The anatomical morphology of root canal systems in maxillary second molars (MSMs) is complex and shows diverse variations, which leads to challenging root canal treatments that could end in failure. Therefore, understanding the diverse nature of root canal anatomy is an important prerequisite for the successful treatment of MSMs. The fused root is among the most prevalent root variants of MSMs, exhibiting a distribution rate ranging from 23.9% to 42.25% within the Chinese population. Fused roots are often accompanied by complex root canal fusion, as the incidence of root canal fusion in type VI fused roots of MSMs is 90.5% within the Chinese population. There are several treatment strategies for the root canal variations in MSMs, including the location of the root canal orifice and clearing and filling of the isthmus within the fused root canal. Cone-beam computed tomography, dental operating microscopy, and digital dynamic and static navigation technologies can be employed to accurately identify the root canal variations associated with fused roots. In the treatment of fused root canals, for the cleaning and filling of the isthmus in fused canals, enhanced chemical preparation, timely application of laser-assisted irrigation, photodynamic therapy, and micro-apical surgery significantly improve the success rate of endodontic procedures. The treatment strategies and prevalence of root canal variation of MSMs from a native Chinese population were summarized in this paper to provide guidance and reference for the successful treatment of MSMs.

Objective To investigate the effects of Erianin on cell proliferation and apoptosis in human oral squamous cell carcinoma (OSCC) cells, providing a research foundation for the clinical treatment of OSCC. Methods Erianin was applied to OSCC cells (CAL27 and SCC9) at concentrations of 0, 2.5, 5, and 10 μmol/L. The inhibitory effect of Erianin on OSCC cell proliferation was evaluated using CCK-8 and soft agar colony formation assays. Western blotting (WB) was employed to analyze the expression levels of anti-apoptotic proteins B-cell lymphoma-extra large (Bcl-xL), B-cell lymphoma-2 (Bcl-2), myeloid cell leukemia-1 (Mcl-1), and apoptotic protein cleaved-Caspase 3 (c-Caspase 3) in OSCC cells. Caspase 3 activity was further assessed using a caspase 3 activity detection kit to examine the pro-apoptotic effect of Erianin in OSCC cells. Mcl-1 overexpression was induced in CAL27 cells via plasmid transfection, and the influence of Mcl-1 on the effects of Erianin in CAL27 cells was analyzed by WB and caspase 3 activity measurement. All animal experiments were approved by the Ethics Committee of Hunan Cancer Hospital. A CAL27 xenograft mouse model was established and randomly divided into two groups (n = 5): the treatment group received intraperitoneal injection of Erianin (25 mg/kg), while the control group was injected with phosphate-buffered saline (PBS) as the vehicle. Immunohistochemistry (IHC) was used to detect the expression levels of Ki67 and Mcl-1 in the tumor tissues. Results Erianin inhibited the proliferation of CAL27 and SCC9 cells in a dose-dependent manner and downregulated the protein expression of Mcl-1, with minimal effects on Bcl-2 and Bcl-xL. Furthermore, Erianin induced apoptosis in OSCC cells, as evidenced by increased expression of c-Caspase 3 and enhanced caspase 3 activity (P<0.001). Overexpression of Mcl-1 inhibited the Erianin-induced increase in c-Caspase 3 protein levels and caspase 3 activity. In vivo results were consistent with the in vitro findings. After Erianin treatment, CAL27 cell growth in nude mice was suppressed (P<0.001), and the expression levels of the proliferation marker Ki67 and the anti-apoptotic protein Mcl-1 in the tumor tissues were downregulated (P<0.001). Conclusion Erianin exhibits potent anti-tumor effects, effectively inhibiting the proliferation of OSCC cells and inducing apoptosis. The underlying mechanism may involve the downregulation of the pro-survival protein Mcl-1.

Objective To investigate the changes of dentin surface and the effects of different surface treatments on the rebonding effect following non-destructive restoration removal by an Er:YAG laser and to provide reference for oral clinical operation. Methods This study was approved by the ethics review committee of the unit. Using computer-aided design and computer-aided manufacturing (CAD/CAM) technology, 102 zirconia specimens (4 mm × 4 mm × 1.5 mm) were fabricated. In total, 110 impacted third molar teeth were extracted, and 102 dentine blocks (4 mm × 4 mm × 2 mm) were prepared. The zirconia specimen and dentin blocks were bonded with resin cement before removal with an Er: YAG laser. Three disassembled dentin blocks were randomly selected, and the components of dentin surface elements were analyzed by energy dispersive X-ray spectroscopy (EDX). The removed dentin blocks were randomly divided into three groups (n = 33) based on the different surface treatments: control group (no treatment), sandblasting group (50 μm, Al₂O₃ sandblasting), and laser irradiation group (Er: YAG laser irradiation, parameters were set to 10 Hz, 60 mJ, 0.6 W). Three dentin blocks were randomly selected in each group for scanning electron microscopy (SEM) observation, and the residual resin on dentin surface of remaining 30 dentin blocks in each group were observed under an optical microscope at 20 times magnification. Scores were obtained using the adhesive remnant index (ARI) method. Three groups of dentin blocks (n = 30) that underwent different surface treatments were rebonded with resin cement according to standard procedures and then divided into two subgroups for aging (n = 15). One subgroup was subjected to a 37 ℃ water bath for 24 h, and the other subgroup was subjected to 5 000 thermal cycles after a 37 ℃ water bath for 24 h, and the micro-shear bonding strength of each group was measured. The microshear bonding strength of each group was measured, and fracture modes were analyzed. The differences of dentine surface ARI between the three groups, as well as the inter-group differences in fracture mode, and bonding strength, and the intra-group differences before and after aging were compared between the three groups. Results When zirconia was removed by Er: YAG laser, there was no obvious damage on the dentin surface, but C and Si elements in dentin increased significantly. After different surface treatments, the ARI scores of the sandblasting and laser irradiation groups were lower than those of the control group (P<0.05), while ARI was not significantly different between the sandblasting and laser irradiation groups (P>0.05). The dentin surface morphology was also different. There was a large amount of residual resin on the dentin surface of the control group. In the sandblasting group, the residual resin was lower, the dentin surface was rough, and the dentin tubules were visible. A large amount of residual resin was observed on the dentin surface of the laser irradiation group. After 24 h of water bath at 37 ℃, the bonding strengths of the control group, sandblasting group, and laser irradiation group were (6.13 ± 2.40) MPa, (9.39 ± 2.00) MPa, and (5.85 ± 1.44) MPa, respectively, and the bonding strength of the sandblasting group was significantly higher than that of the other two groups (P<0.05). After being subjected to 24 h of water bath at 37 ℃ and 5 000 thermal cycles, the bonding strengths of the control group, sandblasting group, and laser irradiation group were (5.39 ± 0.83) MPa, (8.45 ± 1.20) MPa and (4.84 ± 1.43) MPa, respectively. The bonding strength of the sandblasting group was significantly higher than that of the other two groups (P<0.05). There was no significant difference between the control group, sandblasting group, and laser irradiation group before and after 5 000 thermal cycles following 24 h of water bath at 37 ℃ (P>0.05). In the control group, sandblasting group, and laser irradiation group, cohesive fracture was not observed. The fracture mode was mainly adhesive fracture. Before and after 5 000 thermal cycles, the frequency of mixed fracture in the sandblasting group was significantly higher than that in the other two groups (P<0.05). Conclusion Er: YAG laser removal of zirconia does not damage dentin, but a large amount of resin remains on the dentin surface after removal. The sandblasting process can effectively remove these residual resins, thereby improving the dentine rebonding effect.

Objective To investigate the application effect of bovine pericardium in horizontal bone augmentation surgery in the aesthetic area and to assess its clinical feasibility in guided bone regeneration (GBR). Methods This study was approved by the Ethics Committee. A total of 29 patients with anterior tooth loss accompanied by labial bone defects were selected, and horizontal bone augmentation was performed using a bovine pericardium membrane combined with particulate or block bone grafts. Centered on the virtual implant in the preoperative design, labial bone thickness at the implant neck and 1-5 mm below it was measured at different time points: preoperatively (T0), immediately postoperatively (T1), and 6 months postoperatively (T2). The results were used to assess bone regeneration outcomes. Additionally, the visual analog scales (VASs) of postoperative pain and swelling were recorded, and whether any complications such as infection or wound dehiscence occurred were monitored. Results Immediately after surgery, labial bone thickness of all implants significantly increased, with an average increase more than 3 mm. Six months after surgery, the bone augmentation was well maintained. Specifically, labial bone thickness 3-5 mm below the shoulder of the implant was greater than 3 mm. The VAS scores showed that postoperative pain and swelling peaked on the third day and then gradually decreased, with good recovery 10 days after surgery. No complications such as infection or wound dehiscence occurred during the follow-up period. Conclusion Bovine pericardium shows good bone augmentation effect and biocompatibility in horizontal bone augmentation in the anterior aesthetic area, and it is suitable for various horizontal bone augmentation surgeries in the aesthetic area.

Objective To investigate the association between monocyte to high-density lipoprotein cholesterol ratio (MHR) and periodontitis and to provide new epidemiologic evidence on the factors affecting periodontitis. Methods Data on MHR, periodontitis, and other covariates were selected from the NHANES(National Health and Nutrition Examination) database for 3 cycles of subjects in 2009-2010, 2011-2012, and 2013-2014, and a total of 8 456 study subjects were included. The study participants were grouped according to the prevalence of periodontitis (presence or absence), and three regression models (unadjusted covariates, partially adjusted covariates, and fully adjusted covariates) were constructed to analyze the relationship between MHR and periodontitis by using a weighted logistic regression method with stepwise adjustment for confounders. MHR was divided into four groups from Q1 to Q4 according to quartiles from small to large for weighted trend analysis, and the nonlinear relationship between MHR (continuous) and periodontitis was analyzed using a restricted cubic spline with subgroup analysis and sensitivity analysis. Results All three logistic regression models showed a positive association between MHR and periodontitis (OR = 2.92, 95%CI: 2.14-3.99, P<0.001 (not adjusted); OR = 1.97, 95%CI: 1.39-2.78, P<0.001 (partially adjusted); OR = 1.62, 95%CI: 1.10-2.39, P = 0.017 (fully adjusted)). Trend analysis showed a significantly higher risk of developing periodontitis in the Q4 group compared with the Q1 group in both single (OR = 1.92, 95% CI: 1.58-2.33, P<0.001) and multifactorial analyses (OR = 1.30, 95% CI: 1.03-1.64, P = 0.029). Restricted cubic spline results did not support a nonlinear relationship between MHR and periodontitis (P for nonlinear>0.05), subgroup analysis showed no significant interaction between the covariates and MHR (P>0.05), and sensitivity analysis also showed a positive correlation between MHR and periodontitis (OR = 1.67, 95%CI: 1.31-2.14, P<0.001). Conclusion MHR is positively associated with the risk of developing periodontitis.

Objective To analyze the status and trends of the disease burden of periodontal disease among women of reproductive age (15-49 years) in China from 1990 to 2021, and to provide a reference for the development of periodontal disease prevention and control strategies for women of reproductive age. Methods Using the global burden of disease (GBD) data from 1990 to 2021, this study investigated the periodontal disease burden among women of reproductive age, including prevalence, incidence, disability-adjusted life years (DALYs), DALY rates, and their corresponding standardized indicators. Joinpoint 5.2.0.0 software was used for time trend analysis of DALYs, age-specific DALY rates, and annual average percentage change (AAPC) values. A log-linear regression model was used to test trends for DALYs and DALY rates. Results Compared with 1990, the prevalence and incidence of periodontal disease among Chinese women in 2021 increased by 45.67% (per 100,000 people) and 29.29% (per 100,000 people), respectively. The distribution of periodontal disease among women (15-49 years) showed a continuous and rapid upward trend, with the growth rate increasing rapidly with age. The number of cases increased the fastest in the 45-49 age group, and the prevalence increased the fastest in the 35-44 age group. The incidence of periodontal disease continued to rise with age, with the fastest increase in the 35-44 age group among women of reproductive age. The Joinpoint regression model results showed that periodontal disease led to an expanding trend in the disease burden among women of reproductive age in China, with an AAPC of DALYs = 1.20% and an AAPC of DALY rate = 1.25% (P<0.001). Conclusion The periodontal disease burden among Chinese women aged 15-49 years showed a gradually increasing trend from 1990 to 2021.

Objective To explore the clinical manifestations, diagnosis, differential diagnosis, and treatment of granulomatous cheilitis complications after treatment in patients with upper lip venous malformations, as well as to provide a reference for their clinical diagnosis and treatment. Methods This report provides details on the clinical manifestations, diagnosis, differential diagnosis, and treatment of a case of granulomatous cheilitis after the treatment of upper lip venous malformation, and then analyzes granulomatous cheilitis alongside the related literature. The patient, a 30-year old male, was first seen in the dermatology department of another hospital with bright red spots on his lips, diagnosed with allergic dermatitis and received symptomatic treatment, and the erythema did not improve. He was diagnosed with ‘cavernous hemangioma’ and was treated with polydocanol and bleomycin injections. The bright red spots on his lips improved, but the swelling worsened for more than half a year. He then sought treatment at the oral mucosal department of our hospital. At the time of consultation, the swelling of the upper lip and perilabial skin was obvious, and there was a red patch on the right side of the upper lip, that was congested with blood. The upper lip was tough, with hard nodules, unclear borders, and poor mobility. Pathological examination showed epithelial hyperplasia of the upper lip mucosa, surface hyperkeratosis, subepithelial fibrous tissue hyperplasia, and chronic inflammation of the mucosa and minor salivary glands. Focal histiocyte, lymphocyte, and plasma cell infiltration was seen in the submucosal layer, with granulomatous inflammatory manifestations. Based on the patient's medical history, clinical manifestations, and histopathological manifestations, the diagnosis of granulomatous cheilitis was made. Tretinoin 0.3 mL (40 mg/mL, 1 mL/vial) was injected into the deep layer of the mucosa of the right and left upper lips for local block treatment. Prednisone acetate tablets (10 mg/Qd) were taken orally, and after 1 week of follow-up, the symptoms improved, so the original treatment was continued. After 2 weeks of follow-up, the swelling of the lips improved significantly, and the oral prednisone acetate tablets were adjusted to 5 mg/Qd. After 4 weeks of follow-up, the shape of the lips was largely back to normal, and the color and suppleness of the lips had improved significantly. The local block treatment and oral medication were stopped, and the patient was instructed to apply the topical tretinoin ointment Bid on the upper lip. Results The patient had a follow-up visit 8 weeks later, at which their lip color, shape, and texture remained normal, and the patient was instructed to stop the medication and follow up. A review of the literature suggests that the etiology of granulomatous cheilitis is unknown and that it is associated with genetic predisposition, odontogenic infections, allergic factors, microbial infections, and immunological factors. It needs to be clinically differentiated from diseases such as lip venous malformations, lip angioneurotic oedema, Crohn's disease, and tuberculosis. At present, the clinical treatment of granulomatous cheilitis is still based on local glucocorticoid block therapy or a combination of oral glucocorticoid drugs. In this case, the area of erythema on the lips decreased in size, but swelling occurred and continued to worsen after polydocanol and bleomycin injection treatment. Pre-existing venous malformation should be considered as a complication associated with injectable drugs that can produce granulomatous cheilitis. Conclusion The injection-based treatment of lip venous malformation may be complicated by granulomatous cheilitis, and in the process of clinical diagnosis and treatment, it is necessary to be aware to the existence of drug-related factors in the occurrence and development of granulomatous diseases.

Endodontic and periapical lesions are prevalent infectious diseases primarily caused by bacteria and their metabolic byproducts. The most widely used treatment method today is root canal therapy, which aims to remove infectious substances from the root canal. Root canal sealers can fill areas that core filling materials cannot reach, effectively reducing the risk of reinfection through their antimicrobial properties thus improving the success rate of root canal treatment. Various strategies have been employed to enhance the antimicrobial efficacy of root canal sealers through different mechanisms such as mechanical interlocking or chemical bonding. These strategies include antibiotic modification, quaternary ammonium compounds modification, nanoparticle modification, and others. Overall, antimicrobial modification strategies are increasingly diverse, and their effectiveness in enhancing the antimicrobial properties of sealers is beyond doubt. Root canal sealers modified with quaternary ammonium compounds and nanoparticles have shown certain advantages in antibiofilm activity and have potential clinical prospects. However, whether these modified materials have long-term antimicrobial effects, whether they can perform similarly in vivo as they do in vitro, and their biocompatibility are issues that still need to be addressed. In the future, the preparation of root canal sealers with ideal multidimensional properties will require further long-term and in-depth exploration.

Root caries is a prevalent chronic oral disease with an average global prevalence of 41.5%, characterized by high incidence, low rate of treatment, and high rate of retreatment. Root caries is primarily caused by core microbiome-induced dysbiosis and has multiple risk factors, including gingival recession, root surface exposure, and salivary dysfunction. The traditional preventive measures and treatments such as fluoride, mineralizing agents, and restorative materials, are unable to restore or maintain oral microecological homeostasis. Recent studies have demonstrated that probiotics, prebiotics, synbiotics, and antimicrobial peptides may prevent and treat root caries by reversing dysbiosis. In addition, these biotherapeutics can reduce acid production by acidiferous bacteria, promote alkali production (hydrogen peroxide and ammonia) by alkali-producing bacteria, inhibit biofilm formation, decrease extracellular polysaccharide production, and suppress microbial adhesion and aggregation. It is expected to play an important role in the prevention and control of root caries. This article aims to review oral probiotics (Streptococcus oligofermentans, Streptococcus oralis subsp. dentisani, and Streptococcus salivarius), prebiotics (arginine, nitrates, and synthetic compounds), synbiotics, and antimicrobial peptides (gallic acid-polyphemusin I and LH12) to provide evidence and guidance for root caries management through microecological modulation.

Periodontitis, a chronic inflammatory disease caused by plaque biofilm, is characterized by the irreversible pathological destruction of periodontal supporting tissues, including gums, periodontal membranes, alveolar bone, and cementum, resulting in tooth loosening and dislocation in severe cases. Currently, research on the pathogenesis, early diagnosis, and treatment of periodontitis is limited. Circular RNAs (circRNAs), previously considered “splicing noise”, have gained increasing research attention with the development of high-throughput sequencing technologies and bioinformatics. CircRNAs are non-coding RNAs lacking a 5' cap and 3' poly(A) tail, with a unique covalently closed ring structure, high expression, long half-life, and resistance to nuclease degradation, which can regulate splicing, encode proteins, and act as microRNA and RNA-binding protein sponges. In recent years, circRNAs have been reported to be involved in the occurrence and development of periodontitis, suggesting its potential role as a therapeutic target for periodontitis treatment. In this study, we described the biological function of circRNAs and their role in the development of periodontitis and the regulation of periodontal homeostasis and immune microenvironment. We found that circRNAs affect periodontal homeostasis and immune microenvironment by regulating the apoptosis of periodontal tissue cells (such as periodontal ligament stem cells and gingival fibroblasts) and regulating immune cells or cytokines, respectively. This review article summarizes the latest research progress on the association between circRNAs and periodontitis to provide a scientific basis for the development of novel diagnostic, therapeutic, and prognostic strategies for periodontitis.