RNA-sequencing analysis reveals the potential molecular mechanism of RAD54B in the proliferation of inflamed human dental pulp cells.

AIM: To investigate the role of RAD54B in the proliferation of inflamed human dental pulp cells (hDPCs) induced by lipopolysaccharide (LPS). METHODOLOGY: Normal, carious and pulpitic human dental pulp tissues were collected. Total RNA was subjected to RNA-sequencing (seq) and gene expression profiles were studied by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Differentially expressed genes (DEGs) in homologous recombination repair (HRR) were validated with qRT-PCR. The expression of RAD54B and TNF-α in human dental pulp tissues was detected using immunohistochemistry. HDPCs were cultured and RAD54B level in hDPCs was detected after LPS stimulation using western blot. CCK-8 was used to investigate the proliferation of hDPCs transfected with negative control (Nc) small interfering RNA (siRNA), RAD54B siRNA, P53 siRNA or both siRNAs with or without LPS stimulation. Flow cytometry was used to detect the cell cycle distribution, and western blot and immunofluorescence were used to analyse the expression of RAD54B, P53 and P21 under the above treatments. One-way and two-way anova followed by least significant difference posttest were used for statistical analysis. RESULTS: RNA-seq results identified DEGs amongst the three groups. KEGG pathway analysis revealed enrichment of DEGs in the replication and repair pathway. HRR and non-homologous end joining (NHEJ) components were further verified and qRT-PCR results were basically consistent with the sequencing data. RAD54B, an HRR accessory factor highly expressed in carious and pulpitic tissues as compared to that in normal pulps, was chosen as our gene of interest. High RAD54B expression was confirmed in inflamed human dental pulp tissues and LPS-stimulated hDPCs. Upon RAD54B knockdown, P53 and P21 expressions in hDPCs were upregulated whereas the proliferation was significantly downregulated, accompanied by increased G2/M phase arrest. After inhibiting P53 expression in RAD54B-knockdown hDPCs, P21 expression and cell proliferation were reversed. CONCLUSIONS: Gene expression profiles of normal, carious and pulpitic human dental pulp tissues were revealed. HRR components were elucidated to function in dental pulp inflammation. Amongst the DEGs in HRR, RAD54B regulated the proliferation of inflamed hDPCs via P53/P21 signalling. This research deepens our understanding of dental pulp inflammation and provides new insight to clarify the underlying mechanisms.

Clinical and radiological outcomes of dynamic navigation in endodontic microsurgery: a prospective study.

OBJECTIVES: This study was aimed at evaluating the clinical and radiological outcomes of novel dynamic navigation (DN)-aided endodontic microsurgery (EMS), with an analysis of potential prognostic factors. MATERIALS AND METHODS: Forty-six teeth from 32 patients who received DN-aided EMS were included. Clinical and radiographic assessments were performed at least 1 year postoperatively. Two calibrated endodontists assessed radiological outcomes according to two-dimensional (2D) periapical radiography (PA) and three-dimensional (3D) cone-beam computed tomography (CBCT) imaging using Rud's and Molven's criteria and modified PENN 3D criteria, respectively. Fisher's exact test was used for statistical analysis of the predisposing factors. RESULTS: Of the 32 patients with 46 treated teeth, 28 with 40 teeth were available for follow-up. Of the 28 patients, four (five teeth) refused to undergo CBCT and only underwent clinical and PA examinations, and the remaining 24 (35 teeth) underwent clinical, PA, and CBCT examinations. Combined clinical and radiographic data revealed a 95% (38/40) success rate in 2D healing evaluations and a 94.3% (33/35) success rate in 3D healing evaluations. No significant effect was found in sex, age, tooth type, arch type, preoperative lesion volume, preoperative maximum lesion size, presence/absence of crown and post, and the root canal filling state on the outcome of DN-aided EMS. CONCLUSIONS: DN-aided EMS has a favorable prognosis and could be considered an effective and reliable treatment strategy. Further investigations with larger sample sizes are required to confirm these results. CLINICAL RELEVANCE: DN-aided EMS could be considered an effective and reliable treatment strategy.

Conservative endodontic microsurgery to protect critical anatomical structures-selective curettage: a case series.

BACKGROUND: Endodontic microsurgery has yielded highly successful outcomes in preserving teeth with persistent or recurrent cases of periapical periodontitis that could not be successfully treated by nonsurgical endodontic approaches. To avoid complications in conditions in which periapical lesions invade anatomical structures such as the nasopalatine nerve tube and mandibular canal, selective curettage has been proposed as an alternative choice of complete curettage in surgery. CASE PRESENTATION: The 8 cases reported herein had undergone root canal treatment and/or retreatment but still presented with symptoms, such as recurring sinus tracts and persistent dull pain. The radiographic examination indicated a large area of radiolucency that was associated with the tooth and had invaded adjacent critical anatomical structures. The patients opted for selective curettage via endodontic microsurgery, and the lesions were histologically confirmed as periapical cysts or granulomas. The follow-up results for one year or more indicated that the affected teeth were clinically asymptomatic and exhibited complete or incomplete healing radiographically. CONCLUSION: This case series provides clinical evidence for the feasibility of selective curettage in endodontic microsurgery, which can avoid complications caused by damage to the adjacent critical anatomical structures.

Activated KCNQ1 channel promotes fibrogenic response in hereditary gingival fibromatosis via clustering and activation of Ras.

BACKGROUND AND OBJECTIVE: Activated potassium channels were found to be strongly correlated with gingival overgrowth (GO) phenotype as we reviewed syndromic hereditary gingival fibromatosis (HGF). Nevertheless, the functional roles of potassium channels in gingival fibrosis or gingival overgrowth remained uncovered. The aim of the present study was to explore the pathogenic role of aberrantly activated potassium channel in Hereditary Gingival Fibromatosis (HGF). METHODS: Gingival tissues were collected from 9 HGF patients and 15 normal controls. Expression of KCNQ1 was detected by immunohistochemistry. Gingival fibroblasts were isolated, and outward K+ currents were detected by whole-cell patch-clamp analysis, transmembrane potential was determined by flow cytometry. Normal human gingival fibroblasts (NHGFs) were transfected with KCNQ1 adenovirus or treated with KCNQ1 selective agonist ML277 and antagonist chromanol 293B. Accumulation of Extracellular Matrix (ECM) was measured by Western blotting and Sircol Soluble Collagen Assay. Content of secreted TGF-ß1 was measured by ELISA. Active RAS pull-down assay and cell immunofluorescence were utilized to verify RAS activation. RESULTS: KCNQ1 was upregulated in gingival tissues derived from HGF patients and HGF gingival fibroblasts presented increased outward K+ currents than NHGFs. Overexpression of KCNQ1, or KCNQ1 agonist ML277, promoted fibrotic responses of NHGFs. TGF-ß1 and KCNQ1 channels formed a positive feed-back loop. ML277 generated lateral clustering and activation of Ras on plasma membrane, followed by augmented MAPK/AP-1 signaling pathway output. JNK or ERK1/2 inhibitors suppressed ML277-induced AP-1 and ECM upregulation. CONCLUSION: Activation of KCNQ1 potassium channel promoted fibrogenic responses in NHGFs via Ras/MAPK/AP-1 signaling.

Role of Ku70 in the apoptosis of inflamed dental pulp stem cells.

AIM: The study aimed to investigate the effects of DNA repair proteins on cell apoptosis in human DPSCs during inflammation. METHODS: Lipopolysaccharide (LPS) was used to stimulate inflammation in dental pulp in vivo and in vitro. We identified the activation of DSB response and DNA repair proteins in inflamed pulp tissue and in LPS-treated human DPSCs. Then we transfected the cells with Ku70 (a key protein involved in NHEJ) siRNA and detected the expression changes of γ-H2A.X, DNA repair proteins and cell apoptosis. RESULTS: Immunohistochemical staining showed that at 4 and 6 days of pulpitis the expression of Ku70 and γ-H2A.X significantly increased. The levels of γ-H2A.X, Ku70, Xrcc4, and Rad51 increased considerably in the LPS-treated DPSCs. Furthermore, decreased expression of Ku70 could increase the number of γ-H2A.X foci, apoptotic cells and reduce cell viability in DPSCs. CONCLUSIONS: The results indicate that NHEJ pathway was the main mechanism involved in DNA damage response induced by repeated LPS stimulation in DPSCs. Meanwhile, the findings suggested that Ku70 serves importantly in the apoptosis of DPSCs in the inflammatory environment.

Wnt16 is involved in intramembranous ossification and suppresses osteoblast differentiation through the Wnt/ß-catenin pathway.

In the course of embryonic development skeletal elements form either through intramembranous or endochondral ossification. Wnt proteins play diverse roles during vertebrate skeletal development. Wnt16 is a key factor in developing long bones, but its exact role in craniofacial bone formation remains unclear. This study was initially undertaken to investigate the expression of Wnt16 during craniofacial bone development in mouse embryos. Wnt16 expression in the osteoid of calvaria, maxilla, and mandible started later than that of ALP and osteocalcin (OCN), but before mineralization of the craniofacial bones, suggesting that Wnt16 is involved in intramembranous ossification in the head. To confirm this, MC3T3-E1 cells were transfected with an adenovirus containing Wnt16 (Ad-Wnt16). Ad-Wnt16 cells showed decreased ALP activity and less mineralized nodule formations compared with control cells. In addition, the mRNA levels of osteogenic markers were reduced. Moreover, Wnt16 activated ß-catenin signaling in MC3T3-E1 cells at both transcription and protein levels as shown by a TOPflash luciferase reporter gene assay and western blot analysis. On the other hand, Wnt/ß-catenin pathway blockade by Dickkopf 1 abrogated the suppression of mineralization by Wnt16. Our findings suggest that Wnt16 is involved in intramembranous ossification and suppresses osteoblast differentiation through the Wnt/ß-catenin pathway.

Comparison of Accuracy and Operation Time in Robotic, Dynamic, and Static-Assisted Endodontic Microsurgery: An In Vitro Study.

INTRODUCTION: This study aimed to compare the accuracy and operation time (OT) of robotic-assisted endodontic microsurgery (RA-EMS), dynamic navigation-guided (DN-guided) EMS, and static navigation-guided (SN-guided) EMS. METHODS: Seventy-two teeth from three sets of standardized jaw models (TrueTooth, DELendo, Santa Barbara, CA) randomly assigned into 3 groups underwent osteotomy and root-end resection. Preoperative plans and postoperative cone-beam computed tomography images were imported into an accuracy analysis system and aligned based on the anatomical structures to assess accuracy. The OT was recorded from the moment the foot pedal was pressed down until the bur reached the target depth. Statistical analyses were conducted using Kruskal-Wallis and Scheirer-Ray-Hare tests, with significance set at P < .05. RESULTS: RA-EMS exhibited significantly higher accuracy than DN- and SN-guided EMS in terms of platform, angular, and resection angular deviations (P < .05). Additionally, RA-EMS exhibited significantly higher accuracy than DN-guided EMS in resection length deviation (P < .05). Significant differences were also observed in OTs between the 3 approaches, with SN-guided EMS showing the shortest OT, followed by RA-EMS and DN-guided EMS. Differences in jaw types within the DN-guided EMS group were observed in terms of angular deviation (P < .05). CONCLUSIONS: All 3 treatment approaches demonstrated acceptable clinical accuracy and OT. RA-EMS exhibited superior accuracy, suggesting its potential application prospects in endodontics. Further high-quality clinical studies are warranted.

Evaluation of a Novel Drilling Approach for Dynamic Navigation-Aided Endodontic Microsurgery: A Surgical Simulation Comparison Study.

INTRODUCTION: This study investigated the feasibility of a novel drilling approach that integrates a pilot trephine into dynamic navigation (DN) for guided osteotomy and root-end resection (RER) with unimanual operation in endodontic microsurgery. METHODS: Two operators with varying levels of DN experience performed guided osteotomy and RER using 2 unimanual drilling methods with DN-aided operation on 3-dimensional printed jaw models. Method 1 (M1) involved drilling with a conventional trephine. Method 2 (M2) involved drilling with a pilot trephine, followed by drilling with a conventional trephine. Accuracy, time, and safety of M1 and M2 were compared. Accuracy measurements included platform deviation (PD), end deviation (ED), angular deviation (AD), resection length deviation (RLD), and resection bevel angle (RBA). Additional parameters included osteotomy and RER time (OT) and bur slippage number (BSN). Statistical analyses were conducted using a 2-sample t-test or Mann-Whitney U test, with the significance level set at .05. RESULTS: The PD, AD, RBA, and BSN in the M2 group were significantly less than in the M1 group (P < .05). For M1, the novice operator (NO) exhibited significantly higher values of PD, ED, OT, and BSN than the experienced operator (EO) (P < .05). For M2, the NO exhibited significantly higher value of ED only (P < .05), and drilling depth >7 mm was significantly associated with a longer OT (P < .05). CONCLUSION: In this surgical simulation comparison study, the incorporation of a pilot drill improved the accuracy and safety of DN-aided endodontic microsurgery.

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. Additionally, ambiguous clinical indications for root canal medication and non-standardized dressing protocols must be clarified. Inappropriate intracanal medication may present side effects and jeopardize the therapeutic outcomes. Indeed, clinicians have been aware of these concerns for years. Based on the current evidence of studies, this article reviews the properties of various irrigants and intracanal medicaments and elucidates their effectiveness and interactions. The evolution of different kinetic irrigation methods, their effects, limitations, the paradigm shift, current indications, and effective operational procedures regarding intracanal medication are also discussed. This expert consensus aims to establish the clinical operation guidelines for root canal irrigation and a position statement on intracanal medication, thus facilitating a better understanding of infection control, standardizing clinical practice, and ultimately improving the success of endodontic therapy.

GATA4 inhibits odontoblastic differentiation of dental pulp stem cells through targeting IGFBP3.

OBJECTIVE: The odontogenic differentiation of human dental pulp stem cells (HDPSCs) is associated with reparative dentinogenesis. Transcription factor GATA binding protein 4 (GATA4) is proved to be essential for osteoblast differentiation and bone remodeling. This study clarified the function of GATA4 in HDPSCs odontoblast differentiation. METHODS: The change in GATA4 expression during reparative dentin formation was detected by immunohistochemistry staining. The expression of GATA4 during HDPSCs odontoblastic differentiation was detected by western blot and quantitative polymerase chain reaction. The effect of GATA4 on odontoblast differentiation was investigated following overexpression lentivirus transfection. RNA sequencing, dual luciferase assay and chromatin immunoprecipitation (CHIP) were conducted to verify downstream targets of GATA4. GATA4 overexpression lentivirus and small interference RNA targeting IGFBP3 were co-transfected to investigate the regulatory mechanism of GATA4. RESULTS: Upregulated GATA4 was observed during reparative dentin formation in vivo and the odontoblastic differentiation of HDPSCs in vitro. GATA4 overexpression suppressed the odontoblastic potential of HDPSCs, demonstrated by decreased alkaline phosphatase activity (p < 0.0001), mineralized nodules formation (p < 0.01), and odonto/osteogenic differentiation markers levels (p < 0.05). RNA sequencing revealed IGFBP3 was a potential target of GATA4. CHIP and dual luciferase assays identified GATA4 could activate IGFBP3 transcription. Additionally, IGFBP3 knockdown recovered the odontoblastic differentiation defect caused by GATA4 overexpression (p < 0.05). CONCLUSIONS: GATA4 inhibited odontoblastic differentiation of HDPSCs via activating the transcriptional activity of IGFBP3, identifying its promising role in regulating HDPSCs odontoblast differentiation and reparative dentinogenesis.

Cell-scaffold interactions in tissue engineering for oral and craniofacial reconstruction.

Tissue engineering (TE) is critical in oral and craniofacial reconstruction. One of the most popular topics on the biomaterial-based tissue regeneration process may be the interaction between cells and scaffolds. An increasing number of studies have identified the variables affecting cell-scaffold interaction. The creation and investigation of new scaffolds for TE and regenerative medicine based on specific interactions have become possible owing to these findings. This review discusses the effects of various types of scaffold materials on cells in TE. Because the intrinsic properties of scaffolds are essential, the influence of the physical, chemical, mechanical, and biological characteristics of scaffold materials on cell-scaffold interaction that has been discovered in recent research is elaborated in this review. The components carried by scaffolds, the degradation process, and the role of degraded products in cell-scaffold interactions are examined. Further, the roles of cells, including cell types, functions, and adhesion mechanisms, and extracellular matrix are discussed. Finally, the latest research progress on cell-scaffold interactions among various engineered tissues or organs in the oral and craniofacial region is summarized. A deeper understanding of cell-scaffold interactions is anticipated to benefit the development of TE and regenerative medicine.

Accuracy and Efficiency of Endodontic Microsurgery Assisted by Dynamic Navigation Based on Two Different Registration Methods: An In Vitro Study.

INTRODUCTION: This study aimed to compare the accuracy and efficiency of dynamic navigation-assisted endodontic microsurgery (DN-EMS) using two different registration methods. METHODS: Three-dimensional-printed jaw models, including 40 teeth, were divided into two groups (n = 20). Cone-beam computed tomography images of all teeth were scanned under the same exposing parameters. An endodontic dynamic navigation system (DHC-ENDO1) was used to plan the drilling paths. Dynamic navigation-assisted endodontic microsurgery (DN-EMS) was performed using either U-shaped tube (UT) or tooth cusp (TC) registration method. The accuracy was determined by platform deviation, end deviation, angular deviation, resection angle, and resection length deviation. The registration efficiency was defined as the time required to complete the registration procedure. Osteotomy volume of each resection was calculated by Mimics 21.0. Statistical analyses were performed using IBM SPSS Statistics 24.0. Comparisons between groups were performed using the independent sample t test or Mann-Whitney U test. P < .05 was adopted as significant difference. RESULTS: The UT group was significantly more accurate in terms of mean platform deviation, end deviation, angular deviation, and resection angle (P < .05). Resection length deviation did not differ significantly between the registration groups. The UT group was significantly more efficient than the TC group (P < .05). No significant differences were found in the osteotomy volumes between the two groups. CONCLUSIONS: In the model-based surgical simulation comparison, DN-EMS based on UT registration is more accurate and efficient than the TC method but requires an additional registration device. TC technique may be a reasonable alternative to UT registration in certain clinical tasks.

Effect of Field of View and Voxel Size on CBCT-Based Accuracy of Dynamic Navigation in Endodontic Microsurgery: An In Vitro Study.

INTRODUCTION: This study aimed to evaluate the influence of field of view (FOV) and voxel size on the accuracy of dynamic navigation (DN)-assisted endodontic microsurgery (EMS). METHODS: Nine sets of maxillary and mandibular 3-dimensional-printed jaw models composed of 180 teeth were divided into 9 groups with different FOVs (80 × 80 mm, 60 × 60 mm, and 40 × 40 mm) and voxel sizes (0.3 mm, 0.16 mm, and 0.08 mm). The endodontic DN system was used to plan and execute the EMS. The accuracy of the DN-EMS was represented by the platform deviation, end deviation, angular deviation, resection angle, and resection length deviation. Statistical analyses were performed using SPSS 24.0, and the significance level was set at P < .05. RESULTS: The average platform deviation, end deviation, angular deviation, resection angle, and resection length deviation were 0.69 ± 0.31 mm, 0.93 ± 0.44 mm, 3.47 ± 1.80°, 2.35 ± 1.76°, and 0.41 ± 0.29 mm, respectively. No statistically significant differences in accuracy were observed between the nine FOV and voxel size groups. CONCLUSIONS: FOV and voxel size did not appear to play an important role in the accuracy of DN-EMS. Considering the image quality and radiation dose, it is reasonable to select a limited FOV (such as 40 × 40 mm and 60 × 60 mm) to cover only the registration device, involved teeth, and periapical lesion. The voxel size should be selected according to the required resolution and cone-beam computed tomography units.

Analysis of the accuracy of a dynamic navigation system in endodontic microsurgery: A prospective case series study.

OBJECTIVES: To evaluate the accuracy of a dynamic navigation system (DNS) for guided osteotomy and root-end resection during endodontic microsurgery (EMS) and assess its prognosis. METHODS: Nine patients who met inclusion criteria underwent DNS-guided EMS. Osteotomy and root-end resection were performed with assistance of DNS (DHC-ENDO1, DCARER Medical Technology, Suzhou, China). The preoperative virtually planned path and postoperative cone-beam computed tomography images were superimposed using DNS software. Accuracy was assessed based on deviations in the platform, apex, and angle of the osteotomy, as well as in the length and angle of the root-end resection. Follow-up evaluations were performed after at least a year postoperatively. RESULTS: Among the nine patients (11 teeth with 12 roots), the mean platform, apex, and angular deviation of the osteotomy were 1.05 mm, 1.2 mm, and 6.24°, respectively. The mean length and angle deviation of the root-end resection were 0.46 mm and 4.9°, respectively. Significant differences were observed according to tooth position. The platform and apex deviated significantly less in the posterior than in the anterior teeth (p < .05). No significant differences were observed according to arch type, side, and depth of the surgical path (p > .05). Eight patients were evaluated after at least a year postoperatively; clinical and radiographic evaluation revealed a 90% success rate (9/10 teeth). CONCLUSIONS: This study demonstrated high accuracy of DNS in EMS. Furthermore, DNS-guided EMS had a success rate similar to that of freehand EMS over a short-term follow-up. Further study with a larger sample size is necessary. CLINICAL SIGNIFICANCE: The present novel DNS technology is a viable method for guided osteotomy and root-end resection in EMS. CLINICAL TRIAL REGISTRATION NUMBER: ChiCTR2100042312.

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.

Experts consensus on the procedure of dental operative microscope in endodontics and operative dentistry.

The dental operative microscope has been widely employed in the field of dentistry, particularly in endodontics and operative dentistry, resulting in significant advancements in the effectiveness of root canal therapy, endodontic surgery, and dental restoration. However, the improper use of this microscope continues to be common in clinical settings, primarily due to operators' insufficient understanding and proficiency in both the features and established operating procedures of this equipment. In October 2019, Professor Jingping Liang, Vice Chairman of the Society of Cariology and Endodontology, Chinese Stomatological Association, organized a consensus meeting with Chinese experts in endodontics and operative dentistry. The objective of this meeting was to establish a standard operation procedure for the dental operative microscope. Subsequently, a consensus was reached and officially issued. Over the span of about four years, the content of this consensus has been further developed and improved through practical experience.

Novel nonsense mutation in MSX1 causes tooth agenesis with cleft lip in a Chinese family.

Tooth agenesis is one of the most common developmental disorders in humans. Previous studies have attributed non-syndromic tooth agenesis to mutations in several genes, including MSX1, PAX9, EDA, and AXIN2. In this study, we investigated a Chinese family with tooth agenesis combined with cleft lip. Genomic DNA was isolated from blood samples of all available family members. Candidate genes MSX1 and PAX9 were amplified by the PCR and directly sequenced. A novel heterozygous mutation at c.C565T, exon 2 of MSX1, was identified in affected members. To analyze the effect of the nonsense mutation on MSX1 expression, vectors containing wild-type and mutated MSX1 were constructed and transfected into COS7 cell lines. Real-time PCR showed that the mRNA expression of the mutated MSX1 was dramatically reduced compared with that of the wild-type MSX1. Our findings suggest that the nonsense mutation in MSX1 might have resulted in rapid degradation of the mutated transcript and caused the phenotype of tooth agenesis with cleft lip in the Chinese family.

Analysis of Online Consultations and Emergent Treatments of Operative Dentistry and Endodontics during the COVID-19 Epidemic.

BACKGROUND: The purpose of the present study is to evaluate the characteristics of online consultations and emergent dental treatments and analyze the status of diseases related to operative dentistry and endodontics (ODE) during the COVID-19 epidemic. METHODS: Online consultations were collected from 3 February to 21 April 2020. The electronic medical record system was accessed to collect clinical diagnoses and emergent dental treatments from 9 January to 21 April 2020. RESULTS: A total of 2419 patients visited us and received treatments 2 weeks before the lockdown. The number of patients decreased to 537 during the 76 days of the lockdown. Among them, dental examinations accounted for the majority of visits (88.83%). After 7 April, the outpatient number increased to 36.79 ± 6.63 per day, but the proportion of dental examinations and treatments did not change significantly. A total of 1218 online consultations were completed before the lockdown. The most common dental problem was pulpitis (48.1%). After 7 April, consultations surged from 23.15 ± 8.54 to 44.43 ± 12.63 per day. Consultations related to pulpitis, apical periodontitis, or dental caries remained stable. CONCLUSIONS: Correct understanding, active treatments, and appropriate psychological interventions for the ODE staff during the COVID-19 epidemic are necessary. Our results may provide references to arrange staff and treat patients more efficiently for future epidemics.

Endodontic Microsurgery of Posterior Teeth with the Assistance of Dynamic Navigation Technology: A Report of Three Cases.

When nonsurgical endodontic treatment fails, surgical treatment is an alternative approach for treating periapical disease. However, endodontic microsurgery (EMS), particularly in anatomically challenging areas, such as the posterior teeth, is a skill-sensitive task that can present a unique set of challenges for the surgeon. In recent years, digital guidance technology has been applied more frequently in dentistry. Dynamic navigation (DN) is a pioneering technology that uses an optical positioning device controlled by a sophisticated computerized interface and dedicated three-dimensional surgical path planning software program. This technique has also recently been introduced in the field of EMS to improve accuracy and avoid related complications. This case report presents a novel approach to DN-assisted EMS and describes its application in posterior teeth. After undergoing DN-assisted EMS, all patients were completely asymptomatic at the follow-up visit. Radiographic examinations performed immediately and 3-9 months after EMS revealed that the root resection was performed accurately without complications. The DN technique has been proven to be a feasible, predictable, and time-saving system for assisting EMS in cases requiring treatment in anatomically challenging areas, such as in the posterior teeth.