Alveolar Bone Research Articles

Multimodal inhibitory effect of matcha on Porphyromonas gingivalis.

Periodontitis, a multifactorial inflammatory disease of the oral cavity, results in alveolar bone destruction, and is a major cause of tooth loss of humans. In addition, emerging evidence has demonstrated associations between periodontitis and a wide range of other chronic inflammation-driven disorders, including diabetes mellitus, preterm birth, cardiovascular disease, aspiration pneumonia, rheumatoid arthritis, cognitive disorder, and cancer. In the present study, we report that matcha, a product of Camellia sinensis, hampers Porphyromonas gingivalis, a major periodontal pathobiont, in not only a series of in vitro experiments but also a pilot intervention clinical trial of patients with periodontitis, in which matcha mouthwash statistically significantly reduced the P. gingivalis number in saliva, as compared to the pre-intervention level. Taken together, we suggest that matcha may have clinical applicability for prevention and treatment of periodontitis.

Sulfated Chitosan-Modified CuS Nanocluster: A Versatile Nanoformulation for Simultaneous Antibacterial and Bone Regenerative Therapy in Periodontitis.

Periodontitis, a prevalent chronic inflammatory disease worldwide, is triggered by periodontopathogenic bacteria, resulting in the progressive destruction of periodontal tissue, particularly the alveolar bone. To effectively address periodontitis, this study proposed a nanoformulation known as CuS@MSN-SCS. This formulation involves coating citrate-grafted copper sulfide (CuS) nanoparticles with mesoporous silica (MSNs), followed by surface modification using amino groups and sulfated chitosan (SCS) through electrostatic interactions. The objective of this formulation is to achieve efficient bacteria removal by inducing ROS signaling pathways mediated by Cu2+ ions. Additionally, it aims to promote alveolar bone regeneration through Cu2+-induced pro-angiogenesis and SCS-mediated bone regeneration. As anticipated, by regulating the surface charges, the negatively charged CuS nanoparticles capped with sodium citrate were successfully coated with MSNs, and the subsequent introduction of amine groups using (3-aminopropyl)triethoxysilane was followed by the incorporation of SCS through electrostatic interactions, resulting in the formation of CuS@MSN-SCS. The developed nanoformulation was verified to not only significantly exacerbate the oxidative stress of Fusobacterium nucleatum, thereby suppressing bacteria growth and biofilm formation in vitro, but also effectively alleviate the inflammatory response and promote alveolar bone regeneration without evident biotoxicity in an in vivo rat periodontitis model. These findings contribute to the therapeutic effect on periodontitis. Overall, this study successfully developed a nanoformulation for combating bacteria and facilitating alveolar bone regeneration, demonstrating the promising potential for clinical treatment of periodontitis.

NOD2 contributes to Parvimonas micra-induced bone resorption in diabetic rats with experimental periodontitis.

Type 2 diabetes mellitus (T2DM) may affect the oral microbial community, exacerbating periodontal inflammation; however, its pathogenic mechanisms remain unclear. As nucleotide-binding oligomerization domain 2 (NOD2) plays a crucial role in the activation during periodontitis (PD), it is hypothesized that changes in the oral microbial community due to diabetes enhance periodontal inflammation through the activation of NOD2. We collected subgingival plaque from 180 subjects who were categorized into two groups based on the presence or absence of T2DM. The composition of oral microbiota was detected by 16S rRNA high-throughput sequencing. In animal models of PD with or without T2DM, we assessed alveolar bone resorption by micro-computerized tomography and used immunohistochemistry to detect NOD2 expression in alveolar bone. Primary osteoblasts were cultured in osteogenic induction medium with high or normal glucose and treated with inactivated bacteria. After 24h of inactivated bacteria intervention, the osteogenic differentiation ability was detected by alkaline phosphatase (ALP) staining, and the expressions of NOD2 and interleukin-12 (IL-6) were detected by western blot. The relative abundance of Parvimonas and Filifactor in the T2DM group was increased compared to the group without T2DM. In animal models, alveolar bone mass was decreased in PD, particularly in T2DM with PD (DMPD) group, compared to controls. Immunohistochemistry revealed NOD2 in osteoblasts from the alveolar bone in both the PD group and DMPD group, especially in the DMPD group. In vitro, intervention with inactivated Parvimonas significantly reduced ALP secretion of primary osteoblasts in high glucose medium, accompanied by increased expression of NOD2 and IL-6. The results suggest that T2DM leading to PD may be associated with the activation of NOD2 by Parvimonas.

Multifunctional Nanofibrous Hollow Microspheres for Enhanced Periodontal Bone Regeneration.

Destructive periodontitis destroys alveolar bone and eventually leads to tooth loss. While guided bone regeneration, which is based on creating a physical barrier to hinder the infiltration of epithelial and connective tissues into defect sites, has been widely used for alveolar bone regeneration, its outcomes remain variable. In this work, a multifunctional nanofibrous hollow microsphere (NFHMS) is developed for enhanced alveolar bone regeneration. The NFHMS is first prepared via combining a double emulsification and a thermally induced phase separation process. Next, E7, a short peptide with high specific affinity to bone marrow-derived stem cells (BMSCs), is conjugated onto the surface of NFHMS. After that, bone forming peptide (BFP), a short peptide derived from bone morphology protein 7 isloaded in calcium phosphate (CaP) nanoparticles, which are further encapsulated in the hollow space of the NFHMS-E7 to form NFHMS-E7-CaP/BFP. The NFHMS-E7-CaP/BFP selectively promoted the adhesion of BMSCs and expelled the adhesion of fibroblasts and epithelial cells. In addition, the BFP is sustainedly released from the NFHMS-E7-CaP/BFP to enhance the osteogenesis of BMSCs. A rat challenging fenestration defect model showed that the NFHMS-E7-CaP/BFP significantly enhanced alveolar bone tissue regeneration. This work provides a novel bioengineering approach for guided bone regeneration.

Vertical and transverse treatment effects of Invisalign First system compared to Hyrax maxillary expanders with fixed appliances in mixed dentition patients

ABSTRACT Objectives To compare vertical and transverse changes in mixed dentition patients treated with the Invisalign First System (IFS) to those treated with a banded hyrax expander with fixed appliances (Hyrax) and control groups, and to assess the efficiency rate of dental arch expansion with IFS. Materials and Methods The study included 80 mixed dentition patients, with 40 in each group (IFS and Hyrax) and 40 controls from the American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection. Skeletal and dental vertical dimension changes and arch width changes between pretreatment (T1) and posttreatment (T2) were evaluated. Results Age at T1, time interval (T1-T2), sex, and Angle class did not significantly differ among the groups. Mandibular plane angle changes showed a similar reduction for the control and IFS groups, with no changes in the Hyrax group. However, the differences among the three groups did not reach statistical significance (P = .06). The Hyrax group showed significantly greater expansion in maxillary intermolar width compared to the IFS group, 4.4 vs 2.5 mm, respectively. The efficiency of maxillary expansion using IFS ranged from 52.3% to 76.87%. Conclusions During the mixed dentition stage, no significant changes occurred in vertical dimensions among the control, Hyrax, and IFS groups. Although there was a trend suggesting a greater reduction in mandibular plane angle in the IFS group compared to the Hyrax group, this may not be clinically significant given the less than 1° difference. IFS can be a viable option for addressing mild arch width deficiencies, with a predictable increase in intermolar width of approximately 2.5 mm.

Early infiltrating NKT lymphocytes attenuate bone regeneration through secretion of CXCL2.

Trauma rapidly mobilizes the immune response of surrounding tissues and activates regeneration program. Manipulating immune response to promote tissue regeneration shows a broad application prospect. However, the understanding of bone healing dynamics at cellular level remains limited. Here, we characterize the landscape of immune cells after alveolar bone injury and reveal a pivotal role of infiltrating natural killer T (NKT) cells. We observe a rapid increase in NKT cells after injury, which inhibit osteogenic differentiation of mesenchymal stem cells (MSCs) and impair alveolar bone healing. Cxcl2 is up-regulated in NKT cells after injury. Systemic administration of CXCL2-neutralizing antibody or genetic deletion of Cxcl2 improves the bone healing process. In addition, we fabricate a gelatin-based porous hydrogel to deliver NK1.1 depletion antibody, which successfully promotes alveolar bone healing. In summary, our study highlights the importance of NKT cells in the early stage of bone healing and provides a potential therapeutic strategy for accelerating bone regeneration.

Periodontal pathogen Aggregatibacter actinomycetemcomitans JP2 correlates with colonic leukocytes decrease and gut microbiome imbalance in mice.

Evidence suggests that translocation of oral pathogens through the oral-gut axis may induce intestinal dysbiosis. This study aimed to evaluate the impact of a highly leukotoxic Aggregatibacter actinomycetemcomitans (Aa) strain on the gut microbiota, intestinal mucosal integrity and immune system in healthy mice. Eight-week-old male C57BL6 mice were divided into control (n = 16) and JP2 groups (n = 19), which received intragastric gavage with PBS and with a suspension of Aa JP2 (HK921), respectively, twice a week for 4 weeks. Colonic lamina propria, fecal material, serum, gingival tissues, and mandibles were obtained for analyses of leukocyte populations, inflammatory mediators, mucosal integrity, alveolar bone loss, and gut microbiota. Differences between groups for these parameters were examined by non-parametric tests. The gut microbial richness and the number of colonic macrophages, neutrophils, and monocytes were significantly lower in Aa JP2-infected mice than in controls (p < .05). In contrast, infected animals showed higher abundance of Clostridiaceae, Lactobacillus taiwanensis, Helicobacter rodentium, higher levels of IL-6 expression in colonic tissues, and higher splenic MPO activity than controls (p < .05). No differences in tight junction expression, serum endotoxin levels, and colonic inflammatory cytokines were observed between groups. Infected animals presented also slightly more alveolar bone loss and gingival IL-6 levels than controls (p < .05). Based on this model, intragastric administration of Aa JP2 is associated with changes in the gut ecosystem of healthy hosts, characterized by less live/recruited myeloid cells, enrichment of the gut microbiota with pathobionts and decrease in commensals. Negligible levels of colonic pro-inflammatory cytokines, and no signs of mucosal barrier disruption were related to these changes.

Osteosarcoma with widespread metastasis in a 1-year-old crossbred rabbit.

A 14-month-old female spayed, small crossbred rabbit presented for assessment of a small, hard subcutaneous nodule in the right axilla. Serum biochemistry showed markedly increased serum ALP activity. A whole-body CT revealed an aggressive, monostotic osteolytic, and productive lesion within the left alveolar process of the maxilla, with erosion of the alveolar bone and secondary premolar depression. Innumerable metastatic osseous masses were present throughout the body, including cerebral, pulmonary, hepatic, subcutaneous, and skeletal muscular metastases. Postmortem findings confirmed widespread, metastatic osteosarcoma, with the primary lesion within the left maxilla.

Dual-Polymer Functionalized Melanin-AgNPs Nanocomposite with Hydroxyapatite Binding Ability to Penetrate and Retain in Biofilm Sequentially Treating Periodontitis.

Periodontitis is the leading cause of adult tooth missing. Thorny bacterial biofilm and high reactive oxygen species (ROS) levels in tissue are key elements for the periodontitis process. It is meaningful to develop an advanced therapeutic system with sequential antibacterial/ antioxidant ability to meet the overall goals of periodontitis therapy. Herein, a dual-polymer functionalized melanin-AgNPs (P/D-MNP-Ag) with biofilm penetration, hydroxyapatite binding, and sequentially treatment ability are fabricated. Polymer enriched with 2-(Dimethylamino)ethyl methacrylate (D), can be protonated in an acid environment with enhanced positive charge, promoting penetration in biofilm. The other polymer is rich in phosphate group (P) and can chelate Ca2+, promoting the polymer to adhere to the hydroxyapatite surface. Melanin has good ROS scavenging and photothermal abilities, after in situ reduction Ag, melanin-AgNPs composite has sequentially transitioned between antibacterial and antioxidative ability due to heat and acid accelerated Ag+ release. The released Ag+ and heat have synergistic antibacterial effects for bacterial killing. With Ag+ consumption, the antioxidant ability of MNP recovers to scavenge ROS in the inflammatory area. When applied in the periodontitis model, P/D-MNP-Ag has good therapeutical effects to ablate biofilm, relieve inflammation state, and reduce alveolar bone loss. P/D-MNP-Ag with sequential treatment ability provides a reference for developing advanced oral biofilm eradication systems.

Radiographic evaluation of hard tissue changes in open flap technique versus flapless technique for implant placement

Open flap technique allows the clinician to directly visualize the alveolar bone and assess bone morphology of the ridge.However, this technique is relatively invasive and causes patient discomfort and marginal bone loss due to decreased supraperiosteal blood supply whereas the Flapless technique is one of the latest minimally invasive surgical methods of implant placement without the need to raise a mucoperiosteal flap to overcome the bone resorption process. The present study was designed to evaluate the hard tissue changes in open flap technique versus flapless ṭechnique for implant placement at the different time interval. Minimum thirty edentulous sites from Out Patient Department, Department of Periodontology (IDST) were randomly allocated to the following two groups by the flip of coin: Group I - Implant with open flap technique (fifteen sites) and Group II - Implant with flapless technique (fifteen sites). Patients were evaluated radiographically for crestal bone loss (mesial and distal) at Baseline (Immediately after implant placement), At the time of prosthetic loading and 3 months after prosthetic loading in both the groups. The result of the present study revealed that Sites where implants were placed with flapless technique showed lesser mean crestal bone loss scores as compared to sites where implants were placed with open flap technique, although the difference was insignificant. It can be concluded that flapless procedure may be considered as a better treatment option as compared to implant placed with open flap technique in terms of minimal pain, inflammation and less crestal bone loss associated with flapless technique than open flap technique.

Comparing the modified socket-shield technique with the conventional immediate implantation technique in the anterior dentition: A 5-year retrospective clinical study.

The aim of this retrospective clinical study was to compare the 5-year radiological and clinical outcomes of patients undergoing immediate implantation with or without the modified socket-shield technique. Patients who underwent anterior tooth replacement via the modified socket-shield technique (MSST) or the conventional immediate implantation technique (CIIT) between 2016 and 2017 were included. The labial bone thickness was assessed at different measurement levels (0, 2, 4 and 6 mm apical to the implant shoulder (IS)) postoperatively (T1), 6 months postoperatively (T2) and 5 years postoperatively (T3). The pink aesthetic score (PES) was evaluated before surgery (T0) and at T2 and T3. Implant success, complications and patient satisfaction were evaluated at every visit. Thirty-six patients (18 in the MSST group) underwent follow-up for 5 years, with no cases of implant failure. Two cases of exposure were detected in the MSST group, but there were no significant effects on hard or soft tissue. Patients in the MSST group showed less and more stable bone resorption than did those in the CIIT group at any measurement level and any time. A higher PES was achieved in the MSST group. Patient satisfaction was similar in both groups. The MSST is a reliable immediate implantation method because of its ability to preserve the alveolar bone and provide superior recovery of aesthetics.

Umbelliferone reduces inflammation and ligature-induced osteoclastic alveolar bone resorption in mice.

This study aimed to investigate the effects of Umbelliferone (UMB) on the inflammation underlying alveolar bone resorption in mouse periodontitis. Male Swiss mice subjected to a ligature of molars were grouped as non-treated (NT), received UMB (15, 45, or 135 mg/kg) or saline daily for 7 days, respectively, and were compared with naïve mice as control. Gingival tissues were evaluated by myeloperoxidase (MPO) activity and interleukin-1β level by ELISA. The bone resorption was directly assessed on the region between the cement-enamel junction and the alveolar bone crest. Microscopically, histomorphometry of the furcation region, immunofluorescence for nuclear factor-kappa B (NF-ĸB), and immunohistochemistry for tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CTSK) were performed. Systemically, body mass variation and leukogram were analyzed. Periodontitis significantly increased MPO activity, interleukin-1β level, and NF-ĸB+ immunofluorescence, and induced severe alveolar bone and furcation resorptions, besides increased TRAP+ and CTSK+ cells compared with naïve. UMB significantly prevented the inflammation by reducing MPO activity, interleukin-1β level, and NF-ĸB+ intensity, besides reduction of resorption of alveolar bone and furcation area, and TRAP+ and CTSK+ cells compared with the NT group. Periodontitis or UMB treatment did not affect the animals systemically. UMB improved periodontitis by reducing inflammation and bone markers.

The Role of Dental Arch Dimensions and Impacted Third Molars on Mandibular Anterior Segment Crowding.

This study aimed to investigate the potential impact of arch dimensions and unerupted third molars on mandibular anterior segment crowding. This study included a total of 240 subjects with an average age of 18 years seeking orthodontic treatment. Panoramic radiographs, alginate impressions, and study models were taken for measurements. This study utilized the Ganss ratio to calculate the ratio of retromolar space to the width of the crown of the third molar, along with other measurements such as intercanine and intermolar widths, arch perimeter, and arch length to assess dental arch dimensions. We found that the Ganss ratio and angle B values on both the right and left sides were significantly different between the noncrowding and crowding groups, suggesting a potential role for third molars in mandibular anterior segment crowding. Additionally, there was an increase in angle A on both sides in the crowding group, indicating a more acute angle between the anterior teeth. This study also observed a reduction in the retromolar space on the third molars in the crowding group, further supporting the potential role of third molars in mandibular anterior segment crowding. The findings of our study provide substantial evidence to suggest that third molars may contribute to mandibular anterior segment crowding. These findings highlight the importance of carefully evaluating dental arch dimensions and the presence of third molars when assessing and treating mandibular anterior segment crowding.

The Anti-Inflammatory Effect of Nigella sativa Toothpaste on Porphyromonas gingivalis Bacteria Through Decreased TNF-α, MMP-9, PGE-2 Expression in Wistar Rats.

The main principle in preventing periodontal disease is to improve oral hygiene. The bacteria that cause the onset of periodontal disease, one of which is the Porphyromonas gingivalis bacterium, causes inflammation. Persistent inflammation causes tissue damage and alveolar bone resorption by secreting proinflammatory cytokines, matrix metalloproteinase-9 (MMP-9), prostaglandin E2 (PGE-2), and anti-inflammatory cytokines. In this case, preventive treatment is needed, such as using toothpaste that contains anti-inflammatories so that the progression of the disease does not get worse. The traditional ingredient currently being developed is Nigella sativa, which has anti-inflammatory properties. Therefore, this study analyzes the potential of toothpaste containing Nigella sativa on the expression of tumor necrosis factor-α (TNF-α), MMP-9, and PGE-2 in the Wistar rat model induced by Porphyromonas gingivalis bacteria. This study aims to prove the potential of Nigella sativa toothpaste to decrease the expression of PGE-2, TNF-α, and MMP-9 in the gingiva of rats induced by Porphyromonas gingivalis bacteria. Forty-five healthy male Wistar rats were used, consisting of the negative control group, which was only injected with Porphyromonas gingivalis bacteria ATCC3322. The positive control group was given enzyme toothpaste, and the treatment group was assigned 1 mg of Nigella sativa paste using a microbrush for 30 seconds on the gingiva incisors mandibular with a circular motion, given two times a day for a week. Immunohistochemical to see the expression of TNF-α, PGE-2, and MMP-9. Parametric comparative analysis using a one-way analysis of variance test was performed to analyze differences between groups. Nigella sativa toothpaste significantly reduced proinflammatory cytokines, as seen through the expression of TNF-α, PGE-2, and MMP-9 on days 3, 5, and 7 (p <0.05). In the limit of studied animal model, this trial indicates that giving toothpaste with black seed extract (Nigella sativa) could inhibit inflammatory mediators, as seen from the decreased expression of MMP-9, TNF-α, and PGE-2 seen from the 3rd, 5th, and 7th days.

Can narrow-diameter implants enhance patient-reported outcomes for mandibular implant-retained overdentures?

A systematic review and meta-analysis. To evaluate and compare stability and functionality between narrow and standard implant-retained mandibular overdentures in edentulous patients from multiple perspectives. Assessments included clinical parameters [survival rate (SR) and marginal bone loss (MBL)], along with patient-reported outcome measures (PROMs) including patient satisfaction and oral health-related quality of life (OHRQoL). The study protocol followed PRISMA criteria for reporting reviews and meta-analyses. Using appropriate keywords, electronic search was conducted in each of the following databases: Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus, up to July 22, 2022. There were no restrictions based on language, publication type, or publication date. Additionally, ongoing studies were explored in ClinicalTrials.gov and WHO ICTRP, while cross-references in each selected study were manually examined. The eligible studies were randomized controlled trials (RCTs) or controlled clinical trials (CCTs) comparing narrow implants (diameter ≤ 3.5 mm) to standard implants (diameter > 3.5-4.5 mm) retaining mandibular overdentures in edentulous patients. Excluded were studies with unclear implant diameter information, fewer than 5 patients per group, observational studies, reviews, and laboratory studies. Two authors independently conducted study selection, data collection, and analysis, resolving any discrepancies through discussion with a third author. Methodological quality was assessed using RoB-2 and ROBINS-I tools. Implant SR and MBL measurements at final follow-up were recorded, while patient satisfaction and OHRQoL were evaluated using visual analogue scale (VAS-100) and oral health impact profile (OHIP) questionnaire, respectively. After duplicate removal, 782 publications and 83 registered clinical trials were identified, of which 26 were eligible for full-text assessment. Ultimately, the quantitative evaluation included 12 publications from 8 independent studies: 4 parallel design RCTs and 4 CCTs. Risk of bias assessment revealed variations among the studies, with only one study being rated as having low risk. The follow-up periods ranged from 1 to 3 years. Meta-analysis showed no significant difference in SR and MBL between narrow and standard implant groups (p = 0.29 and p = 0.93, respectively), with considerable heterogeneity (I2 = 100% and I2 = 78%, respectively). Regarding PROMs, the narrow implant group showed significantly higher levels of patient satisfaction (mean difference (MD): 8.18; 95% CI: 5.83 to 10.53; p < 0.00001; I2 = 36%) and exhibited a significant improvement in OHRQoL (MD: -4.36; 95% CI: -6.83 to -1.89; p < 0.001; I2 = 55%) compared to the standard implant group. For implant-retained mandibular overdentures, the use of narrow implants is associated with comparable SR and MBL, along with higher patient satisfaction and better OHRQoL improvement as compared to standard implants, offering a viable alternative option for patients with diminished alveolar bone width.

Polarized M2 macrophages induced by glycosylated nano-hydroxyapatites activate bone regeneration in periodontitis therapy.

To investigate the association between periodontal macrophage polarization states and the alveolar bone levels, and to assess whether glycosylated nano-hydroxyapatites (GHANPs) could improve bone regeneration in periodontitis by inducing macrophage M2 polarization. The change of macrophage polarization state in inflammatory periodontal tissues (with bone loss) was examined using clinical gingival samples. The relationship between macrophage phenotype and bone level in periodontal bone loss and repair was evaluated using a mouse periodontitis model. The effect of GHANPs on macrophage polarization was assessed by the in vitro model of lipopolysaccharide (LPS)-stimulated inflammation. The polarization-related markers were detected by immunofluorescence staining, real-time polymerase chain reaction and enzyme-linked immunosorbent assay analysis. The therapeutic effect of GHANPs on alveolar bone loss was explored in experimental periodontitis by histological staining and micro-CT analysis. A lower macrophage M2/M1 ratio was observed in periodontitis-affected human gingival tissues. The results of animal experiments demonstrated a positive correlation between a lower Arg-1/iNOS ratio and accelerated alveolar bone loss; also, the proportion of Arg-1-positive macrophages increased during bone repair and regeneration. The administration of GHANPs partially restored M2 macrophage polarization after LPS stimulation. GHANPs increased alveolar bone repair and regeneration in experimental periodontitis induced by ligation, potentially related to their macrophage M2 transition regulation. The findings of this study indicate that the induction of macrophage M2 polarization can be considered a viable approach for enhancing inflammatory bone repair. Additionally, GHANPs show potential in the clinical treatment of periodontitis.

Effect of fence tray matching care on excess adhesive and bracket placement accuracy for orthodontic bonding: an in vitro study

ObjectiveThis study aimed to evaluate the effect of fence tray matching care (FTMC) in bracket bonding by measuring excess adhesive, as well as linear and angular deviations, and by comparing it with the half-wrapped tray (HWT).Materials and methodsAn intraoral scanner was used to acquire data on the maxillary dental arch of a patient with periodontitis.Furthermore, 20 maxillary dental arch models were 3D printed. Using 3Shape, PlastyCAD software, and 3D printing technology, 10 FTMC (method I) and HWT (method II) were obtained. By preoperative preparation, intraoperative coordination, and postoperative measurement, the brackets were transferred from the trays to the 3D-printed maxillary dental arch models. Additionally, the bracket’s excess adhesive as well as linear and angular deviations were measured, and the differences between the two methods were analyzed.ResultsExcess adhesive was observed in both methods, with FTMC showing less adhesive (P< 0.001), with a statistical difference. Furthermore, HWT’s vertical, tip and torque, which was significantly greater than FTMC (P< 0.05), with no statistical difference among other respects. The study data of incisors, canines, and premolars, showed that the premolars had more adhesive residue and were more likely to have linear and angular deviations.ConclusionsThe FTMC had higher bracket bonding effect in comparison to HWT, and the adhesive residue, linear and angular deviations are smaller. The fence tray offers an intuitive view of the precise bonding of the bracket, and can remove excess adhesive to prevent white spot lesions via care, providing a different bonding method for clinical applications.

Application of autogenous dentinal block to increase alveolar bone volume: a clinical case

Introduction. Materials based on extracted teeth in various studies have been radiographically and histologically proven to be effective in osteoplastic operations. These materials can be used in the form of crushed dentin matrix, a fragment of the tooth’s root and an autogenous dentin block. The purpose of this clinical case was to evaluate the effectiveness of using an autogenous dentin block to increase the alveolar process of the jaws in the preimplantation period.Description of a clinical case. Patient F., 30 years old, applied to the clinic of the Clinical Center of Maxillofacial, Plastic Surgery and Dentistry Russian University of Medicine with a complaint of a missing tooth in the frontal region of the lower jaw. At the time of treatment, the patient was already undergoing orthodontic treatment in another medical institution in Moscow. The patient underwent a clinical and radiological examination together with a prosthodontst. A diagnosis of «partial secondary adentia», «atrophy of the alveolar ridge in the frontal part of the lower jaw» and «dystopia of teeth 1.8, 2.8, 3.8, 4.8» was established. A comprehensive treatment plan has been drawn up. At the first stage, the patient underwent extraction of teeth 1.8, 2.8, 3.8, 4.8 for orthodontic indications with simultaneous bone grafting of the alveolar ridge in the area of the missing tooth 3.1. At the second stage, the patient underwent a trephine biopsy in the area of augmentation and installation of a dental implant in the area of missing tooth 3.1. The third stage was rational prosthodontic treatment on a dental implant in the department of prosthodontics.Results. The present study showed that autogenous dentinal block can serve as an alternative material for alveolar ridge augmentation.

A 3D In-vitro model of the human dentine interface shows long-range osteoinduction from the dentine surface

Emerging regenerative cell therapies for alveolar bone loss have begun to explore the use of cell laden hydrogels for minimally invasive surgery to treat small and spatially complex maxilla-oral defects. However, the oral cavity presents a unique and challenging environment for in vivo bone tissue engineering, exhibiting both hard and soft periodontal tissue as well as acting as key biocenosis for many distinct microbial communities that interact with both the external environment and internal body systems, which will impact on cell fate and subsequent treatment efficacy. Herein, we design and bioprint a facile 3D in vitro model of a human dentine interface to probe the effect of the dentine surface on human mesenchymal stem cells (hMSCs) encapsulated in a microporous hydrogel bioink. We demonstrate that the dentine substrate induces osteogenic differentiation of encapsulated hMSCs, and that both dentine and β-tricalcium phosphate substrates stimulate extracellular matrix production and maturation at the gel-media interface, which is distal to the gel-substrate interface. Our findings demonstrate the potential for long-range effects on stem cells by mineralized surfaces during bone tissue engineering and provide a framework for the rapid development of 3D dentine-bone interface models.

Long-term survival rates of tapered self-tapping bone-level implants after immediate placement: a positional effective rationale

BackgroundImmediate implant placement has gained popularity due to its several advantages. However, immediate placement has its challenges, including concerns about primary stability and bone formation around the implant. The aim of the present study is to evaluate the clinical outcomes of tapered, sand-blasted, and acid-etched internal submerged dental implants in various regions of the jaw bones and to provide a positional rationale for immediate implant placement.MethodsBetween 2009 and 2018, a single surgeon at Seoul National University Dental Hospital in Seoul, Korea, immediately inserted 49 dental implants with tapered bone-level design after extraction, in a total of 34 patients. The clinical outcomes were collected and evaluated, focusing on location of implant placement and marginal bone loss (MBL), with consideration of other parameters such as implant diameter and length.ResultsOf 49 immediately installed Luna® (Shinhung Co., Seoul, Korea) dental implants, 23 were placed in the mandible, and 26 were set in the maxilla. The mean age of patients at the time of installation was 65.91 years, ranging from 40 to 86 years. The average follow-up period was 7.43 years, with a range of 5 to 14 years. After a 5-year retrospective evaluation of tapered, sand-blasted, and acid-etched internal submerged dental implants for immediate implant placement, the cumulative survival rate was 93.88%, with 100% survival rate in the mandible and premolar region of both the maxilla and mandible.ConclusionsAfter a 5-year evaluation, tapered, sand-blasted, and acid-etched internal submerged dental implants demonstrated good efficacy for immediate placement in various locations within the dental arches, exhibiting effective clinical performance.