The prosthetic dentistry has changed a lot in the digital age, showing bright prospects. However, in the stage of weak artificial intelligence, the high efficiency, high accuracy and high standard of oral diagnosis and treatment cannot be separated from the efficient communication and cooperation between dentists and dental technicians. This research will start with the analysis and classification of problems existing in the dentist-technician relationship in the digital era of weak artificial intelligence and propose current ideal objectives and methods of dentist-technician relationship. At last, we will put forward three perspectives on the relationship between dentists and dental technicians.

Objective To investigate the correlation between ageing changes in primary cilia and oral mucosal wound healing. Methods A wound model was constructed for buccal oral mucosa of mice at different ages, and samples were collected at 1, 3 and 5 days after modeling. The healing process was observed by HE staining, the tissue remodeling by MASSON staining, the re-epithelialization process by immunofluorescence staining, and the difference of cell proliferation level during the wound healing process by EdU labeling. By constructing mice with specific knockout of the primary cilia key molecule Ift140 in oral mucosal epithelial, the difference of oral mucosal wound healing speed between knockout and control mice was observed. Results The oral mucosal epithelium of aged mice had decreased self-renewal ability and the occurrence rate of primary cilia was reduced. Mucosal healing was delayed after wound, and the proliferation rate of keratinocytes was reduced and the migration rate to the wound bed was slowed. Conditional knockdown of Ift140 in oral mucosal epithelial K14-positive cells interfered with primary cilia formation and delayed the wound healing process. Conclusion Age-related changes in primary cilia of mouse oral mucosal epithelium delay oral mucosal wound healing.

Objective To synthesize mesoporous bioactive glass nanoparticles(MBGN)-enhanced poly-caprolactone(PCL)electrospun nanofiber 3D bone tissue engineering(BTE) scaffolds and to investigate the in vitro anti-inflammatory function of this scaffold. Methods PCL membranes were obtained by electrospinning; MBGN was synthesized by sol-gel method, and the MBGN-enhanced PCL electrospun nanofiber 3D bone tissue engineering scaffold PCL@MBGN was synthesized by dispersion, homogenization, filtering, freeze-drying, thermal self-assembly of gelatin, and surface modification with carboxymethyl chitosan, etc. The scaffolds were characterized by scanning electron microscopy and energy dispersive spectrometer. CCK-8 assay and live/dead staining assay were used to detect the biocompatibility of the scaffolds. Lipopolysaccharide(LPS) was used to stimulate RAW264.7 cells for 12 h to induce polarization toward M1 type, and then PCL@MBGN extracts with different MBGN additions were used to stimulate cells for 48 h. The expression level characteristic surface markers of M1 and M2 macrophages, CD86 and CD206, were detected by flow cytometry. qRT-PCR was used to detect the transcriptional levels of inflammation-related cytokines such as tumor necrosis factor alpha(TNF-α), interleukin-1 beta(IL-1β), interleukin-4(IL-4), inducible nitric oxide synthase(iNOS), and other cytokines. Results With the increase of MBGN addition, the spherical particles on the fiber surface increased under SEM, but did not significantly affect the macroscopic morphology of the scaffolds. PCL@MBGN not only possessed good in vitro biocompatibility, but also inhibited LPS-induced polarization of pro-inflammatory M1 macrophages (P<0.01). To some extent, the scaffolds promoted the polarization of anti-inflammatory M2 macrophages (P<0.01), inhibited the transcription of pro-inflammatory cytokines, including IL-1β, TNF-α and iNOs (P<0.05), and promoted the transcription of anti-inflammatory cytokine IL-4 (P<0.05), exerting an in vitro anti-inflammatory effect. Conclusion In this study, a nanofibrous scaffold PCL@MBGN with 3D structure was successfully prepared. The addition of MBGN did not significantly affect the morphology of the scaffold. The scaffolds were non-cytotoxic, had anti-inflammatory effects. The results suggest that PCL@MBGN has great potential for application in bone defect repair in inflammatory environments.

Objective The cementum mineralization is important for cementum repair after root resorption. This study aims to investigate the role of Wnt/β-catenin signaling pathway in regulating the mineralization of cementocyes under mechanical stress. Methods The IDG-CM6 cells were subjected to osteogenic-induced medium for 21 days and then harvested for establishing in vitro mechanical loading model for 6 h. RNA-seq technique was used to screen the differentially expressed genes in IDG-CM6 cells under stress. Alizarin red staining was applied to observe the mineralization of IDG-CM6 cells, and the expression levels of β-catenin and osteogenic factors, Runx2 and Osterix, were detected by real-time fluorescence quantitative polymerase chain reaction(RT-qPCR)and Western blot. The expressions of β-catenin and Runx2 were also observed by immunofluorescence staining. After knockdown of β-catenin in IDG-CM6 cells by siRNA technology, the mineralization of IDG-CM6 cells and the expression levels of Runx2 and Osterix were detected under mechanical stress. Results The mineralization of IDG-CM6 cells and the expression levels of Runx2 and Osterix were increased under mechanical stress. The bioinformatic analysis, RT-qPCR, Western blot and immunofluorescence staining showed that mechanical stress could promote β-catenin expression and knockdown of β-catenin could reverse the mineralization promotion effect produced by mechanical stress. Conclusion Wnt/β-catenin pathway is involved in the regulation of cementum mineralization and plays an important role in cementum mineralization after root resorption.

Objective To evaluate the efficacy of different acoustic irrigation activators assisted with smear layer removal in curved root canals. Methods Sixty-six extracted human mature molars with L-shaped root canals in Vertucci type Ⅰ configuration system were chosen. The mean angles of curvature, radius and curve length after ProTaper Next instrumentation were 39.9°±8.4°, (2.5±1.1) mm and (4.7±0.5) mm respectively. They were randomly assigned to one control group(n=6) and five experimental groups(n=12) for final irrigation as follows: no additional irrigation, Manual dynamic irrigation (MDI), Ultrasonic activation with a K-type file size 15/.02 (U-K) and Irrisafe20/.00 (U-IRR), Sonic activation with EndoActivator25/.04 (EA) and EDDY20/.04 (ED). The apical 6 mm of root canals were cleaved in half as the curved outer and inner sidewalls, and observed with scanning electron microscopy (SEM) in three 2 mm segments each as coronal-middle-apical thirds. The smear layer was evaluated using a five-score scale and a statistical analysis was conducted. Results All tested groups had a cleaner canal wall than the control group at any level of the root canal curved portion (P<0.05). At the coronal-third of outer canal wall, both U-IRR and ED scored smaller than others, and had a significant difference with MDI and EA (P<0.05); at the inner wall, U-K scored the highest and was inferior to both U-IRR and the two sonic activators (P<0.05). At the middle-third part and also the most curved canal area, ED was superior to U-K at two sidewalls and to EA at the inner wall (P<0.05). At the apical-third of outer canal wall, U-IRR and ED were superior to MDI (P<0.05); at the inner wall, there was no statistical difference among them. The cleanliness at apical outer wall was unsatisfactory, which was inferior to coronal inner wall in MDI/EA/ED and to apical inner wall in U-K/U-IRR (P<0.05). Conclusion ED and U-IRR assisted with smear layer removal have better performance in curved root canal, and the cleanliness at apical outer canal wall needs to be enhanced.

Objective To study the differences in the marginal and internal adaptation of milled monolithic zirconia crowns with CAD/CAM fiber post-core, cast Ti post-core, prefabricated fiber post/resin core and dentin abutment group. Methods Thirty-two maxillary first molars in vitro were randomly divided into four groups(n=8):A-cast Ti post-core, B-prefabricated fiber post/resin core, C-CAD/CAM fiber post-core, D-dentin abutment. The crowns of Group A,B,C were cut 2 mm coronal to the cemento-enamel junction, and the post-and-core production was performed after complete root canal treatment, post canal and tooth preparation. The abutments of the four groups were in the same shape, and all of them were restored by milled monolithic zirconia crowns. Marginal adaptation and internal adaptation were examined using a light-body silicone and a 3D inspection software, Geomagic Wrap 2021 Qualify. The data were statistically analyzed with two-way analyses of variance. Results The milled monolithic zirconia crown in dentin abutment group had the best marginal and internal adaptation. The appearance of post-core would lead to the decrease of monolithic zirconia crown fitness. Cast Ti post-core had the greatest influence, and its marginal and internal fitness was the worst, followed by prefabricated fiber post-core and CAD/CAM, and there was no significant difference in marginal and internal adaptation between the two groups. Conclusion The marginal and internal adaptation of the four groups of monolithic zirconia crowns meet clinical requirements, and the appearance of post-core will affect the adaptation of monolithic zirconia crowns.

Objective To investigate the effects of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser combined with scaling and root planing (SRP) on the clinical outcomes and the dynamics of subgingival flora in periodontitis patients with type 2 diabetes mellitus (T2DM). Methods Sixteen periodontitis patients with T2DM admitted to the Department of Periodontology of the Affiliated Stomatology Hospital of Nanjing Medical University from August 2021 to January 2022 were randomly divided into Nd:YAG group and SRP group. Patients in the Nd:YAG group received SRP and Nd:YAG laser treatment; the SRP group received SRP treatment only. Probing depth (PD), clinical attachment loss (CAL) and bleeding on probing (BOP) positive rates, fasting plasma glucose (FPG), glycated hemoglobin (HbA1c) and body mass index (BMI) were used to assess the periodontal status and glycemic control of patients before and after treatment. Subgingival plaque samples (PD≥5 mm) were collected at baseline and 3 months after treatment and analyzed by 16S rRNA full-length sequencing. Results Compared with baseline, PD was significantly lower in both the Nd:YAG and SRP groups at 3 months after treatment(P<0.05), and the Nd:YAG group was significantly lower than the SRP group (P<0.05); there was no statistically significant difference before and after treatment in CAL(P>0.05); BOP was significantly improved in both groups (P<0.05), but the difference between groups was not significant (P>0.05). VAS score in the Nd:YAG group was significantly lower than that in the SRP group (P<0.05). FPG, HbA1c levels and BMI were not significantly different after 3 months of treatment compared with baseline (P>0.05). Bacterial flora analysis showed that the abundance of g Leptotrichia and f Leptotrichiaceae was significantly higher in the Nd:YAG group after 3 months of treatment compared with that at baseline (P< 0.05), and that the p Bacteroidetes and c Bacteroidiawere significantly higher in the SRP group after 3 months of treatment. Conclusion Nd:YAG laser combined with SRP improves clinical periodontal parameters and reduces pain in periodontitis patients with T2DM, but there is no significant advantage in terms of glucose metabolism levels. Changes in the composition of the main subgingival microflora are observed in the short term after treatment and an increase in health-associated taxa following laser treatment.

Objective To study the correlation between morphological features and the anatomy of the root canal of the first mandibular premolars in dental panoramic tomograms (DPTs) in order to provide reference for clinical diagnosis and treatment. Methods DPTs and cone-beam CT (CBCT) of implant patients were selected and a total of 532 samples from 266 patients were included. CBCT was used to identify the number and morphology of root canals according to Vertucci classification, and type Ⅰ was recorded as a single canal, and the rest was a complex root canal. The length on DPTs was measured to obtain the ratio. And then the correlation of morphological features with root canal anatomy was analyzed. Results There were significant differences between single and complex root canals in gender, the ratio of 1/2 horizontal mesiodistal diameter in the root to maximum mesiodistal diameter, the sudden disappearance of root canal images and their location (P<0.05). The receiver operating characteristic (ROC) curve was generated with an AUC value of 0.851. The sensitivity for diagnosing complex canals was 0.765 and the specificity was 0.846. Conclusion Whether and where root canal images suddenly disappear, gender and the ratio of 1/2 horizontal mesiodistal diameter in the root to maximum mesiodistal diameter are of practical significance for determining the anatomical complexity of root canals.

Objective To investigate the therapeutic effect and influencing factors of hopeless teeth with Stage Ⅳ Grade C periodontitis after complete periodontal treatment. Methods A total of 63 patients with Stage Ⅳ Grade C periodontitis were enrolled in this retrospective study. Their 307 hopeless teeth were divided into the retained group and the lost group according to the retention two years later. In the retained group,teeth were further divided into the improved group and the unchanged group considering whether bone resorption was restored to mid-third of root on the image and clinical examination. According to the clinical data, age, gender, dental position,underlying disease, smoking status, family genetics, dentition integrity, type of periodontitis, treatment process and baseline periodontal clinical indicators were measured and analyzed. Results The 2-year survival rate of 307 teeth was 83.1%, and the prognosis was significantly improved in 46.2% of the teeth. The family genetics, integrity of dentition,timeliness of one-month review, regularity of maintenance treatment, surgical conditions,and clinical indicators of affected teeth at the baseline were statistically different between the retained group and the lost group. Regression analysis showed that the main risk factors were no flap surgery, family history, baseline deep attachment loss value and high looseness. Conclusion For Stage Ⅳ Grade C periodontitis, most hopeless teeth can be preserved in the short term. In clinical treatment, personalized treatment plan should be carried out according to risk factors to improve the retention rate.

Objective To analyze clinical characteristics of patients at different ages with cone-beam computed tomography(CBCT), providing clues for clinical diagnosis and treatment of impacted canine. Methods Forty-eight patients with impacted maxillary canine-linked incisor root resorption were selected and divided into three groups of varied ages: 11-14 years old, 15-19 years old, 20-30 years old. Clinical characteristics, maxillofacial bone morphology, impacted canine position and other indicators of patients in different age groups were measured and analyzed. SPSS 22.0 software package was used for ANOVA and chi-square test. Results There were statistical differences in the overjet and overbite, impacted tooth position, the position of incisor with root absorption, lateral incisor shape, excess dentition space, and anterior arch width of patients with impacted maxillary canine-linked incisor root resorption at varied ages. Patients aged 11-14 years were more likely to have overjet and overbite, labial impacted canine, and root resorption of lateral incisors. The width of anterior arch was narrower in patients aged 15-19 years. Patients aged 20-30 years were more prone to have palatal impacted canine, root resorption of central and lateral incisors, morphological abnormality of lateral incisors and excess dentition space. Conclusion Clinical characteristics of patients with impacted maxillary canine-linked incisor root resorption at varied ages are different. In the early diagnosis and treatment of patients with impacted teeth of different ages, attention should be paid to overjet and overbite, impacted tooth position, the position of incisor with root absorption, lateral incisor shape, excess dentition space, and anterior arch width to prevent adjacent tooth root resorption.

Objective To observe the changes of craniomaxillofacial soft and hard tissues before and after the treatment of skeletal Class Ⅱ malocclusion with invisible functional appliance in adolescents, and to explore its correction mechanism. Methods Lateral cephalometric films of 22 adolescent patients(9 males, 13 females, average age 11.2 years)who were treated with the invisible functional appliance were measured and statistically analyzed before and after treatment. Results The difference was significant, such as the ANB, NA-PA, overjet. TUL-E and TLL-E were decreased and the SNB, U1-L1, Go-Gn, Cd-Go, ANS-Me, ANS-Me/N-Me, Z angle Cm-Sn-Ls, FH-N'Pg', S-Go and Ar-Go were increased. Conclusion The invisible functional appliance can effectively promote the growth and development of the mandible and improve the relationship between the maxilla and mandible, but it will not lead to the increase of mandibular plane angle due to clockwise rotation of the mandible.

Copine 7(CPNE7), a calcium phospholipid-binding protein found in preameloblast-conditioned medium(PACM), is initially expressed and secreted by dental epithelial cells. CPNE7 plays an important role in the differentiation of dental mesenchymal cells to odontoblasts. Recently, accumulating evidence has demonstrated that CPNE7 can induce the tertiary dentin formation and reduce the permeability of dentin by promoting mineral deposition in dentinal tubules, which allows CPNE7 to be applied in dentin repair. Besides, CPNE7 has shown positive effects on cementogenesis, but has no obvious relationship to the formation of periodontal ligament(PDL). In this study, we summarized research progress of the roles and mechanisms of CPNE7 in the development of dentin and periodontium, offering new approaches to treating related diseases.

Periodontitis is a kind of chronic disease characterized by progressive destruction of periodontal supporting tissue. Related studies have shown that periodontitis with Porphyromonas gingivalis as the main pathogen is related to the occurrence and development of non-alcoholic fatty liver disease, but the relationship between the two is still unclear. This article will review the epidemiology, biological mechanism and other aspects to explore the correlation between the two diseases and further provide possible research directions.

Clear aligner technique has developed rapidly in the past few years. Patients prefer clear aligners because of superior esthetics and comfort, while the effectiveness and stability of anchorage control in clear aligners are still controversial. Molar mesial tipping and anchorage loss are easy to manifest in clinical treatment. This article reviews recent published studies based on six factors including posterior teeth anchorage preparation, anterior teeth intrusion overtreatment, tooth movement pattern, intermaxillary traction,intramaxillary traction and vertical facial type. The review aims to provide reference for clinical treatment design.

Fixed full-arch prosthesis supported by implants is a viable treatment for potential edentulous patients with severe periodontitis. The definition of immediate implant placement is the extraction of a natural tooth followed by immediate placement of a dental implant. It will bring great convenience to patients by reducing the number of visits and shortening the treatment period. However, clinical studies on immediate implant placement in patients with severe periodontitis are rare, and its clinical effects remain controversial. In this review, the impact of severe periodontitis on immediate implant placement with full-arch prostheses, the clinical effects of immediate implant placement in patients with severe periodontitis, and the application of digital technology are discussed and summarized.

Along with the development of digital medical imaging,digital treatment increasingly personalized. Under the influence of digitization, here comes a technology system containing data acquisition, three-dimensional reconstruction, computer design, virtual planning and computer-assisted production and intraoperative guidance. At the same time, digital guide and navigation technology emerges. The appearance of these technologies has greatly shortened learning cycles of clinicians, significantly improved the accuracy and reduced the risk of surgeries, and even maximally promoted the development of precision medicine. From the perspective of medical imaging, we aimed to introduce the components and application of digital guide and navigation technology and its prospect is briefly discussed.