BMC Oral Health最新文献

Background: Periodontitis is a chronic inflammatory disease characterized by the destruction of the components of the periodontium. It significantly impacts oral health and has been linked to systemic conditions like cardiovascular disease and diabetes. The critical role of neutrophils in the occurrence and development of chronic periodontitis has been paid increasing attention. The study aimed to explore the protective effects of D-mannose on chronic periodontitis and determine whether its underlying mechanisms is related to neutrophils.

Methods: To explore the protective effects of D-mannose on chronic periodontitis, the eight-week-old Sprague Dawley rat model of lipopolysaccharide (LPS)-induced periodontitis was established, followed by D-mannose treatment by oral gavage. To evaluate the protective effects of D-mannose against periodontal bone loss, methylene blue staining, hematoxylin and eosin (H&E) staining, and micro-CT scanning were utilized. Then, immunofluorescence (IF), Western Blot, and RT-PCR were applied to assess the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, and IL-17), anti-inflammatory cytokine (IL-10), tumor necrosis factor-alpha (TNF-α), granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), ten-eleven translocation 2 (TET2), and key glycolytic enzymes (HK1, HK2, PFKFB3), and to examine D-mannose's impact on the recruitment and activation of neutrophils in the gingiva. Additionally, neutrophils isolated from the peripheral blood of healthy rats were treated with LPS and D-mannose, and changes in the expression levels of myeloperoxidase (MPO), IL-1β, IL-6, IL-17, IL-10, and TET2 were observed via IF.

Results: In vivo, D-mannose inhibited LPS-induced alveolar bone resorption in rats. After D-mannose treatment, the expression levels of IL-17 (p<0.01) and TET2 (p<0.01) were suppressed by IF, and the expression levels of IL-1β (p<0.05), IL-17 (p<0.05) and TET2 (p<0.01) were downregulated by WB. The results of qPCR showed that D-mannose reduced the expression levels of IL-1β (p<0.05), IL-6 (p<0.01), IL-17 (p<0.01), TNF-α (p<0.01), G-CSF (p<0.01), GM-CSF (p<0.01), TET2 (p<0.01), HK1 (p<0.01), HK2 (p<0.01), and PFKFB3 (p<0.01). D-mannose also inhibited the recruitment and activation of neutrophils in LPS-treated rat gingival tissues. In vitro, the results of IF showed that D-mannose inhibited the activation of neutrophils stimulated by LPS, downregulated the expression of IL-1β (p < 0.05), IL-6, IL-17 (p < 0.01), and TET2 (p < 0.01), and upregulated the expression of IL-10 (p < 0.01).

Conclusions: D-mannose can alleviate chronic periodontitis in rats by regulating the functions of neutrophils, potentially associated with the expression of TET2 and glycolysis, providing new insights into the potential application of D-mannose to chronic periodontitis.

Background: This study focused on the aging mechanism and degradation of mechanical and structural features of elastodontic appliances (EA) under artificial and intraoral aging to achieve oral myofunctional therapy with particular removable silicone elastomer devices.

Materials and methods: EAs artificially aged in saliva with different pH values were investigated through cyclic compression testing along with characterization techniques (Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy), and characterization analysis was also performed on clinically retrieved EAs.

Results: Artificial aging was found to have minimal effect on the structural properties of EAs, and intraorally aged samples showed perceptible micro-morphology. The Mullins index and peak stress decreased (P<0.01), while the compression set increased with prolonged aging time. Samples in alkaline saliva showed the largest Mullins effect (P<0.05).

Conclusions: The aging mechanism of the elastomer was found to be the crosslinking of main chains and scission of side chains. The presence of OH- enhanced the rupture degree of side bonds. The decline in viscoelastic properties was shown to be more severe with longer service durations.

Clinical relevance: Research on how the salivary environment and pH affect the aging characteristics of EAs is vital for guiding clinical applications and future modifications to extend their clinical lifetime.

Background: Placing implants deep sub-gingivally may affect the accuracy of implant impression techniques and the fit of final restoration.

Purpose: The aim of this in-vitro study was to evaluate the effect of soft tissue thickness on accuracy of conventional and digital implant impression techniques.

Methods: Four parallel implant analogues (A, B, C, D) placed in each of two epoxy resin models representing edentulous mandible covered by flexible polyurethane material with two different thickness two mm and four mm. A total of sixty impressions performed, thirty impressions for each model divided into four groups (n = 15 per group) GI (C2mm) open tray impression with two mm implant depth, GII (C4mm) open tray impression with four mm implant depth, GIII (D2mm) digital impression with two mm implant depth, GIV (D 4 mm) digital impression with four mm implant depth. Impressions from open tray technique were poured to get stone casts while impressions from digital scanning technique were printed as three-dimensional printed casts. The six inter-implant distances between analogues were measured using Co-ordinate measuring machine, deviations compared to reference models were calculated. Data was collected, tabulated and statistically analyzed using One-way ANOVA test to detect significances between groups.

Results: For conventional impressions there was significant difference between C2mm/C4mm (P < 0.001) regarding interimplant distance, while in digital impressions there was no significant difference between D2mm/D4mm AB(p = 0.110), BC(p = 0.066), CD(p = 0.710), AD(p = 0.084), AC(p = 0.067) and BD(p = 0.072). There was significant difference between conventional and digital impression techniques C2mm/D2mm, C4mm/D4mm (P < 0.001).

Conclusion: Within the limitations of this in-vitro study digital impressions provide more accurate outcomes with implants placed deeper subgingivally than conventional impressions.

Trial registration: Retrospectively registered.

Background: Taste buds' innervation is necessary to sustain their cell turnover, differentiated taste buds and nerve fibers in circumvallate papilla (CVP) disappear following glossopharyngeal nerve transection. Normally, taste buds recover to baseline number in about 70 days. Bone marrow stem cell (BM-MSC) derived exosomes or their combination with Zinc chloride are used to assess their potential to speed up the regeneration process of CVP following bilateral deafferentation.

Methods: Twenty-eight male Sprague-Dawley rats were randomly divided into four groups; Group I: subjected to sham operation followed by IP injection of saline. The other experimental groups (II, III and IV) were subjected to surgical bilateral transection of glossopharyngeal nerve. Group II received single IP injection of saline. Group III received single IV injection of BM-MSC-derived exosomes (100 µg). Group IV received single IV injection of BM-MSC-derived exosomes and single IP injection of zinc chloride (5 mg/kg). After 28 days, CVP was dissected and prepared for histological and histomorphometric analysis, RT-PCR for cytokeratin 8 gene expression, ELISA to assess protein level of brain-derived neurotrophic factor, redox state analysis of malondialdehyde and glutathione content, followed by statistical analysis.

Results: Histopathologically, group II exhibited great tissue damage with marked reduction in taste buds and signs of degeneration in the remaining ones. Group III was close to control group with marked improvement in taste buds' number and structure. Group IV showed inferior results when compared to group III, with many immature taste buds and signs of degeneration. Statistical results showed that groups I and III have significantly higher values than groups II and IV regarding taste buds' number, cytokeratin 8, and reduced glutathione. However, malondialdehyde demonstrated high significant values in group IV compared to groups I and III. Regarding brain-derived neurotrophic factor, group III had significantly higher values than group II.

Conclusion: BM-MSC-derived exosomes have superior regenerative potentials in acceleration of CVP and nerve healing following bilateral transection of glossopharyngeal nerve in contrary to its combination with zinc chloride.

Background: This study aimed to evaluate the knowledge, awareness, and practice of intraoral scanners (IOS) and the factors affecting their accuracy amongst dental interns and practitioners.

Methods: This was an observational cross-sectional study in which data was collected from a representative population in Saudi Arabia, with the help of online questionnaires. The forms were distributed to 500 dental interns and practitioners and the questionnaire's validity and reliability were evaluated for vetting and remarks. The questionnaire consisted of three parts: the participants' demographic details, questions on the awareness and knowledge of participants regarding IOS, and the factors affecting the accuracy in clinical use of IOS. Questions were to be answered with 'yes', 'no' and 'I don't know'. Descriptive statistical analysis was performed using the control chart technique and the chi-squared test, with statistical significance set at p < 0.05.

Results: Most of the participants (58%) knew about the IOS and its applications (47.5%), but the majority of the participants did not use IOS in their clinics (43.5%). The majority of males (57.39%) and females (50.86%) strongly agreed that cost was a barrier to purchasing an IOS. To better get more knowledge on IOS, the specialists 66 (16.5%) and interns 54 (13.5%) chose continuing dental education programs and workshops. There was a significant association (p < 0.05) of knowledge and awareness, perception, and factors affecting parameters with different categories and years of experience.

Conclusion: Within the limitations of this study, most participants had a positive stance towards IOS but due to inadequate knowledge and understanding, its use and applications were minimal. IOS was well-received regardless of operator training and experience. There is a significant need to increase awareness of this concept, as it may increase treatment efficiency and effectiveness.

Background: Utilization of oral health services is a global public health challenge. Low- and middle-income countries are disproportionately affected. Uganda is one of the low- and middle-income countries where only 4% of the population has access to oral health services. Northern Uganda is one of the regions in the country with limited information about oral health utilization.

Objective: To assess factors associated with utilization of oral health services among adults aged 18-70 years in Lira district, Northern Uganda.

Methods: This was a quantitative cross-sectional study conducted in Lira District. Multistage sampling was used to select 576 respondents. Data was collected using a researcher-administered structured questionnaire that was adopted, modified, and pretested. Data was analyzed at three levels, including univariate, bivariate, and multivariate at 0.05 significance level.

Results: Of the 634 respondents, 576 responded, giving a 90.9% response rate. Results show that utilization of oral health services was 20.5% (118) among adults aged 18-70 years in 6 months. Predictors of utilization of oral services among this age group are: having not attended any formal education (AOR = 0.2, 95%CI 0.06-0.62), having poor attitudes towards oral health services (AOR = 0.55, 95%CI 0.34-0.89), having cultural influence on the utilization of the oral health services (AOR = 4.84, 95% CI 2.77-8.43), accessing the services from private not-for-profit facilities (AOR = 4.67, 95% CI 1.79-12.16), being un sure of the availability of the equipment used (AOR = 0.42, 95% CI 0.18-0.9), and availability of friendly services (AOR = 2.53, 95% CI 1.12-5.50).

Conclusions and recommendations: Utilization of oral health services is low in Lira district, with only 2 in 10 of the adults aged 18-70years of age utilizing oral health services in 6 months. To improve utilization, targeted health education campaigns should address cultural barriers and attitudes, while ensuring that public health facilities are better equipped and provide more user-friendly services.

Background: Proximal caries datasets for training artificial intelligence (AI) algorithms commonly include clinician-annotated radiographs. These conventional annotations are susceptible to observer variability, and early caries may be missed. Micro-computed tomography (CT), while not feasible in clinical applications, offers a more accurate imaging modality to support the creation of a reference-standard dataset for caries annotations. Herein, we present the Academic Center for Dentistry Amsterdam-Diagnostic Insights for Radiographic Early-caries with micro-CT (ACTA-DIRECT) dataset, which is the first dataset pairing dental radiographs and micro-CT scans to enable higher-quality annotations.

Methods: The ACTA-DIRECT dataset encompasses 179 paired micro-CT scans and radiographs of early proximal carious teeth, along with three types of annotations: conventional annotations on radiographs, micro-CT-assisted annotations on radiographs, and micro-CT annotations (reference standard). Three dentists independently annotated proximal caries on radiographs, both with and without micro-CT assistance, enabling determinations of interobserver agreement and diagnostic accuracy. To establish a reference standard, one dental radiologist annotated all caries on the related micro-CT scans.

Results: Micro-CT support improved interobserver agreement (Cohen's Kappa), averaging 0.64 (95% confidence interval [CI]: 0.59-0.68) versus 0.46 (95% CI: 0.44-0.48) in its absence. Likewise, average sensitivity and specificity increased from 42% (95% CI: 34-51%) to 63% (95% CI: 54-71%) and from 92% (95% CI: 88-95%) to 95% (95% CI: 92-97%), respectively.

Conclusion: The ACTA-DIRECT dataset offers high-quality images and annotations to support AI-based early caries diagnostics for training and validation. This study underscores the benefits of incorporating micro-CT scans in lesion assessments, providing enhanced precision and reliability.

Background: Volatile organic compounds (VOCs) are ubiquitous environmental pollutants which have been suggested to have adverse effects on human health. While the influence of environmental pollutant exposures on periodontitis has attracted elevating attention in recent years, the epidemiological evidence on the association between VOCs exposure and periodontitis was scarce. This study aimed to investigate the potential mediating role of systemic inflammation factors in the complex association between VOCs exposure and periodontitis.

Methods: Utilizing data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014, we examined the impacts of VOCs exposure on periodontitis. Concentrations of urinary metabolites of VOCs (mVOCs) were measured using electrospray tandem mass spectrometry to evaluate internal VOCs exposure. Multivariable logistic regression, restricted cubic spline regression (RCS), Bayesian kernel machine regression (BKMR) and Quantile g-computation (QGC) models were performed to investigate the impacts of VOCs exposure on periodontitis. Mediation models were applied to assess the mediated effects of systemic inflammation on the association between mixed VOCs exposure and periodontitis. Besides, we analyzed the association between mixed VOCs exposure and periodontitis in stratified age, gender, and smoking status subgroups.

Results: 1,551 participants were ultimately included for further analyses, of whom 45.20% suffering from periodontitis. Multivariable logistic regression and RCS identified positive associations between single urinary mVOCs and periodontitis (P < 0.05). Notably, BKMR and QGC models suggested that mixed VOCs exposure was significantly associated with periodontitis, with 2-Aminothiazoline-4-carboxylic acid (ATCA) contributing the most (conditional posterior inclusion probability = 0.997). Moreover, systemic inflammation markers (leukocyte and lymphocyte counts) were found to partly mediate the association between VOCs exposure and periodontitis (P < 0.05). No interaction effect was identified between mixed VOCs exposure and periodontitis in age, gender and smoking status subgroups (P > 0.05).

Conclusion: This study demonstrated a positive association between VOCs exposure and periodontitis, which was potentially mediated by systemic inflammation factors. Further longitudinal researches are demanded to clarify the underlying mechanisms.

Objective: Distraction osteogenesis is a primary treatment for severe mandibular hypoplasia. Achieving the ideal mandible movement direction through precise distraction vector control is still a challenge in this surgery. Therefore, the aim of this study was to apply Optical See-Through (OST) Augmented Reality (AR) technology for intraoperative navigation during mandibular distractor installation and analyze the feasibility to evaluate the effectiveness of AR in a phantom experiment.

Methods: Phantom was made of 3D-printed mandibular models based on preoperative CT scans and dental arch scans of real patients. Ten sets of 3D-printed mandible models were included in this study, with each set consisting of two identical mandible models assigned to the AR group and free-hand group. 10 sets of mandibular distraction osteogenesis surgical plans were designed using software, and the same set of plans was shared between the AR and free-hand groups. Surgeons performed bilateral mandibular distraction osteogenesis tasks under the guidance of AR navigation, or the reference of the preoperative surgical plan displayed on the computer screen. The differences in angular errors of distraction vectors and the distance errors of distractor positions under the guidance of the two methods were analyzed and compared.

Results: 40 distractors were implanted in both groups, with 20 cases in each. In intra-group comparisons between the left and right sides, the AR group exhibited a three-dimensional spatial angle error of 1.88 (0.59, 2.48) on the left and 2.71 (1.33, 3.55) on the right, with P = 0.085, indicating no significant bias in guiding surgery on both sides of the mandible. In comparisons between the AR group and the traditional free-hand (FH) group, the average angle error was 1.94 (1.30, 2.93) in the AR group and 5.06 (3.61, 9.22) in the free-hand group, with P < 0.0001, resulting in a 61.6% improvement in accuracy. The average displacement error was 1.53 ± 0.54 mm in the AR group and 3.56 ± 1.89 mm in the free-hand group, with P < 0.0001, indicating a 57% improvement in accuracy.

Conclusion: Augmented Reality technology for intraoperative navigation in mandibular distraction osteogenesis is accurate and feasible. A large randomized controlled trial with long-term follow-up is needed to confirm these findings.

Trial registration: The project has been registered with the Chinese Clinical Trial Registry, with registration number ChiCTR2300068417. Date of Registration: 17 February 2023.

Background: Dentin hypersensitivity (DH) is a common oral condition that is associated with severe dental pain. Pain relief is a key focus of the treatment of DH. The purpose of this study was to evaluate the blocking and antacid effects of gallic acid (GA) combined with sodium fluoride (NaF) on dentinal tubules in vitro.

Methods: Ninety dentin discs from human third molars were treated with 6% citric acid for 2 min. Then, the surface morphologies of ten dentin discs were observed by scanning electron microscopy (SEM). The remaining samples were randomly divided into four groups: the NaF group, which was treated with 1000 ppm NaF; the GA group, which was treated with 4000 ppm GA; the GA + NaF group, which was treated with 1000 ppm NaF + 4000 ppm GA; and the blank group, which was treated with deionized water. The dentin permeability of each sample was measured with a water-filled system before processing and after 7 days of treatment. Dentin morphology and surface deposits were observed by SEM. Then, samples from the NaF, GA + NaF and blank groups were subjected to an acid challenge by incubation with 0.02% citric acid for 2 min. SEM and a water-filled system were used to evaluate the blocking and antacid effects of NaF and GA + NaF.

Results: 1. NaF and GA + NaF significantly decreased dentin permeability. The effect of the GA + NaF treatment was more significant. After acid challenge, both groups still exhibited decreased dentin permeability compared with the initial assessment. 2. Compared with the NaF group, the GA + NaF group had more mineral deposits on the dentin surface and dentin tubules. After acid challenge, the deposits in the GA + NaF group were still clearly visible.

Conclusion: The combined effect of GA and NaF on reducing dentin permeability by blocking open dentin tubules is better than that of NaF alone. After acid challenge, the GA + NaF treatment still had a better effect.