Expert consensus on irrigation and intracanal medication in root canal therapy

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment. However, irrigant selection or irrigation procedures are far from clear. The vapor lock effect in the apical region has yet to be solved, impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes.

Expert consensus on difficulty assessment of endodontic therapy

Endodontic diseases are a kind of chronic infectious oral disease. Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha. However, it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy(RCT). Recent research, encompassing bacterial etiology and advanced imaging techniques, contributes to our understanding of the root canal system’s anatomy intricacies and the technique sensitivity of RCT. Success in RCT hinges on factors like patients, infection severity, root canal anatomy, and treatment techniques. Therefore, improving disease management is a key issue to combat endodontic diseases and cure periapical lesions. The clinical difficulty assessment system of RCT is established based on patient conditions, tooth conditions, root canal configuration, and root canal needing retreatment, and emphasizes pre-treatment risk assessment for optimal outcomes. The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT. These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

Molecular events in the jaw vascular unit:A traditional review of the mechanisms involved in inflammatory jaw bone diseases

Inflammatory jaw bone diseases are common in stomatology,including periodontitis,peri-implantitis,medication-related osteonecrosis of the jaw,radiation osteomyelitis of the jaw,age-related osteoporosis,and other specific infections.These diseases may lead to tooth loss and maxillofacial deformities,severely affecting patients'quality of life.Over the years,the reconstruction of jaw bone deficiency caused by inflammatory diseases has emerged as a medical and socioeconomic challenge.Therefore,exploring the pathogenesis of inflammatory diseases associated with jaw bones is crucial for improving prognosis and developing new targeted therapies.Accumulating evidence indicates that the integrated bone formation and dysfunction arise from complex interactions among a network of multiple cell types,including osteoblast-associated cells,immune cells,blood vessels,and lymphatic vessels.However,the role of these different cells in the inflammatory process and the'rules'with which they interact are still not fully understood.Although many investigations have focused on specific pathological processes and molecular events in inflammatory jaw diseases,few articles offer a perspective of integration.Here,we review the changes and mechanisms of various cell types in inflammatory jaw diseases,with the hope of providing insights to drive future research in this field.

Clinicopathological study of malignant peripheral nerve sheath tumors in the head and neck:Case reports and review of literature

BACKGROUND Malignant peripheral nerve sheath tumor(MPNST)is a rare and aggressive soft tissue sarcoma that poses a major diagnostic and therapeutic challenge.CASE SUMMARY We retrospectively reviewed patients with head and neck MPNSTs treated in our hospital from 2000 to 2021.The clinical features,pathological manifestations,treatments,and prognoses were summarized.We also reviewed the literature,focusing on MPNST in the mandible and maxilla.The study population consisted of five women and five men aged 22–75 years(mean age,49 years).Of the 10 patients,7 were initial cases and 3 were recurrent cases.All lesions were sporadic.The most common site was the mandible.The most frequently encountered symptoms were a progressive mass and local swelling.Complete or partial loss of trimethylation at lysine 27 of histone H3(H3K27me3)was evident on staining in four of nine cases(one case was excluded due to lack of tissue for evaluation of loss of H3K27me3).The 2-and 5-year disease-specific survival rates were 86%a nd 43%,respectively.The average survival time was 64 mo.CONCLUSION MPNST is a highly malignant tumor with a poor prognosis,prone to a high risk of recurrence and distant metastasis.Complete surgical resection is the main treatment.

Expert consensus on digital guided therapy for endodontic diseases

Digital guided therapy(DGT)has been advocated as a contemporary computer-aided technique for treating endodontic diseases in recent decades.The concept of DGT for endodontic diseases is categorized into static guided endodontics(SGE),necessitating a meticulously designed template,and dynamic guided endodontics(DGE),which utilizes an optical triangulation tracking system.Based on cone-beam computed tomography(CBCT)images superimposed with or without oral scan(OS)data,a virtual template is crafted through software and subsequently translated into a 3-dimensional(3D)printing for SGE,while the system guides the drilling path with a real-time navigation in DGE.DGT was reported to resolve a series of challenging endodontic cases,including teeth with pulp obliteration,teeth with anatomical abnormalities,teeth requiring retreatment,posterior teeth needing endodontic microsurgery,and tooth autotransplantation.Case reports and basic researches all demonstrate that DGT stand as a precise,time-saving,and minimally invasive approach in contrast to conventional freehand method.This expert consensus mainly introduces the case selection,general workflow,evaluation,and impact factor of DGT,which could provide an alternative working strategy in endodontic treatment.

An in vitro study on the efficacy of removing calcium hydroxide from curved root canal systems in root canal therapy

To compare the efficacy of various irrigants(citric acid, ethylenediaminetetraacetic acid(EDTA) and Na OCl) and techniques in removing Ca(OH)2in two types of curved root canal systems, simulated root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH)2removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution: 10% citric acid or2.5% Na OCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH)2. The percentage of Ca(OH)2removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10% citric acid and 17% EDTA were applied to remove Ca(OH)2from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH)2removal in the canals.In simulated root canals, we found that 10% citric acid removed more Ca(OH)2than 2.5% NaOCl in the 0–1 mm group from the apex level(Po0.05). Ultrasonic and Endo Activator activation significantly removed more Ca(OH)2than a size 30 K file in the apical third(Po0.05). However, there were no significant differences in any sections of the canals for 10% citric acid or 17%EDTA in removing Ca(OH)2in extracted human teeth. We concluded that it was effective to remove residual Ca(OH)2using the decalcifying solution with Endo Activator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH)2removal was provided based on the conclusions of this study and the methods recommended in previous studies.

Human β-defensin 3 gene modification promotes the osteogenic differentiation of human periodontal ligament cells and bone repair in periodontitis

Efforts to control inflammation and achieve better tissue repair in the treatment of periodontitis have been ongoing for years.Humanβ-defensin 3,a broad-spectrum antimicrobial peptide has been proven to have a variety of biological functions in periodontitis;however,relatively few reports have addressed the effects of human periodontal ligament cells(h PDLCs)on osteogenic differentiation.In this study,we evaluated the osteogenic effects of h PDLCs with an adenoviral vector encoding humanβ-defensin 3 in an inflammatory microenvironment.Then humanβ-defensin 3 gene-modified rat periodontal ligament cells were transplanted into rats with experimental periodontitis to observe their effects on periodontal bone repair.We found that the humanβ-defensin 3 gene-modified h PDLCs presented with high levels of osteogenesis-related gene expression and calcium deposition.Furthermore,the p38 MAPK pathway was activated in this process.In vivo,humanβ-defensin 3 gene-transfected rat PDLCs promoted bone repair in SD rats with periodontitis,and the p38 mitogen-activated protein kinase(MAPK)pathway might also have been involved.These findings demonstrate that humanβ-defensin 3 accelerates osteogenesis and that humanβ-defensin 3 gene modification may offer a potential approach to promote bone repair in patients with periodontitis.

Sustained delivery of vascular endothelial growth factor mediated by bioactive methacrylic anhydride hydrogel accelerates peripheral nerve regeneration after crush injury

Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration arriving at the injury site results in unsatisfactory outcomes.Therefore,there is an urgent need for a treatment method that can increase the effective drug concentration in the injured area.In this study,we first fabricated a gelatin modified by methacrylic anhydride hydrogel and loaded it with vascular endothelial growth factor that allowed the controlled release of the neurotrophic factor.This modified gelatin exhibited good physical and chemical properties,biocompatibility and supported the adhesion and proliferation of RSC96 cells and human umbilical vein endothelial cells.When injected into the epineurium of crushed nerves,the composite hydrogel in the rat sciatic nerve crush injury model promoted nerve regeneration,functional recovery and vascularization.The results showed that the modified gelatin gave sustained delivery of vascular endothelial growth factors and accelerated the repair of crushed peripheral nerves.

Oral and maxillofacial pain as the first sign of metastasis of an occult primary tumour:A fifteen-year retrospective study

BACKGROUND Metastatic adenocarcinoma of the jaw(MAJ)is a rare disease that accounts for 1%-3%of all oral and maxillofacial malignant tumours.Oral and maxillofacial pain may be the first symptom of metastatic spread of an occult primary tumour.Therefore,early identification of oral and maxillofacial pain by dental professionals is critical.AIM To explore the clinical and computerized tomography(CT)features of MAJ with oral and maxillofacial pain as the first symptom.METHODS The medical records of all patients who were treated in our hospital between January 2006 and February 2020,and diagnosed with MAJ with oral and maxillofacial pain as the first symptom,were reviewed retrospectively.Clinical data were collected on age,sex,medical history,clinical manifestations,site of metastasis,and site of the primary lesion.CT features were analysed in detail,and a radiological classification scheme comprising five types:Osteolytic,osteoblastic,mixed,cystic,and alveolar bone resorption was proposed.RESULTS The primary sites of MAJ were the lungs(n=6),liver(n=4),kidneys(n=2),prostate(n=1),and gastric cardia(n=1).Five tumours were classified as the osteolytic type,all with a permeative margin(100%,P<0.05),and three were classified as the mixed type,mostly with a moth-eaten margin(80%,P<0.05).The cystic(n=3)and alveolar bone resorption(n=1)types had geographic margins,and the osteoblastic type(n=1)had sclerotic margins.Moreover,nine tumours showed periosteal reaction and five showed a localised soft tissue mass,while the occurrence of jaw expansion was relatively rare.CONCLUSION MAJ has complex clinical and CT features.Oral and maxillofacial pain may be the first sign of a primary tumour affecting other sites.

E26 transformation-specific 1 is implicated in the inhibition of osteogenic differentiation induced by chronic high glucose by directly regulating Runx2 expression

Chronic high glucose(HG) plays a crucial role in the pathogenesis of diabetes-induced osteoporosis by inhibiting the differentiation and proliferation of osteoblasts. This study aims to examine the role of E26 transformation-specific 1(ETS1) in the inhibition of osteoblast differentiation and proliferation caused by chronic HG, as well as the underlying mechanism. Chronic HG treatment downregulated ETS1 expression and inhibited differentiation and proliferation of MC3 T3-E1 cells. Downregulation of ETS1 expression inhibited the differentiation and proliferation of MC3 T3-E1 cells under normal glucose conditions, and ETS1 overexpression attenuated the damage to cells exposed to chronic HG. In addition, ETS1 overexpression reversed the decrease in runt-related transcription factor 2(Runx2) expression in MC3 T3-E1 cells treated with chronic HG. Using chromatin immunoprecipitation(ChIP) and luciferase reporter assays, we confirmed that ETS1 directly bound to and increased the activity of the Runx2 promoter. In summary, our study suggested that ETS1 was involved in the inhibitory effect of chronic HG on osteogenic differentiation and proliferation and may be a potential therapeutic target for diabetes-induced osteoporosis.

Conservative endodontic management using a calcium silicate bioceramic sealer for delayed root fracture:A case report and review of the literature

BACKGROUND The success rate of conservative endodontic management for root fracture varies greatly based on different methods used.It has been rarely reported that calcium silicate-based materials are applied in root fracture treatment.CASE SUMMARY A 38-year-old male patient presented with spontaneous pain from the upper left anterior teeth for 1 wk.The spontaneous pain was subsequently relieved,but pain on mastication persisted for 3 d.The patient had a dental trauma from a boxing match 15 years ago.Cone beam computed tomography showed that the maxillary left central incisor had oblique fracture lines and a radiolucent lesion around the fracture line.The tooth was diagnosed with an oblique root fracture with no healing and symptomatic apical periodontitis.In the following conservative endodontic management,the coronal and apical fragments of the canal both were chemo-mechanically prepared and obturated using a single cone gutta-percha with iRoot SP(Innovative BioCreamix Inc,Vancouver,Canada),a new calcium silicate-based bioceramic root canal sealer.At follow-ups at 1,6,12,and 24 mo,the patient was asymptomatic and the radiolucency around the fracture line was healing radiographically.CONCLUSION Conservative root canal treatment is an alternative treatment in some cases of oblique root fracture with no healing.The application of bioceramic sealers and single core obturation techniques may also be essential to obtain an excellent outcome.

Intentional replantation combined root resection therapy for the treatment of typeⅢradicular groove with two roots:A case report

BACKGROUND A radicular groove is an anatomic malformation that usually initiates at the central fossa,extending along the root at varying lengths and depths and predisposes the involved tooth to a severe periodontal defect.Severe grooves that extend to the root apex often lead to complex combined periodontal-endodontic lesions.They are a serious challenge for doctors to diagnose and treat.CASE SUMMARY In this report,we described a patient with a maxillary lateral incisor with a deep palatogingival groove with two roots,which led to complex combined periodontal-endodontic lesions.Suggested treatment modalities included curettage of the affected tissues,elimination of the groove by grinding and/or sealing with a variety of filling materials,and surgical procedures.In this case,a combination of endodontic therapy,intentional replantation,and root resection were used,which resulted in periodontal/periradicular healing after 12 mo.CONCLUSION Intentional replantation and root resection offer a predictable procedure and should be considered a viable treatment modality for the management of palatogingival grooves,especially for two-rooted teeth.

Maxillary first premolars:Ⅰ.Morphology of the apical constriction

Objective： To investigated the apical constriction morphology of maxillary first premolars in the Chinese population. Methods： Eighty recently extracted human maxillary first premolars from a native Chinese population were used. The number and shape of apical constrictions were recorded under a dental operating microscope （DOM） at 12.5 × 2.5 magnification. After access preparation, a new K-file was inserted into the canal until the tip of the file was just seen at the apical constriction under the DOM. The teeth with files in the canals were X-rayed from a mesiodistal direction using a direct digital radiography （DDR） system, and the distance between the file tip and the center of radiographic apex was directly measured from the computer screen using DDR measurement software. Results： The percentage of teeth with an apical constriction was 78.5% （102/130）. The most common apical constriction shapes were oval （55.9%） and round （35.3%）. The mean distance between the apical constriction and the anatomical tip of the root was 0.61 mm, and 84.3% （86/102） were within 1 mm. Conclusion： The most common shape of an apical constriction was oval or round, and the distance to the apex was mostly within 1 mm, indicating that root canal therapy should stop 1 mm from the radiographic apex.

The roles of focal adhesion and cytoskeleton systems in fluid shearstress-induced endothelial cell response

Focal adhesions are polyproteins linked to extracellular matrix and cytoskeleton,which play an important role in the process of transforming force signals into intracellular chemical signals and subsequently triggering related physiological or pathological reactions.The cytoskeleton is a network of protein fibers in the cytoplasm,which is composed of microfilaments,microtubules,intermediate filaments,and cross-linked proteins.It is a very important structure for cells to maintain their basic morphology.This review summarizes the process of fluid shear stress transduction mediated by focal adhesion and the key role of the cytoskeleton in this process,which focuses on the focal adhesion and cytoskeleton systems.The important proteins involved in signal transduction in focal adhesion are introduced emphatically.The relationship between focal adhesion and mechanical transduction pathways are discussed.In this review,we discuss the relationship between fluid shear stress and associated diseases such as atherosclerosis,as well as its role in clinical research and drug development.

Cystic teratoma of the parotid gland:A case report

BACKGROUND Teratoma is a common tumor,but rarely occurs in the parotid region.Only nine cases have been reported in the current literature.Although it is generally detected in infancy or childhood,it is commonly asymptomatic.Computed tomography(CT)and magnetic resonance imaging(MRI)have important roles in the diagnosis of teratoma.CASE SUMMARY A 36-year-old man developed a lump located below the left auricular lobule 3 years ago.Physical examination revealed a nearly-circular tumor in the left parotid gland region with a defined border,firm texture,and significant movement.Calcification,fat,keratinized substances,and typical fat-liquid levels was observed on CT and MRI.A diagnosis of cystic teratoma of the parotid gland was established preoperatively and confirmed by postoperative pathology.Following surgery,the patient developed temporary facial paralysis.There was no recurrence of teratoma during the 15-mo follow-up period.CONCLUSION When an asymptomatic mass in the parotid region is identified,parotid gland teratoma should be included in the differential diagnosis.Imaging examinations are helpful in the diagnosis.

Clinical management of primary odontogenic sarcoma in the mandible:a case report after WHO nomination

Ameloblastic fibro-odontosarcoma(AFOS)now designated as odontogenic sarcoma is an extremely rare odontogenic tumor,which histologically presents as a biphasic neoplasm with a malignant mesenchymal component plus ameloblastic epithelium.Here we report a 27-year-old Chinese female with the complaint of a painful swelling for half a month in the right mandible.A segmental mandibulectomy,with an immediate mandibular reconstruction using a free vascularized osteocutaneous fibular flap was performed using surgical guide models.Histological analysis revealed a primary odontogenic sarcoma.The postoperative period was uneventful,and no clinical indication of recurrence or metastasis was observed during the 3-year follow-up.No adjuvant therapy was proposed.This is the first odontogenic sarcoma case reported in China after the new World Health Organization classification of odontogenic lesions.

Tetrahedral framework nucleic acid carrying angiogenic peptide prevents bisphosphonate-related osteonecrosis of the jaw by promoting angiogenesis

The significant clinical feature of bisphosphonate-related osteonecrosis of the jaw(BRONJ)is the exposure of the necrotic jaw.Other clinical manifestations include jaw pain,swelling,abscess,and skin fistula,which seriously affect the patients’life,and there is no radical cure.Thus,new methods need to be found to prevent the occurrence of BRONJ.Here,a novel nanoparticle,t FNA-KLT,was successfully synthesized by us,in which the nanoparticle tetrahedral framework nucleic acid(tFNA)was used for carrying angiogenic peptide,KLT,and then further enhanced angiogenesis.TFNA-KLT possessed the same characteristics as tFNA,such as simple synthesis,stable structure,and good biocompatibility.Meanwhile,tFNA enhanced the stability of KLT and carried more KLT to interact with endothelial cells.First,it was confirmed that tFNA-KLT had the superior angiogenic ability to tFNA and KLT both in vitro and in vivo.Then we apply tFNA-KLT to the prevention of BRONJ.The results showed that tFNA-KLT can effectively prevent the occurrence of BRONJ by accelerating angiogenesis.In summary,the prepared novel nanoparticle,tFNA-KLT,was firstly synthesized by us.It was also firstly confirmed by us that tFNA-KLT significantly enhanced angiogenesis and can effectively prevent the occurrence of BRONJ by accelerating angiogenesis,thus providing a new avenue for the prevention of BRONJ and a new choice for therapeutic angiogenesis.

Characterization of oral bacterial diversity of irradiated patients by high-throughput sequencing

The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy.Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients.Eight patients with head and neck cancers were involved in this study.For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy.A total of 147 232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis,representing 3 460 species level operational taxonomic units(OTUs) and 140 genus level taxa.Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics.Moreover,the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves.This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.

3D bioprinted hyaluronic acid‑based cell‑laden scaffold for brain microenvironment simulation

Treatments for lesions in central nervous system(CNS)are always faced with challenges due to the anatomical and physiological particularity of the CNS despite the fact that several achievements have been made in early diagnosis and precision medicine to improve the survival and quality of life of patients with brain tumors in recent years.Understanding the complexity as well as role of the microenvironment of brain tumors may suggest a better revealing of the molecular mechanism of brain tumors and new therapeutic directions,which requires an accurate recapitulation of the complex microenvironment of human brain in vitro.Here,a 3D bioprinted in vitro brain matrix-mimetic microenvironment model with hyaluronic acid(HA)and normal glial cells(HEBs)is developed which simulates both mechanical and biological properties of human brain microenvironment in vivo through the investigation of the formulation of bioinks and optimization of printing process and parameters to study the effects of different concentration of gelatin(GA)within the bioink and different printing structures of the scaffold on the performance of the brain matrix-mimetic microenvironment models.The study provides experimental models for the exploration of the multiple factors in the brain microenvironment and scaffolds for GBM invasion study.

Expert consensus on early childhood caries management

Early childhood caries(ECC)is a significant chronic disease of childhood and a rising public health burden worldwide.ECC may cause a higher risk of new caries lesions in both primary and permanent dentition,affecting lifelong oral health.The occurrence of ECC has been closely related to the core microbiome change in the oral cavity,which may be influenced by diet habits,oral health management,fluoride use,and dental manipulations.So,it is essential to improve parental oral health and awareness of health care,to establish a dental home at the early stage of childhood,and make an individualized caries management plan.Dental interventions according to the minimally invasive concept should be carried out to treat dental caries.This expert consensus mainly discusses the etiology of ECC,caries-risk assessment of children,prevention and treatment plan of ECC,aiming to achieve lifelong oral health.