TNF-α-licensed exosome-integrated titaniumaccelerated T2D osseointegration by promoting autophagy-regulated M2 macrophage polarization.

Type 2 diabetes (T2D) is on a notable rise worldwide, which leads to unfavorable outcomes during implant treatments. Surface modification of implants and exosome treatment have been utilized to enhance osseointegration. However, there has been insufficient approach to improve adverse osseointegration in T2D conditions. In this study, we successfully loaded TNF-α-treated mesenchymal stem cell (MSC)-derived exosomes onto micro/nano-network titanium (Ti) surfaces. TNF-α-licensed exosome-integrated titanium (TNF-exo-Ti) effectively enhanced M2 macrophage polarization in hyperglycemic conditions, with increased secretion of anti-inflammatory cytokines and decreased secretion of pro-inflammatory cytokines. In addition, TNF-exo-Ti pretreated macrophage further enhanced angiogenesis and osteogenesis of endothelial cells and bone marrow MSCs. More importantly, TNF-exo-Ti markedly promoted osseointegration in T2D mice. Mechanistically, TNF-exo-Ti activated macrophage autophagy to promote M2 polarization through inhibition of the PI3K/AKT/mTOR pathway, which could be abolished by PI3K agonist. Thus, this study established TNF-α-licensed exosome-immobilized titanium surfaces that could rectify macrophage immune states and accelerate osseointegration in T2D conditions.

A novel CAF-cancer cell crosstalk-related gene prognostic index based on machine learning: prognostic significance and prediction of therapeutic response in head and neck squamous cell carcinoma.

BACKGROUND: Cancer-associated fibroblast (CAF)-cancer cell crosstalk (CCCT) plays an important role in tumor microenvironment shaping and immunotherapy response. Current prognostic indexes are insufficient to accurately assess immunotherapy response in patients with head and neck squamous cell carcinoma (HNSCC). This study aimed to develop a CCCT-related gene prognostic index (CCRGPI) for assessing the prognosis and response to immune checkpoint inhibitor (ICI) therapy of HNSCC patients. METHODS: Two cellular models, the fibroblast-cancer cell indirect coculture (FCICC) model, and the fibroblast-cancer cell organoid (FC-organoid) model, were constructed to visualize the crosstalk between fibroblasts and cancer cells. Based on a HNSCC scRNA-seq dataset, the R package CellChat was used to perform cell communication analysis to identify gene pairs involved in CCCT. Least absolute shrinkage and selection operator (LASSO) regression was then applied to further refine the selection of these gene pairs. The selected gene pairs were subsequently subjected to stepwise regression to develop CCRGPI. We further performed a comprehensive analysis to determine the molecular and immune characteristics, and prognosis associated with ICI therapy in different CCRGPI subgroups. Finally, the connectivity map (CMap) analysis and molecular docking were used to screen potential therapeutic drugs. RESULTS: FCICC and FC-organoid models showed that cancer cells promoted the activation of fibroblasts into CAFs, that CAFs enhanced the invasion of cancer cells, and that CCCT was somewhat heterogeneous. The CCRGPI was developed based on 4 gene pairs: IGF1-IGF1R, LGALS9-CD44, SEMA5A-PLXNA1, and TNXB-SDC1. Furthermore, a high CCRGPI score was identified as an adverse prognostic factor for overall survival (OS). Additionally, a high CCRGPI was positively correlated with the activation of the P53 pathway, a high TP53 mutation rate, and decreased benefit from ICI therapy but was inversely associated with the abundance of various immune cells, such as CD4+ T cells, CD8+ T cells, and B cells. Moreover, Ganetespib was identified as a potential drug for HNSCC combination therapy. CONCLUSIONS: The CCRGPI is reliable for predicting the prognosis and immunotherapy response of HSNCC patients and may be useful for guiding the individualized treatment of HNSCC patients.

Ebselen restores peri-implantitis-induced osteogenic inhibition via suppressing BMSCs ferroptosis.

It is hard to reconstruct bone defects in peri-implantitis due to osteogenesis inhibited by excessive reactive oxygen species (ROS). Ferroptosis, a recently identified regulated cell death characterized by iron- and ROS- dependent lipid peroxidation, provides us with a new explanation. Our study aims to explore whether ferroptosis is involved in peri-implantitis-inhibited osteogenesis and confirm ebselen, an antioxidant with glutathione peroxidase (GPx)-like activity, could inhibit ferroptosis and promote osteogenesis in peri-implantitis. In this study, we used LPS to mimic the microenvironment of peri-implantitis. The osteogenic differentiation of bone-marrow-derived mesenchymal stem cells (BMSCs) was assessed by alkaline phosphatase (ALP), Alizarin Red S, and mRNA and protein expression of osteogenic-related markers. Ferroptosis index analysis included iron metabolism, ROS production, lipid peroxidation and mitochondrial morphological changes. Iron overload, reduced antioxidant capability, excessive ROS, lipid peroxidation and the characteristic mitochondrial morphological changes of ferroptosis were observed in LPS-treated BMSCs, and adding Ferrostatin-1 (Fer-1) restored the inhibitory effect of ferroptosis on osteogenic differentiation of BMSCs. Furthermore, ebselen ameliorated LPS-induced ferroptosis and osteogenic inhibition, which were reversed by erastin. Our results demonstrated that ferroptosis is involved in osteogenic inhibition in peri-implantitis and ebselen could attenuate osteogenic dysfunction of BMSCs via inhibiting ferroptosis.

Magnetic graphene oxide nanocomposites induce cytotoxicity in ADSCs via GPX4 regulating ferroptosis.

Magnetic graphene oxide nanocomposites (MGO NPs) have been widely studied in biomedical applications. However, their cytotoxicity and underlying mechanisms remain unclear. In this study, the biosafety of MGO NPs was investigated, and the mechanism involved in ferroptosis was further explored. MGO can produce cytotoxicity in ADSCs, which is dependent on their concentration. Ferroptosis was involved in MGO NP-induced ADSC survival inhibition by increasing total ROS and lipid ROS accumulation as well as regulating the expression levels of ferroptosis-related genes and proteins. GPX4 played a critical role in the MGO NP-induced ADSC ferroptosis process, and overexpressing GPX4 suppressed ferroptosis to increase cell survival. This study provides a theoretical basis for the biosafety management of MGO NPs used in the field of biomedical treatment.

ATG7-mediated autophagy protects human gingival myofibroblasts from irradiation-induced apoptosis.

BACKGROUND: Apoptosis resistance of myofibroblasts is critical in pathology of irradiation-induced fibrosis and osteoradionecrosis of the jaw (ORNJ). However, molecular mechanism of apoptosis resistance induced by irradiation in oral myofibroblasts remains largely obscure. METHODS: Matched ORNJ fibroblasts and normal fibroblasts pairs from gingival were primarily cultured, and myofibroblast markers of α-SMA and FAP were evaluated by qRT-PCR and western blot. CCK8 assay and flow cytometric analysis were performed to investigate the cell viability and apoptosis under irradiation treatment. Autophagy-related protein LC3 and ATG7, and punctate distribution of LC3 localization were further detected. After inhibition of autophagy with inhibitor CQ and 3-MA, as well as transfected ATG7-siRNA, cell viability and apoptosis of ORNJ and normal fibroblasts were further assessed. RESULTS: Compared with normal fibroblasts, ORNJ fibroblasts exhibited significantly higher α-SMA and FAP expression, increased cell, viability and decreased apoptosis under irradiation treatment. LC3-II and ATG7 were up-regulated in ORNJ fibroblasts with irradiation stimulation. After inhibition of irradiation-induced autophagic flux with lysosome inhibitor CQ, LC3-II protein was accumulated and punctate distribution of LC3 localization was increased in ORNJ fibroblasts. Moreover, autophagy inhibitor CQ and 3-MA enhanced the irradiation-induced apoptosis but inhibited viability of ORNJ fibroblasts. Silencing ATG7 with siRNA could obviously weaken irradiation-induced LC3-II expression, and promoted irradiation-induced apoptosis of ORNJ fibroblasts. After knockdown of ATG7, finally, p-AKT(Ser473) and p-mTOR(Ser2448) levels of ORNJ fibroblasts were significantly increased under irradiation. CONCLUSION: Compared with normal fibroblasts, human gingival myofibroblasts are resistant to irradiation-induced apoptosis via autophagy activation. Silencing ATG7 may evidently inhibit activation of autophagy, and promote apoptosis of gingival myofibroblasts via Akt/mTOR pathway.

Selenomethionine protects oxidative-stress-damaged bone-marrow-derived mesenchymal stem cells via an antioxidant effect and the PTEN/PI3K/AKT pathway.

Dental implant surgery is currently a routine therapy for the repair of missing dentition or dentition defects. Both clinical and basic research have elucidated that oxidative stress caused by the accumulation of reactive oxygen species (ROS) for various reasons impairs the process of osteointegration after dental implantation. Therefore, the osteogenic micro-environment must be ameliorated to decrease the damage caused by oxidative stress. Selenomethionine (SEMET) has been reported to play an important role in alleviating oxidative stress and accelerating cell viability and growth. However, it remains unclear whether it exerts protective effects on bone-marrow-derived mesenchymal stem cells (BMSCs) under oxidative stress. In this study, we explored the influence of selenomethionine on the viability and osteogenic differentiation of BMSCs under oxidative stress and the underlying mechanisms. Results showed that 1 µM selenomethionine was the optimum concentration for BMSCs under H2O2 stimulation. H2O2-induced oxidative stress suppressed the viability and osteogenic differentiation of BMSCs, manifested by the increases in ROS production and cell apoptosis rates, and by the decrease of osteogenic differentiation-related markers. Notably, the aforementioned oxidative damage and osteogenic dysfunction induced by H2O2 were rescued by selenomethionine. Furthermore, we found that the PTEN expression level was suppressed and its downstream PI3K/AKT pathway was activated by selenomethionine. However, when PTEN was stimulated, the PI3K/AKT pathway was down-regulated, and the protective effects of selenomethionine on BMSC osteogenic differentiation diminished, while the inhibition of PTEN up-regulated the protective effects of selenomethionine. Together, these results revealed that selenomethionine could attenuate H2O2-induced BMSC dysfunction through an antioxidant effect, modulated via the PTEN/PI3K/AKT pathway, suggesting that selenomethionine is a promising antioxidant candidate for reducing oxidative stress during the process of dental implant osteointegration.

Titanium implant alters the effect of zoledronic acid on the behaviour of endothelial cells.

OBJECTIVES: To evaluate the effect of zoledronic acid (ZA) on human umbilical vein endothelial cells (HUVECs) attached to different surfaces. MATERIALS AND METHODS: A total of three groups were evaluated in this study: sandblasting and acid etching (SLA) + HUVECs; mechanically polished (MP) + HUVECs; and plastic cell culture plates + HUVECs. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, surface roughness and water contact angle were tested for titanium surface characterisation. ZA was added at different concentrations (0, 1, 10, 50 and 100 µM). Cell adhesion, proliferation, viability, apoptosis and gene expression were evaluated. RESULTS: Mechanically polished and SLA surfaces showed negative effects on cell adhesion and proliferation and promoted cell apoptosis with 100 µM ZA (p < .05). The highest expression of intercellular adhesion molecule-1 (ICAM-1) and angiopoietin-1 was found on SLA surfaces (p < .01). The lowest expression of platelet-endothelial cell adhesion molecule-1 and ICAM-1 was found on MP surfaces (p < .05). A significant decrease in von Willebrand factor was detected on MP and SLA surfaces (p < .001). CONCLUSIONS: Zoledronic acid has an anti-angiogenic effect on HUVECs attached to titanium implants, while the SLA surface might stimulate HUVECs to express angiogenic and adhesive factor genes despite ZA treatment.

Influence of bone density on the accuracy of artificial intelligence-guided implant surgery: An in vitro study.

STATEMENT OF PROBLEM: Artificial intelligence (AI) has been found to be applicable in medical tests and diagnostics. However, studies on the application of AI technology in oral implantology are lacking. In addition, whether bone density affects the accuracy of guided implant surgery has not been determined. PURPOSE: The purpose of this in vitro study was to determine the clinical reliability of an AI-assisted implant planning software program with an in vitro model. An additional goal was to determine the effect of bone density on the accuracy of static computer-assisted implant surgery (CAIS). MATERIAL AND METHODS: Ten participants with missing mandibular left first molars were selected for analysis, and surgical fully guided templates were designed by using an AI implant planning software program. Jaw models were produced in 3 filling rate groups (group L: 25%; group M: 40%; group H: 55%, higher filling rate with representatives of the denser simulated bone density) by 3-dimensional (3D) printing. The preoperative and postoperative positions of the implants were compared by measuring the value of deviation through oral scanning. The mean 3D shoulder and apical and angular deviations were calculated for each group. The data were analyzed using 1-way ANOVA (α=.05 corrected for multiple testing by using Bonferroni-Holm adjustment). RESULTS: The mean ±standard deviation 3D shoulder and apical and angular deviations were 0.80 ±0.32 mm, 1.43 ±0.47 mm, and 3.68 ±1.30 degrees. These values were lower than the clinical safety distance of the fully guided implant template. A significantly lower mean 3D apical deviation (1.12 ±0.33 mm, P=.023) and angular deviation (2.81 ±1.11 degrees, P=.018) were observed in group L than in group H (1.68 ±0.37 mm, 4.32 ±0.99 degrees). However, no significant differences were found among the 3 groups in 3D deviation at the shoulder (P>.05). CONCLUSIONS: AI implant planning software program could design the ideal implant position through self-learning. The accuracy of the AI-assisted designed implant template in this study indicated its clinical reliability. Higher bone density led to increased implant deviations.

Micro/nano topography of selective laser melting titanium inhibits osteoclastogenesis via mediation of macrophage polarization.

Selective laser melting (SLM) titanium (Ti) implants have shown good prospects for personalized clinical application, but further research is necessary to develop stabilized long-term properties. Since surface modification has been proven bioactive for osseointegration, conventional Ti surface treatment technologies, including sandblasting/acid-etching (SLA) and sandblasting/alkali-heating (SAH), were applied to construct micro and micro/nano surfaces. The SAH group with netlike nano-structure topography exhibited appropriate surface roughness and high hydrophilicity, and as expected, the osseointegration capacities in vivo of the three groups were in order of SAH > SLA > SLM. Besides, both in vivo and in vitro studies revealed that the SLA- and SAH-treated SLM Ti implants significantly inhibited osteoclast activity of peri-implants. Considering the close associations between osteoclasts and macrophages, the effects of Ti surface topography on macrophage polarization were detected. The results showed that the SLA- and SAH-treated SLM Ti implants, especially the latter, had the capacity to promote macrophage polarization to the M2 phenotype. Moreover, the cell culture supernatants of M2 macrophages and RAW264.7 cells seeded on SLA- and SAH-treated SLM Ti surfaces had an adverse effect on osteoclastogenesis. Collectively, this study demonstrated that micro/nano topographies of SLM Ti implants were effective for osseointegration promotion, and their inhibition of osteoclastogenesis might be attributed to macrophage polarization. Our findings shed some light on clinical application of SLM Ti implants and also prove a specific association between macrophage polarization and osteoclastogenesis.

Whole-genome resequencing reveals loci with allelic transmission ratio distortion in F1 chicken population.

Allelic transmission ratio distortion (TRD) is the significant deviation from the expected ratio under Mendelian inheritance theory, which may be resulted from multiple disrupted biological processes, including germline selection, meiotic drive, gametic competition, imprint error, and embryo lethality. However, it is less known that whether or what extent the allelic TRD is present in farm animals. In this study, whole-genome resequencing technology was applied to reveal TRD loci in chicken by constructing a full-sib F1 hybrid population. Through the whole-genome resequencing data of two parents (30 ×) and 38 offspring (5 ×), we detected a total of 2850 TRD SNPs (p-adj < 0.05) located within 400 genes showing TRD, and all of them were unevenly distributed on macrochromosomes and microchromosomes. Our findings suggested that TRD in the chicken chromosome 16 might play an important role in chicken immunity and disease resistance and the MYH1F with significant TRD and allele-specific expression could play a key role in the fast muscle development. In addition, functional enrichment analyses revealed that many genes (e.g., TGFBR2, TGFBR3, NOTCH1, and NCOA1) with TRD were found in the significantly enriched biological process and InterPro terms in relation to embryonic lethality and germline selection. Our results suggested that TRD is considerably prevalent in the chicken genome and has functional implications.

The temporal shift of peri-implant microbiota during the biofilm formation and maturation in a canine model.

OBJECTIVES: Although the mature peri-implant biofilm composition is well studied, there is very little information on the succession of in vivo dental implant colonization. The aim of this study was to characterize the temporal changes and diversity of peri-implant supra-mucosal and sub-mucosal microbiota during the process of the plaque maturation. MATERIALS AND METHODS: Dental implants (n = 25) were placed in the mandible of 3 beagle dogs. Illumina MiSeq sequencing of the hypervariable V3-V4 region of the 16S rRNA gene amplicons was used to characterize the supra/sub-mucosal microbiota in the peri-implant niches at 1day (T1), 7days (T2), 14days (T3), 21days (T4) and 28days (T5) after Phase Ⅱ surgery of the healing abutment placement. QIIME, Mothur, LEfSe and R-package were used for downstream analysis. RESULTS: A total of 1184 operational taxonomic units (OTUs), assigned into 22 phyla, 264 genera and 339 species were identified. In supra-mucosal niches, the alpha parameters of shannon, sobs and chao1 displayed significant differences between T1 and other time-points. However, in sub-mucosal niches, only sobs, chao1, and ace indexes displayed significant differences between T1 and T3, and T1 and T5. Beta-diversity showed statistically significant difference between T1 and T2, T3, T4, T5 within both sub-mucosal and supra-mucosal plaque. The phyla Bacteroidetes, Proteobacteria and Firmicutes were the most dominant phyla of both sub-mucosal and supra-mucosal niches at all time-points and Firmicutes increased during the maturation of peri-implant plaque. At the genus level, Neisseria decreased significantly after T1 suggesting the establishment of an anaerobic microenvironment. A decrease of Porphyromonas during the formation of sub-mucosal microbial community was also detected. Co-occurrence network analysis exhibited a more complicated co-occurrence relationship of bacterial species in the sub-mucosal niches. Fusobacterium nucleatum, Filifactor villosus, and some other species may play a crucial role in biofilm maturation. CONCLUSIONS: The present results suggested that the development of peri-implant biofilm followed a similar pattern to dental plaque formation. Sub-mucosal biofilm may go through a more complicated procedure of maturation than supra-mucosal biofilm.

Micro/nano-textured hierarchical titanium topography promotes exosome biogenesis and secretion to improve osseointegration.

BACKGROUND: Micro/nano-textured hierarchical titanium topography is more bioactive and biomimetic than smooth, micro-textured or nano-textured titanium topographies. Bone marrow mesenchymal stem cells (BMSCs) and exosomes derived from BMSCs play important roles in the osseointegration of titanium implants, but the effects and mechanisms of titanium topography on BMSCs-derived exosome secretion are still unclear. This study determined whether the secretion behavior of exosomes derived from BMSCs is differently affected by different titanium topographies both in vitro and in vivo. RESULTS: We found that both micro/nanonet-textured hierarchical titanium topography and micro/nanotube-textured hierarchical titanium topography showed favorable roughness and hydrophilicity. These two micro/nano-textured hierarchical titanium topographies enhanced the spreading areas of BMSCs on the titanium surface with stronger promotion of BMSCs proliferation in vitro. Compared to micro-textured titanium topography, micro/nano-textured hierarchical titanium topography significantly enhanced osseointegration in vivo and promoted BMSCs to synthesize and transport exosomes and then release these exosomes into the extracellular environment both in vitro and in vivo. Moreover, micro/nanonet-textured hierarchical titanium topography promoted exosome secretion by upregulating RAB27B and SMPD3 gene expression and micro/nanotube-textured hierarchical titanium topography promoted exosome secretion due to the strongest enhancement in cell proliferation. CONCLUSIONS: These findings provide evidence that micro/nano-textured hierarchical titanium topography promotes exosome biogenesis and extracellular secretion for enhanced osseointegration. Our findings also highlight that the optimized titanium topography can increase exosome secretion from BMSCs, which may promote osseointegration of titanium implants.

Effect of socket-shield technique on alveolar ridge soft and hard tissue in dogs.

AIM: To study the soft and hard tissue alterations of the alveolar ridge after socket-shield technique. MATERIALS AND METHODS: In four Beagle dogs, the following treatments (Tx) were randomly assigned to 32 extraction sockets: Tx1: blood clot; Tx2: Bio-Oss Collagen; Tx3: socket-shield technique and blood clot; Tx4: socket-shield technique and Bio-Oss Collagen. The width and height alterations of the buccal bone plate were calculated by CBCT scans. The dimensional alterations of the buccal aspect of the alveolar ridge at different time points were calculated by impressions using digital imaging analysis. The dogs were sacrificed for micro-CT and histologic analysis 3 months after surgery. RESULTS: Width, height and dimensional alterations of Tx3 and Tx4 were significantly lower than those of Tx1 and Tx2. Bone morphological parameters displayed no significant differences among four groups except for the trabecular thickness of Tx1 and Tx2. The quantity and quality of hard tissue containing the residual teeth of Tx3 and Tx4 were much greater than those of Tx1 and Tx2. CONCLUSIONS: Socket-shield technique may be beneficial in preserving the soft and hard tissue of the alveolar ridge, which is better than simple bone grafting in the extraction socket.

Esthetic Evaluation of Implant-Supported Single Crowns: The Implant Restoration Esthetic Index and Patient Perception.

PURPOSE: To test the validity and reliability of a newly developed Implant Restoration Esthetic Index (IREI) and to compare esthetic outcomes reported by patients and professionals. MATERIALS AND METHODS: Ten graduate students and 10 prosthodontists assessed esthetic outcomes of 27 single-tooth implants with the IREI. Six peri-implant soft tissue parameters were measured using visual analog scales: mesial papilla presence, distal papilla presence, gingival trigone, soft tissue curvature, alveolar process deficiency, and soft tissue color and texture, as well as the six crown parameters: crown contour, crown position, crown labial convexity, crown characterization, crown color and translucency, and abutment visibility. The validity was tested based on Pearson's correlation. The internal consistency reliability was analyzed by Cronbach's alpha. Interclass correlation coefficients (ICC) were calculated to express the test-retest reliability and the inter-rater reliability. The correlations between patient and professional evaluations were analyzed by Pearson's correlation. RESULTS: The IREI demonstrated significant correlation (p < 0.05) to the pink esthetic score and white esthetic score (PES/WES). The internal consistency reliability showed a Cronbach's Alpha of 0.830. The test-retest reliability was excellent in both the graduate student group and the prosthodontist group, with ICCs of 0.961 and 0.952, respectively (p < 0.05). The inter-rater reliability was acceptable, with ICCs of 0.649 and 0.667, respectively (p < 0.05). Low correlation coefficients were found between patient and professional evaluations. CONCLUSIONS: The results of this study indicated that the IREI was considered a valid and reliable index involving sufficient parameters for professional esthetic evaluation of single-tooth implant restorations. The patient-reported esthetic outcomes had poor or no significant correlation to professional-reported outcomes.

Influence of Lateral-Medial Sinus Width on No-Grafting Inlay Osteotome Sinus Augmentation Outcomes.

PURPOSE: Intrasinus new bone formation (BF) has been observed after no-grafting osteotome sinus augmentation, and it is hypothesized to be influenced by the dimensions of the maxillary sinus. The aim of this clinical trial is to evaluate the influence of lateral-medial sinus width (SW) on no-grafting osteotome sinus augmentation outcomes using cone-beam computed tomography. PATIENTS AND METHODS: All patients recruited for this prospective study were treated with no-grafting osteotome sinus augmentation with simultaneous implant placement. Cone-beam computed tomography was obtained before, immediately after, and 6 months after the surgical procedure to use for measurements. Descriptive statistics were calculated and univariate, bivariate, and multivariate analysis were conducted to evaluate the influence of average SW and other relevant factors on procedure outcomes, including new BF, residual bone resorption (BR), and change of peri-implant bone height (CPBH). RESULTS: A total of 48 implants placed in 32 elevated sinuses of 29 patients were included. The average SW was 11.3 ± 1.8 mm. Intrasinus BF measured 1.7 ± 0.9 mm at 6 months after surgery. The amount of BR was 0.3 ± 0.9 mm, and CPBH was calculated as 1.3 ± 1.3 mm. Multivariate analysis showed a negative correlation between SW and BF (r = -0.469, P = .001), as well as between SW and CPBH (r = -0.562, P = .001). A positive correlation was discovered between SW and BR (r = 0.311, P = .027) in general. CONCLUSIONS: The lateral-medial SW was observed to have a negative correlation with new BF and CPBH after no-grafting osteotome sinus augmentation.

Comparative Study on the Genetic Diversity of GHR Gene in Tibetan Cattle and Holstein Cows.

Due to the phenotype-based artificial selection in domestic cattle, the underlying functional genes may be indirectly selected and show decreasing diversity in theory. The growth hormone receptor (GHR) gene has been widely proposed to significantly associate with critical economic traits in cattle. In the present study, we comparatively studied the genetic diversity of GHR in Tibetan cattle (a traditional unselected breed, n = 93) and Chinese Holstein cow (the intensively selected breed, n = 94). The Tibetan yak (n = 38) was also included as an outgroup breed. A total of 21 variants were detected by sequencing 1279 bp genomic fragments encompassing the largest exon 9. Twelve haplotypes (H1∼H12) constructed by 15 coding SNPs were presented as a star-like network profile, in which haplotype H2 was located at the central position and almost occupied by Tibetan yaks. Furthermore, H2 was also identical to the formerly reported sequence specific to African cattle. Only haplotype H5 was simultaneously shared by all three breeds. Tibetan cattle showed higher nucleotide diversity (0.00215 ± 0.00015) and haplotype diversity (0.678 ± 0.026) than Holstein cow. Conclusively, we found Tibetan cattle have retained relatively high genetic variation of GHR. The predominant presence of African cattle specific H2 in the outgroup yak breed would highlight its ancestral relationship, which may be used as one informative molecular marker in the phylogenetic studies.

Unconventional Dental Implant Placement Through an Impacted Maxillary Central Incisor in Stable Contact With Enamel and Dentin: A Case Report.

When edentulism is accompanied by an impacted tooth, conventional treatment usually involves traumatic tooth extraction, which would inevitably destroy the surrounding alveolar bone and cause unfavorable esthetics, especially for anterior teeth. Recently, implant placement through the impacted tooth or residual root has been proposed as an alternative to invasive extraction. A particular type of integration has been observed between dentin/cementum and titanium implant, while enamel-implant contact has not been reported. In this article, an implant was placed through the impacted maxillary central incisor, thereby avoiding an invasive extraction surgery. The buccal section of the tooth, including crown enamel, was retained in situ for buccal alveolar ridge preservation. The follow-up results were satisfactory, and a stable enamel-implant contact was observed. Combining with previous similar studies, this technique opens intriguing possibilities and brings fresh insight for the concept of dentointegration. More histological and clinical studies with long-term follow-up are warranted before endorsing this technique in routine application.

Effect of artificial landmarks of the prefabricated auxiliary devices located at different arch positions on the accuracy of complete-arch edentulous digital implant scanning: An in-vitro study.

OBJECTIVES: To examine the effect of artificial landmarks of prefabricated auxiliary devices (PAD) located at different arch positions on the accuracy of complete-arch edentulous digital implant scanning. METHODS: A reference model containing four analogs and PAD were fabricated by a 3D printer (AccuFab-C1s, 3DShining). 10 digital scans were performed using an intraoral scanner (Aoralscan 3, 3DShining), sv 1.0.0.3115, with artificial landmarks located at different arch positions: group I, without any artificial landmarks; group II, with artificial landmarks at the anterior region; group III, with artificial landmarks at the posterior region. group IV: with artificial landmarks at both anterior and posterior regions. For group V: Conventional open-tray splinted impressions. The reference file and conventional stone casts were digitalized by using a dental laboratory scanner. The related files were imported into inspection software for trueness and precision assessment. Statistical analysis was performed with One-way ANOVA and Kruskal-Wallis test. The level of significance was set at α=0.05. RESULTS: For the global accuracy assessment, significantly higher global trueness was seen in group II (p < 0.01), III (p < 0.001), IV (p < 0.001) and V (p < 0.001) than group I. Significantly higher global precision was seen in group III (p < 0.001), IV (p < 0.001) and V (p < 0.001) than group I. For the local accuracy assessment, the PAD primarily improved accuracy on the linear deviations. CONCLUSIONS: Artificial landmarks of PAD at different arch positions significantly influenced the scanning accuracy. Applying the PAD in group IV could achieve comparable outcomes to conventional open-tray splinted impressions. Artificial landmarks on the posterior region may be more pivotal than those on the anterior region. CLINICAL SIGNIFICANCE: Group IV could achieve comparable accuracy to conventional open-tray splinted impressions.

Effect of prefabricated auxiliary devices and scanning patterns on the accuracy of complete-arch implant digital impressions.

OBJECTIVES: This study aimed to evaluate the impact of prefabricated auxiliary devices (PAD) and scanning patterns on the accuracy of complete-arch implant digital impressions. METHODS: An edentulous maxillary model was inserted with four parallel implant analogs and four PAD. The model was scanned with D2000 dental laboratory scanner as the reference scans. Test scans were obtained by 8 different scanning patterns (SP), which including SPA, SPB, SPC, SPD, SPE, SPF, SPG and SPH, with (test group) or without (control group) using the PAD by an intraoral scanner (Aoralscan 3, 3DShining). SPA was the scanning pattern recommended by the manufacturer. Each scanning time was recorded. The related files were imported into inspection software for assessment. Aligned Ranks Transformation ANOVA, Kruskal-Wallis and Mann-Whitney tests were used to evaluate the values. The level of significance was set at α = 0.05. RESULTS: The scanning patterns significantly influenced the linear accuracy in the test group and the scanning time for both groups. Lower linear trueness in the test group was found in SPF (p<0.05) and SPG (p<0.05). Longer scanning time was found in SPB and SPG for both groups. The test group demonstrated linear accuracy enhancement in all the scanning patterns; angular trueness enhancement was seen in SPA (p<0.05), SPC (p<0.01) and SPH (p<0.01). Significant longer scanning time was found in SPB (p<0.05), SPF (p<0.05), SPG (p<0.05) and SPH (p<0.05) when using PAD. CONCLUSION: The scanning patterns impact the accuracy differently depending on the PAD's existence. The scanning time can be significantly influenced by the scanning patterns and the PAD. CLINICAL SIGNIFICANCE: In daily clinical practice, selecting a suitable scanning pattern is significant in achieving accurate digital impressions. The PAD demonstrated effective linear accuracy enhancement in all the scanning patterns tested.

Size-Dependent Effect of Titania Nanotubes on Endoplasmic Reticulum Stress to Re-establish Diabetic Macrophages Homeostasis.

In patients with diabetes, endoplasmic reticulum stress (ERS) is a crucial disrupting factor of macrophage homeostasis surrounding implants, which remains an obstacle to oral implantation success. Notably, the ERS might be modulated by the implant surface morphology. Titania nanotubes (TNTs) may enhance diabetic osseointegration. However, a consensus has not been achieved regarding the tube-size-dependent effect and the underlying mechanism of TNTs on diabetic macrophage ERS. We manufactured TNTs with small (30 nm) and large diameters (100 nm). Next, we assessed how the different titanium surfaces affected diabetic macrophages and regulated ERS and Ca2+ homeostasis. TNTs alleviated the inflammatory response, oxidative stress, and ERS in diabetic macrophages. Furthermore, TNT30 was superior to TNT100. Inhibiting ERS abolished the positive effect of TNT30. Mechanistically, topography-induced extracellular Ca2+ influx might mitigate excessive ERS in macrophages by alleviating ER Ca2+ depletion and IP3R activation. Furthermore, TNT30 attenuated the peri-implant inflammatory response and promoted osseointegration in diabetic rats. TNTs with small nanodiameters attenuated ERS and re-established diabetic macrophage hemostasis by inhibiting IP3R-induced ER Ca2+ depletion.