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Background: Oral and maxillofacial tissue defects resulting from factors such as trauma or infection, can significantly impact both facial function and aesthetics. Additionally, the complex anatomical structure of the face often increases the difficulty of treatment. With the advantages of controlled release, targeted delivery, and enhanced mechanical properties, injectable hydrogels have been investigated for the treatment of oral and maxillofacial diseases. In the field of regeneration, injectable hydrogels have a structure similar to the extracellular matrix (ECM) and are biocompatible, which can be used as scaffolds for tissue regeneration. Objective: This review aims to summarize the literature on the current status and limitations of injectable hydrogels in the field of oral tissue regeneration. Methods: We searched Pubmed and Web of Science databases to find and summarize the articles on the application of injectable hydrogels in tissue regeneration. Conclusions: This review focuses on the current status and limitations of injectable hydrogels in the field of tissue regeneration (periodontal tissue, dentin‐pulp complex, bone and cartilage, salivary gland regeneration, and mucosal repair). Although fully studied in animal models, there are still challenges in clinical transformation of injectable hydrogels in promoting tissue regeneration. [ABSTRACT FROM AUTHOR]

Periodontal disease is considered one of the diabetic complications with high morbidity and severity. Recent studies demonstrated the involvement of the epigenome on diabetic complications. Histone modifications change chromatin architecture and gene activation. Histone modifications have been reported to alter chromatin structure and regulate gene transcription. In this study, we investigated the impacts of H3 lysine 4 trimethylation (H3K4me3) and specific histone methyltransferases of H3K4 methylation, su(var)3-9, enhancer-of-zeste, and trithorax domain 1A (SETD1A) on periodontal tissue affected by the diabetic condition. We observed the increase in H3K4me3 and SETD1A in gingival tissue of diabetic rats compared with the normal rats. Cultured human fibroblasts (hGFs) confirmed a high glucose-induced increase in H3K4me3 and SETD1A. We further demonstrated that high glucose increased the gene expression of matrix metalloproteinase (MMP) 1 and MMP13, which were canceled by sinefungin, an SETD1A inhibitor. Our investigation suggests that diabetes triggers histone modifications in the gingival tissue, resulting in gingival inflammation. Histone modifications may play crucial roles in the development of periodontal disease in diabetes. [ABSTRACT FROM AUTHOR]

Understanding the composition and function of cells constituting tissues and organs is vital for unraveling biological processes. Single-cell analysis has allowed us to move beyond traditional methods of categorizing cell types. This innovative technology allows the transcriptional and epigenetic profiling of numerous individual cells, leading to significant insights into the development, homeostasis, and pathology of various organs and tissues in both animal models and human samples. In this review, we delve into the outcomes of major investigations using single-cell transcriptomics to decipher the cellular composition of mammalian teeth and periodontal tissues. The recent single-cell transcriptome-based studies have traced in detail the dental epithelium-ameloblast lineage and dental mesenchyme lineages in the mouse incisors and the tooth germ of both mice and humans; unraveled the microenvironment, the identity of niche cells, and cellular intricacies in the dental pulp; shed light on the molecular mechanisms orchestrating root formation; and characterized cellular dynamics of the periodontal ligament. Additionally, cellular components in dental pulps were compared between healthy and carious teeth at a single-cell level. Each section of this review contributes to a comprehensive understanding of tooth biology, offering valuable insights into developmental processes, niche cell identification, and the molecular secrets of the dental environment.

In this study, we established an experimental rat model to simulate orthodontic tooth movement relapse and a human periodontal ligament stem cell (PDLScs) model. Our aim was to explore the relationship between microRNA-146a (miR-146a) expression in periodontal tissue, the inflammatory factor interleukin-6 (IL-6), and orthodontic relapse subsequent to mechanical intervention. In the animal experiment, a total of 30 healthy male Wistar rats were randomly allocated to either the control group (n=6) or the model group (n=24). In the model group, the orthodontic appliance was removed 14 days after force application. Gingival crevicular fluid (GcF) and periodontal tissue samples were collected at intervals of days 0, 7, 14, and 21 following removal of the orthodontic appliance to assess alterations in miR-146a and IL-6 expressions. In the in vitro cell culture study, human premolar tooth tissue was isolated 24 hours following the addition of the transfection reagent to harvest PDLScs. Reverse transcription quantitative polymerase chain reaction was employed to evaluate the expression levels of the miRNA-146a gene, while Western blot analysis was utilized to assess the production of the IL-6 protein. As a result in comparison to the control group, the protein expression of IL-6 notably escalated to its peak value in the model-day 7 group (p<0.05). Subsequently, although experiencing a slight decline, the IL-6 expression in the modelday 14 group remained significantly elevated compared to control group (p<0.05). In the model-day 21 group, the protein expression of IL-6 approached that of the control group, with no significant difference observed (p>0.05). conversely, in relation to the control group, the gene expression of miR-146a drastically decreased to its lowest point in the model-day 7 group (p<0.05). While exhibiting a slight increase, the miR-146a expression in the model-day 14 group remained significantly diminished compared to control group (p<0.05). Following the identification of human periodontal ligament cells (hPDLcs) through immunofluorescence in the in vitro study, a subsequent experiment was conducted to specifically inhibit miR-146a expression. In comparison to the control group, the protein expression of IL-6 demonstrated a significant increase in the anti-miRNA oligodeoxyribonucleotide (AMO) group, where miR-146a expression was effectively suppressed (p<0.05). Throughout the process of orthodontic tooth movement relapse in rats, there was a notable reduction in the gene expression of miR-146a, accompanied by a significant increase in the expression of IL-6. [ABSTRACT FROM AUTHOR]

Introduction: P. gingivalis are the main bacteria that cause periodontal diseases. One of the clinical signs of periodontal disease is alveolar bone resorption. Tofu liquid waste is a typical high water-containing biomass and isoflavones. Isoflavones is a polyphenol that has an anti-inflammatory effect by reducing pro-inflammatory cytokine expression. This study aims to evaluate whether systemic administration of different tofu liquid waste doses has effects on decreasing alveolar bone resorption of the Wistar rats' periodontal tissues induced by P. gingivalis. Materials and methods:: This is true experimental research, with a randomized posttest-only group design. The groups are K (-) for the normal group, K (+) for the negative control group, and K-1, K-2, and K-3 for group induced with P.gingivalis [0.03 mL(1x 109CFU/mL)] and administrated with 6, 12, and 18 mL/kgBW tofu liquid waste respectively every day for 28 days. Results: Freeze-dried technique result showed tofu liquid waste still contains isoflavone (daidzin and glycitin). There is no difference in mean in all parameters between K(-) and K-3. K(+) has difference mean with K-1, K-2, and K-3. Correlation test showed there was a positive correlation between the dose levels of tofu liquid waste with osteoblasts and OPG, and a negative correlation between the dose levels of tofu liquid waste with lymphocytes, neutrophils, osteoclasts, RANKL, alveolar bone resorption, and periodontal ligament space. Conclusion: Tofu liquid waste administration has effects on decreasing the alveolar bone resorption of Wistar rat (Rattus norvegicus) periodontal tissues induced by P. gingivalis and 18 mL/kgBW has the highest effect. [ABSTRACT FROM AUTHOR]

Introduction: Periodontal disease is an infectious syndrome presenting inflammatory aspects. Radiographic evaluation is an essential complement to clinical assessment but has limitations such as the impossibility of assessing tissue inflammation. It seems essential to consider new exploration methods in clinical practice. Ultrasound of periodontal tissues could make it possible to visualize periodontal structures and detect periodontal diseases (periodontal pocket measurement and the presence of intra-tissue inflammation). Clinical Innovation Report: An ultrasound probe has been specially developed to explore periodontal tissues. The objective of this clinical innovation report is to present this device and expose its potential. Discussion: Various immediate advantages favor using ultrasound: no pain, no bleeding, faster execution time, and an image recording that can be replayed without having to probe the patient again. Ultrasound measurements of pocket depth appear to be as reliable and reproducible as those obtained by manual probing, as do tissue thickness measurements and the detection of intra-tissue inflammation. Conclusions: Ultrasound seems to have a broad spectrum of indications. Given the major advances offered by ultrasound imaging as a complementary aid to diagnosis, additional studies are necessary to validate these elements and clarify the potential field of application of ultrasound imaging in dentistry. [ABSTRACT FROM AUTHOR]

Proper management of orthodontic treatment in diabetic patients is essential due to the heightened risk of periodontal tissue breakdown associated with hyperglycemia. Cacao bean extracts (CBE) are known to reduce the inflammatory response and increase synthesis and angiogenesis in periodontitis. Therefore, this study aims to examine the effect of CBE on preventing periodontal tissue breakdown in diabetes with orthodontic force. A total of 25 Wistar rats were divided randomly into 5 groups, including non-diabetes, diabetes, diabetes cacao 125, 250, and 500 mg/kg BW. Diabetic rats were induced with the stratified dose of Streptozotocin, and a 30-g-force from orthodontic device was applied in all groups. Diabetes cacao group was given CBE for 7 days using a gastric probe. GCF samples were used to analyze the eNOS level through the ELISA method. NFκB, Collagen-1, and FGF-2 expression were then assessed using the immunohistochemical method, while the number of fibroblasts and blood vessels was observed using hematoxylin-eosin stained tissue. The data obtained were analyzed with one-way ANOVA and post hoc tests, with p < 0.05. CBE at a dose of 250 mg/kg BW significantly increased eNOS level, Collagen-1, and FGF-2 expression, and the number of fibroblasts and blood vessels in diabetes groups. Meanwhile, the treatment decreased NFκB expression in diabetes groups (p < 0.05). This study proved that CBE increased periodontal ligament synthesis and angiogenesis and decreased inflammatory response, thereby preventing periodontal tissue breakdown in diabetic rat models with tooth movement. [Display omitted] [ABSTRACT FROM AUTHOR]

Signal regulatory protein alpha (SIRPα) is mainly expressed by cells of myeloid origin. This membrane glycoprotein is shown to be involved in regulation of different inflammatory conditions, such as colitis and arthritis. However, SIRPα has not been investigated in relationship to periodontitis, an inflammatory condition affecting the tooth supporting tissues. We aim to investigate if resident cells in the periodontium express SIRPα and whether a possible expression is affected by inflammatory conditions. Primary human keratinocytes, fibroblasts, periodontal ligament cells, and osteoblasts were cultured with or without the pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) or interleukin-1-beta (IL-1β). All different periodontal cell types showed a basal mRNA expression of SIRPα. Pro-inflammatory cytokines induced a 2–3-fold significant increase in SIRPα expression in both cultured human gingival fibroblasts and osteoblasts but neither in keratinocytes nor in periodontal ligament cells. Tissue sections from human gingival tissue biopsies were histochemically stained for SIRPα. Epithelial keratinocytes and gingival fibroblasts stained positive in sections from periodontally healthy as well as in sections from periodontitis. In periodontitis sections, infiltrating leukocytes stained positive for SIRPα. We highlight our finding that oral keratinocytes, gingival fibroblasts, and periodontal ligament cells do express SIRPα, as this has not been presented before. The fact that inflammatory stimulation of gingival fibroblasts increased the expression of SIRPα, while an increased expression by gingival fibroblasts in periodontitis tissue in situ could not be detected, is indeed contradictory.

Periodontal tissue is tissue that surrounds the teeth and functions to keep the teeth in place. Various examinations can be carried out to determine the condition of the periodontal tissue, such as gingival index, bleeding on probing (BOP), and probing depth. In general, periodontal disease can be caused by 2 factors: local and systemic. One example of periodontal disease caused by systemic factors is infection with a disease or due to the influence of systemic treatment. COVID-19 is a family of coronaviridae viruses and severe acute respiratory syndrome discovered in December 2019 in Wuhan, Hubei Province, China. Transmission of this virus initially came from animals to humans (zoonosis) and then occurred on a large scale between humans. Various measures to prevent transmission and increase the severity of COVID-19 infection have been implemented, including the COVID-19 vaccination program. To determine the picture of the periodontal tissue of patients at RSGMP Soelastri Surakarta after COVID-19 vaccination. This study used research subjects, namely RSGMP Soelastri Surakarta patients who had received at least 1 dose of vaccine, and the research data were analyzed using Microsoft Excel. There were images in the periodontal tissue of patients after COVID-19 vaccination in the form of probing depth in 26 respondents and bleeding on probing in 38 respondents. Based on the results of the research and discussion above, it can be concluded that there is a picture of periodontal tissue in the form of bleeding on positive probing for bleeding in patients at RSGMP Soelastri Surakarta after 3 doses of COVID-19 vaccination with the AstraZeneca vaccine. [ABSTRACT FROM AUTHOR]

Abstract Background The surgically facilitated orthodontic strategy has been a promising strategy for orthodontic treatment recently. Therefore, the present meta-analysis was conducted to assess the available scientific evidence regarding the clinical outcomes, including the potential detrimental effects associated with these surgical procedures, with the aim of providing much more evidence-based information for clinical practice. Methods An electronic search of three databases (PubMed, Cochrane, and Embase) and a manual search of relevant articles published up to May 2023 were carried out. Clinical trials (≥ 10 subjects) that utilized surgically facilitated orthodontic strategies with clinical and/or radiographic outcomes were included. Meta-analyses and sub-group analyses were performed to analyze the standardized mean difference (SMD) or weighted mean difference (WMD), and confidence interval (CI) for the recorded variables. Results Nineteen studies published from Oct 2012 to May 2023 met the inclusion criteria. Based on the analysis outcomes, corticotomy treatment significantly decreased the alignment duration (WMD: -1.08 months; 95% CI = -1.65, -0.51 months, P = 0.0002), and accelerated the canine movement (WMD: 0.72 mm; 95% CI = 0.63, 0.81 mm, P

Background: The surgically facilitated orthodontic strategy has been a promising strategy for orthodontic treatment recently. Therefore, the present meta-analysis was conducted to assess the available scientific evidence regarding the clinical outcomes, including the potential detrimental effects associated with these surgical procedures, with the aim of providing much more evidence-based information for clinical practice. Methods: An electronic search of three databases (PubMed, Cochrane, and Embase) and a manual search of relevant articles published up to May 2023 were carried out. Clinical trials (≥ 10 subjects) that utilized surgically facilitated orthodontic strategies with clinical and/or radiographic outcomes were included. Meta-analyses and sub-group analyses were performed to analyze the standardized mean difference (SMD) or weighted mean difference (WMD), and confidence interval (CI) for the recorded variables. Results: Nineteen studies published from Oct 2012 to May 2023 met the inclusion criteria. Based on the analysis outcomes, corticotomy treatment significantly decreased the alignment duration (WMD: -1.08 months; 95% CI = -1.65, -0.51 months, P = 0.0002), and accelerated the canine movement (WMD: 0.72 mm; 95% CI = 0.63, 0.81 mm, P < 0.00001) compared to the traditional orthodontic group. The periodontally accelerated osteogenic orthodontic (PAOO) strategy markedly reduced the total treatment duration (SMD: -1.98; 95% CI = -2.59, -1.37, P < 0.00001) and increased the bone thickness (SMD:1.07; 95% CI = 0.74, 1.41, P < 0.00001) compared to traditional orthodontic treatment. Conclusion: The present study suggests that facilitated orthodontic treatment in terms of corticotomy and PAOO strategy may represent attractive and effective therapeutic strategy for orthodontic patients. [ABSTRACT FROM AUTHOR]

This article reviews the emerging field of periodontal tissue analysis in the context of forensic trauma assessment. Periodontal tissues are examined for their unique potential to improve the accuracy and scope of forensic investigations. They respond dynamically to different types of injuries, exhibiting distinct histological changes and features, thereby providing insights into the nature and timing of injuries. Although this method is promising, it also poses notable challenges, including contamination risks, post-mortem changes, and interpretation of histological results. Future implications will focus on advances in molecular analysis, integration of imaging technology, and establishment of reference databases. Standardization, quality assurance, and interdisciplinary collaboration are essential for reliable periodontal tissue analysis. In summary, periodontal tissue analysis is a dynamic and promising tool with significant implications in forensics, provided that it is used ethically and in accordance with the highest standards. This emerging field highlights the use of periodontal tissue analysis and the commitment of forensic experts needed to unravel the complexities of trauma, offering a potential path in the field of forensic science. [ABSTRACT FROM AUTHOR]

The aesthetic constancy and functional stability of periodontium largely depend on the presence of healthy mucogingival tissue. Soft tissue management is crucial to the success of periodontal surgery. Recently, synthetic substitute materials have been proposed to be used for soft tissue augmentation, but the tissue compatibility of these materials needs to be further investigated. This study aims to assess the in vitro responses of human gingival mesenchymal stromal cells (hG-MSCs) cultured on a Gelatin/Polycaprolactone prototype (GPP) and volume-stable collagen matrix (VSCM). hG-MSCs were cultured onto the GPP, VSCM, or plastic for 3, 7, and 14 days. The proliferation and/or viability were measured by cell counting kit-8 assay and resazurin-based toxicity assay. Cell morphology and adhesion were evaluated by microscopy. The gene expression of collagen type I, alpha1 (COL1A1), α-smooth muscle actin (α-SMA), fibroblast growth factor (FGF-2), vascular endothelial growth factor A (VEGF-A), transforming growth factor beta-1 (TGF-β1), focal adhesion kinase (FAK), integrin beta-1 (ITG-β1), and interleukin 8 (IL-8) was investigated by RT-qPCR. The levels of VEGF-A, TGF-β1, and IL-8 proteins in conditioned media were tested by ELISA. GPP improved both cell proliferation and viability compared to VSCM. The cells grown on GPP exhibited a distinct morphology and attachment performance. COL1A1, α-SMA, VEGF-A, FGF-2, and FAK were positively modulated in hG-MSCs on GPP at different investigation times. GPP increased the gene expression of TGF-β1 but had no effect on protein production. The level of ITG-β1 had no significant changes in cells seeded on GPP at 7 days. At 3 days, notable differences in VEGF-A, TGF-β1, and α-SMA expression levels were observed between cells seeded on GPP and those on VSCM. Meanwhile, GPP showed higher COL1A1 expression compared to VSCM after 14 days, whereas VSCM demonstrated a more significant upregulation in the production of IL-8. Taken together, our data suggest that GPP electrospun nanofibers have great potential as substitutes for soft tissue regeneration in successful periodontal surgery. [ABSTRACT FROM AUTHOR]

Silk fibroin (SF) film/porous SF-nanohydroxyapatite (nHA) double-layer composite scaffolds were fabricated by a combination of electrospinning, casting and freeze-drying. The results showed that the tensile strength and elongation of the SF film layer were significantly improved through the bridging effect of SF/(ε-caprolactone) fibers in the SF matrix. The pore size in SF-nHA porous scaffold layer was approximately 213 μm, and nHA enhanced the compressive strength of the scaffold. CCK-8 assay showed that the SF/SF-nHA scaffold not only had no obvious cytotoxicity but also significantly promoted cell proliferation. The scaffold has the potential to be used for periodontal tissue regeneration. [ABSTRACT FROM AUTHOR]

Background/purpose: The ligature-induced periodontitis model is an effective approach to induce inflammation and bone loss similar to that of human periodontitis. Previous clinical and in vitro studies have shown the involvement of lymphocytes in periodontitis, while, the local and systemic profile of immune cells associated with periodontitis in the ligature-induced periodontitis model in mice remains unclear. Materials and methods: Experimental periodontitis was constructed in mice by ligating around the maxillary second molars for 14 and 28 days, respectively. Alveolar bone loss was assessed by micro-computed tomography (micro-CT). Hematoxylin and eosin (H&E) and tartrate-resistant acid phosphatase (TRAP) staining were used to evaluate the histological changes in the periodontal tissues. B and T cells in the cervical lymph nodes, spleen, and peripheral blood were analyzed by flow cytometry. Results: The 14-day ligation effectively induced significant periodontal inflammation and alveolar bone loss in C57BL/6J mice, which were progressive and maintained for a relatively long-term period until day 28. In addition, CD3+ T cells and CD19+ B cells were the dominant population in both health and disease, and the B cell population within the cervical lymph nodes (LN) increased significantly under periodontitis condition, while, no significant differences of the T and B cell population among the spleen and peripheral blood were observed. Conclusion: The ligature-induced periodontitis mice model was established to perform a longitudinal assessment of changes in periodontal tissues morphologically and histologically, meanwhile, explore the local and systemic changes of the predominant immune-associated cells.

Introduction: Periodontal disease is an infectious syndrome presenting inflammatory aspects. Radiographic evaluation is an essential complement to clinical assessment but has limitations such as the impossibility of assessing tissue inflammation. It seems essential to consider new exploration methods in clinical practice. Ultrasound of periodontal tissues could make it possible to visualize periodontal structures and detect periodontal diseases (periodontal pocket measurement and the presence of intra-tissue inflammation). Clinical Innovation Report: An ultrasound probe has been specially developed to explore periodontal tissues. The objective of this clinical innovation report is to present this device and expose its potential. Discussion: Various immediate advantages favor using ultrasound: no pain, no bleeding, faster execution time, and an image recording that can be replayed without having to probe the patient again. Ultrasound measurements of pocket depth appear to be as reliable and reproducible as those obtained by manual probing, as do tissue thickness measurements and the detection of intra-tissue inflammation. Conclusions: Ultrasound seems to have a broad spectrum of indications. Given the major advances offered by ultrasound imaging as a complementary aid to diagnosis, additional studies are necessary to validate these elements and clarify the potential field of application of ultrasound imaging in dentistry.

The ligature-induced periodontitis model is an effective approach to induce inflammation and bone loss similar to that of human periodontitis. Previous clinical and in vitro studies have shown the involvement of lymphocytes in periodontitis, while, the local and systemic profile of immune cells associated with periodontitis in the ligature-induced periodontitis model in mice remains unclear. Experimental periodontitis was constructed in mice by ligating around the maxillary second molars for 14 and 28 days, respectively. Alveolar bone loss was assessed by micro-computed tomography (micro-CT). Hematoxylin and eosin (H&E) and tartrate-resistant acid phosphatase (TRAP) staining were used to evaluate the histological changes in the periodontal tissues. B and T cells in the cervical lymph nodes, spleen, and peripheral blood were analyzed by flow cytometry. The 14-day ligation effectively induced significant periodontal inflammation and alveolar bone loss in C57BL/6J mice, which were progressive and maintained for a relatively long-term period until day 28. In addition, CD3+ T cells and CD19+ B cells were the dominant population in both health and disease, and the B cell population within the cervical lymph nodes (LN) increased significantly under periodontitis condition, while, no significant differences of the T and B cell population among the spleen and peripheral blood were observed. The ligature-induced periodontitis mice model was established to perform a longitudinal assessment of changes in periodontal tissues morphologically and histologically, meanwhile, explore the local and systemic changes of the predominant immune-associated cells. [ABSTRACT FROM AUTHOR]

Investigation on the effect of Piezo1 on periodontal tissue and periodontal ligament fibroblasts (PDLFs) under mechanical stress and the underlying mechanism. The orthodontic tooth movement rat model was established via an orthodontic spiral tension spring. PDLFs were cultured and subjected to 2.0 g/cm2 static compressive loading. Blocked the Piezo1 via Piezo1 inhibitor, GsMTx4. TUNEL staining and flow cytometry determined the apoptosis rate of periodontal tissue and PDLFs in rats. Expression of Piezo1, p‐p38 and ERK1/2 was analysed by immunofluorescence assay and western blotting. Piezo1 inhibitor GsMTx4 relieved the increased expression of Piezo1, ERK1/2 and p‐p38, and alleviated apoptosis in periodontal tissue and PDLFs under compressive loading. Piezo1 inhibition can alleviate force‐induced apoptosis and damage in rats' periodontal tissue and PDLFs, and regulate the p38/ERK1/2 signalling pathway. [ABSTRACT FROM AUTHOR]

Purpose: To use and evaluate two methods for measuring gingival thickness (GT) at mandibular incisors of orthodontic patients and compare their performance in assessing periodontal anatomy through soft tissue thickness.Materials and Methods: The sample consisted of 40 consecutive adult orthodontic patients. GT was measured just before bracket placement at both central mandibular incisors, mid-facially on the buccal aspect, 2 mm apically to the free gingival margin with two methods: clinically with an ultrasound device (USD) and radiographically with cone-beam computed tomography (CBCT).Results: CBCT measurements were consistently higher than USD measurements, with the difference ranging from 0.13 mm to 0.21 mm. No statistically significant difference was noted between the repeated CBCT measurements at the right central incisor (bias = 0.05 mm; 95% CI = -0.01, 0.11; p = 0.104). Although the respective results for the left incisor statistically indicated that the measurements were not exactly replicated, the magnitude of the point estimate was small and not clinically significant (bias = 0.06 mm; 95% CI = 0.01, 0.11; p = 0.014). Small differences between CBCT measurements made by the 2 examiners at the left central incisor (bias = 0.06 mm; 95% CI = 0.01, 0.11; p = 0.014) were detected. However, this difference was minor and also not clinically significant. The respective analysis on the right incisor showed no statistically significant difference (bias = 0.05 mm; 95% CI = -0.01, 0.11; p = 0.246).Conclusions: Based on reproducibility, CBCT imaging for gingival thickness assessment proved to be as reliable as ultrasound determination. However, CBCT consistently yielded higher values, albeit at a marginal level, than did the ultrasound device. [ABSTRACT FROM AUTHOR]

Abstract Orthodontic tooth movement relies on bone remodeling and periodontal tissue regeneration in response to the complicated mechanical cues on the compressive and tensive side. In general, mechanical stimulus regulates the expression of mechano-sensitive coding and non-coding genes, which in turn affects how cells are involved in bone remodeling. Growing numbers of non-coding RNAs, particularly mechano-sensitive non-coding RNA, have been verified to be essential for the regulation of osteogenesis and osteoclastogenesis and have revealed how they interact with signaling molecules to do so. This review summarizes recent findings of non-coding RNAs, including microRNAs and long non-coding RNAs, as crucial regulators of gene expression responding to mechanical stimulation, and outlines their roles in bone deposition and resorption. We focused on multiple mechano-sensitive miRNAs such as miR-21, - 29, -34, -103, -494-3p, -1246, -138-5p, -503-5p, and -3198 that play a critical role in osteogenesis function and bone resorption. The emerging roles of force-dependent regulation of lncRNAs in bone remodeling are also discussed extensively. We summarized mechano-sensitive lncRNA XIST, H19, and MALAT1 along with other lncRNAs involved in osteogenesis and osteoclastogenesis. Ultimately, we look forward to the prospects of the novel application of non-coding RNAs as potential therapeutics for tooth movement and periodontal tissue regeneration.

Periodontal tissue stem cells, which play a crucial role in maintaining the homeostasis of periodontal tissues, are found in the periodontal ligament (PDL). These cells have long been referred to as mesenchymal stem/stromal cells (MSCs), and their clinical applications have been extensively studied. However, tissue stem cells in the PDL have not been thoroughly investigated, and they may be different from MSCs. Recent advances in stem cell biology, such as genetic lineage tracing, identification of label-retaining cells, and single-cell transcriptome analysis, have made it possible to analyze tissue stem cells in the PDL in vivo. In this review, we summarize recent findings on these stem cell populations in PDL and discuss future research directions toward developing periodontal regenerative therapy.

The periodontal ligament is located between the bone (alveolar bone) and the cementum of the tooth, and it is connected by tough fibers called Sharpey's fibers. To maintain healthy teeth, the foundation supporting the teeth must be healthy. Periodontal diseases, also known as tooth loss, cause the alveolar bone to dissolve. The alveolar bone, similar to the bones in other body parts, is repeatedly resorbed by osteoclasts and renewed by osteogenic cells. This means that an old bone is constantly being resorbed and replaced by a new bone. In periodontal diseases, the alveolar bone around the teeth is absorbed, and as the disease progresses, the alveolar bone shrinks gradually. In most cases, the resorbed alveolar bone does not return to its original form even after periodontal disease is cured. Gum covers the tooth surface so that it matches the shape of the resorbed alveolar bone, exposing more of the tooth surface than before, making the teeth look longer, leaving gaps between the teeth, and in some cases causing teeth to sting. Previously, the only treatment for periodontal diseases was to stop the disease from progressing further before the teeth fell out, and restoration to the original condition was almost impossible. However, a treatment method that can help in the regeneration of the supporting tissues of the teeth destroyed by periodontal diseases and the restoration of the teeth to their original healthy state as much as possible is introduced. Recently, with improvements in implant material properties, implant therapy has become an indispensable treatment method in dentistry and an important prosthetic option. Treatment methods and techniques, which are mainly based on experience, have gradually accumulated scientific evidence, and the number of indications for treatment has increased. The development of bone augmentation methods has contributed remarkably to the expansion of indications, and this has been made possible by various advances in materials science. The induced pluripotent stem cell (iPS) cell technology for regenerating periodontal tissues, including alveolar bone, is expected to be applied in the treatment of diseases, such as tooth loss and periodontitis. This review focuses on the alveolar bone and describes clinical practice, techniques, and the latest basic research. [ABSTRACT FROM AUTHOR]

The aesthetic constancy and functional stability of periodontium largely depend on the presence of healthy mucogingival tissue. Soft tissue management is crucial to the success of periodontal surgery. Recently, synthetic substitute materials have been proposed to be used for soft tissue augmentation, but the tissue compatibility of these materials needs to be further investigated. This study aims to assess the in vitro responses of human gingival mesenchymal stromal cells (hG-MSCs) cultured on a Gelatin/Polycaprolactone prototype (GPP) and volume-stable collagen matrix (VSCM). hG-MSCs were cultured onto the GPP, VSCM, or plastic for 3, 7, and 14 days. The proliferation and/or viability were measured by cell counting kit-8 assay and resazurin-based toxicity assay. Cell morphology and adhesion were evaluated by microscopy. The gene expression of collagen type I, alpha1 (COL1A1), α-smooth muscle actin (α-SMA), fibroblast growth factor (FGF-2), vascular endothelial growth factor A (VEGF-A), transforming growth factor beta-1 (TGF-β1), focal adhesion kinase (FAK), integrin beta-1 (ITG-β1), and interleukin 8 (IL-8) was investigated by RT-qPCR. The levels of VEGF-A, TGF-β1, and IL-8 proteins in conditioned media were tested by ELISA. GPP improved both cell proliferation and viability compared to VSCM. The cells grown on GPP exhibited a distinct morphology and attachment performance. COL1A1, α-SMA, VEGF-A, FGF-2, and FAK were positively modulated in hG-MSCs on GPP at different investigation times. GPP increased the gene expression of TGF-β1 but had no effect on protein production. The level of ITG-β1 had no significant changes in cells seeded on GPP at 7 days. At 3 days, notable differences in VEGF-A, TGF-β1, and α-SMA expression levels were observed between cells seeded on GPP and those on VSCM. Meanwhile, GPP showed higher COL1A1 expression compared to VSCM after 14 days, whereas VSCM demonstrated a more significant upregulation in the production of IL-8. Taken together, our data suggest that GPP electrospun nanofibers have great potential as substitutes for soft tissue regeneration in successful periodontal surgery.

This systematic review aims to investigate the possibilities of ultrasound imaging in the field of periodontal tissues exploration to visualize periodontal anatomical structures and to assess reliability in clinical evaluation using the PRISMA guidelines. An electronic search through the MEDLINE database was realized to identify studies that have explored ultrasonography in the field of periodontal imaging published from 2000 to March 2022. The search resulted in 245 records; after exclusions, a total of 15 papers were included in the present review. Various publications have shown the possibility of using intraoral ultrasound for a precise exploration of intraoral tissues and to perform measurements of periodontal structures. Studies argue that ultrasounds open the prospect of a complete paradigm shift on the diagnosis and follow-up of periodontal disease. However, there is currently no clinical device dedicated to periodontal ultrasound. This field is still under-studied, and studies are needed to explore the large field of applications from periodontal assessment to treatment reassessment, including surgery. Researchers should focus their efforts to develop special intraoral ultrasound device and explore the possibilities of clinical periodontal applications. [ABSTRACT FROM AUTHOR]

Human periodontal ligament cells (hPDLCs) are known as ideal seed cells for the regeneration of periodontal tissues. Several factors (i.e., vitamin D3, luteolin, and 6-bromoindirubin-3′-oxime) have been shown to promote osteogenic differentiation of hPDLCs. In this study, we aim to investigate the effect of vitamin A on cell proliferation, migration, and osteogenic differentiation of hPDLCs. hPDLCs were cultured in osteogenic induction medium supplemented with different concentrations of vitamin A. Cell proliferation and migration assays were conducted after 24, 48, and 72 h of incubation, whereas osteogenic differentiation and osteogenesis-related gene expression were assessed after 21 d only. Our results demonstrated that 1-µM vitamin A stimulation exerted the most potent promotion effect on cell proliferation, migration, and osteogenic differentiation of hPDLCs. It also induced significant upregulation of osteogenic differentiation–related genes and mitochondrial complexes II and IV in hPDLCs. Vitamin A may serve as a promising potential candidate for periodontal tissue regeneration. [ABSTRACT FROM AUTHOR]

Orthodontic tooth movement relies on bone remodeling and periodontal tissue regeneration in response to the complicated mechanical cues on the compressive and tensive side. In general, mechanical stimulus regulates the expression of mechano-sensitive coding and non-coding genes, which in turn affects how cells are involved in bone remodeling. Growing numbers of non-coding RNAs, particularly mechano-sensitive non-coding RNA, have been verified to be essential for the regulation of osteogenesis and osteoclastogenesis and have revealed how they interact with signaling molecules to do so. This review summarizes recent findings of non-coding RNAs, including microRNAs and long non-coding RNAs, as crucial regulators of gene expression responding to mechanical stimulation, and outlines their roles in bone deposition and resorption. We focused on multiple mechano-sensitive miRNAs such as miR-21, - 29, -34, -103, -494-3p, -1246, -138-5p, -503-5p, and -3198 that play a critical role in osteogenesis function and bone resorption. The emerging roles of force-dependent regulation of lncRNAs in bone remodeling are also discussed extensively. We summarized mechano-sensitive lncRNA XIST, H19, and MALAT1 along with other lncRNAs involved in osteogenesis and osteoclastogenesis. Ultimately, we look forward to the prospects of the novel application of non-coding RNAs as potential therapeutics for tooth movement and periodontal tissue regeneration. [ABSTRACT FROM AUTHOR]

Periodontal tissue stem cells, which play a crucial role in maintaining the homeostasis of periodontal tissues, are found in the periodontal ligament (PDL). These cells have long been referred to as mesenchymal stem/stromal cells (MSCs), and their clinical applications have been extensively studied. However, tissue stem cells in the PDL have not been thoroughly investigated, and they may be different from MSCs. Recent advances in stem cell biology, such as genetic lineage tracing, identification of label-retaining cells, and single-cell transcriptome analysis, have made it possible to analyze tissue stem cells in the PDL in vivo. In this review, we summarize recent findings on these stem cell populations in PDL and discuss future research directions toward developing periodontal regenerative therapy. [ABSTRACT FROM AUTHOR]

This research aimed to evaluate Mask R-CNN and U-Net convolutional neural network models for pixel-level classification in order to perform the automatic segmentation of bi-dimensional images of US dental arches, identifying anatomical elements required for periodontal diagnosis. A secondary aim was to evaluate the efficiency of a correction method of the ground truth masks segmented by an operator, for improving the quality of the datasets used for training the neural network models, by 3D ultrasound reconstructions of the examined periodontal tissue. Methods: Ultrasound periodontal investigations were performed for 52 teeth of 11 patients using a 3D ultrasound scanner prototype. The original ultrasound images were segmented by a low experienced operator using region growing-based segmentation algorithms. Three-dimensional ultrasound reconstructions were used for the quality check and correction of the segmentation. Mask R-CNN and U-NET were trained and used for prediction of periodontal tissue's elements identification. Results: The average Intersection over Union ranged between 10% for the periodontal pocket and 75.6% for gingiva. Even though the original dataset contained 3417 images from 11 patients, and the corrected dataset only 2135 images from 5 patients, the prediction's accuracy is significantly better for the models trained with the corrected dataset. Conclusions: The proposed quality check and correction method by evaluating in the 3D space the operator's ground truth segmentation had a positive impact on the quality of the datasets demonstrated through higher IoU after retraining the models using the corrected dataset. [ABSTRACT FROM AUTHOR]

Periodontal tissue supports teeth in the alveolar bone socket via fibrous attachment of the periodontal ligament (PDL). The PDL contains periodontal fibroblasts and stem/progenitor cells, collectively known as PDL cells (PDLCs), on top of osteoblasts and cementoblasts on the surface of alveolar bone and cementum, respectively. However, the characteristics and lineage hierarchy of each cell type remain poorly defined. This study identified periodontal ligament associated protein-1 (Plap-1) as a PDL-specific extracellular matrix protein. We generated knock-in mice expressing CreERT2 and GFP specifically in Plap-1-positive PDLCs. Genetic lineage tracing confirmed the longstanding hypothesis that PDLCs differentiate into osteoblasts and cementoblasts. A PDL single-cell atlas defined cementoblasts and osteoblasts as Plap-1-Ibsp+Sparcl1+ and Plap-1-Ibsp+Col11a2+, respectively. Other populations, such as Nes+ mural cells, S100B+ Schwann cells, and other non-stromal cells, were also identified. RNA velocity analysis suggested that a Plap-1highLy6a+ cell population was the source of PDLCs. Lineage tracing of Plap-1+ PDLCs during periodontal injury showed periodontal tissue regeneration by PDLCs. Our study defines diverse cell populations in PDL and clarifies the role of PDLCs in periodontal tissue homeostasis and repair. [ABSTRACT FROM AUTHOR]

Background: Periodontal disease is a chronic inflammatory disease caused by periodontal bacteria. Recently, periodontal phototherapy, treatment using various types of lasers, has attracted attention. Purpose: This in vitro study was aimed to compare and evaluate the effect of lasers with different wave lengths on proliferation and differentiation of periodontal ligament stem cells to stimulate periodontal reattachment. Materials and Methods: A randomized and controlled study design was used to evaluate the effect of low-level laser therapy (LLLT) delivered at different doses over dental fibroblast cell culture in high glucose medium. Results: Comparison between MTT Assay results for the normal group under wavelength 635 and 980 under laser energy 0.5, 1, and 2 and after 24, 48, 72, and 96 hours. All results were significant except the results after 24 hours in MTT 635 assay, Conclusion: The response of cell viability was significantly higher for non-diabetic cases in comparison to diabetic ones for both 635 & 980 nm lasers with different doses and at different time points. Our results also suggested that the cell viability was dosed dependent. [ABSTRACT FROM AUTHOR]

Multiple systems and associated factors have been described in the literature to assess the prognosis of teeth with periodontal disease. Nowadays there is a tendency among clinicians to consider implants as the best solution after tooth extraction, in cases of teeth with a questionable prognosis. However, the value of the natural tooth must be considered, as the proprioception of the periodontal ligament is preserved, and it adapts to stress during functional loads. We first review the literature focusing on analyzing the factors that should guide decision-making to maintain or extract a tooth with a compromised periodontium. Then, we propose a schematic diagram of prognostic indicators to reflect the main factors to consider and the survival rate that each one represents when preserving or extracting a tooth. [ABSTRACT FROM AUTHOR]

Abstract Background The biocompatibility of NeoMTA Plus® (Avlon BioMed Inc., Bradenton, Fl) as a furcal perforation repair material is not fully understood. This study compares the biocompatibility of Mineral Trioxide Aggregate (MTA Angelus) and NeoMTA Plus® as delayed furcation perforation repair materials. Methods Pulpotomy and root canal obturation were performed in 72 premolars in six mongrel dogs and then a standardized furcal perforation was performed. The coronal access was left open for three weeks. After curetting, cleaning and drying of the perforations, these teeth were divided into three equal groups (N = 24 teeth/ 2 dogs each) according to the material used for perforation repair; group I: NeoMTA Plus®, group II: MTA Angelus and group III: no material (positive control). The coronal access cavities were sealed with a filling material. The inflammatory cell count and qualitative pathology (presence of calcific bridge, configuration of fibrous tissue formed, examination of tissue surrounding the furcation area, histology of intraradicular bone and the inflammatory nature of tissues) were carried out after one week (subgroup A, N = 8 teeth), one month (subgroup B, N = 8 teeth) and three months (subgroup C, N = 8 teeth). The inflammatory cell count was expressed as mean ± SD and statistically analyzed. P-value 0.05). In contrast to group II, there was no significant differences in inflammatory cell count between the subgroups in groups I and III (P > 0.05). NeoMTA Plus® exhibited better qualitative pathological features than MTA Angelus after one week and nearly similar features after one month and three months of repair. Conclusion NeoMTA Plus® has a better early biocompatibility than MTA Angelus after one week of delayed furcation perforation repair and a similar late biocompatibility after one month and three months.

The periodontal ligament is located between the bone (alveolar bone) and the cementum of the tooth, and it is connected by tough fibers called Sharpey’s fibers. To maintain healthy teeth, the foundation supporting the teeth must be healthy. Periodontal diseases, also known as tooth loss, cause the alveolar bone to dissolve. The alveolar bone, similar to the bones in other body parts, is repeatedly resorbed by osteoclasts and renewed by osteogenic cells. This means that an old bone is constantly being resorbed and replaced by a new bone. In periodontal diseases, the alveolar bone around the teeth is absorbed, and as the disease progresses, the alveolar bone shrinks gradually. In most cases, the resorbed alveolar bone does not return to its original form even after periodontal disease is cured. Gum covers the tooth surface so that it matches the shape of the resorbed alveolar bone, exposing more of the tooth surface than before, making the teeth look longer, leaving gaps between the teeth, and in some cases causing teeth to sting. Previously, the only treatment for periodontal diseases was to stop the disease from progressing further before the teeth fell out, and restoration to the original condition was almost impossible. However, a treatment method that can help in the regeneration of the supporting tissues of the teeth destroyed by periodontal diseases and the restoration of the teeth to their original healthy state as much as possible is introduced. Recently, with improvements in implant material properties, implant therapy has become an indispensable treatment method in dentistry and an important prosthetic option. Treatment methods and techniques, which are mainly based on experience, have gradually accumulated scientific evidence, and the number of indications for treatment has increased. The development of bone augmentation methods has contributed remarkably to the expansion of indications, and this has been made possible by various advances in materials science. The induced pluripotent stem cell (iPS) cell technology for regenerating periodontal tissues, including alveolar bone, is expected to be applied in the treatment of diseases, such as tooth loss and periodontitis. This review focuses on the alveolar bone and describes clinical practice, techniques, and the latest basic research.

• Acidification is induced in the gingival sulcus of mechanically forced tooth. • Buffering the gingival acidity ameliorates orthodontic mechanical allodynia. • ASIC3 is involved in the mechanical allodynia induced by orthodontic force. • Tooth movement causes ASIC3 phosphorylation in the periodontal tissue. Tooth movements associated with orthodontic treatment often cause tooth pain. However, the detailed mechanism remains unclear. Here, we examined the involvement of periodontal acidification caused by tooth movement in mechanical tooth pain hypersensitivity. Elastics were inserted between the first and second molars to move the teeth in Sprague-Dawley rats. Mechanical head-withdrawal reflex threshold to first molar stimulation and the pH of the gingival sulcus around the tooth were measured. The expression of acid-sensing ion channel 3 (ASIC3) in trigeminal ganglion neurons and phosphorylation of ASIC3 in the periodontal tissue were analyzed. The mechanical head-withdrawal reflex threshold to first molar stimulation and pH in the gingival sulcus decreased on day 1 after the elastic insertion. These decreases recovered to the sham level by buffering periodontal acidification. Periodontal inhibition of ASIC3 channel activity reversed the decreased mechanical head-withdrawal reflex threshold to first molar stimulation. On day 1 after elastic insertion, the tooth movement did not change the number of ASIC3 immunoreactive trigeminal ganglion neurons innervating the periodontal tissue but increased phosphorylated-ASIC3 levels in the periodontal tissue. Periodontal acidification induced by tooth movement causes phosphorylation of ASIC3, resulting in mechanical pain hypersensitivity in mechanically forced tooth. [ABSTRACT FROM AUTHOR]

Periodontal disease is one of the most common diagnoses in small animal veterinary medicine. This infectious disease of the periodontium is characterized by the inflammation and destruction of the supporting structures of teeth, including periodontal ligament, cementum, and alveolar bone. Traditional periodontal repair techniques make use of open flap debridement, application of graft materials, and membranes to prevent epithelial downgrowth and formation of a long junctional epithelium, which inhibits regeneration and true healing. These techniques have variable efficacy and are made more challenging in veterinary patients due to the cost of treatment for clients, need for anesthesia for surgery and reevaluation, and difficulty in performing necessary diligent home care to maintain oral health. Tissue engineering focuses on methods to regenerate the periodontal apparatus and not simply to repair the tissue, with the possibility of restoring normal physiological functions and health to a previously diseased site. This paper examines tissue engineering applications in periodontal disease by discussing experimental studies that focus on dogs and other animal species where it could potentially be applied in veterinary medicine. The main areas of focus of tissue engineering are discussed, including scaffolds, signaling molecules, stem cells, and gene therapy. To date, although outcomes can still be unpredictable, tissue engineering has been proven to successfully regenerate lost periodontal tissues and this new possibility for treating veterinary patients is discussed. [ABSTRACT FROM AUTHOR]

Background. Determining what dentists know and believe about periodontal tissue properties is important to establish prevention practices. The present study aimed to investigate the knowledge, attitude, and practice of general dental practitioners about the properties of periodontal tissue around retainable teeth in Birjand, Northeast Iran. Methods. The knowledge, practice, and attitude of 91 dentists about periodontal tissue properties around retainable teeth were assessed by a validated researcher-made questionnaire. Results. The results showed that the mean score of dentists’ attitude, knowledge, and practice were 70.7, 88.2, and 77, respectively. The mean score of the attitude of male dentists was higher than females significantly (P = 0.014). Conclusion. It is highly recommended that continuing courses should be held to improve their knowledge.

Periodontitis is commonly observed and is an important concern in dental health. It is characterized by a multifactorial etiology, including imbalance of oral microbiota, mechanical stress, and systemic diseases such as diabetes mellitus. The current standard treatments for periodontitis include elimination of the microbial pathogen and application of biomaterials for treating bone defects. However, the periodontal tissue regeneration via a process consistent with the natural tissue formation process has not yet been achieved. Developmental biology studies state that periodontal tissue is composed of neural crest-derived ectomesenchyme. To elucidate the process of periodontal regeneration, it is essential to understand the developmental background and intercellular cross-talk. Several recent studies have reported the efficacy of transplantation of mesenchymal stem cells for periodontal tissue regeneration. In this review, we discuss the basic knowledge of periodontal tissue regeneration using mesenchymal stem cells and highlight the potential of stem cell-based periodontal regenerative medicine.

This systematic review aims to investigate the possibilities of ultrasound imaging in the field of periodontal tissues exploration to visualize periodontal anatomical structures and to assess reliability in clinical evaluation using the PRISMA guidelines. An electronic search through the MEDLINE database was realized to identify studies that have explored ultrasonography in the field of periodontal imaging published from 2000 to March 2022. The search resulted in 245 records; after exclusions, a total of 15 papers were included in the present review. Various publications have shown the possibility of using intraoral ultrasound for a precise exploration of intraoral tissues and to perform measurements of periodontal structures. Studies argue that ultrasounds open the prospect of a complete paradigm shift on the diagnosis and follow-up of periodontal disease. However, there is currently no clinical device dedicated to periodontal ultrasound. This field is still under-studied, and studies are needed to explore the large field of applications from periodontal assessment to treatment reassessment, including surgery. Researchers should focus their efforts to develop special intraoral ultrasound device and explore the possibilities of clinical periodontal applications.

Photobiomodulation (PBM) has been demonstrated as a non-invasive and painless technique with great potential to accelerate orthodontic tooth movement (OTM). However, there is a great inconsistency among PBM protocols and reported outcomes, probably due to the poor translatability of preclinical knowledge into early clinical practice. Hence, this review aims to fill this gap by establishing the state-of-the-art on both preclinical and clinical applications of PBM, and by comprehensively discussing the most suitable stimulation protocols described in the literature. This review was conducted according to PRISMA guidelines. A bibliographic search was carried out in the PubMed, Scopus and Cochrane databases using a combination of keywords. Only studies written in English were eligible and no time limit was applied. A total of 69 studies were selected for this review. The revised literature describes that PBM can effectively reduce orthodontic treatment time and produce analgesic and anti-inflammatory effects. We found that PBM of 640 ± 25, 830 ± 20 and 960 ± 20 nm, delivered at a minimum energy density per irradiation point of 5 J/cm 2 daily or every other day sessions is robustly associated with increased tooth movement rate. Pain relief seems to be achieved with lower irradiation doses compared to those required for OTM acceleration. For the first time, the bioeffects induced by PBM for the acceleration of OTM are comprehensively discussed from a translational point of view. Collectively, the evidence from preclinical and clinical trials supports the use of PBM as a coadjuvant in orthodontics for enhancing tooth movement and managing treatment-associated discomfort. Overall, the revised studies indicate that optimal PBM parameters to stimulate tissue remodelling are wavelengths of 830 ± 20 nm and energy densities of 5-70 J/cm 2 applied daily or every other day can maximize the OTM rate, while lower doses (up to 16 J/cm 2 per session) delivered in non-consecutive days seem to be optimal for inducing analgesic effects. Future research should focus on optimizing laser parameters and treatment protocols customized for tooth and movement type. By fine-tuning laser parameters, clinicians can potentially reduce treatment times, improve patient comfort and achieve more predictable outcomes, making orthodontic care more efficient and patient-friendly, thus consolidating PBM usage in orthodontics., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The periodontal ligaments (PDLs) with specific orientations to tooth-root surfaces play a key role in generating biomechanical responses between the alveolar bone and cementum as a tooth-supporting tissue. However, control of angulations and regeneration of the ligamentous tissues within micron-scaled interfaces remains challenging. To overcome this limitation, this study investigated surface fabrications with microgroove patterns to control orientations of rat PDL cells in vitro and fibrous tissues in vivo. After being harvested, rat PDL cells were cultured and three different microgroove patterns (∠PDL groove = 0°, ∠PDL groove = 45°, and ∠PDL groove = 90°) were created by the digital slicing step in 3D printing. Cell-seeded scaffolds were subcutaneously transplanted at 3 and 6 weeks. In histology images, rat PDL cells were spatially controlled to angularly organize following the microgroove patterns and fibrous tissues were formed in scaffolds with specific angulations, which were reflected by additively manufactured microgroove topographies. Based on the results, specifically characterized surface topographies were significant to directly/indirectly organizing rat PDL cell alignments and fibrous tissue orientations. Therefore, interactions between surface topographies and tissue organizations could be one of the key moderators for the multiple tissue complex (bone-ligament-cementum) neogenesis in periodontal tissue engineering. [ABSTRACT FROM AUTHOR]

This research aimed to evaluate Mask R-CNN and U-Net convolutional neural network models for pixel-level classification in order to perform the automatic segmentation of bi-dimensional images of US dental arches, identifying anatomical elements required for periodontal diagnosis. A secondary aim was to evaluate the efficiency of a correction method of the ground truth masks segmented by an operator, for improving the quality of the datasets used for training the neural network models, by 3D ultrasound reconstructions of the examined periodontal tissue. Methods: Ultrasound periodontal investigations were performed for 52 teeth of 11 patients using a 3D ultrasound scanner prototype. The original ultrasound images were segmented by a low experienced operator using region growing-based segmentation algorithms. Three-dimensional ultrasound reconstructions were used for the quality check and correction of the segmentation. Mask R-CNN and U-NET were trained and used for prediction of periodontal tissue’s elements identification. Results: The average Intersection over Union ranged between 10% for the periodontal pocket and 75.6% for gingiva. Even though the original dataset contained 3417 images from 11 patients, and the corrected dataset only 2135 images from 5 patients, the prediction’s accuracy is significantly better for the models trained with the corrected dataset. Conclusions: The proposed quality check and correction method by evaluating in the 3D space the operator’s ground truth segmentation had a positive impact on the quality of the datasets demonstrated through higher IoU after retraining the models using the corrected dataset.

Objective This study aimed to investigate the expression of autophagy-related factors microtubule-associated protein l light chain 3 (LC3) and the apoptosis-related factors BCL2-associated X protein (Bax) and B cell lymphoma-2 (Bcl-2) in the periodontal tissue of experimental diabetic rats. These data were used to explore the potential mechanism in diabetes-induced periodontal tissue lesions. Methods A total of 32 Sprague Dawley (SD) rats were randomly assigned into diabetes (group D, n = 16) and control groups (group N, n = 16). The diabetic group was induced by intraperitoneal injection of 1% streptozotocin (STZ, 60 mg/kg) and the control group was injected with citrate buffer (0.1mol/L). Rats were sacrificed after 4 and 8 weeks of feeding and collected as D1, N1 groups and D2, N2 groups, and the maxilla were retained for analysis. The changes in periodontal tissue structure were observed by hematoxylin-eosin (HE) staining. The expression and distribution of LC3, Bax and Bcl-2 in the periodontium of the rats was detected by immunohistochemical (SP) staining. Results Diabetic rats showed several changes compared to control animals including sparse alveolar bone trabecular structure, loss of the lamina dura and absorption of the local alveolar bone. The positive expression level of LC3 in the gingival epithelial, periodontal ligament and alveolar bone of group D1 was significantly higher than in the N1, N2 and D2 groups (P < 0.05). The level of Bax expression in the group D2 rats was significantly higher than those in the N1, N2 and D1 groups (P < 0.05), while the positive degree of Bcl-2 was significantly lower than those of other groups (P < 0.001). LC3 was negatively correlated with Bax and was irrelevant with Bcl-2; Bcl-2 was not correlated with Bax. Conclusions The expression of LC3, Bax and Bcl-2 changes in the periodontal tissue of diabetic rats may indicate that autophagy and apoptotic are involved in the process of periodontal tissue damage in diabetic rats. These changes may be one of the mechanisms of periodontal tissue lesions.

Purpose: To investigate the risk of debonding of resin‐bonded fixed dental prosthesis frameworks and the effects on the periodontal tissue in patients with reduced alveolar bone levels. Materials and methods: The abutment teeth were the upper central incisor and the canine. Resin‐bonded fixed dental prosthesis framework fabricated using zirconia was set to models with five different alveolar bone levels. A 200‐N load (the maximum clenching force of the anterior teeth) was applied to the center of the pontic to analyze the internal stress on the framework, adhesive cement, and periodontal tissue using finite element analysis. Results: The mean maximum principal stress generated in the framework was 25.33 and 29.35 MPa in the models with the normal and the lowest alveolar bone level, respectively. Regarding shear stress on the adhesive cement, stress concentration was observed on the connector side in all models, and it increased on the cervical side of the central incisor as the alveolar bone level decreased. In addition, the mean maximum and minimum principal strains generated on the periodontal ligament of the central incisor and canine tended to increase as alveolar bone loss progressed. Furthermore, the mean maximum principal stress on the cortical bone was the greatest in the model with the most significant bone loss at 5.10 MPa. Conclusions: This study suggested that the risk of debonding and periodontal tissue damage might be higher when resin‐bonded fixed dental prosthesis frameworks were used in patients with reduced alveolar bone levels compared to those in a healthy state. [ABSTRACT FROM AUTHOR]

Extracellular Vesicles (EVs) are small lipid-enclosed particles containing biological molecules such as RNA and proteins that have emerged as vital modulators of intercellular communication. Increasingly, studies have shown that EVs play an essential role in the occurrence and prognosis of oral diseases. EVs are increasingly considered a research hotspot of oral diseases. In addition, the characteristics of carrying active molecules have also been studied in oral tissue regeneration. Evidence has shown that EVs regulate the homeostasis of the inflammatory microenvironment, promote angiogenesis, and repair damaged tissues. In this review, we summarized the characteristics of EVs and highlighted the role of EVs in oral tissue regeneration, including dental pulp, periodontal tissue, cartilage, and bone. We also discussed their deficiencies and prospects as a potential therapeutic role in the regeneration treatment of oral disease.

Background: The biocompatibility of NeoMTA Plus® (Avlon BioMed Inc., Bradenton, Fl) as a furcal perforation repair material is not fully understood. This study compares the biocompatibility of Mineral Trioxide Aggregate (MTA Angelus) and NeoMTA Plus® as delayed furcation perforation repair materials. Methods: Pulpotomy and root canal obturation were performed in 72 premolars in six mongrel dogs and then a standardized furcal perforation was performed. The coronal access was left open for three weeks. After curetting, cleaning and drying of the perforations, these teeth were divided into three equal groups (N = 24 teeth/ 2 dogs each) according to the material used for perforation repair; group I: NeoMTA Plus®, group II: MTA Angelus and group III: no material (positive control). The coronal access cavities were sealed with a filling material. The inflammatory cell count and qualitative pathology (presence of calcific bridge, configuration of fibrous tissue formed, examination of tissue surrounding the furcation area, histology of intraradicular bone and the inflammatory nature of tissues) were carried out after one week (subgroup A, N = 8 teeth), one month (subgroup B, N = 8 teeth) and three months (subgroup C, N = 8 teeth). The inflammatory cell count was expressed as mean ± SD and statistically analyzed. P-value < 0.05 was considered significant. Results: In all subgroups, the control group exhibited the highest number of inflammatory cell count, followed by MTA Angelus group and the least inflammatory cell count was shown by NeoMTA Plus® group. There was a significant difference in the inflammatory cell count between the NeoMTA Plus® and MTA Angelus after one week (P < 0.05) while no significant differences were recorded between them after one month and three months (P > 0.05). In contrast to group II, there was no significant differences in inflammatory cell count between the subgroups in groups I and III (P > 0.05). NeoMTA Plus® exhibited better qualitative pathological features than MTA Angelus after one week and nearly similar features after one month and three months of repair. Conclusion: NeoMTA Plus® has a better early biocompatibility than MTA Angelus after one week of delayed furcation perforation repair and a similar late biocompatibility after one month and three months. [ABSTRACT FROM AUTHOR]

Introduction: Periodontal disease is an inflammatory response of the periodontal tissues, resulting in tissue destruction, bone loss and eventually tooth loss. Determining what dentists know and believe about periodontal tissue properties is important in order to establish prevention practices. The aim of this study was to investigate the knowledge, attitude and practice of general dentists in Birjand about the properties of periodontal tissue around retainable teeth. Materials and methods: A cross-sectional study was conducted on 91 general dentists by the census method. Knowledge, practice and attitude of general dentists about periodontal tissue properties around retainable teeth were assessed by a validated researcher-made questionnaire applied in Birjand city. Data was analyzed using ANOV At-test or nonparametric equivalent, at a significant level of 0.05.Results and discussion: The results showed that the mean score of dentists' attitude, knowledge and practice about the characteristics of periodontal tissue around retainable teeth were 70.7, 88.2 and 77, respectively. The mean score of attitude of male dentists was significantly higher than in female ones (P=0.014), however, in the two other scales, no significant difference was observed (P>0.05). Also, a significant inverse relationship was observed between dentists' knowledge and their work experience, but no significant difference in the attitude and practice based on work experience (P>0.05). Conclusions: According to the results of this study, although dentists have good attitude and practice regarding the characteristics of periodontal tissue around retainable teeth, their knowledge was insufficient and appeared relatively moderate. So, it is highly recommended that retraining courses should be held to improve their knowledge. [ABSTRACT FROM AUTHOR]

Electronic Nicotine vaping cigarettes (E-cigs) are spreading worldwide. Their popularity came as representing an alternative to traditional tobacco cigarettes (T-cigs). Despite the recognition as a tool for smoking cessation and being a safer alternative, latest research showed their negative impact. On periodontal and peri-implant tissues, information on E-cigs effect is scarce. This review updates the available research regarding the different aspects of E-cigs vaping on periodontal and peri-implant tissues at clinical and microbial levels, in addition to periodontal treatment results in individuals using E-cig. [ABSTRACT FROM AUTHOR]

Aim: To study the dental and periodontal status of women with breast cancer (BCa) having tamoxifen or aromatase inhibitors (AIs) treatment in comparison with control healthy women. Methods: Fifty‐one women on tamoxifen therapy, 52 women on AIs therapy and 52 systemically healthy controls were included in the study. The total number of teeth, the number of teeth indicated for extraction, the number of decayed teeth, and the duration of medication were recorded. Periodontal status was evaluated with gingival index (GI); plaque index (PI); bleeding on probing (BOP); probing depth (PD) and clinical attachment loss (CAL). Results: The lowest number of teeth and decayed teeth was found in AIs users (P <.001 and P =.003 respectively). The highest CAL value was seen in AIs users (P =.042) whereas no significant difference was found between the groups in terms of PI, GI, and PD (P =.102, P =.233, and P =.306, respectively). Lower PI was observed in patients using AIs for less than 2 years (P =.048). Conclusions: While tamoxifen did not affect the dental and periodontal condition, AIs medication adversely affected the dental and periodontal condition by more tooth loss and higher CAL. [ABSTRACT FROM AUTHOR]

Understanding the composition and function of cells constituting tissues and organs is vital for unraveling biological processes. Single-cell analysis has allowed us to move beyond traditional methods of categorizing cell types. This innovative technology allows the transcriptional and epigenetic profiling of numerous individual cells, leading to significant insights into the development, homeostasis, and pathology of various organs and tissues in both animal models and human samples. In this review, we delve into the outcomes of major investigations using single-cell transcriptomics to decipher the cellular composition of mammalian teeth and periodontal tissues. The recent single-cell transcriptome-based studies have traced in detail the dental epithelium-ameloblast lineage and dental mesenchyme lineages in the mouse incisors and the tooth germ of both mice and humans; unraveled the microenvironment, the identity of niche cells, and cellular intricacies in the dental pulp; shed light on the molecular mechanisms orchestrating root formation; and characterized cellular dynamics of the periodontal ligament. Additionally, cellular components in dental pulps were compared between healthy and carious teeth at a single-cell level. Each section of this review contributes to a comprehensive understanding of tooth biology, offering valuable insights into developmental processes, niche cell identification, and the molecular secrets of the dental environment., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Shinsuke Ohba reports a relationship with the Japan Society for the Promotion of Science (JSPS), Naito Foundation, and Takeda Science Foundation that include funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V.)