Bone volume and height changes for lateral window sinus floor elevation using two types of deproteinized bovine bone mineral: A retrospective cohort study of 1-4 years.

OBJECTIVE: To compare bone volume and height changes of two types of deproteinized bovine bone mineral (DBBM) for lateral window sinus floor elevation (LSFE) with simultaneous implant placement. MATERIALS AND METHODS: This retrospective cohort study involved 72 patients who underwent LSFE using low-temperature sintered cancellous bone-derived DBBM (C-DBBM) or high-temperature two-step sintered epiphyseal-derived DBBM (E-DBBM). Cone-beam computed tomography (CBCT) was acquired preoperatively, immediately postoperatively, 6 months and 1-4 years post-surgery. Bone volume (BV), apical bone height (ABH), endo-sinus bone gain (ESBG), and crestal bone level (CBL) were evaluated through three-dimensional fitting and superimposition. Linear mixed models (LMM) were employed to analyze factors influencing the reduction of BV (ΔBV) and ESBG (ΔESBG). RESULTS: The E-DBBM group showed no significant change in BV 1-4 years post-surgery, while the C-DBBM group demonstrated a significant reduction (p = .006) with volume stability of 85.86%. Bone height in the E-DBBM group increased at 6 months and subsequently decreased at 1-4 years (p = .003). In the C-DBBM group, it decreased at 6 months (p = .014), then further decreased at 1-4 years (p = .001). ΔESBG was lower in the E-DBBM group than the C-DBBM group from immediate postoperative to 1-4 years (p = .009). LMM showed graft material type was the primary factor influencing ΔBV (p = .026) and ΔESBG (p = .003). CONCLUSIONS: Within the limitations of this study, both types of DBBM could achieve favorable clinical outcomes. E-DBBM demonstrated enhanced stability in maintaining bone volume and height.

Clinical efficacy of a two-piece abutment conforming to the concept of one abutment one time in the posterior region: A clinical pilot study.

OBJECTIVES: To assess the impact of a two-piece abutment workflow on enhancing the stability of the alveolar bone and gingiva surrounding the dental implant, and to determine the level of patient satisfaction. MATERIALS AND METHODS: A total of 48 patients with dentition defect in the posterior region were included and divided into two groups: the two-piece abutment workflow (TAW) and the sealing screw with submerged healing workflow (SHW). Marginal bone level (MBL), soft tissue indicators, oral hygiene indicators, and patient satisfaction were assessed and recorded partially at 0, 3, 6, and 12 months after surgery. The primary outcome was the change of MBL in different time periods. A generalized linear mixed model (GLMM) was used to take into account the correlated nature of the data, and adjust for potential confounding factors within inter-group differences. RESULTS: The survival rate of implants and prosthesis reached 100% at 12-month follow-up, with an average decrease of 0.25 mm (SD 0.23 mm) of MBL in the TAW group and 0.48 mm (SD 0.45 mm) in the SHW group. The change of MBL in the TAW group (0.15 ± 0.31 mm) was significantly lower than the SHW group (0.41 ± 0.41 mm) through the analysis of GLMM within 6 months, while no significance was found in 12 months. Moreover, less gingival pain and oppression during prosthesis loading, and less time consumption overall duration were showed in the TAW group through Visual Analogue Scale (VAS, p < 0.05). CONCLUSIONS: Within a 6-month period, the two-piece abutment workflow showed superior efficacy in preserving the integrity of the marginal bone level. Furthermore, it streamlined treatment procedures and mitigated discomfort, hence increasing patient satisfaction.

Outcome of nonsurgical management of large cyst-like periapical lesions using a modified apical negative pressure irrigation system: a case series study.

OBJECTIVE: To assess the effectiveness of a self-constructed modified apical negative pressure irrigation (ANPI) system employing commonly used clinical instruments in nonsurgical root canal therapy (NSRCT) for large cyst-like periapical lesions (LCPLs). METHODS: From 2017 to 2022, 35 patients diagnosed with LCPLs (5-15 mm) via preoperative clinical and radiographic evaluations of endodontic origin underwent NSRCT combined with ANPI. These patients were subjected to postoperative clinical and radiographic follow-up at 3 months, 6 months, 1 year, 2 years, 3 years, and 4 years, with a CBCT scan specifically conducted at 6-month follow-up. Through the reconstruction of three-dimensional cone beam computed tomography (CBCT) data, an early prognosis was facilitated by monitoring changes in lesion volume. Various treatment predictors-including sex, type of treatment, lesion size, preoperative pain, jaw, type of teeth involved, sealer extrusion, and the number of root canals-were meticulously analyzed. The evaluation of post-treatment outcomes leveraged both clinical observations and radiographic data collected during the follow-up periods. The Kruskal‒Wallis test and one-way ANOVA were also conducted to determine the independent factors influencing treatment outcomes. A significance level of 5% was established. RESULTS: Thirty-five teeth from 35 patients with a median age of 28 years (range 24-34) were treated; the median follow-up duration was 19 months (range 12-26). The overall success rate was 91.4%, with a median lesion reduction of 77.0% (range 54.2-96.4%) at 6 months. Patients under 30 years of age exhibited a significantly greater success rate than older patients did (100.0% vs. 80.0%, p = 0.037). Other factors, such as sex, jaw, treatment type, preoperative pain, cyst size, tooth location, sealer extrusion, and the number of roots, did not significantly impact treatment outcomes. CONCLUSIONS: Despite limitations related to the observational case-series study design and relatively small sample size, our findings suggest that utilizing the ANPI in the NSRCT for LCPLs may hold promise. The notably higher success rate in patients younger than 30 years is worth noting.

Clinical outcomes and risk factor analysis of dental implants inserted with lateral maxillary sinus floor augmentation: A 3- to 8-year retrospective study.

AIM: To evaluate the 3- to 8-year outcomes of dental implants placed with lateral sinus floor augmentation (LSFA) and to identify factors affecting implant survival. MATERIALS AND METHODS: This retrospective study was performed by screening all implants placed with LSFA procedures, which were conducted between January 2012 and December 2016. Subantral bone gain (SABG) and apical bone height (ABH) were assessed using panoramic radiographs. The cumulative survival rate of implants was analysed using life-table analysis and Kaplan-Meier survival curves. The influential risk factors affecting survival were assessed using univariate log-rank tests and multivariable mixture cure rate model. Implant complications were recorded. RESULTS: Based on the established criteria, a total of 449 patients (760 implants) were included in this study. In the 3- to 8-year follow-up (mean ± SD, 5.81 ± 1.33 years), 15 implants in 14 patients failed, with a CRS of 96.81% on an implant basis and 95.07% on a patient basis. A history of periodontitis and poor compliance with supportive periodontal treatment was associated with a significantly higher risk of implant failure at both implant and patient levels. Significant decreases in ABH occurred during each yearly interval except for 3 years. A similar trend has been observed for SABG at 1, 2, 6 and 8 years. The total complication rate was 31.84% on implant basis, with peri-implant mucositis (21.58%) being the most frequent biologic complication and porcelain cracking (5.00%) being the most common technical complication. CONCLUSIONS: Implant with LSFA is a reliable treatment option in atrophic maxilla. A history of periodontitis without regular supportive periodontal treatment was identified as a predictor for implant failure. Slight but significant shrinkage of vertically augmented bone can be observed after implant placement.

Mesenchymal stem cells and dental implant osseointegration during aging: from mechanisms to therapy.

Dental implants are widely used to replace missing teeth, providing patients with unparalleled levels of effectiveness, convenience, and affordability. The biological basis for the clinical success of dental implants is osseointegration. Bone aging is a high-risk factor for the reduced osseointegration and survival rates of dental implants. In aged individuals, mesenchymal stem cells (MSCs) in the bone marrow show imbalanced differentiation with a reduction in osteogenesis and an increase in adipogenesis. This leads to impaired osseointegration and implant failure. This review focuses on the molecular mechanisms underlying the dysfunctional differentiation of aged MSCs, which primarily include autophagy, transcription factors, extracellular vesicle secretion, signaling pathways, epigenetic modifications, microRNAs, and oxidative stress. Furthermore, this review addresses the pathological changes in MSCs that affect osseointegration and discusses potential therapeutic interventions to enhance osseointegration by manipulating the mechanisms underlying MSC aging.

Titanium surface interacting with blood clot enhanced migration and osteogenic differentiation of bone marrow mesenchymal stem cells.

Introduction: Blood clot formation is the initial phase upon implantation, and the feature of blood clot orchestrates the following complement system activation, coagulation cascade, and bone marrow mesenchymal stromal cells (BMSCs) recruitment. This study aimed to investigate the effect of implant surface on blood-material interactions and subsequent BMSC cellular behaviors. Methods: This study was established to imitate the physiological process of implantation in vivo and in vitro. Whole blood was incubated with polished titanium (PT) surfaces and sandblasted and double acid-etching (SLA) surfaces for 10 min or 2 h, then seeded with BMSCs. The adhesion, proliferation, migration, and differentiation of cells were studied at specific time points. Titanium implants were implanted into the tibia in vivo and were screwed out after implantation. The activation of the coagulation cascade, platelets, complement system, and clot networks were assessed and further quantitatively analyzed. Results: Compared with the PT surface, the SLA surface induced the earlier and stronger blood coagulation cascade and formed a more stratified clots network with fibrinogen, platelets, and CD14 positive cell. The adhesion, proliferation, and migration of BMSCs were enhanced by pre-incubated surfaces. The higher levels of the osteogenic-related genes, ALP activity, and calcium nodule formation were showed on SLA surfaces with blood incubation. Conclusion: SLA titanium surfaces play a role in influencing the formation of blood clots and coordinating surface-blood interactions and cell biological processes. These findings provide the idea of modifying the blood clots formed on the implant surface by biomaterials modification and thus has implications for the development of better osteogenic biomaterials.

Clinical and patient-centered outcomes following rehabilitation of atrophic edentulous maxilla using six implants placed simultaneously with bilateral maxillary sinus augmentation: A retrospective case series.

OBJECTIVES: To evaluate treatment success, patient satisfaction, and oral health-related quality of life (OHRQoL) after rehabilitation of atrophic edentulous maxilla (AEM) with six implants placed simultaneously with bilateral maxillary sinus floor augmentation (MSFA). MATERIALS AND METHODS: The selected patients were fully edentulous with atrophic maxillary posterior residual ridges and rehabilitated with six implants placed simultaneously with bilateral MSFA and immediate All-on-4 provisional fixed prosthesis (PFP). After 7-12 months of implant surgery, all patients have received an All-on-6 definitive fixed prosthesis (DFP). After at least one year of function with DFP, clinical and radiographic examinations were performed. Patient satisfaction was assessed through a visual analog scale (VAS). The OHRQoL before treatment (T0), during provisional (T1), and after definitive prosthesis (T2) was evaluated using OHI-14. RESULTS: 20 maxillary edentulous patients were rehabilitated with 120 implants, 20 immediate All-on-4 PFP, and 20 All-on-6 DFP. Of those, 12 patients have passed at least a year follow-up after DFP insertion and were eligible to be included in the assessment of treatment success. After a mean of 20 (12-36) months follow-up, the implant and prosthesis survival rates were 100%. The success rate at the implant level was 98.6%. The mean marginal bone loss (MBL) was 0.09 ± 0.06 mm. No prosthetic or postoperative complications, and the mean general satisfaction was (91.75 ± 7.06). There was a significant improvement in all OHIP-14 domains during the final All-on-6 prosthesis (T2) (P < 0.01). CONCLUSIONS: Rehabilitation of atrophic edentulous maxilla using six implants with simultaneous bilateral MSFA and immediate All-on-4 PFP is a successful treatment approach associated with minimal postoperative complications and significant improvement in OHRQoL.

Strontium-modified titanium substrate promotes osteogenic differentiation of MSCs and implant osseointegration via upregulating CDH2.

OBJECTIVES: Our previous studies showed that strontium (Sr)-modified sand-blasted, large grit, acid etched titanium surface (Sr-SLA) is beneficial for osseointegration; however, the supporting mechanisms have not been explored in detail. MATERIALS AND METHODS: Whole-transcriptome RNA sequencing of peri-implant bone tissue was performed, and CDH2 was selected as a key mediator of Sr-SLA-mediated osseointegration. To test this hypothesis, a lentivirus-mediated vector targeting the silencing of the CDH2 gene was used in mesenchymal stem cells (MSCs) prior to seeding on Ti substrates. The effects of CDH2 interference on MSCs vitality, differentiation, and ß-catenin signaling activity were evaluated. In vivo, a recombinant adeno-associated virus 9 vector carrying an artificial siRNA that target CDH2 (AAV9-CDH2i) was intravenously injected in mice, followed by tibial surgery with implant placement. Osseointegration were monitored using micro-CT analysis. RESULTS: CDH2 expression in MSCs on Sr-SLA was higher than the control group, which was in parallel with the enhanced cell migration, adhesion, and upregulation of early osteogenic markers. Knocking down CDH2 in MSCs resulted in decreased cell viability and osteogenic differentiation, and the elevated biocompatibility and osteoinductive effect of Sr-SLA were greatly diminished. Surprisingly, Sr-SLA-induced upregulation of CDH2 was not followed by restriction of ß-catenin signaling because Sr-SLA also promoted the expression and nuclear translocation of ß-catenin. Systemic administration of AAV9-CDH2i effectively knocked down CDH2 expression in bone marrow cells, and in turn, inhibited bone formation induced by Sr-SLA. CONCLUSIONS: The results indicated that CDH2 is required for Sr-SLA-mediated bone regeneration, which reveals a new mechanism to explain the osteoinductive effect of Sr-SLA. Thus, biomaterial modifications targeting CDH2 may help improve early osseointegration and bone healing.

Marginal bone loss of tissue- or bone-level implants after simultaneous guided bone regeneration in the posterior mandibular region: A retrospective cohort study.

PURPOSE: To analyze the marginal bone loss (ΔMBL) of tissue- or bone-level implants after placed with simultaneous guided bone regeneration (GBR). MATERIALS AND METHODS: A total of 151 patients who received 104 tissue-level or 128 bone-level implants placement with simultaneous GBR in the mandibular posterior region between January 2011 and December 2016 were included in this study. The marginal bone level (MBL) was recorded using the radiographic data obtained at implant placement, second-stage surgery, and the follow-up visit. Generalized estimating equation (GEE) was used to compare the ΔMBL of tissue- and bone-level implants, and the influencing factors of ΔMBL were further analyzed. RESULTS: At the last follow-up visit, the MBL of tissue-level implants was 0.73 ± 0.86 mm, above the rough-smooth interface, while that of bone-level implants was 0.82 ± 1.05 mm, above the implant platform. The ΔMBL of tissue-level implants was 1.03 mm, which was slightly higher than 0.81 mm of bone-level implants, but there was no significant difference (p > 0.05). No contributing factor associated with ΔMBL was identified by multivariate regression analysis in this study. CONCLUSION: Within the limits of this retrospective analysis, the ΔMBL of tissue-level implants is similar to that of bone-level implants after placed with simultaneous GBR, and both types of implants can achieve desirable marginal bone stability.

Remodeling of the osteoimmune microenvironment after biomaterials implantation in murine tibia: Single-cell transcriptome analysis.

Osseointegration seems to be a foreign body reaction equilibrium due to the complicated interactions between the immune and skeletal systems. The heterogeneity of the osteoimmune microenvironment in the osseointegration of implant materials remains elusive. Here, a single-cell study involving 40043 cells is conducted, and a total of 10 distinct cell clusters are identified from five different groups. A preliminary description of the osteoimmune microenvironment revealed the diverse cellular heterogeneity and dynamic changes modulated by implant properties. The increased immature neutrophils, Ly6C + CCR2hi monocytes, and S100a8hi macrophages induce an aggressive inflammatory response and eventually lead to the formation of fibrous capsule around the stainless steel implant. The enrichment of mature neutrophils, FcgR1hi and differentiated immunomodulatory macrophages around the titanium implant indicates favorable osseointegration under moderate immune response. Neutrophil-depletion mice are conducted to explore the role of neutrophils in osseointegration. Neutrophils may improve bone formation by enhancing the recruitment of BMSCs via the CXCL12/CXCR3 signal axis. These findings contribute to a better knowledge of osteoimmunology and are valuable for the design and modification of 'osteoimmune-smart' biomaterials in the bone regeneration field.

The role of dendritic cells in the immunomodulation to implanted biomaterials.

Considering the substantial role played by dendritic cells (DCs) in the immune system to bridge innate and adaptive immunity, studies on DC-mediated immunity toward biomaterials principally center on their adjuvant effects in facilitating the adaptive immunity of codelivered antigens. However, the effect of the intrinsic properties of biomaterials on dendritic cells has not been clarified. Recently, researchers have begun to investigate and found that biomaterials that are nonadjuvant could also regulate the immune function of DCs and thus affect subsequent tissue regeneration. In the case of proteins adsorbed onto biomaterial surfaces, their intrinsic properties can direct their orientation and conformation, forming "biomaterial-associated molecular patterns (BAMPs)". Thus, in this review, we focused on the intrinsic physiochemical properties of biomaterials in the absence of antigens that affect DC immune function and summarized the underlying signaling pathways. Moreover, we preliminarily clarified the specific composition of BAMPs and the interplay between some key molecules and DCs, such as heat shock proteins (HSPs) and high mobility group box 1 (HMGB1). This review provides a new direction for future biomaterial design, through which modulation of host immune responses is applicable to tissue engineering and immunotherapy.

Bioinformatics analysis of LMAN1 expression, clinical characteristics, and its effects on cell proliferation and invasion in glioma.

Glioma is the most common primary central nervous system malignant tumor with high heterogeneity and poor prognosis. So far, the complex pathological process of glioma has not been fully elucidated, and there is a lack of effective biomarkers for the diagnosis and molecular targeted therapy of glioma. Using bioinformatics methods, 77 upregulated and 89 downregulated differentially expressed genes (DEGs) were detected by intersection analysis in different gene expression datasets of glioma cases from public databases. Then, GO and KEGG pathway analysis revealed that the biological functions of these upregulated DEGs were mainly focused on immune response, and the signaling pathways were mainly enriched in integrin family cell surface interactions. The overexpression of the LMAN1 gene of interest was then confirmed using the TCGA dataset and further verified by qRT-PCR in 29 clinical samples and 5 glioma cell lines. Furthermore, high expression of LMAN1 was found to be associated with higher WHO grade, IDH status, and 1p/19q co-deletion. Survival analysis showed that high expression of LMAN1 was associated with poor prognosis in glioma. Gene set enrichment analysis (GSEA) indicated that many cancer-related pathways were associated with LMAN1-high phenotype. Protein-protein interaction (PPI) analysis revealed significant interaction between LMAN1 and MCFD2, F8, and TMED10. Finally, cell experiments showed that LMAN1 knockdown significantly inhibited the proliferation, migration and invasion and promoted apoptosis in glioma cells. This study highlighted the malignant role of LMAN1 in gliomas and provided a potentially valuable biomarker for prognosis evaluation and molecular targeted therapy of glioma.

Improved osseointegration of strontium-modified titanium implants by regulating angiogenesis and macrophage polarization.

Strontium (Sr) has shown strong osteogenic potential and thereby been widely incorporated into dental and orthopedic implants. However, the improved osseointegration of strontium-modified titanium implants through regulation of angiogenesis and macrophage polarization is still beginning to be explored. Here, we demonstrated that the angiogenic capacity of human umbilical vein endothelial cells on the Sr-incorporated micro/nano titanium (SLA-Sr) surface was also significantly improved through the up-regulated expression of the HIF-1α protein and Erk1/2 phosphorylation. Meanwhile, SLA-Sr not only switched macrophage polarization towards the M2 phenotype, but also expressed a high level of pro-angiogenic platelet-derived growth factor. Furthermore, macrophage secretion induced by SLA-Sr was also capable of enhancing angiogenesis of human umbilical vein endothelial cells. In vivo experimental results also showed early vascularized implant osseointegration of SLA-Sr with the type H vessel formation around the SLA-Sr implant. This study emphasized the synergistic role of Sr in the regulation of macrophage polarization and angiogenesis, and therefore depicted the therapeutic potential of SLA-Sr for rapidly vascularized osseointegration.

Matrine Exerts Pharmacological Effects Through Multiple Signaling Pathways: A Comprehensive Review.

As The main effective monomer of the traditional Chinese medicine Sophora flavescens Ait, matrine has a broad scope of pharmacological activities such as anti-tumor, anti-inflammatory, analgesic, anti-fibrotic, anti-viral, anti-arrhythmia, and improving immune function. These actions explain its therapeutic effects in various types of tumors, cardiopathy, encephalomyelitis, allergic asthma, rheumatoid arthritis (RA), osteoporosis, and central nervous system (CNS) inflammation. Evidence has shown that the mechanism responsible for the pharmacological actions of matrine may be via the activation or inhibition of certain key molecules in several cellular signaling pathways including the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR), transforming growth factor-ß/mothers against decapentaplegic homolog (TGF-ß/Smad), nuclear factor kappa B (NF-κB), Wnt (wingless/ integration 1)/ß-catenin, mitogen-activated protein kinases (MAPKs), and Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways. This review comprehensively summarizes recent studies on the pharmacological mechanisms of matrine to provide a theoretical basis for molecular targeted therapies and further development and utilization of matrine.

The Effect of Initial Biologic Width on Marginal Bone Loss: A Retrospective Study.

PURPOSE: To evaluate the short-term effect of dental implant placement, mucosa thickness, and their combined effects (initial biologic width) on marginal bone loss. MATERIALS AND METHODS: This was a retrospective study on patients who received implant surgery in the posterior region without bone augmentation surgery between 2012 and 2016, and implants had been loaded for more than 12 months. Each patient received radiographic examination before and after implant surgery, before the stage-two surgery, and during the 1- to 5-year follow-up. The thickness of mucosa, depth of dental implant placement, and crestal bone loss were evaluated on digital radiographs. The interaction was discussed by defining the combination of initial mucosal thickness and implantation depth as the initial biologic width. The implants were divided into four study groups based on the quartile of the initial biologic width. RESULTS: This study included 266 patients (94 male and 172 female, 22 to 85 years of age, mean age: 51.43 years), with 413 dental implants placed including 239 Straumann implants and 174 Ankylos implants. The average follow-up was 21.50 months. After 1 to 5 years, the median crestal bone loss around implants was 0.35 mm (0.30 mm for Straumann BL and 0.40 mm for Ankylos). The implants were divided into four groups: group A (≤ 2.85 mm), group B (2.85 to 3.40 mm), group C (3.40 to 3.97 mm), and group D (> 3.97 mm). Group B showed significantly less crestal bone loss than group A (0.38 mm vs 0.25 mm; P < .05) and group C (0.25 mm vs 0.40 mm; P < .05) during the follow-up. Significantly more crestal bone loss around implants was observed in the thin mucosa group than in the thick mucosa group (0.50 mm vs 0.30 mm; P < .001), while implants placed beneath the bone level displayed a significantly higher amount of marginal bone loss than implants placed even with the bone crest (0.50 mm vs 0.10 mm; P < .001). CONCLUSION: The initial biologic width has an effect on crestal bone loss. When the initial biologic width was between 2.85 and 3.40 mm, the marginal bone loss was lowest. Based on radiographic evaluation, implants placed in thick gingiva and even with the bone level showed less alveolar marginal bone loss compared with implants placed in thin gingiva and below the crestal bone level.

Peri-implant marginal bone changes with implant-supported metal-ceramic or monolithic zirconia single crowns: A retrospective clinical study of 1 to 5 years.

STATEMENT OF PROBLEM: Monolithic zirconia has excellent mechanical and biologic properties. However, evidence of the clinical properties of implant-supported monolithic zirconia prostheses is limited. PURPOSE: The purpose of this retrospective clinical study was to compare the peri-implant marginal bone changes of metal-ceramic and monolithic zirconia single crowns in the posterior region after prosthetic loading. MATERIAL AND METHODS: A total of 224 participants treated with 327 implants restored with either metal-ceramic or monolithic zirconia single crowns in the posterior region between 2012 and 2016 were included in this study. Clinical outcomes, including the plaque index, peri-implant probing depth, and bleeding on probing, were recorded, and the marginal bone level was recorded by using the panoramic radiographs obtained at implant placement, second-stage surgery, and the most recent follow-up visit. The included parameters were analyzed with the nonparametric Mann-Whitney tests (α=.05). RESULTS: The mean follow-up time was 30.4 months, and the cumulative survival rate of implants was 100% and that of the prostheses was 99.1%. The plaque index was 0.46 in the metal-ceramic group, which was significantly higher (P<.05) than 0.37 in the monolithic zirconia group. However, no significant differences (P>.05) were observed in peri-implant probing depth and bleeding on probing between the 2 groups. The marginal bone level at implant placement, second-stage surgery, and the most recent follow-up visit was above the implant platform in both the metal-ceramic and monolithic zirconia groups. The marginal bone changes of the metal-ceramic group was 0.31 mm in the healing period and 0.38 mm in the prosthetic loading period, while in the monolithic zirconia group, it was 0.25 mm in the healing period and 0.43 mm in the prosthetic loading period; no significant differences (P>.05) were observed between the 2 groups. CONCLUSIONS: The peri-implant marginal bone level change was comparable after prosthetic loading for metal-ceramic and monolithic zirconia single crowns, although monolithic zirconia was associated with reduced plaque.

Microbial profiles of peri-implant mucositis and peri-implantitis: Submucosal microbial dysbiosis correlates with disease severity.

OBJECTIVE: To investigate the microbiome characteristics of peri-implant mucositis (PM) and peri-implantitis (PI), and to analyse the correlation between disease severity and submucosal microbial dysbiosis. MATERIALS AND METHODS: A cross-sectional study design was conducted. Submucosal biofilm samples from 27 PM sites and 37 PI sites from 64 patients were collected and analysed using 16S rRNA gene sequencing (Illumina). Differences in microbiological profiles between PM and PI were evaluated using the α-diversity, ß-diversity and linear discriminant analysis effect size (LEfSe) analysis. The relative abundances of the taxa at the phylum and genus levels were compared using the Wilcoxon rank test and logistic regression. The microbial dysbiosis index (MDI) was calculated, and its relationship with clinical measurements (probing depth, bleeding on probing and marginal bone loss, among others) was analysed using Pearson's correlation coefficient. RESULTS: The overall microbiome distribution in the PM and PI sites was similar according to α- and ß-diversity. Twenty-three taxa at the genus level and two taxa at the phylum level showed significant differences in relative abundance between the two clinical classifications. Five taxa at the genus level were screened out for the MDI calculation after logistic regression. No clinical measurements but marginal bone loss showed a significant positive correlation with microbial dysbiosis. CONCLUSION: The microbiome richness, diversity and distribution were similar in PM and PI sites, including both common periodontal bacteria and novel species. In addition, an increase in marginal bone loss was significantly associated with submucosal microbial dysbiosis.

Retrospective Study of Short Versus Standard Posterior Implants and Analysis of Implant Failure Risk Factors.

PURPOSE: To compare the clinical and radiographic outcomes of short implants (≤ 8 mm) vs standard implants (> 8 mm, < 10 mm) and to uncover risk factors influencing implant failure in short implants. MATERIALS AND METHODS: Short and standard implants were compared in the aspect of survival rates, biologic and mechanical complications, and marginal bone loss. To analyze risk factors of implant failure in short implants, several variables were taken into consideration, including sex, age, time interval, arch, implant brand, additional surgery, prosthesis material, restoration, smoking status, and crown-root ratio. RESULTS: Three hundred twenty-one short implants and 136 standard implants were retrospectively followed up from 12 to 104 months with an average of 40 months (3.33 years) in short implants and 34 months (2.83 years) in standard implants. The survival rates of short implants were 95.6% at the implant-based analysis and 94.9% at the patient-based analysis, and rates of 96.3% and 94.0%, respectively, were calculated for standard implants. No statistically significant differences were observed between short and standard implants with respect to survival rate, complications, or marginal bone loss. The failure rates were 4.2% for implants and 5.4% for patients in total implants with an average of 38 months (3.17 years). In analyzing risk factors of short implants for survival rate, single short implants resulted in a higher failure rate compared with splinted short implants, while no significant variable was found in standard implants. CONCLUSION: Short implants tend to be a reliable alternative in atrophic posterior regions. Splinted prostheses were more ideal for short implant restorations.

Evaluation of the antibacterial effects and mechanism of Plantaricin 149 from Lactobacillus plantarum NRIC 149 on the peri-implantitis pathogens.

Peri-implantitis is a common reversible disease after tooth implantation, caused by a variety of pathogenic microorganisms. Based on non-surgical or surgical treatment principles, supplementation by local or systemic drugs might enhance treatment efficacy. Porphyromonas gingivalis (Pg) (ATCC 33,277) and Prevotella intermedius (Pi) (ATCC 25,611) were used as test strains. The effects of Pln 149 on the biofilm formation and growth of four periodontal pathogens were evaluated by RT-PCR, fluorescence microscopy, and scanning electron microscopy. The antibacterial mechanism was tested by the patch-clamp technique. The cytotoxicity of Pln 149 (125 µg/ml) to bone marrow stromal cell (BMSC) was assessed using an MTT assay. Pln 149 exhibited significant inhibitory effects on Pg and Pi (P < 0.05), with significant differences in the biofilm images of fluorescence microscope and scanning electron microscope (P < 0.05). Pln 149 could change the sodium channel currents and exerted no cytotoxicity on bone marrow stromal cell. Pln 149 could inhibit the biofilm formation and growth of periodontal pathogens. Considering the absence of antimicrobial resistance and cytotoxicity, we suggest that the Pln 149 from Lactobacillus plantarum 149 might be a promising option for managing peri-implantitis.

Effects of strontium-incorporated micro/nano rough titanium surfaces on osseointegration via modulating polarization of macrophages.

Macrophages perform multiple functions in both inflammation and wound healing, and are one of the fore front cells during implant osseointegration that influence subsequent process. Essential trace element modification may effectively modulate titanium implant surface biological properties. In this work, strontium (Sr) incorporated micro/nano rough titanium surfaces (Sr-SLA) was fabricated by hydrothermal treatment, and immunoreaction of macrophages was further investigated. In vitro results revealed that Sr doping inhibited inflammatory response of macrophages, further attenuated the inhibitory effect on following bone marrow derived cells (BMSCs) osteogenic differentiation. The regulation of macrophages by Sr-SLA likely involved ERK signaling pathway. Consistently, the in vivo study showed that compared with titanium surface sand-blasted with large grit and double acid-etched (SLA) implants, Sr-SLA implants could enhance new bone formation accompanied with more alternatively activated M2 macrophages infiltration and less classically activated M1 macrophages infiltration. These results reveal the immunomodulatory ability of Sr-SLA of adjusting the functional status of macrophages through inhibiting M1 polarization while promoting M2 polarization.