Resorption Area Research Articles

Bone impairment in atypical hemolytic and uremic syndrome treated by long-term eculizumab.

Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy, related to complement dysregulation, including Factor H deficiency (FH) treated by lifelong eculizumab therapy. Its long-term tolerance is not yet fully described. We report two patients with genetic FH deficiency receiving long-term eculizumab and displaying a peculiar bone phenotype. First case is a 13-year-old girl, presenting with bone pains, arthritis, and deformities, for which X-rays and MRI described multifocal osteochondritis. Bone biopsy revealed an active remodeling bone (many areas of bone formation and resorption) and C3c accumulation on immunohistochemical staining. The second patient is an 11-year-oldgirl, displaying mechanical bone pains, for which bone scintigraphy found hypofixation of wrists and ankles. These findings could be consistent with a side effect of eculizumab, as C3c accumulation may result from the downstream C5-blockade. Alternatively, bone alterations could be due to the absence of FH, as described in murine models. Further investigations are required to characterize bone disease in aHUS.

Moesin controls cell-cell fusion and osteoclast function.

Cell-cell fusion is an evolutionarily conserved process that is essential for many functions, including fertilisation and the formation of placenta, muscle and osteoclasts, multinucleated cells that are unique in their ability to resorb bone. The mechanisms of osteoclast multinucleation involve dynamic interactions between the actin cytoskeleton and the plasma membrane that are still poorly characterized. Here, we found that moesin, a cytoskeletal linker protein member of the Ezrin/Radixin/Moesin (ERM) protein family, is activated during osteoclast maturation and plays an instrumental role in both osteoclast fusion and function. In mouse and human osteoclast precursors, moesin inhibition favors their ability to fuse into multinucleated osteoclasts. Accordingly, we demonstrated that moesin depletion decreases membrane-to-cortex attachment and enhances the formation of tunneling nanotubes (TNTs), F-actin-based intercellular bridges that we reveal here to trigger cell-cell fusion. Moesin also controls HIV-1- and inflammation-induced cell fusion. In addition, moesin regulates the formation of the sealing zone, the adhesive structure determining osteoclast bone resorption area, and thus controls bone degradation, via a β3-integrin/RhoA/SLK pathway. Supporting our results, moesin - deficient mice present a reduced density of trabecular bones and increased osteoclast abundance and activity. These findings provide a better understanding of the regulation of cell-cell fusion and osteoclast biology, opening new opportunities to specifically target osteoclast activity in bone disease therapy.

Evaluation of the efficacy of different irrigation activation techniques in removing of calcium hydroxide on teeth with the simulated internal root resorption cavity: a confocal laser scanning microscope analysis.

The aim of this study is to evaluate the effect of different irrigation activation methods on root canal sealer penetration in teeth with simulated internal root resorption (IRR) and calcium hydroxide (CH) applied using a confocal laser scanning microscope (CLSM). 60 incisors with a single root and a single canal were included in the study. IRR cavities were created in the middle third of the root canal, and CH was placed. The samples were randomly divided into 4 groups (n = 15) according to the irrigation activation method to be tested: standard needle irrigation (SNI), sonic activation (EDDY), photon-induced photoacoustic flow (PIPS), and shock wave enhanced emission photoacoustic flow (SWEEPS). After irrigation activation applications, the root canals were obturated. Sections of 1.0 ± 0.1mm were taken from the apical, middle, and coronal regions of each sample. The penetration area (µm2) and maximum penetration depth (µm) of the root canal sealer were examined by CLSM and analyzed using ImageJ software. Statistical analysis was performed with a one-way ANOVA and post-hoc Tukey test at the P < 0.05 significance level. Among all irrigation activation methods tested, both the penetration area and maximum penetration depth of the root canal sealer were greater in the coronal region than in the apical region (p < 0.05). In the IRR region, there was no difference in terms of maximum penetration depth between PIPS and SWEEPS (p > 0.05), it was highest in SWEEPS (p < 0.05). PIPS and SWEEPS were better than other irrigation activation methods in the penetration of root canal sealer in the resorption areas of teeth with IRR.

Interleukin-18 binding protein regulates mast cell activation and mast cell induced osteoclastogenesis of rheumatoid arthritis.

Mast cell activation induces pathological responses, including increased osteoclastogenesis in rheumatoid arthritis (RA). Interleukin (IL)-18 binding protein (IL-18BP) has anti-inflammatory effects. In this study, we evaluated the effect of IL-18BP on mast cell activation and mast cell induced osteoclastogenesis. Mast cells were activated by IL-33 (100 ng/mL) and cultured with IL-18BP (10, 50, and 100 ng/mL). The proliferation, apoptosis, and necroptosis of mast cells were measured using flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of mast cell enzymes, matrix metalloproteinase (MMP), soluble RANKL (sRANKL), and pro-inflammatory cytokines in the culture media. Monocytes from patients with RA patients (n=5) were cultured with activated mast cells with various concentrations of IL-18BP. TRAP+ multinucleated osteoclasts, bone resorption area, and osteoclast differentiation-related genes were measured. Proliferation of tryptase+chymase+c-kit+FcεR1+ mast cells was suppressed following incubation with IL-18BP (10, 50, and 100 ng/mL). RNA expression levels of tryptase and chymase were reduced by 100 ng/mL IL-18BP. Additionally, the levels of MMP-3/9, IL-17A, IL-6, TNF-α, and sRANKL were significantly inhibited by 100 ng/mL IL-18BP. Annexin V+ and annexin V-PI+ mast cells were reduced following incubation with 100 ng/mL IL-18BP. The addition of IL-33 significantly stimulated mast cell and increased TRAP+ multinucleated cells and bone resorption area, and these effects were suppressed by IL-18BP. The osteoclast-related genes (TRAP, ATP6v0d2, RANK, and cathepsin K) expression were suppressed by IL-18BP. IL-18BP suppressed mast cell activation and mast cell induced osteoclastogenesis. This suggests a potential anti-arthritic role for IL-18BP in patients with RA.

Histomorphological assessment of the germanium-doped calcium phosphate ceramics on reparative osteogenesis in rabbits with systemic osteoporosis

Bone fractures are mostly urgent in nature, complex in pathogenetic, diagnostic and therapeutic aspects, and reparative osteogenesis is multimodal and depends on the balanced and reciprocal interaction of many factors. The results of histological studies for osteoreplacement of bone defects in rabbits with systemic osteoporosis are presented. The purpose of the work is histomorphological evaluation of bone regenerates after osteoreplacement with germanium-doped hydroxyapatite ceramics in rabbits with secondary osteoporosis. Experimental osteoporosis in rabbits (n=18) was induced by administration of 0.4% dexamethasone solution. In animals of the experimental group, bone defects were replaced with granules of hydroxyapatite ceramics doped with germanium, and in animals of the control group, they healed under a blood clot. Histological sections were made on a rotary microtome with a thickness of 5 to 10 μm and stained with Weigert's iron hematoxylin and 1% alcohol-based eosin solution (manufactured by Diapath, Italy). On the 60th day of reparative osteogenesis in the animals of the experimental group, the site of the bone defect was flled with compact bone tissue with minor remnants of spongy bone tissue. Slightly expanded Haversian canals were noted. In the control group, the defect site was flled with coarse and spongy bone tissue. Bone beams of various thicknesses with a small number of osteoblasts and single walled osteocytes were visualized. A signifcant number of osteocyte lacunae were empty due to the process of osteocyte lysis. Haversian canals are signifcantly dilated with a small number of vessels. Also, lacunae of bone tissue resorption and acellular areas were observed on histological specimens. Histomorphological assessment of bone regenerates confrms the realization of osteoconductive, osteointegrative and osteoinductive properties of calcium-phosphate ceramics doped with germanium in conditions of osteoporotic fractures of tubular bones. Keywords: systemic osteoporosis, bone fractures, cancellous and compact bone tissue, histological sections, histomorphological changes, rabbits.

Characterization and quantification of in-vitro equine bone resorption in 3D using μCT and deep learning-aided feature segmentation

High cyclic strains induce formation of microcracks in bone, triggering targeted bone remodeling, which entails osteoclastic resorption. Racehorse bone is an ideal model for studying the effects of high-intensity loading, as it is subject to focal formation of microcracks and subsequent bone resorption. The volume of resorption in vitro is considered a direct indicator of osteoclast activity but indirect 2D measurements are used more often. Our objective was to develop an accurate, high-throughput method to quantify equine osteoclast resorption volume in μCT 3D images. Here, equine osteoclasts were cultured on equine bone slices and imaged with μCT pre- and postculture. Individual resorption events were then isolated and analyzed in 3D. Modal volume, maximum depth, and aspect ratio of resorption events were calculated. A convolutional neural network (CNN U-Net-like) was subsequently trained to identify resorption events on post-culture μCT images alone, without the need for pre-culture imaging, using archival bone slices with known resorption areas and paired CTX-I biomarker levels in culture media. 3D resorption volume measurements strongly correlated with both the CTX-I levels (p < 0.001) and area measurements (p < 0.001). Our 3D analysis shows that the shapes of resorption events form a continuous spectrum, rather than previously reported pit and trench categories. With more extensive resorption, shapes of increasing complexity appear, although simpler resorption cavity morphologies (small, rounded) remain most common, in acord with the left-hand limit paradigm. Finally, we show that 2D measurements of in vitro osteoclastic resorption are a robust and reliable proxy.

Myocardial CD34+ Stromal Cells/Telocytes Demonstrate a Dynamic Pattern of Interactions with CD68+ Macrophages During Post-Myocardial Infarction Healing

Introduction: Myocardial CD34-positive (+) stromal cells/telocytes (SC/TCs) have been recently recognized as a novel type of resident cells involved in post-myocardial infarction (MI) repair. Alternatively, CD68-positive (+) macrophages are well-known constituents in this process. However, the relationship between these two cell populations remains mostly obscure. Therefore, this study was aimed to determine whether resident CD34+ SC/TCs and phagocytic CD68+ macrophages have any evident pattern of interactions during the inflammatory and proliferative phases of post-MI scar formation. Methods: A large transmural MI was induced in middle-aged male Sprague-Dawley rats (n = 15) under ketamine and xylazine anesthesia by permanent ligation of the left anterior descending coronary artery. The post-MI rats were infused with BrdU (5-bromo-2'-deoxyuridine) in a dose of 12.5 mg/kg/day for 72 hours via intraperitoneal osmotic minipumps on day 0, 4, or 11 after surgery. The rats were euthanized on day 3, 7 and 14 after MI, and their hearts were processed for histology and immunostaining. Results: On the third day after MI, CD34+ SC/TCs and CD68+ macrophages were absent within the core of the necrotic tissue, whereas both types of cells were juxtaposed in the space surrounding the area of coagulative necrosis. Furthermore, the presence of BrdU labeling in the nuclei of numerous CD34+ SC/TCs suggests their proliferation in the region of the active macrophage clearing. On the seventh day after MI, CD68+ macrophages were observed to have had advanced toward the center of the necrotic region leaving behind the area occupied primarily with acellular basement membranes from the resorbed CMs, whereas most of CD34+ SC/TCs trailed slightly behind. In part, such delay in centripetal progression of CD34+ SC/TCs through the areas of resorption could be attributed to the fact that these cells, in contrast to macrophages, often migrated along the acellular basement membranes left from the dead CMs that required phagocytic removal of necrotic debris to occur first. On the fourteenth day after MI, the population of CD68+ cells appeared notably reduced and demonstrated a patchy distribution predominantly along the remnants of the necrotic tissue. Meanwhile, the substantially expanded population of CD34+ SC/TCs were observed throughout the entire transmural scar, excluding the areas containing dead “mummified” CMs, aggregates of myofibroblasts and the fibroelastic thickening in subepicardial and subendocardial regions. Conclusion: Our findings, for the first time, demonstrate that populations of resident CD34+ SC/TCs and phagocytic CD68+ macrophages exhibit a dynamic pattern of interactions during early phases of post-MI scar formation, suggesting their importance in the process of post-ischemic myocardial healing. Supported by Camden Health Research Initiative. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Morphological characterization and transcriptome analysis of opercular deformity in golden pompano (Trachinotus ovatus)

Skeletal deformity is one of the major threats to aquaculture because of its negative effects in important economic losses. Recently, a high rate of opercular deformities was observed in farmed golden pompano (Trachinotus ovatus), which is a key species for marine cage culture in the South China Sea. In the present study, a structural, histological, and biochemical analysis of the deformed opercular complex in T. ovatus was carried out using micro-CT, Inductively Coupled Plasma Mass Spectrometry (ICP-MS), paraffin section, and staining. A 3D reconstruction of the deformed and normal opercular complex has revealed an inward folding of both opercle and subopercle, and frequently affected branchiostegal rays being coated by the deformed opercle and subopercle. In addition, an increased Ca, P, and Mg content was identified in the deformed opercle. The Hematoxylin-eosin (HE) and tartrate resistant acid phosphatase (TRAP) staining of the deformed opercle have shown a higher osteoclast activity and increased bone resorption area. Further analyses on the difference of gene expression between the deformed and normal opercle have been performed using Illumina sequencing platform. As a result, a total of 1220 DEGs (including 508 up-regulated and 712 down-regulated genes) were identified. DEGs related to osteoblast and osteoclast differentiation revealed an important role of bone metabolism in opercular deformity. Moreover, GO and KEGG analysis of these DEGs showed that they were significantly enriched in functions and pathways related to muscle form, development and contraction. Additionally affected pathways including ion homeostasis suggested that functions of gills such as breathing and osmoregulation might be affected by the deformed opercle.

Customized three-dimensional printed ceramic bone grafts for osseous defects: a prospective randomized study

Ridge resorption can result in insufficient bone volume for implant surgery, necessitating bone substitutes to restore the resorption area. Recent advances in computer-aided design and manufacturing enable the use of alloplastic bone graft materials with customizable compositions or shapes. This randomized study evaluated the clinical effectiveness of a customized three-dimensional (3D) printed alloplastic bone material. Sixty patients requiring guided bone regeneration for implant installation following tooth extraction due to alveolar bone resorption were recruited at two institutions. The participants were randomly allocated to either a group that received 3D-printed patient-customized bone graft material or a group that received conventional block bone graft material. Implant installation with bone harvesting was performed approximately 5 months after bone grafting. Histological and radiological assessments of the harvested bone area were performed. The experimental group had a significantly higher percent bone volume and a smaller tissue surface than the control group. Bone volume, bone surface, bone surface/volume ratio, bone surface density (bone surface/total volume), and bone mineral density did not differ significantly between groups. Patient-customized bone graft materials offer convenience and reduce patient discomfort. The findings suggest 3D-printed patient-customized bone graft materials could be used as an alternative for simpler bone grafting procedures.

Bone resorption around the annular closure device during a postoperative follow-up of 8years.

Annular closure device (ACD) implantation is considered to be an effective means of preventing reherniation after microdiscectomy; however, there is an issue: the bone may resorb around the ACD. The causes of vertebral bone resorption remain unexplored; the dynamics of changes in bone resorption around the ACD have not yet been assessed or characterized. One hundred thirty-three patients underwent ACD implantation after microdiscectomy, and 107 of them were followed up for 8years after surgery (Oswestry, VAS). Lumbar CT scans helped characterize the bone resorption area around the ACD. The median of follow-up was 85 [74; 93] months (from 73 to 105months). The prevalence of bone resorption around the ACD was up to 63.6%, and it was mainly around the polymer mesh of the ACD (70.6%). The resorbed bone volume increased with time and reached its maximum of 5.2 cm3 (12% of the vertebral body volume) once a sclerotic rim developed around the bone resorption area. No differences in VAS pain intensity or in Oswestry Disability Index were found between patients with resorption and patients without it (p > 0.05). The volume of the intervertebral disc before surgery is a predictor of bone resorption (OR = 0.79, p = 0.009): if it is less than 13.2 cm3, the risk of bone resorption increases significantly (p < 0.05). The majority of patients (up to 63.6%) with implanted ACDs have vertebral bone resorption around them. The bone resorption area around the ACD mesh increases with time to up to 12% of the vertebral body volume, with no clinical evidence, though. The formation of a sclerotic rim prevents the bone resorption area from further growth. If the volume of the intervertebral disc before surgery is less than 13.2 cm3, the risk of bone resorption increases significantly.

Regeneration of the apical region of the tooth after the treatment of destructive periodontitis with cement resorption

Aim. Destructive changes in the tissues of the tooth and periodontium entail resorption of the hard tissues of the tooth in the apical region. The goal is to identify morphological changes in root tissues with destructive periodontitis and resorption phenomena after the treatment of the tooth with calcium-containing preparations using a scanning electron microscope. Materials and methods. Examination of teeth treated for destructive forms of periodontitis with apical resorption was performed using a JSM-6490LV scanning electron microscope (JEOL, Japan) with an energy-dispersive attachment INCA Penta FETx3 (OXFORD Instruments, England). Results. In the apical part of the root there is a cellular mixed layered cementum. The dentin and the dentin-cementum junction are highly calcified. On top of them is cellular cement with lacunae of cementoblasts. The relief of the zone of cell-free cement has a wavy structure, consists of dense collagen fibers with a high content of calcium. With external root resorption, we observe extensive destruction of the cementoblast layer. An area of newly formed cementum was found inside the apical foramen. On the apical surface, where the resorption covered the dentin layer, there was an area of newly formed cementum. Its cellular layer consisted of round-shaped cells rising above the tissue of a homogeneous structure, smoothly flowing into the spongy tissue denting the bone. Discussion. It can be assumed that prolonged use of calcium-containing drugs leads to calcification. The presence of dense connective tissue in the periodontium indicates regenerative processes. The control of cement formation remains uncertain. Conclusions. Perhaps we are seeing a reparative atypical regeneration of the cement of the apical part of the tooth root. Dentinal calcification. In the lateral parts of the apical region, there is an outer layer of cementum with no cementoblasts. An increase in the thickness of the cement was noted. It can be assumed that we observe the phenomenon of osteogenesis in the area of strong resorption.

Pulp revascularization procedure for external inflammatory dental root resorption treatment

To assess the effectiveness of pulp revascularization procedure in children with external inflammatory root resorption (EIRR) after constant teeth injury. The study comprised 17 children aged 6-10 years diagnosed with EIRR as a long-term complication of dental trauma in 19 teeth. EIRR was diagnosed with periapical radiographs and CBCT was performed to further assess the pathology extension. Pulp revascularization was carried out in all 19 teeth. There was no resorption progression in all cases. EIRR areas were substituted by bone. In 10 from 19 teeth with early stages of root development bone or cement-like tissue ingrowth into the root canal was observed radiologically. In cases of severe EIRR this ingrowth may partially compensate for lost tissues which is confirmed by a high percentage (94.7%) of functional teeth during mean follow up time of 38±10 months. Pulp revascularization is an effective method for retaining teeth with EIRR for a relatively long period of time and allows maintaining alveolar bone volume both due to functional tooth preservation and healing of bone lesions in periapical and resorption areas.

COMPARATIVE ASSESSMENT OF THE ROOT CANAL IRRIGATION QUALITY WITH EXPERIMENTAL INTRA-ROOT RESORPTION IN VITRO

Introduction. To date, intra-root resorption of teeth is poorly understood, although it is often encountered in dental clinics. This study aimed on assess and comparison of different methods of irrigation and antiseptic solutions activation used for root canal treatment, and focus on cleaning the area of simulated intra-root resorption. Methods. 24 extracted teeth were used, which the simulation of internal resorption was reproduced by dissection the inside of the root canal under the control of an electron microscope (Karl Kaps, Germany) in. Distilled water, sodium hypochlorite 5.25 %, sodium hypochlorite 3 %, chlorhexidine 2 % were used for comparative assessment of irrigation quality by staining with Indian Ink dye. Results. When using an endodontic needle and passive irrigation with the studied irrigation solutions, the dye remained on the inner surfaces of the root canal walls, which indicated their insufficient cleaning. The use of auxiliary cleaning methods - sound and ultrasonic irrigation nozzles - showed better cleaning of the root canal resorption zone. When using the sound activation of the irrigator with the EndoActivator device, the dye partially remained in the simulated resorption zone, while a significant part of the root canal system was cleaned. The use of ultrasonic activation of the irrigator with the P5 XS device showed that all dye-stained root canals of the samples were cleaned. Zones of simulated root resorption did not show any dye residues visually and under electron microscope control. Conclusions. The quality of root canal cleaning in case of intra-root resorption in terms of visual assessment of their transparency and under the control of an electron microscope was more pronounced when using methods of activating irrigation solutions with sound and ultrasonic activators.

Comparison of Orthodontic Tooth Movement of Regenerated Bone Induced by Carbonated Hydroxyapatite or Deproteinized Bovine Bone Mineral in Beagle Dogs.

Orthodontic treatments often involve tooth movement to improve dental alignment. In this study, we aimed to compare tooth movement in regenerated bone induced by two different bone fillers, carbonated hydroxyapatite (CAP) and deproteinized bovine bone mineral (DBBM). Four beagle dogs were used in this comparative study. The first, second, and fourth lower mandibular premolars (P1, P2, and P4) on both sides of the mouth were extracted, and CAP was implanted into the extraction site on the left side and DBBM into the right side. Following regenerative bone healing, orthodontic devices were attached to perform orthodontic tooth movement of the lower third mandibular premolar (P3) on both sides. X-ray examination, intraoral scan, and histological analysis were performed. The Mann-Whitney U test was used for statistical analysis, and p < 0.05 was considered significant. Bone regeneration and orthodontic tooth movement were observed in the CAP and DBBM groups. Histologically, normal periodontal tissue remodeling was observed on the compression and tension sides of CAP and DBBM. No statistical difference was observed in the number of osteoclasts around the periodontal ligament and the root resorption area. Orthodontic tooth movement of regenerated bone induced by CAP and DBBM was therefore achieved.

Experimental study of subcutaneous adipose-derived stem cells inhibiting orthodontic root resorption

To investigate the effect of human subcutaneous adipose-derived stem cells (hADSCs) local transplantation on orthodontically induced root resorption (OIRR) and provide theoretical and experimental basis for the clinical application of hADSCs to inhibit OIRR. Forty 8-week-old male Sprague Dawley rats were randomly divided into experimental group and control group, with 20 rats in each group, to establish the first molar mesial orthodontic tooth movement (OTM) model of rat right maxillary. The rats in the experimental group were injected with 25 μL of cell suspension containing 2.5×10 5 hADSCs on the 1st, 4th, 8th, and 12th day of modeling, while the rats in the control group were injected with 25 μL of PBS. The rat maxillary models were obtained before and after 7 and 14 days of force application, and 10 rats in each group were killed and sampled after 7 and 14 days of force application. The OTM distance was measured by stereomicroscope, the root morphology of the pressure side was observed by scanning electron microscope and the root resorption area ratio was measured. The root resorption and periodontal tissue remodeling of the pressure side were observed by HE staining and the root resorption index was calculated. The number of cementoclast and osteoclast in the periodontal tissue on the pressure side was counted by tartrate resistant acid phosphatase staining. The TOM distance of both groups increased with the extension of the force application time, and there was no significant difference ( P<0.05). There was no significant difference in OTM distance between the experimental group and the control group after 7 and 14 days of force application ( P>0.05). Scanning electron microscope observation showed that small and shallow scattered resorption lacunae were observed on the root surface of the experimental group and the control group after 7 days of force application, and there was no significant difference in the root resorption area ratio between the two groups ( P>0.05); after 14 days of application, the root resorption lacunae deepened and became larger in both groups, and the root resorption area ratio in the experimental group was significantly lower than that in the control group ( P<0.05). The range and depth of root absorption in the experimental group were smaller and shallower than those in the control group, and the root absorption index in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). The number of cementoclast in the experimental group was significantly lower than that in the control group after 7 and 14 days of force application ( P<0.05); the number of osteoclasts in the experimental group was significantly lower than that in the control group after 14 days of force application ( P<0.05). Local transplantation of hADSCs may reduce the area and depth of root resorption by reducing the number of cementoclasts and osteoclasts during OTM in rats, thereby inhibiting orthodontic-derived root resorption.

Treatment of Teeth with Root Resorptions: A Case Report and Systematic Review

Aim. This article presents an evaluation of different multidisciplinary treatment approaches to managing teeth with external and internal root resorptions.&#x0D; Methods. This study presents a clinical case of a 35-year-old female patient referred to Akdeniz University for dental issues. A comprehensive review of the literature was conducted, encompassing 21 articles sourced from PubMed and Web of Science over the past decade, including case reports and case series.&#x0D; Results. Case Report. A clinical case of a 35-year-old female patient seeking treatment for dental aesthetic concerns was reported and discussed. Intraoral examination revealed discoloration of maxillary anterior teeth and a sinus tract in the apical region of tooth #11. The resorption area was sealed with mineral trioxide aggregate. Afterward, the coronal part of the root was filled using the warm-vertical compaction method. During the final visit, non-vital bleaching was applied to teeth #11 and #21. After all these procedures, aesthetic coronal restorations were completed. Systematic Review. In the context of this clinical case, a literature review was conducted, encompassing an assessment of a total of 25 cases of external and internal resorptions. Among these cases, a combination of surgical and endodontic treatments was applied in 12 cases, while non-surgical endodontic treatment was performed in 13 cases.&#x0D; Conclusions. In the present case report, a patient who had both external and internal root resorptions was treated with mineral trioxide aggregate and flap operation, with no subsequent complications during the follow-up sessions. Among the 21 reports included in our review, 24 out of 25 treated teeth demonstrated successful outcomes, while only one tooth necessitated extraction.

Evaluation of Different Techniques and Materials for Filling in 3-dimensional Printed Teeth Replicas with Perforating Internal Resorption by Means of Micro–Computed Tomography

IntroductionThe aim of this study was to evaluate the filling ability of 2 obturation techniques in 3-dimensional (3D) printed teeth with perforating internal resorption (PIR). MethodsA maxillary central incisor was instrumented and scanned by micro–computed tomographic (micro-CT) imaging. The 3D model was exported in the stereolithographic format and, with the aid of OrtogOnBlender software (Cícero Moraes, Sinop, SP, Brazil), a PIR in the middle third of the root canal was designed. Thirty-two replicas were printed in surgical resin and distributed into 4 groups (n = 8) according to the obturation technique and the material used: 2 groups used the hybrid technique, 1 with Bio-C Sealer (BCS; Angelus, Londrina, PR, Brazil)/gutta-percha (GP; VDW GmbH, Munich, Germany) + Bio-C Repair (BCR; Angelus, Londrina, PR, Brazil) and the other with BioRoot (BR; Septodont, Saint Maur des Fosses, France)/gutta-percha (GP) + Biodentine (BD; Septodont, Saint Maur des Fosses, France), and 2 groups used the incremental technique, 1 with BCR and the other with BD. Postobturation micro-CT imaging was performed to measure the percentage volume of voids and laser confocal microscopy to measure the surface roughness (μm) of the repair cements. Data were compared using analysis of variance and Kruskal-Wallis tests. ResultsRegarding the filling volume in the apical third, the BCS/GP + BCR (89.70 ± 5.15), BR/GP + BD (87.70 ± 8.43), and BCR (84.20 ± 9.00) groups showed the highest percentages compared with the BD group (69.70 ± 6.88) (P < .05). In the area of internal resorption, the BCS/GP + BCR (96.00 ± 2.64) and BCR (95.30 ± 2.93) groups showed the highest percentages compared with the BR/GP + BD group (91.50 ± 1.35) (P < .05). The BD group showed intermediate values that were sometimes similar to the BCS/GP + BCR and BCR groups and similar to the BR/GP + BD group (P > .05). Regarding the quality of the filling in the perforation area, the BCR group showed better results compared with the BD group (P < .001). Regarding roughness, the BCR group (1.66 ± 0.65) showed lower surface roughness compared with the BD group (2.51 ± 0.89) (P < .05). ConclusionsThe capacity and quality of the filling in teeth with PIR were superior with the incremental technique with BCR and the hybrid technique with BCS/GP + BCR.

AMPKα1 negatively regulates osteoclastogenesis and mitigates pathological bone loss

Osteoclasts are specialized cells responsible for bone resorption, a highly energy-demanding process. Focus on osteoclast metabolism could be a key for the treatment of osteolytic diseases including osteoporosis. In this context, AMP-activated protein kinase α1 (AMPKα1), an energy sensor highly expressed in osteoclasts, participates in the metabolic reconfiguration during osteoclast differentiation and activation. This study aimed to elucidate the role of AMPKα1 during osteoclastogenesis in vitro and its impact in bone loss in vivo. Using LysMcre/0AMPK⍺1f/f animals and LysMcre/0 as control, we evaluated how AMPKα1 interferes with osteoclastogenesis and bone resorption activity in vitro. We found that AMPKα1 is highly expressed in the early stages of osteoclastogenesis. Genetic deletion of AMPKα1 leads to increased gene expression of osteoclast differentiation and fusion markers. In addition, LysMcre/0AMPK⍺1f/f mice had an increased number and size of differentiated osteoclast. Accordingly, AMPKα1 negatively regulates bone resorption in vitro, as evidenced by the area of bone resorption in LysMcre/0AMPK⍺1f/f osteoclasts. Our data further demonstrated that AMPKα1 regulates mitochondrial fusion and fission markers upregulating Mfn2 and downregulating DRP1 (dynamics-related protein 1) and that Ctskcre/0AMPK⍺1f/f osteoclasts lead to an increase in the number of mitochondria in AMPK⍺1-deficient osteoclast. In our in vivo study, femurs from Ctskcre/0AMPK⍺1f/f animals exhibited bone loss associated with the increased number of osteoclasts, and there was no difference between Sham and ovariectomized group. Our data suggest that AMPKα1 acts as a negative regulator of osteoclastogenesis, and the depletion of AMPKα1 in osteoclast leads to a bone loss state similar to that observed after ovariectomy.

Study of bone density according to СT data before and in the remote period after unicondylar knee arthroplasty

Background. Unicondylar knee arthroplasty has become popular among orthopedists in recent years. The main complication of this technology is the instability of the tibial component of the endoprosthesis due to the development of local osteoporosis in the area of arthroplasty. Patients with decreased bone density are at high risk of developing instability of the tibial component of the endoprosthesis. Therefore, determining the levels of bone mineral density in patients with osteopenia before arthroplasty make it possible to calculate the risk of complications in the long term. Objective: to evaluate the bone mineral density according to the computed tomography (CT) of the tibial plateau resection zone for unicondylar arthroplasty in patients at risk. Materials and methods. The state of three cortical layer zones was assessed: anterior, middle, posterior and 4 zones of the plateau cut plane. The optical density of bone tissue was measured on CT images of the tibial plateau of the knee joint using the Hounsfield scale. Changes in bone structures in the area of placing tibial component of the endoprosthesis were studied in 2 groups of patients: group I — ten individuals who had undergone unicondylar knee arthroplasty 3–6 years ago and complained of negative phenomena in the prosthetic knee, group II — ten patients who had undergone unicondylar arthroplasty 1.2–2 years ago. These patients underwent CT densitometry at the follow-up examination. Results. Before arthroplasty, the maximum optical density of bone tissue was statistically the same. The density of the cortical layer was maximal in the anterior part of the bone (~ 720 HU), minimal — in the posterior part (580 HU). For the spongy bone zone, the maximum optical density was observed in the anterior part (~ 470 HU), and in the posterior part, it was lower. In 3–6 years, patients of group I showed a significant decrease in the optical density of the bone, both in its cortical layer and in the cancellous tissue. The greatest losses were detected in the medial zones of the cancellous bone. Patients had areas of cortical layer resorption, and in some individuals, its complete absence. At the same time, the absorption index of the cortical layer in the areas of destruction did not exceed 100 HU. The maximum optical density of the cortical layer in the zones also decreased. In patients of group II, 1.5–2 years after arthroplasty, there were no noticeable changes in the bone structures in the surgery area. Changes occurred in the medial zones of the cancellous bone of the tibial plateau. Patients with osteopenia reported changes in bone optical density already in the first years after arthroplasty, although they do not lead to instability of the tibial component of the endoprosthesis. Conclusions. Patients with decreased bone density (osteopenia) during joint arthroplasty are at risk of developing local osteoporosis in the area of bone resection. The first signs of resorption of the cancellous bone can be observed 1.5–2 years after arthroplasty. Timely treatment measures can slow down the further progression of osteoporosis.

The Effect of PDLSCs on Orthodontic Tooth Movement – A Review

Background: Stem cells have been widely used in various fields of the health sector, one of which is dental health. Teeth with malocclusion require orthodontic treatment to achieve good function and aesthetics. Orthodontic tooth movement (OTM) occurs due to a bone remodeling process, namely deposition in areas of tension and resorption in areas of pressure. Differentiated stem cells are thought to influence OTM through several different mechanisms. Purpose: This narrative review seeks to explain how stem cells affect the mobility of orthodontic teeth. Review(s): OTM is aided by inflammatory mediators that are produced as a result of the induction of stem cells in the periodontal ligament. These mediators control osteoclast and osteoblast differentiation and proliferation, as well as bone remodeling. Periodontal ligament stem cells (PDLSCs) are important local immune response modulators in the inflammatory milieu and have an impact on a range of immune cells. Conclusion: PDLSCs, which are included in mesenchymal stem cells (MSCs), play a role in OTM through various mechanisms that can cause acceleration in OTM.