The articles related to Cariology and Endodontology published in Chinese Journal of Stomatology from August 1953 to July 2023 were summarized. Total 1 247 articles accounting for 12.5% of the journal′s publications were involved, which reflected the progress of Cariology and Endodontology in China. The publications of five pioneers and nine chairmen of Chinese Stomatological Association Society of Cariology and Endodontology were also recorded. Whether in clinical diagnosis and treatment or cutting-edge scientific research of Cariology and Endodontology, China is catching up with or has exceeded the international professions. Over the past 70 years, China has made outstanding achievements in dental caries and endodontics. Regards to occlusal diseases, dental developmental diseases, pulp biology, pulp and periradicular diseases, and operative dentistry, a significant progress also has been made. While the articles published in the Chinese Journal of Stomatology represent only a portion of the approaches within Cariology and Endodontology, they nonetheless provide valuable insights into the development of these fields in China.

Dental caries is a prevalent infectious disease caused by microbial metabolism, affecting the hard tissues of teeth. According to data from the Fourth National Oral Health Epidemiological Survey, there is a gradual increase in caries prevalence in China, particularly among children and elderly individuals. As an etiological factor for dental lesions, caries not only impact oral health but also exhibit significant associations with various systemic diseases, suggesting that systemic diseases may serve as potential risk factors of caries development. To effectively implement the plan of national oral health action, researchers investigate the pathogenesis of caries actively while concurrently develop innovative preventive and treatment strategies based on advanced concepts and technologies, aiming to comprehensively enhance China′s oral health status. Therefore, this article provides insights into the pathogenesis of caries, its correlation with systemic diseases, as well as cutting-edge research advancements pertaining to novel preventive measures for caries.

Deep caries occurs when caries progresses to the deep dentin layer, and further progression has the risk of pulp exposure, which may affect pulp vitality and tooth longevity. Currently, there are no objective standards for the diagnosis of deep caries. In addition, traditional therapy for deep caries emphasizes complete debridement of the decayed tissue, resulting in an incremental high risk of pulp exposure. There are different views on how to deal with the remaining dentin after caries removal, and root canal treatment is often adopted directly after pulp exposure. In recent years, due to advances in dental pulp biology, bioactive pulp-capping materials, and clinical evidence-based medicine, the principle of deep caries treatment has shifted to pulp protection. Based on the latest international research progress, evidence-based medicine and expert consensus, we present a series of advancements in this article, including the terminology of deep caries, pathological changes and defense mechanisms of the pulp close to the deep caries, treatment principles of deep caries, technical strategies for carious tissues removal, and the decision-making of treatment protocols after pulp exposure, with the aim of enhancing the understanding of deep caries among dentists, as well as providing a reference for the clinical diagnosis and treatment of deep caries.

Radiation-related caries is a common complication following head and neck tumor radiotherapy. It is a rapidly progressing and widespread destructive disease of tooth tissue after radiotherapy, which greatly affects the life quality of patients after radiotherapy. This article elucidates research progress in the pathogenic mechanisms, diagnosis and caries assessment, treatment, as well as prevention strategies for radiation-related caries, aiming to provide references for clinical prevention and treatment of radiation-related caries.

With the advent of big data era and improvement of computer performance, the artificial intelligence (AI) technology has rapidly boosted in the field of stomatology. Dental caries is one of the cutting-edge research domains in stomatology. The application of AI in dental caries is expected to promote intelligent, precise and high-efficient diagnosis and treatment of caries. This article focuses on the application of AI in medical-aided diagnosis, treatment and risk prediction of caries and discusses their challenges.

Objective:To explore the application prospect of a new pH-responsive tertiary amine monomer dodecylmethylaminoethyl methacrylate (DMAEM) modified resin adhesive (DMAEM@RA) in the prevention and treatment of secondary caries.Methods:Five percents DMAEM was added to the resin adhesive to synthesize DMAEM@RA for modifying. Streptococcus mutans (Sm) and Lactobacillus casei (Lc) biofilms were cultured on resin adhesive and DMAEM@RA, respectively. The culture systems were set up at pH=7.4, 6.0, 5.5, and 5.0. The antimicrobial activity of DMAEM@RA was evaluated by quantitative PCR. The effects of DMAEM@RA on biofilm thickness, bacterial amount, and extracellular polysaccharides were studied by scanning electron microscope (SEM) and extracellular polysaccharide staining. Real-time fluorescence quantitative PCR was used to study the effect of DMAEM@RA on the expression levels of cariogenic genes in Sm. Results:DMAEM@RA could significantly reduce the amount of Sm and Lc under acidic conditions, especially Lc. At pH=5.0, the logarithm value of co-cultured Sm bacteria [lg (CFU/ml)] in DMAEM@RA group (7.58±0.01) was significantly lower than that in control group (7.87±0.03) ( t=14.32, P<0.001), and the logarithm value of Lc bacteria [lg (CFU/ml)] (7.29±0.04) was also significantly lower than that in control group (7.93±0.15) ( t=6.93, P=0.002). SEM observed that the bacteria decreased and the cell fragments appeared in DMAEM@RA group. In addition, DMAEM@RA significantly reduced the biomass of extracellular polysaccharides in the dual-species biofilm under acidic conditions. At pH=5.0, the biomass of extracellular polysaccharides in DMAEM@RA group [(25.13±3.14) mm 3/mm 2] was significantly lower than that in the control group [(42.66±7.46) mm 3/mm 2] ( t=3.75, P=0.020). DMAEM@RA could significantly up-regulate the expressions of gtfB and gtfC genes in Sm under acidic conditions. At pH=5.0, gtfB and gtfC genes were significantly up-regulated by (14.64± 0.44) times and (2.99±0.20) times, respectively ( t=-42.74, P<0.001; t=-13.55, P<0.001). Conclusions:The DMAEM@RA has a good antibacterial effect under acidic conditions, demonstrating that it has a good potential to prevent the occurrence and development of secondary caries.

Objective:To investigate the role and related mechanisms of the LiaSR two-component system in acid tolerance and biofilm formation abilities of Streptococcus mutans (Sm) 593. Methods:The growth curves of various Sm strains in pH=5.5 brian heart infusion (BHI) medium were analyzed. And colony forming unit (CFU) was also performed to evaluate the acid tolerance of Sm. Laurdan probe, H +-K +adenosine triphosphate (ATP)ase activity analysis kit, proton permeability assay and real-time fluorescence quantitative PCR (RT-qPCR) were conducted to detect the acid tolerant mechanisms of LiaSR two-component system in Sm. Crystal violet staining, CFU, SYTOX probe and anthrone-sulfuric method were used to analyze the properties and structures of the Sm biofilms. RT-qPCR was conducted to detect the expression levels of underlying regulated genes. Results:The growth of mutants in acidic BHI were inhibited ( P<0.05). The acid tolerance of mutants significantly decreased compared to the wild-type strain ( P<0.05). In mutants, the activity of H +-ATPase (917.06±59.53 and 469.53±47.65) were elevated by 7.22-folds and 3.70-folds compared to the wild-type strain (127.00±50.71) ( P<0.001, P<0.001) and the encoded gene atpD (3.39±0.21 and 1.94±0.17) were also elevated by 3.39-folds and 1.94-folds compared to the wild-type strain (1.00±0.15) ( P<0.001, P=0.001). The Laurdan generalized polarization of mutants (0.18±0.04 and 0.18±0.05) increased significantly compared to the wild-type strain (0.08±0.05) ( P=0.006, P=0.003) and the expression levels of fabM gene were decreased in mutants (0.52±0.11 and 0.57±0.05) by 1/2 ( P=0.014, P=0.022). In liaR deletion mutant, the reduced terminal pH (4.76±0.01) can also be observed ( P<0.001). The total amount of the biofilms of three Sm didn't show significant differences ( P>0.05). But the number of viable bacteria of mutants′ biofilms were decreased [Sm 593: (12.00±2.80)×10 7 CFU/ml; Sm ΔliaS: (2.95±1.13)×10 7 CFU/ml; Sm ΔliaR: (7.25±1.60)×10 7 CFU/ml] ( P=0.001, P=0.024). The extracellular DNA were increased by 18.00-folds and 6.50-folds in mutants′ biofilms (128.73±15.65 and 46.38±5.52) compared to the wild-type strain (7.16±3.62) ( P<0.001, P=0.003). Water-soluble exopolysaccharides could be found up-regulated in liaS deletion mutant [(138.73±10.12) μg/ml] ( P=0.003) along with the expression level of gtfC gene (1.65±0.39) ( P=0.014). The expression level of gtfD were elevated by 47.43-folds and 16.90-folds in mutants ( P<0.001, P=0.010). Conclusions:The LiaSR two-component system can promote the expression of fabM gene and increase the fluidity of Sm which contributes to acid tolerance. The LiaR can also decrease the proton permeability and restrict the entrance of H +. The LiaSR two-component system can negatively regulate the production of the extracellular matrix in Sm biofilm.

Objective:To investigate the regulative effects of Streptococcus mutans (Sm) antisense vicK RNA (ASvicK) on the multi-species biofilm formed by three common oral streptococci (Sm, Streptococcus sanguinis, and Streptococcus gordonii) (Sm+Ss+Sg). Methods:ASvicK over-expression strain was constructed by using a recombinant plasmid, and three-species biofilm UA159+Ss+Sg and ASvicK+Ss+Sg were cultured. The phenotypes of biofilms were detected by scanning electron microscopy (SEM). Crystal violet (CV) assay was used to detect biofilm biomass. Lactate kit and anthrone-sulfuric acid colorimetric assay were used to determine the abilities of lactic acid and exopolysaccharides production, respectively. The proportions of three-species and expression levels of the cariogenic-related genes in biofilms were detected by TaqMan fluorescence quantitative PCR and real-time fluorescence quantitative PCR. A biofilm demineralization model of human enamel slabs was further constructed, and the hardness of enamel surface was detected.Results:Compared to UA159+Ss+Sg, over-expression of ASvicK could inhibit biofilm formation and lactic acid production in ASvicK+Ss+Sg biofilm significantly decreased by 78.93% ( P<0.001) and 62.23% ( P<0.001), respectively. With ASvicK over-expression, the amounts of water-insoluble and-soluble glucoses in ASvicK+Ss+Sg biofilm were reduced respectively by 39.13% ( P<0.001) and 68.00% ( P<0.001). Compared to the UA159+Ss+Sg Group, the proportion of Sm, the cariogenic bacteria, showed 33.00% reduction ( P<0.01) in Sm+Ss+Sg biofilm, and the gene expressions of cariogenic-relative genes vicK/X, gtfB/C/D, and ftf significantly decreased ( P<0.05). The micro-hardness value of enamel slabs after demineralization by ASvicK+Ss+Sg biofilm was significantly increased to 183.84% ( P<0.001). Conclusions:ASvicK over-expression could reduce the Sm proportion and weaken the cariogenicity of oral Streptococcus biofilm, thereby possibly slowing down the progression of caries.

Objective:To develop and evaluate metal artifact removal systems (MARSs) based on deep learning to assess their effectiveness in removing artifacts caused by different thicknesses of metals in cone-beam CT (CBCT) images.Methods:A full-mouth standard model (60 mm×75 mm×110 mm) was three-dimensional (3D) printed using photosensitive resin. The model included a removable and replaceable target tooth position where cobalt-chromium alloy crowns with varying thicknesses were inserted to generate matched CBCT images. The artifacts resulting from cobalt-chromium alloys with different thicknesses were evaluated using the structural similarity index measure (SSIM) and peak signal-to-noise ratio (PSNR). CNN-MARS and U-net-MARS were developed using a convolutional neural network and U-net architecture, respectively. The effectiveness of both MARSs were assessed through visualization and by measuring SSIM and PSNR values. The SSIM and PSNR values were statistically analyzed using one-way analysis of variance (α=0.05).Results:Significant differences were observed in the range of artifacts produced by different thicknesses of cobalt-chromium alloys (all P<0.05), with 1 mm resulting in the least artifacts. The SSIM values for specimens with thicknesses of 1.0 mm, 1.5 mm, and 2.0 mm were 0.916±0.019, 0.873±0.010, and 0.833±0.010, respectively ( F=447.89, P<0.001). The corresponding PSNR values were 20.834±1.176, 17.002±0.427, and 14.673±0.429, respectively ( F=796.51, P<0.001). After applying CNN-MARS and U-net-MARS to artifact removal, the SSIM and PSNR values significantly increased for images with the same thickness of metal (both P<0.05). When using the CNN-MARS for artifact removal, the SSIM values for 1.0, 1.5 and 2.0 mm were 0.938±0.023, 0.930±0.029, and 0.928±0.020 ( F=2.22, P=0.112), while the PSNR values were 30.938±1.495, 30.578±2.154 and 30.553±2.355 ( F=0.54, P=0.585). When using the U-net-MARS for artifact removal, the SSIM values for 1.0, 1.5 and 2.0 mm were 0.930±0.024, 0.932±0.017 and 0.930±0.012 ( F=0.24, P=0.788), and the PSNR values were 30.291±0.934, 30.351±1.002 and 30.271±1.143 ( F=0.07, P=0.929). No significant differences were found in SSIM and PSNR values after artifact removal using CNN-MARS and U-net-MARS for different thicknesses of cobalt-chromium alloys (all P>0.05). Visualization demonstrated a high degree of similarity between the images before and after artifact removal using both MARSs. However, CNN-MARS displayed clearer metal edges and preserved more tissue details when compared with U-net-MARS. Conclusions:Both the CNN-MARS and U-net-MARS models developed in this study effectively remove the metal artifacts and enhance the image quality. CNN-MARS exhibited an advantage in restoring tissue structure information around the artifacts compared to U-net-MARS.

Objective:To compare and evaluate the difference in maxillary dentition position using an anatomical facebow and jaw movement analyzer.Methods:From March to May 2023, 15 medical interns from Yantai Stomatological Hospital were recruited, including 9 males and 6 females, aged 20-25 years. Digital models and plaster models of maxillary dentition were obtained from the 15 medical interns. The anatomical facebow group (AFB) and jaw movement analyzer group (JMA) were used to transfer the position of the maxillary dentition to the virtual articulator. The virtual occlusal articulator module of exocad denture design software was used to measure the inclination angle of the occlusal plane of the two groups, the distance between the mesio-incisal angle of the left maxillary central incisor and the lateral center point of the lateral condylar sphere of the virtual occlusal articulator, the distance between the mesial buccal cusp of the maxillary first molar and the lateral center point of the lateral condyle sphere of the virtual articulator. The same marks (mesial incisor point of left maxillary central incisor and mesial buccal cusp point of both maxillary first molars) were measured in two groups of maxillary dentition, and the root-mean-square error between 3 points was calculated.Results:The occlusal plane inclination angle in AFB group (9.11°±3.85°) was significantly larger than that in JMA group (4.94°±2.69°) ( t=10.45, P<0.001). There were significant differences between AFB and JMA groups. The distances from the mesial cusp of the left first molar to the lateral center of the left condylar, from the mesial cusp of the left maxillary central incisor to the lateral center of the left condylar[(91.75±3.05), (129.09±4.60) mm]were significantly smaller than those in the JMA group[(95.68±5.45), (132.41±5.64) mm]( t=-4.48, P=0.001; t=-4.21, P=0.001). In both groups of models, the distance of the mesial cusp of the left maxillary central incisor was (8.81±2.56) mm, and the distance between mesial buccal cusp of maxillary left first molar was (7.56±2.49) mm, the distance between mesial buccal cusp of maxillary right first molar was (7.13±2.77) mm; the root mean square error was (7.93± 2.94) mm. Compared with 0, the difference was statistically significant ( t=10.45, P<0.001). Conclusions:There were differences between the two methods (anatomical facebow and the jaw movement analyzer) for transferring the maxillary dentition position to the three-dimensional space position of the virtual articulator.