NK) cells are innately immune to the body's immune system and can actively recognize and kill cancer cells. This study explores the potential for enhancing the killing ability of NK cells by co-culturing the NK cells with the target cells under a static magnetic field (SMF). In this study, NK92-MI cell lines were cultured in the presence of a 0.4-T SMF. The effect of the SMF on NK cell viability was evaluated by means of an MTT assay. Culturing tests were performed with inhibitors of the DAG/IP3, STAT3, ERK, JNK and p38 pathways in order to examine the possible signaling cascade responsible for the SMF effect on the NK92-MI cell viability. Finally, the effect of the SMF on the cytotoxicity of the NK92-MI cells was evaluated by co-culturing the NK cells with K562 leukemia cell lines. The results showed that the application of a 0.4-T SMF significantly increased (p < 0.05) the viability of the NK92-MI cells. Furthermore, the inhibitor tests indicated that the SMF affected cell viability by activating multiple MAPK signaling pathways (ERKs, JNKs, and p38-MAPK). Finally, SMF pre-exposure for 48 hr significantly improved the killing activity of the NK92-MI cells (p < 0.05). That is, pre-exposure to SMF increased the viability of the NK92-MI cells and improved their killing ability against K562 tumor cells. In general, the present results suggest that NK cells pre-exposed to 0.4-T SMF show potential as a tool for immune-therapy treatment of cancer.

Prophylactic supplement with melatonin successfully suppresses the pathogenesis of periodontitis through normalizing RANKL/OPG ratio and depressing the TLR4/MyD88 signaling pathway.

Periodontitis (PD) is an inflammatory disease characterized by gingival inflammation and resorption of alveolar bone. Impaired receptor activator of nuclear factor-kappa B ligand/osteoprotegerin (RANKL/OPG) signaling caused by enhanced production of pro-inflammatory cytokines plays an essential role in the pathogenesis of PD. Considering melatonin possesses significant anti-inflammatory property, this study aimed to determine whether prophylactic treatment with melatonin would effectively normalize RANKL/OPG signaling, depress toll-like receptor 4/myeloid differentiation factor 88 (TLR4/MyD88)-mediated pro-inflammatory cytokine activation, and successfully suppress the pathogenesis of PD. PD was induced in adult rats by placing the ligature at molar subgingival regions. Fourteen days before PD induction, 10, 50, or 100 mg/kg of melatonin was intraperitoneally injected for consecutive 28 days. Biochemical and enzyme-linked immunosorbent assay were used to detect TLR4/MyD88 activity, RANKL, OPG, interleukin 1ß, interleukin 6, and tumor necrosis factor-α levels, respectively. The extent of bone loss, bone mineral intensity, and calcium intensity was further evaluated by scanning electron microscopy, micro-computed tomography, and energy-dispersive X-ray spectroscopy. Results indicated that high RANKL/OPG ratio, TLR4/MyD88 activity, and pro-inflammatory cytokine levels were detected following PD. Impaired biochemical findings paralleled well with severe bone loss and reduced calcium intensity. However, in rats pretreated with melatonin, all above parameters were successfully returned to nearly normal levels with maximal change observed in rats receiving 100 mg/kg. As prophylactic treatment with melatonin effectively normalizes RANKL/OPG signaling by depressing TLR4/MyD88-mediated pro-inflammatory cytokine production, dietary supplement with melatonin may serve as an advanced strategy to strengthen oral health to counteract PD-induced destructive damage.

Effects of two surface finishes on the color of cemented and colored anatomic-contour zirconia crowns.

STATEMENT OF PROBLEM: The esthetic appearance of anatomic-contour zirconia restorations is influenced by the shade of the coloring liquid and the optical properties of the luting cements. However, few studies are available on the effects of surface-finishing methods and luting cements on colored anatomic-contour zirconia restorations. PURPOSE: The purpose of this in vitro study was to investigate the effects of surface finishing methods on the color distribution of colored anatomic-contour zirconia crowns before and after being cemented onto abutments. MATERIAL AND METHODS: Implant-supported anatomic-contour zirconia premolar crowns were fabricated and immersed in A3-coloring liquid for 30 seconds. The colored zirconia crowns were separated into 3 groups according to the method of surface treatment: no treatment (N), polishing (P), and glazing (G). The zirconia crowns without coloring liquid application served as the control group. CIELab color coordinates were obtained, and color differences (ΔE) between shaded crowns were calculated with a spectrophotometer. The color stability of the crown before and after cement application was also investigated. RESULTS: Before cement application, the mean color difference between groups N and P was 2.85 ΔE units, whereas the mean ΔE value between groups N and G was 3.27. Mean ΔE values with and without cement application among groups ranged from 2.75 to 3.45 ΔE units. CONCLUSIONS: The color appearance of the colored zirconia crowns was strongly influenced by the surface-finishing methods and luting cement application.

Effects of various functional monomers' reaction on the surface characteristics and bonding performance of polyetheretherketone.

PURPOSE: Polyetheretherketone (PEEK) is a new polymeric material that has received significant attention in dentistry because of its mechanical properties, biocompatibility, and aesthetics. However, the bonding performance of PEEK to other materials is not preferable. This study aimed to analyze the variations in the surface characteristics of PEEK under the chemical action of primers containing different functional monomers or polymers and to evaluate the bonding performance of PEEK and dental cement. METHODS: Disk-shaped PEEK samples were prepared by dental milling, blasting with alumina oxide, and covering with primers containing functional monomers or polymers. The surface characteristics of the samples were analyzed by microscopy and spectroscopy. The shear bond strength (SBS) between PEEK and dental cement, with and without thermocycling, was tested using a universal testing machine. Finally, the data were statistically analyzed and compared. RESULTS: Functional monomers or polymers were successfully bonded to the surface of PEEK. This treatment significantly improved its hydrophilicity and surface free energy (P < 0.05). The primer containing pentaerythritol triacrylate had the highest SBS without thermocycling (13.89 MPa). Meanwhile, the primers containing urethane dimethacrylate (UDMA) and methyl methacrylate (MMA) (abbreviated as the HC group) showed the highest SBS and lowest reduction (25.51%) after thermocycling. Notably, all the testing groups achieved the ISO10477 standard of 5 MPa. After thermocycling, adhesive failure accounted for the largest proportion of failures in all the groups except the HC group. CONCLUSIONS: The chemical priming treatment can significantly improve the SBS of PEEK and dental cement. Moreover, a primer containing both UDMA and MMA can provide improved bonding for PEEK materials.

Ribonucleic Acid Sequencing Reveals the Upregulation and Resolution of Inflammation and Extracellular Matrix Remodeling in Lidocaine-Treated Human Acute Monocytic Leukemia Cell Line THP-1.

Lidocaine, a local anesthetic widely used in dentistry, is esteemed for its efficacy and safety. Recent research reveals its additional role in modulating the immune system, and particularly in reducing inflammation crucial for protecting tooth-supporting tissues. Notably, monocytes and macrophages, essential cellular components overseeing various physiological and pathological processes, stand as potential mediators of lidocaine's effects. Therefore, this study aimed to investigate how lidocaine influences cell behavior using RNA sequencing. To investigate the effect of lidocaine on THP-1 cells' behavior, we performed an MTT assay and RNA-Seq along with qPCR analyses to evaluate the transcriptomic and proteomic changes in THP-1 cells. Our results showed that a high dose of lidocaine (>1 mM) had a significant cytotoxic effect on THP-1 cells. However, a lidocaine dose lower than 0.5 mM induced a mixed anti-inflammatory profile by significantly upregulating tissue remodeling (GDF15, FGF7, HGF, COL4A3, COL8A2, LAMB2, LAMC2, PDGFRA, and VEGFA) and through the resolution of inflammation (Cpeb4, Socs1, Socs2, Socs3, Dusp1, Tnfaip3, and Gata3) gene cassettes. This study explores the effect of lidocaine on the THP-1 in the M2-like healing phenotype and provides potential applications of lidocaine's therapeutic effectiveness in dental tissue repair.

Physicochemical Characterization, Biocompatibility, and Antibacterial Properties of CMC/PVA/Calendula officinalis Films for Biomedical Applications.

This study reports a carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) composite film that incorporates Calendula officinalis (CO) extract for biomedical applications. The morphological, physical, mechanical, hydrophilic, biological, and antibacterial properties of CMC/PVA composite films with various CO concentrations (0.1%, 1%, 2.5%, 4%, and 5%) are fully investigated using different experiments. The surface morphology and structure of the composite films are significantly affected by higher CO concentrations. X-ray diffraction (XRD) and Fourier transform infrared spectrometry (FTIR) analyses confirm the structural interactions among CMC, PVA, and CO. After CO is incorporated, the tensile strength and elongation upon the breaking of the films decrease significantly. The addition of CO significantly reduces the ultimate tensile strength of the composite films from 42.8 to 13.2 MPa. Furthermore, by increasing the concentration of CO to 0.75%, the contact angle is decreased from 15.8° to 10.9°. The MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay reveals that the CMC/PVA/CO-2.5% and CMC/PVA/CO-4% composite films are non-cytotoxic to human skin fibroblast cells, which is favorable for cell proliferation. Remarkably, 2.5% and 4% CO incorporation significantly improve the inhibition ability of the CMC/PVA composite films against Staphylococcus aureus and Escherichia coli. In summary, CMC/PVA composite films containing 2.5% CO exhibit the functional properties for wound healing and biomedical engineering applications.

The Influence of Dental Virtualization, Restoration Types, and Placement Angles on the Trueness and Contact Space in 3D-Printed Crowns: A Comprehensive Exploration.

The current digital dentistry workflow has streamlined dental restoration production, but the effectiveness of digital virtual design and 3D printing for restorations still needs evaluation. This study explores the impact of model-free digital design and 3D-printing placement angles on restorations, including single crowns and long bridges produced with and without casts. The restorations are 3D printed using resin at placement angles of 0°, 60°, and 90°. Each group of samples was replicated ten times, resulting in a total of 120 restorations. The Root Mean Square Error (RMSE) value was used to evaluate the surface integrity of the restoration. In addition, the contact space, edge gap, and occlusal space of restorations produced by different processes were recorded. The results indicate that there was no significant difference in the RMSE value of the crown group (p > 0.05). Changing the bridge restoration angle from 0° to 90° resulted in RMSE values increasing by 2.02 times (without casts) and 2.39 times (with casts). Furthermore, the marginal gaps in the crown group were all less than 60 µm, indicating good adaptation. In contrast, the bridge group showed a significant increase in marginal gaps at higher placement angles (p > 0.05). Based on the findings, virtual fabrication without casts does not compromise the accuracy of dental restorations. When the position of the long bridge exceeds 60 degrees, the error will increase. Therefore, designs without casts and parallel placement result in higher accuracy for dental restorations.

Optimizing Dental Bond Strength: Insights from Comprehensive Literature Review and Future Implications for Clinical Practice.

This review examines the modifying factors affecting bond strength in various bonding scenarios, particularly their relevance to the longevity of dental restorations. Understanding these factors is crucial for improving clinical outcomes in dentistry. Data were gathered from the PubMed database, ResearchGate, and Google Scholar resources, covering studies from 1992 to 2022. The findings suggest that for dentin-resin bonds, minimizing smear layers and utilizing MMP inhibitors to prevent hybrid layer degradation are essential. In the case of resin-resin bonds, reversing blood contamination is possible, but preventing saliva contamination is more challenging, underscoring its critical importance during clinical procedures. Additionally, while pretreatment on ceramics has minimal impact on bond strength, the influence of specific colorings should be carefully considered in treatment planning. This comprehensive review highlights that although established practices recognize significant bond strength factors, ongoing research provides valuable insights to enhance the clinical experience for patients. Once confirmed through rigorous experimentation, these emerging findings should be swiftly integrated into dental practice to improve patient outcomes.

Exploring Possible Diagnostic Precancerous Biomarkers for Oral Submucous Fibrosis: A Narrative Review.

Oral submucous fibrosis (OSF) stands as a progressive oral ailment, designated as a potentially malignant disorder. OSF has gained widespread recognition as a significant precursor to malignant transformation. In the pursuit of dependable, straightforward, and non-invasive diagnostic measures for the early detection of oral malignant progression, research has delved into potential diagnostic biomarkers of OSF. This comprehensive review delves into current investigations that explore the correlation between various biomarkers and OSF. The molecular biomarkers of OSF are categorized based on cytology and sampling methods. Moreover, this review encompasses pertinent studies detailing how these biomarkers are acquired and processed. Within this scope, we scrutinize four potential biomarkers that hold the promise of facilitating the development of diagnostic tools for detecting early-stage OSF.

Unraveling the Link between Periodontitis and Coronavirus Disease 2019: Exploring Pathogenic Pathways and Clinical Implications.

Periodontitis involves the inflammation of the periodontal tissue, leading to tissue loss, while coronavirus disease 2019 (COVID-19) is a highly transmissible respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is amplified by poor systemic health. Key facilitators of SARS-CoV-2's entry into host cells are angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2). This review reveals that periodontal pockets can serve as a hotspot for virus accumulation, rendering surrounding epithelia more susceptible to infection. Given that ACE2 is expressed in oral mucosa, it is reasonable to suggest that poor periodontal health could increase the risk of COVID-19 infection. However, recent studies have not provided sufficient evidence to imply a significant effect of COVID-19 on periodontal health, necessitating further and more long-term investigations. Nevertheless, there are hypotheses linking the mechanisms of the two diseases, such as the involvement of interleukin-17 (IL-17). Elevated IL-17 levels are observed in both COVID-19 and periodontitis, leading to increased osteoclast activity and bone resorption. Lastly, bidirectional relationships between periodontitis and systemic diseases like diabetes are acknowledged. Given that COVID-19 symptoms may worsen with these conditions, maintaining good oral health and managing systemic diseases are suggested as potential ways to protect against COVID-19.

Clinical Benefits of Minimally Invasive Non-Surgical Periodontal Therapy as an Alternative of Conventional Non-Surgical Periodontal Therapy-A Pilot Study.

Minimally invasive procedures were introduced in periodontics, which could enhance clinical outcomes and reduce post-operative discomfort. However, minimally invasive non-surgical periodontal therapy (MINST) as an alternative modality of conventional non-surgical root surface debridement has not been clearly evaluated by randomized controlled clinical trial. The present study aimed to investigate clinical outcomes and patients' comfort feedback of MINST compared to conventional non-surgical periodontal therapy (CNST). Patients with moderate to severe periodontitis were included. Nine out of ten patients were recruited and completed the post-treatment re-evaluation in this study. Randomized split-mouth design, CNST and MINST on each side, was performed. Clinical parameters, including periodontal probing depth (PD), gingival recession (REC), clinical attachment level (CAL), and gingival bleeding on probing (BOP), were recorded on baseline, 1 month and 3 months post-treatment. Non-parametric statistics were used for analysis. PD, REC, CAL, and BOP were improved after treatment in both CNST and MINST groups. Comfort feedback and gingival recession showed better outcomes in the MINST group than in the CNST group. No statistical significance of parameters was found between CNST and MINST. Within the limitations, minimally invasive non-surgical periodontal therapy could be an alternative modality of conventional non-surgical periodontal therapy. Further studies are required to establish clinical protocol and evidence of MINST.