Objective To study the effect of Er:YAG laserirrigation on root canal system with different mechanical preparation tapers. Methods Er:YAG laser irrigation process was conducted in different prepared resin tooth models(15/. 05, 20/. 06 and 25/. 08). The bubble oscillation in root canal was recorded by a high speed camera and the gray scale integral of the bubbles was calculated. The third molars with vital pulp were collected and divided into three groups for different taper root canal preparation(13/. 02, 15/. 05, 20/. 06 and 25/. 08)after extraction. The root canals were prepared by Er:YAG laser irrigation, hand empty needle washing and 5.25% NaClO, respectively. The specimens were fixed, decalcified, embedded, sectioned and stained by HE. The residual pulp tissue was observed and analyzed statistically. Results Under the same mono-pulse energy, the gray scale integral of air bubbles in root canals of 15/. 05 group was significantly less than 20/. 06 and 25/. 08 group(P<0.05); there was no significant difference between 20/. 06 and 25/. 08 groups(P>0.05). The pathological results showed that the risk of residual pulp in Er:YAG laser group was lower than that of empty needle group under the same condition(P<0.05). Compared with 25/. 08 group, 15/. 05 group had a higher residual risk of residual pulp(P<0.05), but 20/. 06 group had no significant difference(P>0.05). Conclusion Under same parameters, the effect of Er:YAG laser on root canal system has no significant difference between 20/. 06 and 25/. 08 group, but both groups have better cleaningeffects than 15/. 05 group.

Objective To investigate the effects of total flavonoids of rhizomadrynariae(TFRD)on the proliferation and apoptosis of alveolar bone osteoblasts and its mechanism. Methods Osteoblasts from rat alveolar bone were isolated and cultured. The cells were divided into control group, low-dose TFRD group(50 mg/L)and high-dose TFRD group(100 mg/L). After transfection with NC mimic and miR-93-5p mimic, osteoblasts were incubated with high-dose TFRD, which were classified as TFRD+NC mimic group and TFRD+ miR-93-5p mimic group, respectively. Cell proliferation was detected by CCK-8 method. Cell apoptosis was detected by flow cytometry. The expression of miR-93-5p, osteogenic differentiation-related genes(Osteriex and RUNX2), and WNT pathway-related genes(Dishevelled and β-catenin)were detected by RT-qPCR and Western blotting, respectively. Osteogenic differentiation was detected by ALP staining and activity test. Results After TFRD treatment, the proliferation ability of alveolar osteoblasts was increased(P<0.05); apoptosis rate was decreased(P<0.05); ALP activity and the expression of Osteriex and RUNX2 was increased(P<0.05); the expression of miR-93-5p was decreased(P<0.05); the expression of FZD6, Dishevelled and β-catenin was increased(P<0.05), activating the WNT pathway. Overexpression of miR-93-5p reversed the protective effect of TFRD on osteoblasts, leading to the reduction of cell proliferation(P<0.05), the increase of apoptosis rate(P<0.05), the decrease of ALP activity and Osteriex and RUNX2 expression(P<0.05), the increase of miR-93-5p expression(P<0.05), the reduction of FZD6, Disevelled and β-catenin expression(P<0.05), and the inhibition of WNT pathway. Conclusion TFRD promotes proliferation and inhibits apoptosis of alveolar bone osteoblasts through miR-93-5p/FZD6/WNT pathway.

Objective To explore the anatomical characteristics of zygomatic foramen, enrich anatomical data and provide reference for clinical surgery. Methods Sixty-five intact and dry skulls(130 sides)of adults were selected to observe the position, shape, number, distribution and classification of zygomaticofacial foramen, zygomatico-orbital foramen and zygomaticotemporal foramen. Venier calipers and compasses were used to measure the shortest distance between the three foramen and lateral margin of orbit, the infraorbital foramen, and the distance between two zygomaticofacial foramen, zygomatico-orbital foramen and zygomaticotemporal foramen. Results The zygomaticofacial, zygomatico-orbital and zygomaticotemporal foramen were mostly oval, with 0 to 4 on each side, and can be divided into Ⅰ-Ⅴ types, with 3 sides (2.31%), 45 sides (34.62%), 50 sides (38.46%), 23 sides (17.69%), 9 sides (6.92%); 3 sides (2.31%), 51 sides (39.23%), 50 sides (38.46%), 19 sides (14.62%), 7 sides (5.38%); 8 sides (6.15%), 61 sides (46.92%), 29 sides (22.31%), 22 sides (16.92%) and 10 sides (7.69%) for each hole. The same number of zygomaticofacial, zygomatico-orbital or zygomaticotemporal foramen on both sides were divided into A-D (1-4) groups, with 12 (18.46%), 13 (20.00%), 2 (3.08%), 2 (3.08%); 16 (24.62%), 12 (18.46%), 3 (4.62%), 1 (1.54%); 17 (26.15%), 3 (4.62%), 4 (6.15%) and 1 (1.54%) for each hole. The shortest distance from the zygomaticofacial, zygomatico-orbital and zygomaticotemporal foramen to the lateral margin of orbit and infraorbital foramen was (7.70±1.73) mm, (24.64±4.81) mm; (7.60±2.50) mm, (23.32±4.75) mm; (7.83±2.23) mm, (27.83±3.84) mm. When there were two zygomaticofacial, zygomatico-orbital or zygomaticotemporal foramen on one side, the distance between the two zygomaticofacial, zygomatico-orbital and zygomaticotemporal foramen was (7.88±4.90) mm, (5.97±4.71) mm and (9.29±5.83) mm respectively. The distance between the left and right sides was statistically analyzed with P>0.05, and the difference was not statistically significant. Conclusion The anatomy of zygomaticforamen is helpful to understand the course and variation of the nerves and blood vessels in the area. It could provide reference for clinical operation.

Objective To study the effect of Morinda citrifolia juice combined with EDTA on the mechanical properties of dentin, and evaluate the application prospect of MCJ as a root canal irrigation solution. Methods Twenty-one human single-rooted premolars and 36 human third molars were selected and randomly divided into negative control group and five experimental groups according to different immersion protocols. Negative control group: distilled water;experimental group: 5.25% NaClO in group A, 6% MCJ in group B, 17% EDTA in group C, 5.25% NaClO-17% EDTA in group D, and 6% MCJ-17% EDTA in group E. 12 human single-rooted premolars were randomly selected and split in the mesio-distal direction. Each half root was one sample, so there were a total of 24 samples. They were randomly divided into 6 groups, and 4 samples from each group for micro-hardness test. The remaining 9 human single-rooted premolars were split mesio-distally to prepare 36 hourglass dentin sample blocks, and 6 samples were randomly selected from each group for ultimate tensile strength test. After root resection of 36 human third molars, coronal dentin prepared 72 rectangular dentin blocks. After immersion, 6 samples were randomly selected from each group for flexural strength and compressive strength tests, respectively. Results ①In the crown 1/3 area, the dentin micro-hardness in groups B and E were significantly greater than that in groups A, C and D(P<0.05); in the middle 1/3 area of the root, the dentin micro-hardness in group B was significantly greater than that in groups A, C, D, and E(P<0.05);in the apical 1/3 area, the dentin micro-hardness in groups B and E were significantly greater than that in group A(P<0.05). ②The ultimate tensile strength of dentin in groups B, D and E were significantly higher than that in groups A and C(P<0.05). ③The dentin flexural strength of group B was significantly higher than that of groups A and C, and the dentin flexural strength of group E was significantly higher than that of group D(P<0.05). ④The dentin compression strength in groups B and E were significantly higher than that in groups A and D(P<0.05). Conclusion MCJ has less effect on the mechanical properties of dentin than 5.25% NaClO;MCJ combined with 17% EDTA root canal irrigation has less effect on the mechanical properties of dentin than 5.25% NaClO combined with 17% EDTA.

Objective To delineate and analyze the factors affecting the eruption of mandibular third molars in adolescent orthodontic patients. Methods Adolescent orthodontic patients with impacted mandibular third molars at their first visit were retrospectively screened.The record of gender, Angle Classification, development of mandibular third molar, tooth extraction, the angle of mandibular third molar inclination(8-SN), the angle between mandibular second and third molars(7-8axis), the eruption space of mandibular third molars(7D-ABR) and the eruption height of mandibular third molars(8-OP) were measured by software-generated lateral cephalometric radiographs. The cohort were classified into eruption group and un-eruption group according to the degree of impaction of the third molar during the second CBCT image. Logistic regression analysis was utilized to analyze the factors affecting the eruption status of mandibular third molars. Results Among the factors, Angle Class Ⅰ malocclusion, tooth extraction, the root formation of mandibularthirdmolars, a larger angle between the long axis of the third molar and the anterior skull base plane, and a smaller angle between the long axis of the second molar and the third molar were conducive to the eruption of mandibular third molars. Conclusion The eruption status of mandibular third molars after orthodontic treatment is influenced by several factors,including orthodontic extraction, development of mandibular third molars, Angle's classification, 8-OP, 7-8 axis, and 8axis-SN.

Objective To analyze the correlation among periodontitis, oral and gastric Helicobacter pylori by investigating the infection of Helicobacter pylori and periodontal status in 127 patients. Methods From December 2021 to June 2022, 127 cases of patients who were tested for gastric Helicobacter pylori by 14C-urea breath test in Nantong Hospital of Traditional Chinese Medicine or The third People's Hospital of Nantong, were included to fill out the questionnaire and tested for oral Helicobacter pylori and periodontal examination, according to the inclusion and exclusion criteria and following the principle of voluntary participation. Statistical SPSS 20.0 software was used to analyze the data. Results Oral and gastric Helicobacter pylori infections were correlated in 127 patients (P<0.05). Oral Helicobacter pylori infection was also associated with periodontal status (P<0.05). The infection rate of gastric Helicobacter pylori in patients with moderate to severe periodontitis tended to increase, but the difference was not statistically significant (P>0.05). Multivariate Logistic regression analysis of the total population suggested that oral Helicobacter pylori was a risk factor for gastric Helicobacter pylori infection. Conclusion The infection rate of oral Helicobacter pylori is closely related to the infection rate of gastric Helicobacter pylori. Moderate to severe periodontitis can increase the infection rate of Helicobacter pylori.

Objective To analyze the risk factors of peri-implantitis after dental implants in patients with periodontitis, and construct a nomogram prediction model. Methods A total of 203 patients were included into the study, and divided into modeling group(n=142) and validation group(n=61) by random sampling. Based on the independent risk factors of peri-implantitis in patients with periodontitis, the Logistic risk prediction model was established. The model was internally verified by Bootstrap method and the external verification was completed by the verification group. Hosmer-Lemeshow test(H-L test) and the area under the receiver operating characteristic(ROC) curve was used to evaluate the prediction model. Results Smoking history, diabetes history, irregular periodontal treatment, thickness of peri-implant mucosa<2 mm, anterior teeth implantation and adhesive restoration were the independent risk factors for peri-implantitis after dental implantation in patients with periodontitis(P<0.05). According to the above risk factors, a nomogram model was constructed to predict the occurrence of peri-implantitis in patients with periodontitis. H-L test had a significant level of 0.536. The calibration curve showed that the predicted values of the modeling group and the verification group were basically consistent with the measured values. The area under the curve(AUC)of the model group was 0.906, indicating that the model had good prediction accuracy.Conclusion The risk prediction model, consisting of smoking history, diabetes history, irregular periodontal treatment, thickness of peri-implant mucosa<2 mm, anterior teeth implantation and adhesive restoration, may effectively predict the incidence ofperi-implantitis after dental implants in patients with periodontitis.

Objective To observe and analyze the clinical effect of simultaneous root canal preparation combined with ultrasonic washing in root canal treatment of diabetic patients. Methods A total of 80 patients with type 2 diabetes requiring root canal treatment from October 2020 to September 2021 in the General Department of Hefei Stomatology Hospital were selected and randomly divided into study group and control group, with 40 cases in each group. Patients in the study group received root canal treatment with VDW Gold Reciproc root canal motor (controlling the working length during root canal preparation) combined with ultrasonic washing, while the control group received conventional root canal motor combined with syringe irrigation for root canal therapy. Serum interleukin (IL) -6 (IL-6), IL-8, and tumor necrosis factor-α (TNF-α) levels were compared before and 1 week after treatment by IMMULITE1000 Siemens chemiluminescence analyzer. Visual analogue scale (VAS) of pain before treatment and 6, 12, 24, 48 and 72 h after treatment were compared between the two groups. The total effective rate of root canal treatment was evaluated one year after operation. Results One week after completion of treatment, the levels of IL-6, IL-8 and TNF-α were decreased in both groups, and the study group was significantly lower than the control group (P<0.05). The VAS in the study group was lower than that in the control group at different time points after operation, but the difference was statistically significant only at 6 and 12 h after operation (P<0.05). The total effective rate was 95% in the study group and 90% in the control group, which was higher in the study group than in the control group without significant difference (P>0.05). Conclusion Simultaneous root canal preparation combined with ultrasonic washing can effectively reduce postoperative pain and control inflammation in patients with diabetes, which is recommended in clinical practice.

Objective To study the three-dimensional characteristics of anterior maxillary supernumerary teeth in children and their effects on permanent teeth. Methods Based on clinical and CBCT data, retrospective analysis was conducted in aspects of the age, gender, location, number, shape, eruption and effect on permanent anterior teeth of 815 maxillary supernumerary teeth from 594 children. Results There were 815 supernumerary teeth in the anterior maxilla in 594 children, whose average age was 7.98, and the male to female ratio was 3.37:1. One supernumerary tooth was most common(63.97%). Conical shape was much more than others; 84.54% among them were mesiodens, and the crowns located at the palatal side accounted for 78.28%. A total of 440 supernumerary teeth were in inverted direction(53.99%). Most supernumerary teeth were unerupted or impacted, and the eruption rate was 20.61%. There were 555 supernumerary teeth which caused malocclusion(68.10%). Cystic changes and root resorption of permanent teeth were respectively found in 23 cases and 14 cases. Conclusion Maxillary anterior supernumerary teeth in children are prone to malocclusion and need to be removed in time.

Objective By comparing the changes in soft and hard tissue of patients with anterior crossbite dentition treated with the modified FR Ⅲ and “2×4” orthodontic techniques, to evaluate the therapeutic effects of two orthodontic methods, so as to provide theoretical reference for clinical selection and application. Methods Thirty patients with anterior crossbite dentition treated in the outpatient clinic of the Second Affiliated Hospital of North Sichuan Medical College from September 2018 to October 2022 were collected, and divided into the observation group (modified FRⅢ, n=15) and control group (“2×4” orthodontic technique, n=15) according to the treatment method. Changes in the position of hard and soft tissues of the two groups before and after orthodontic treatment were compared. Results After treatment, an increase in the SNA, ANB, MP-FH, Y-axis angle, U1-SN, U1-NA, NLA, PLA, FCA and ULP was revealed in the observation group (P<0.05) along with a decrease in the SNB and L1-MP. In control group, SNA, ANB, MP-FH, U1-SN, U1-NA, Y-axis angle, NLA, FCA increased (P<0.05); SNB, L1-MP, L1-NB decreased (P<0.05). Significant difference was found in the number of changes in SNB, ANB, SN-MP, NLA, L1-NB, PLA and FCA between the two groups (P<0.05). Conclusion Both techniques achieved good treatment outcomes. Anterior teeth were effectively released, followed by the normalized occlusal relationship and facial shape, which is worth promoting for clinical application. The modified FRⅢ could more prominently contribute to improving the lateral appearance and facial shape of soft tissues, while the “2 × 4” orthodontic technique costs less time and provides a better resolution for tooth alignment.

Secondary vertical root fracture is one of the main causes for tooth extraction of endodontically treated teeth. To increase the reservation rate of teeth with vertical root fracture, this case report presented for the first time an endodontically treated premolar with vertical root fracture repaired with both composite resin and bio-ceramic filling material iRoot BP Plus through the intentional replantation, which showed a good treatment result. This case report may provide a new treatment approach for saving the teeth with vertical root fracture.

Regeneration of lost periodontal tissue is the ultimate goal of periodontal treatment, which is of great significance for the clinical improvement of lesions, the long-term survival of teeth and the satisfaction of aesthetic requirements. In recent years, with the development of clinical technology and medical instruments, in order to achieve better interdental tissue regeneration and aesthetic effect, researchers have innovated and improved the periodontal regeneration procedures through various techniques, preserving interdental tissues, improving the primary wound healing quality and reducing gingival recession. This review describes the development and characteristics of various papilla preservation procedures in periodontal tissue regeneration, including traditional papilla preservation flap, minimally invasive papilla preservation technique, entire papilla preservation technique and papilla preservation combined with soft tissue augmentation and focuses on the indications, incision design, and clinical benefits of these approaches in order to provide clinicians with more options for developing personalized treatments.

Bone is an important organ of the human body, with a variety of functions such as support and protection, and the internal bone marrow tissue is the main hematopoietic site. Hematopoiesis and bone homeostasis maintenance are important physiological processes in the bone, which are regulated by a variety of factors, and its destruction will lead to hematopoietic dysfunction, osteoporosis and other diseases. Blood vessels are widely distributed in the bone and, in addition to being ducts for oxygen, nutrients and waste, also play an important role in a variety of physiological and pathological processes within the bone. Studies in recent years have found that bone blood vessels have different subtypes with distinct distribution and properties which form specific vascular microenvironment. The bone vascular microenvironment is composed of a variety of cells and their secreted signaling molecules, such as endothelial cells, which are involved in regulating bone marrow hematopoiesis and bone homeostasis maintenance in a variety of ways. In this paper, the distribution and typing of bone blood vessels, the composition of bone blood vessel microenvironment, and the regulation of hematopoiesis and bone homeostasis by bone blood vessels and their microenvironment are reviewed, in order to deepen the understanding of bone blood vessels and their microenvironment, and provide insights for the treatment of related diseases.

Tooth loss and accompanied changes in oral structure will affect phonetic function. Complete denture restoration plays an important role in the recovery of phonetic function in edentulous patients. However, many factors from the production of complete denture, the patient's own situation and the wearing of denture will affect the phonetic function of complete denture wearer. This review summarizes the influencing factors of phonetic function recovery in the edentulous patients with complete denture restorations, so as to provide guidance for the production of complete denture with better speech articulation and intelligibility of the wearers.

Orthodontic-orthognathic combined treatment, as the main treatment method for maxillofacial deformities, requires the collaboration of orthodontic, surgery, otorhinolaryngology, plastic surgery and other disciplines, and pursuits high precision, high standards and maximum functional repair. The limitations of orthodontic adjustment and surgery often lead to incompatibility between them in surgical plan design. The penetration of artificial intelligence in orthognathic surgery can exactly address this flaw, ensuring its efficiency and precision. This article mainly describes the latest application and potential development trend of artificial intelligence in orthodontic and orthognathic combined treatment.

Tooth eruption undergoes a series of sophisticated physiological procedures that involve the formation and resorption of alveolar bone. Previous studies indicated that dental follicle(DF) plays a key role in tooth eruption by modulating bone remodeling around the tooth. It secretes multiple chemokines to recruit monocytes and facilitate the differentiation and maturation of osteoclasts via RANKL/RANK/OPG axis, eventually leading to the resorption of the coronal alveolar bone to form eruptive pathway. Simultaneously, dental follicle is enriched with dental follicle cells, whose osteogenic activity are subject to TGF-β/BMP and WNT signaling pathway as well as epigenetic regulation, which in turn promotes the formation of basal alveolar bone and provides motive force for tooth eruption. In recent years, studieson bone remodeling mechanisms of tooth eruption have made further progress, and this review elaborates the cellular and molecular mechanisms involved in bone remodeling by dental follicle during tooth eruption.

Cleft lip and palate (CLP) is one of the most common congenital birth defects. The prevalence of CLP varies among different regions and different populations. The prevalence of CLP is slightly higher in males, and the pathogenesis is complex and still needs in-depth research. The current view is that the combined effect of genetic and environmental factors is the main cause of CLP. In this paper, the research progress of NSCL/P in recent years was summarized in terms of the research methods, pathogenic genes, the correlation between genes and WNT signaling pathways, the interaction between genes and environmental factors, and the early prenatal diagnosis of NSCL/P, so as to provide reference for further research on the etiology and prevention of NSCL/P.

Implant restoration has become one of the main options for patients with tooth loss. The development of 3D printing technology has provided new possibilities for implant design and manufacture, and has gradually become a hot research topic. However, bacterial infection-induced peri-implantitis is still an important cause for implant failure. Improving the antibacterial ability of implants is a powerful way to solve this problem. In this paper, various antibacterial methods used in 3D printing implants are reviewed, including process optimization, material modification, surface treatment and 3D printing coating, and their prospects are analyzed. It is hoped that this review can provide a brief understanding of this field and help future research.