The Potential Value of Probiotics after Dental Implant Placement.

Dental implantation is currently the optimal solution for tooth loss. However, the health and stability of dental implants have emerged as global public health concerns. Dental implant placement, healing of the surgical site, osseointegration, stability of bone tissues, and prevention of peri-implant diseases are challenges faced in achieving the long-term health and stability of implants. These have been ongoing concerns in the field of oral implantation. Probiotics, as beneficial microorganisms, play a significant role in the body by inhibiting pathogens, promoting bone tissue homeostasis, and facilitating tissue regeneration, modulating immune-inflammatory levels. This review explores the potential of probiotics in addressing post-implantation challenges. We summarize the existing research regarding the importance of probiotics in managing dental implant health and advocate for further research into their potential applications.

A dual role of HIF1α in regulating osteogenesis-angiogenesis coupling.

OBJECTIVES: The hypoxia-inducible factor 1-α (HIF1α), a key molecule in mediating bone-vessel crosstalk, has been considered a promising target for treating osteoporosis caused by gonadal hormones. However, senile osteoporosis, with accumulated senescent cells in aged bone, has a distinct pathogenesis. The study aimed at revealing the unknown role of HIF1α in aged bone, thus broadening its practical application in senile osteoporosis. MATERIALS AND METHODS: Femurs and tibias were collected from untreated mice of various ages (2 months old, 10 months old, 18 months old) and treated mice (2 months old, 18 months old) underwent 4-w gavage of 2-methoxyestradiol (a kind of HIF1α inhibitor). Bone-vessel phenotypes were observed by microfil infusion, micro-CT and HE staining. Markers of senescence, osteogenesis, angiogenesis, oxidative stress and expression of HIF1α were detected by senescence ß-galactosidase staining, qRT-PCR, western blot and immunostaining, respectively. Furthermore, bone mesenchymal stem cells from young mice (YBMSCs) and aged mice (ABMSCs) were transfected by knockout siRNA and overexpression plasmid of HIF1α. Senescence ß-galactosidase staining, Cell Counting Kit-8, transwell assay, alkaline phosphatase staining, alizarin red-S staining and angiogenesis tests were utilized to assess the biological properties of two cell types. Then, Pifithrin-α and Nutlin-3a were adopted to intervene p53 of the two cells. Finally, H2O2 on YBMSCs and NAC on ABMSCs were exploited to change their status of oxidative stress to do a deeper detection. RESULTS: Senescent phenotypes, impaired osteogenesis-angiogenesis coupling and increased HIF1α were observed in aged bone and ABMSCs. However, 2-methoxyestradiol improved bone-vessel metabolism of aged mice while damaged that of young mice. Mechanically, HIF1α showed opposed effects in regulating the cell migration and osteogenesis-angiogenesis coupling of YBMSCs and ABMSCs, but no remarked effect on the proliferation of either cell type. Pifithrin-α upregulated the osteogenic and angiogenic markers of HIF1α-siRNA-transfected YBMSCs, and Nutlin-3a alleviated those of HIF1α-siRNA-transfected ABMSCs. The HIF1α-p53 relationship was negative in YBMSCs and NAC-treated ABMSCs, but positive in ABMSCs and H2O2-treated YBMSCs. CONCLUSION: The dual role of HIF1α in osteogenesis-angiogenesis coupling may depend on the ROS-mediated HIF1α-p53 relationship. New awareness about HIF1α will be conducive to its future application in senile osteoporosis.

Influence of Different Marginal Forms on Endodontically Treated Posterior Teeth Restored with Lithium Disilicate Glass-Ceramic Onlays: Two-Year Follow-up.

PURPOSE: To evaluate the clinical performance of endodontically treated (ET) teeth restored with two different marginal forms of lithium disilicate glass-ceramic (LDG ceramic) onlays. MATERIALS AND METHODS: A total of 120 posterior teeth were prepared for onlays after ET. The occlusal surfaces of the teeth were removed 1.5 to 2 mm anatomically. Different marginal forms were employed depending on the thickness of the residual axis wall of each tooth: In Group S, a 1-mm shoulder was prepared when the remaining axis wall was > 2 mm (n = 50), and in Group B, a 20- to 30-degree bevel was prepared when the remaining axis wall was ≤ 2 mm (n = 70). The access of the pulp chamber was filled with resin, and 1.5 to 2 mm of the box morphology of the pulp chamber was preserved. The pressed LDG ceramic was applied to the fabricated onlays. The teeth and restorations were checked after 6, 12, and 24 months. All available restored teeth were assessed using modified United States Public Health Service criteria. RESULTS: During the observation period, no tooth fracture occurred. Neither tooth cracks nor secondary caries were observed in Group S or Group B. The 2-year survival rate of the teeth was 100%. Five fractured onlays were observed in Group S in the molar region, while all onlays in Group B were intact (P < .05). The survival rate of the onlays was 95.83%. CONCLUSION: The results demonstrate that LDG ceramic onlays can preserve ET posterior teeth with a highly satisfactory outcome, though the marginal form may affect the survival rate of the onlay.

Effect of different surface treatments and retainer designs on the retention of posterior Pd-Ag porcelain-fused-to-metal resin-bonded fixed partial dentures.

The aim of this study was to investigate the adhesive property of palladium-silver alloy (Pd-Ag) and the simulated clinical performance of Pd-Ag porcelain-fused-to-metal (PFM), resin-bonded, fixed partial dentures (RBFPDs). A total of 40 Pd-Ag discs (diameter=5 mm) were prepared and divided into the following four groups (n=10): a) No sandblasting, used as a control; and b, 50 µm; c, 110 µm; and d, 250 µm aluminum oxide (Al2O3) particles, respectively. Another 50 discs were pre-sandblasted and divided into five groups (n=10) subjected to different treatments: e) Sandblasting, used as a control; f) silane; g) alloy primer; h) silica coating + silane and i) silica coating + alloy primer. All 90 discs were bonded to enamel with Panavia F 2.0 and then subjected to shear bond strength (SBS) testing. The fracture surfaces were examined by scanning electron microscopy. Next, 40 missing maxillary second premolar models were restored with one of the four following RBFPD designs (n=10): I) A premolar occlusal bar combined with molar double rests (MDR); II) both occlusal bars with a wing (OBB); III) a premolar occlusal bar combined with a molar dental band (MDB); and IV) two single rests adjacent to the edentulous space with a wing (SRB) used as a control. All specimens were aged with thermal cycling and mechanical loading. Subsequently, they were loaded until broken. The data were analyzed by one-way analysis of variance. Al2O3 (250 µm) abrasion provided the highest SBS (P<0.05). The alloy primer and silica + silane exhibited increased SBS. Furthermore, fracture analysis revealed that the failure mode varied among the different treatments. Whereas MDB exhibited the highest retention (P<0.05), that of OBB was greater than that of MDR (P<0.05), and the control exhibited the lowest retention. Abrasion with Al2O3 (250 µm) effectively increased the adhesive property of Pd-Ag. Additionally, treatment with the alloy primer and silica coating + silane was able to increase the adhesive property of abraded Pd-Ag. Under the present conditions, all three modified retainer types provided improved outcomes for Pd-Ag PFM RBFPDs compared with the control.

Therapeutic effect of bone marrow mesenchymal stem cells pretreated with acetylsalicylic acid on experimental periodontitis in rats.

Periodontitis is a local inflammatory environment with dysregulation of host responses, which results in destruction of periodontal tissues. Mesenchymal stem cells (MSCs) have been proven to play important roles in tissue regeneration by serving as progenitor cells, but its therapeutic outcomes are yet, evaluated variable and unpredictable because of the influence of local inflammation. Acetylsalicylic acid (ASA) has been reported to benefit for MSCs in terms of inflammation control and tissue regeneration. In this study, we aimed to explore the effect of bone marrow mesenchymal stem cells (BMMSCs) pretreated with ASA (ASA-BMMSCs) on periodontal bone repair in a ligature and bacteria-induced periodontitis model in rats. We show herein that, ASA-BMMSCs treatment reduced inflammatory infiltration and alveolar bone loss in periodontitis rats, reflected by immunohistochemistry staining of OPG/RANK-L and Micro-CT. Levels of TNF-α and IL-17 decreased while IL-10 increased after the treatment of ASA-BMMSCs in periodontitis rats. In addition, less osteoclasts number was detected in ASA-BMMSCs treated group. In vitro study showed that ASA facilitated BMMSCs proliferation and differentiation, which might explain the reduced bone loss in periodontitis. These results together suggest that local application of ASA-BMMSCs in periodontal lesion sites is capable of improving inflammatory microenvironment, promoting alveolar bone regeneration, thus leading to a recovery of periodontal homeostasis. Besides, this study also provides us a new idea that a combined application of ASA and BMMSCs may be a novel approach for periodontitis treatment and periodontal bone regeneration.

The p38 MAPK and NF-κB Pathways are Involved in Cyclic Compressive Force-induced IL-6 Secretion in MLO-Y4 Cells

ABSTRACT We previously revealed the involvement of extracellular regulated protein kinases 1/2 (ERK1/2) in interleukin-6 (IL-6) secretion induced by cyclic compressive force (CCF) in MLO-Y4 cells. In this study, we investigated the contributions of the p38 mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) pathways to IL-6 secretion by stimulating MLO-Y4 cells with CCF. At 80% confluence, different magnitudes (1000μstrain, 2000 μstrain and 4000 μstrain), frequencies (0.5 Hz, 1.0 Hz and 2.0 Hz) and durations (10 min, 30 min, 1 h, 3 h and 6 h) of CCF were loaded onto cells using a four-point bending system. Flow Cytometry (FCM) analysis was used to analyze cell mortality rates after CCF loading. p38 and p65 phosphorylation as well as IκBα degradation in MLO-Y4 cells were detected by Western blotting (WB). Changes in IL-6 secretion after inhibitor treatment were assessed by enzyme-linked immunosorbent assays (ELISAs). Cellular viability was over 90 percent after CCF. p38 and p65 phosphorylation increased under all conditions, whereas IκBα protein levels decreased. However, phosphorylation and degradation were not completely dependent on the loading magnitude, frequency or duration. Furthermore, p38 inhibition using the specific inhibitor SB203580 reduced both p38 phosphorylation and IL-6 secretion. Similarly, NF-κB inhibition using BAY 11-7082 decreased p65 phosphorylation and IL-6 secretion but increased the concentration of IκBα. These findings reveal significant roles for the p38 and NF-κB signaling pathways in IL-6 secretion induced by CCF in MLO-Y4 cells.

TGFß isoforms and receptors mRNA expression in breast tumours: prognostic value and clinical implications.

BACKGROUND: Transforming growth factor beta (TGFß) signalling is involved in both tumour suppression and tumour progression. The mRNA expression levels of the TGFß isoforms and receptors in breast tumours may have prognostic value and clinical implications. METHODS: The mRNA levels of TGFB1, TGFB2, TGFB3, TGFBR1 and TGFBR2 were analysed in primary breast tumours and adjacent normal breast tissues, and the associations with tumour characteristics and patients' overall and relapse-free survival were evaluated, using the public gene expression microarray data from The Cancer Genome Atlas (n = 520) and the Gene Expression Omnibus (four datasets) and our quantitative real-time PCR validation data (n = 71). RESULTS: Significantly higher TGFB1 and TGFB3 mRNA levels and lower TGFBR2 mRNA levels were observed in primary tumours compared with their paired normal tissues. TGFB1 mRNA expression was seemly lower in triple-negative tumours and in tumours from lymph node-negative patients. TGFB3 mRNA expression was significantly lower in estrogen receptor-negative/progesterone receptor-negative/Basal-like/Grade 3 tumours. High TGFB2, TGFB3 and TGFBR2 mRNA levels in tumours were generally associated with better prognosis for patients, especially those diagnosed with lymph node-negative diseases. High TGFBR1 mRNA levels in tumours were associated with poorer clinical outcomes for patients diagnosed with small (diameter ≤ 2 cm) tumours. CONCLUSIONS: The results indicate a reduced responsiveness of tumour cells to TGFß, a preferential up-regulation of TGFB1 in malignant tumours and a preferential up-regulation of TGFB3 in premalignant tumours. The results may not only provide prognostic value for patients but also assist in classifying tumours according to their potential responses to TGFß and selecting patients for TGFß signalling pathway targeted therapies.

ß-Adducin siRNA disruption of the spectrin-based cytoskeleton in differentiating keratinocytes prevented by calcium acting through calmodulin/epidermal growth factor receptor/cadherin pathway.

Here, we report that siRNA transfection of ß-adducin significantly disrupted the spectrin-based cytoskeleton and cytoskeletal arrangements of both ß-adducin and PKCδ by substantially inhibiting the expression of ß-adducin, spectrin and PKCδ proteins in differentiating keratinocytes. However, extracellular Ca2+ treatment blocked the inhibitory effects of the ß-adducin siRNA. Ca2+ also prevented the significant down-regulation of two differentiation markers involucrin and K1/10 and the distinct up-regulation of proliferation marker K14 in ß-adducin siRNA transfected keratinocytes. In addition, ß-adducin knockdown resulted in a substantial reduction of epidermal growth factor receptor (EGFR), cadherin and ß-catenin and enhanced phosphorylation of EGFR on tyrosine 1173 and Ca2+ prevented these changes. Furthermore, Ca2+ blocked the inhibitory effects of ß-adducin siRNA on the expression of calmodulin, phosphorylated-calmodulin (P-CaM((Tyr138))) and myristoylated alanine-rich C-kinase substrate (MARCKS) in keratinocytes. Co-immunoprecipitation studies further revealed that calmodulin, not MARCKS, strongly interacted with EGFR, cadherin and ß-catenin. Our data suggest that Ca2+ plays an important role in regulating the expression and function of ß-adducin to sustain normal organization of the spectrin-based cytoskeleton and the differentiation properties in keratinocytes through the calmodulin/EGFR/cadherin signaling pathway.

The fracture resistance of a CAD/CAM Resin Nano Ceramic (RNC) and a CAD ceramic at different thicknesses.

OBJECTIVES: This study aimed to investigate the influence of restoration thickness to the fracture resistance of adhesively bonded Lava™ Ultimate CAD/CAM, a Resin Nano Ceramic (RNC), and IPS e.max CAD ceramic. METHODS: Polished Lava™ Ultimate CAD/CAM (Group L), sandblasted Lava™ Ultimate CAD/CAM (Group LS), and sandblasted IPS e.max CAD (Group ES) discs (n=8, Ø=10 mm) with a thickness of respectively 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, and 3.0 mm were cemented to corresponding epoxy supporting discs, achieving a final thickness of 3.5 mm. All the 120 specimens were loaded with a universal testing machine at a crosshead speed of 1 mm/min. The load (N) at failure was recorded as fracture resistance. The stress distribution for 0.5 mm restorative discs of each group was analyzed by Finite Element Analysis (FEA). The results of facture resistances were analyzed by one-way ANOVA and regression. RESULTS: For the same thickness of testing discs, the fracture resistance of Group L was always significantly lower than the other two groups. The 0.5 mm discs in Group L resulted in the lowest value of 1028 (112) N. There was no significant difference between Group LS and Group ES when the restoration thickness ranged between 1.0 mm and 2.0 mm. There was a linear relation between fracture resistance and restoration thickness in Group L (R=0.621, P<0.001) and in Group ES (R=0.854, P<0.001). FEA showed a compressive permanent damage in all groups. SIGNIFICANCE: The materials tested in this in vitro study with the thickness above 0.5 mm could afford the normal bite force. When Lava Ultimate CAD/CAM is used, sandblasting is suggested to get a better bonding.

Effect of an experimental zirconia-silica coating technique on micro tensile bond strength of zirconia in different priming conditions.

OBJECTIVES: This study aimed to evaluate the adhesive properties of a MDP-containing resin cement to a colored zirconia ceramic, using an experimental zirconia-silica coating technique with different priming conditions. METHODS: 18 zirconia ceramic discs (Cercon base colored) were divided into two groups: the control group and the experimental zirconia-silica coating group. Specimens in each group were further divided into 3 subgroups (n = 3) according to the priming conditions: no primer, a MDP-containing primer (ED Primer II) or a silane coupling primer (RelyX™ Ceramic Primer). Then resin-composite discs (Filtek™ Z250) were bonded to the treated surface using a MDP-containing resin cement (Panavia F 2.0). The bi-layered specimens were cut into microbars and 20 microbars were randomly selected from each specimen, half of which were stored in 37°C water bath for 24h, and the other half were stored for 30 days. After water storage, the samples were exposed to a micro tensile bond strength test (MTBS). The results were analyzed by ANOVA, while the fracture surfaces were examined by SEM. RESULTS: After 24h water storage, zirconia-silica coating followed by silanization showed a significantly (P<0.001) higher MTBS value 45.0 (10.9)MPa. Water storage affected (P<0.05) MTBS in the control group (24.1-30.3 MPa to 2.8-3.1 MPa), but only partially in the zirconia-silica coating group (20.0-45.1 MPa to 17.4-25.9 MPa). SEM analysis revealed a failure mode change after water storage. SIGNIFICANCE: The combination of zirconia-silica coating with silane coupling can improve the bonding of resin cement to this colored zirconia.