BMC Oral Health最新文献

Objectives: To compare the stress distribution and crack propagation in cracked mandibular first molar restored with onlay, overlay, and two types of occlusal veneers using two different CAD/CAM materials by Finite Element Analysis (FEA).

Materials and methods: A mandibular first molar was digitized using a micro CT scanning system in 2023. Three-dimensional dynamic scan data were transformed, and a 3D model of a cracked tooth was generated. Finite element models of four different models (onlay, overlay, and two types of occlusal veneer restored teeth) were designed. Two different CAD/CAM materials, including Lava Ultimate (LU) and IPS e.max CAD (EMX), were specified for both models. Each model was subjected to three different force loads on the occlusal surfaces. Stress distribution patterns and the maximum von Mises (VM) stresses were calculated and compared.

Results: Compared to the base model, all restorations showed that high-stress concentration moved from the lower margin of the crack area towards the top of the crack area. The EMX-restored onlay, overlay, and occlusal veneer 2 had the lower stress in the cracked area and the lower average von Mises stress levels at the lower margin along the cracked line, especially under the 225N lateral force (P < 0.05). The occlusal veneer 1 filled with resin had a poorer stress distribution and higher stress concentration of stress at the remaining crack than the occlusal veneer 2 without resin filled inside.

Conclusions: The EMX restorations with onlay, overlay, and occlusal veneer 2 showed lower stress concentration at the lower margin of crack surface compared to the LU-restored models. The occlusal veneer with internal resin filler exhibited higher stress on the end of the lower margin of the crack surface.

Clinical relevance: Our results suggest that onlay, overlay ceramic restorations and occlusal veneer (without resin filling inside) may be a favorable method to prevent further crack propagation.

Trial registration: A protocol was specified and registered with the Chinese Clinical Trial Registry (ChiCTR) on 2022-04-12 (registration number: ChiCTR2200058630).

Background: With the improvement of living standards, implant dentures have become the choice of more and more patients with missing teeth. Dentures are not natural teeth, and may cause different degrees of negative impacts on patients in physiological, psychological and social aspects. The objective of this study was to examine the current status of psychological resilience among implant denture patients and the factors that influence it. Additionally, we aimed to analyse the correlation between psychological resilience, social support, and oral health behaviours, with a view to providing a scientific basis for the development of targeted interventions for patients with implant dentures.

Methods: A survey of 238 patients with implant dentures was conducted in the Department of Stomatology of the Affiliated Hospital of Jiangnan University and Wuxi Stomatological Hospital. The survey included a self-designed general information questionnaire, disease condition questionnaire, The Connor-Davidson Resilience Scale (CD-RISC), The Social Support Rating Scale (SSRS), and The oral health behavior scale.

Results: The CD-RISC score of patients with implant dentures was 66.49 ± 15.59, while the SSRS score was 37.90 ± 7.73, and the oral health behaviour score was 34.73 ± 7.92. Multiple linear regression analysis showed that age, economic status, social support, and oral health behavioural status were factors influencing the psychological resilience of patients with implant dentures (all P < 0.05), and the psychological resilience score was positively correlated with the score of oral health behaviours and the score of social support (P < 0.05), and the score of oral health behaviours was positively correlated with the score of social support (P < 0.05). Oral health behaviour partially mediated the relationship between psychological resilience and social support.

Conclusions: The postoperative psychological resilience of patients with implant dentures is at an average level and is affected by various factors, among which social support not only has a direct effect on the psychological resilience of patients with implant dentures, but also has an indirect effect on their psychological resilience through oral health behaviours. Healthcare professionals should actively adopt targeted nursing interventions to improve the psychological resilience of patients, improve their postoperative oral health behaviours, and improve their quality of life.

Clinical trial number: Not applicable.

Background: Adolescent females have a high prevalence of temporomandibular joint (TMJ) anterior disc displacement (ADD), which can lead to condylar resorption and dentofacial deformity. Polycystic ovarian syndrome (PCOS) is a common endocrine disorder that disrupts bone metabolism. However, the effects of PCOS on bone remodeling especially after disc repositioning (DR) surgery are not well understood.

Materials and methods: This was a retrospective study. Patients aged 12 to 20 years diagnosed with ADD were reviewed and matched into 3 groups: A (ADD without PCOS), B (ADD with untreated PCOS), and C (ADD with treated PCOS). Each group was divided into 2 subgroups according to ADD observation (A1, B1, C1) and DR (A2, B2, C2). Condylar height (CH) was measured by MRI at the start (T0) and after more than 6 months follow-up (T1). ∆CH (T1-T0) were compared within and between groups.

Results: 93 patients (157 joints) with an average age of 15.17 ± 2.35 years and follow-up period of 14.04 ± 9.11 months were selected in the study. ∆CH in Group B1 was significantly larger than that in Groups A1 and C1 (p = 0.048, p = 0.018). While in Group B2, it was significant smaller than Groups A2 and C2 (p < 0.001, p = 0.023). There was no significant difference of ∆CH between Groups C2 and A2. DR acquired larger ∆CH than observation within each A, B, C Groups (p < 0.05). Multiple linear regression analysis showed that ∆CH was related to the presence of PCOS (p = 0.003), PCOS treatment (p < 0.001), and DR (p < 0.001).

Conclusions: Adolescent ADD with untreated PCOS can aggravate condylar degeneration and affect bone remodeling after DR. PCOS treatment can improve bone remodeling.

Background: This study aimed to comparatively evaluate the effects of different cavity conditioners on internal adaptation (IA) of glass ionomer-based restorative materials applied to primary teeth.

Methods: 80 extracted primary second molar teeth were randomly assigned to four different cavity conditioner groups [10% polyacrylic acid, 20% polyacrylic acid, 17% ethylene diamine tetraacetic acid (EDTA), 35% phosphoric acid]. Class V cavities were prepared on the buccal surfaces and relevant cavity conditioners were applied, and the samples in each cavity conditioner group were randomly assigned to glass hybrid (GHR) or conventional glass ionomer restoratives (CGIR). Subsequently, restorative materials were applied and all samples were thermocycled (5-55 °C, 5000 cycles) and IA were calculated volumetrically by using a Micro Computed Tomography (Micro-CT) system. IA values was recorded as % and data were analyzed with Mann-Whitney U and Kruskal-Wallis H tests. Statistical significance level was set as 5%.

Results: 35% phosphoric acid showed the lowest mean internal voids (between the cavity-restoration interface) for both restorative materials (for GHR = 0.180% and for CGIR = 0.936%). However, the highest mean internal voids for GHR and CGIR were observed after the use of 17% EDTA (2.438%) and 10% polyacrylic acid (8.483%), respectively. For both restorative materials, 20% polyacrylic acid showed the second lowest mean internal voids (for GHR = 0.321% and for CGIR = 3.580%), however, no significant difference was found between 35% phosphoric acid and 20% polyacrylic acid (p = 0.941 for GHR and p = 0.061 for CGIR). In the samples applied the cavity conditioners other than 17% EDTA, glass hybrid restoratives showed significantly higher IA quality than conventional glass ionomer (p = 0.0001 for 10% polyacrylic acid, p = 0.001 for 20% polyacrylic acid and p = 0.002 for 35% phosphoric acid).

Conclusions: Within the limitations of this study, 35% phosphoric acid and 20% polyacrylic acid were determined to be the most successful cavity conditioners in terms of IA, and glass hybrid restorative system showed superior IA quality than conventional glass ionomer. Further studies are needed to confirm the present results.

Background: Self-medication has been defined as the practice of self-diagnosis and medication use without seeking professional healthcare advice. Its prevalence for alleviating dental problems in Nepali communities has not been explored. This study was conducted to assess self-medication for oral health problems in a community setting in Nepal.

Methods: A community-based cross-sectional study was conducted in two conveniently selected wards of Baraha Municipality of Sunsari district in August 2021 using a pre-validated questionnaire in the Nepali language. The prevalence of self-medication for oral health problems was assessed. The chi-square and Mann-Whitney U tests were used to check its association with demographic variables.

Results: The prevalence of self-medication was found to be 43.3%. The most common health problem leading to self-medication was toothache (78.5%). Around half of the respondents (55.1%) replied achieving temporary relief after its use while around a quarter (25.1%) thought that self-medication was effective in taking care of their problems. Three-quarters of the respondents (75.7%) knew that they had to visit a dentist if their problems persisted. The annual family income was significantly associated with the practice of self-medication for oral health problems. (p = 0.013) CONCLUSION: Self-medication was found to be frequently utilized by the people of Baraha municipality with almost every second person with oral health problems reporting using it to solve their problems. This phenomenon is disproportionately seen in those with lower economic status.

Clinical trial number: Not applicable.

Background: The literature has reported contradictory findings regarding the association of Intra-radicular posts (IRPs) presence and periapical radiolucent lesions (PRLs) prevalence in endodontically treated teeth (ETT). Considering this, the study aimed to investigate the association between IRPs presence and PRLs prevalence.

Methods: A cross-sectional study was conducted to compare PRLs prevalence in ETT with and without IRPs. CBCT images were utilized, and the teeth with at least 2 mm of remaining gutta-percha apical to the post-end were included. Two calibrated assessors assessed the PRLs presence. A stepwise backward binomial logistic regression was conducted to evaluate the effect of age, post presence, gender, tooth position (anterior/posterior), and arch location (maxillary/mandibular) on the likelihood of periapical radiolucency presence. The null hypothesis is that the presence of IRPs does not influence the prevalence of PRLs.

Results: Teeth with IRPs showed significantly higher PRLs prevalence. However, there were insignificant differences in PRLs prevalence with respect to IRPs type or remaining gutta-percha length. The model, including all five predictors, demonstrated significant fit (χ²(7) = 22.528,p = .002), explaining 14.5% of the variance in the presence of radiolucency (Nagelkerke R²). The Hosmer-Lemeshow test showed no evidence of a lack of fit (χ²(8) = 11.550,p = .172), supporting the model's adequacy. The model correctly classified 67.3% of cases, with a sensitivity of 54.5%, specificity of 75.4%, positive predictive value (PPV) of 58.3%, and negative predictive value (NPV) of 72.4%. Among the predictors, post presence was the only statistically significant variable (B = 1.300,p < .001,]OR = 3.670,95%CI[1.985-6.785]).

Conclusions: A higher prevalence of PRLs was noted among the ETT with IRPs. Within the limitations of this study, we recommend that clinicians should carefully weigh the risks and benefits of using IRPs during the restoration of ETT.

Background: Early detection of peri-implant bone defects can improve long-term durability of dental implants. By the advances in cone-beam computed tomography (CBCT) scanners and introduction of new algorithms, it is important to find the most efficient protocol for detection of bone defects. This study aimed to assess the efficacy of metal artifact reduction (MAR) and advanced noise reduction (ANR) algorithms for detection of peri-implant bone defects.

Materials and methods: In this in vitro study, 40 titanium implants were placed in 7 sheep mandibles. Crestal, apical, and Full defects (n = 10 from each type) were created around the implants, and 10 implants were also placed as controls. CBCT scans were obtained in four modes: with MAR, with ANR, with both MAR and ANR, and without any filter. Totally, 28 scans were obtained and evaluated by a radiologist and a maxillofacial surgeon. The observers recorded their observations in a checklist, and data were analyzed by SPSS version 21 using the kappa coefficient of agreement, sensitivity and specificity values, area under the receiver operating characteristic (ROC) curve (AUC), intraclass correlation coefficient, t-test and paired t-test (P < 0.05).

Results: The inter-observer agreement was high for detection of all defects in all modes except with ANR. No significant difference was found in AUC and diagnostic accuracy of different scan modes (P > 0.05). The most common diagnostic error was related to misdiagnosis of control group with full defect with ANR filter, such that the existing bone was not detected. Defect depth was averagely over-estimated while defect length was under-estimated. Correct diagnosis of defects had the highest frequency when both filters were on.

Conclusion: The diagnostic accuracy and sensitivity for detection of different defect types were not significantly different in different scan modes but activation of ANR filter significantly decreased the specificity and positive predictive value compared with no use of filter.

Background: Proper torque control is crucial to the outcome of orthodontic treatment. This study aimed to employ finite element analysis to compare the torque capabilities of a novel spherical self-ligating bracket with a lock-hook system against those of commonly used passive self-ligating and conventional bracket systems, as well as to reveal the biomechanical changes in the periodontal ligament (PDL) during torque expression.

Methods: A maxillary right central incisor, along with its PDL and alveolar bone, were modeled. Three types of brackets were selected: a spherical self-ligating bracket with a lock-hook system, a passive self-ligating bracket (Damon), and a conventional bracket (Discovery). Each bracket was equipped with a 0.022-inch slot and a 0.019 × 0.025-inch stainless steel archwire. A palatal root torque of 20° was applied. The torque moment, as well as the von Mises stress and strain in the PDL, were calculated. A clinical case involving the lingual inclination of the upper anterior teeth was utilized to assess the feasibility of using the spherical self-ligating bracket with the lock-hook system to express torque.

Results: At a twist angle of 20°, the maximum torque generated by the spherical self-ligating bracket with a lock-hook system (27.8 N·mm) was approximately 1.6 times greater than that of the Damon bracket (17.5 N·mm) and the Discovery bracket (17.3 N·mm). As the twist angle increased, both the von Mises stress and the strain in the PDL also increased. When the maximum PDL stress was less than 0.026 MPa and the percentage of the PDL good strain area (defined as the area with PDL strain ≥ 0.3%) exceeded 50%, the torque range for the maxillary incisor was between 10.2 and 17.5 N·mm. The clinical case demonstrated that the use of the spherical self-ligating bracket with the lock-hook system effectively corrected the unfavorable linguoclination of the maxillary incisors.

Conclusions: The spherical self-ligating bracket with a lock-hook system can significantly enhance torque expression. The optimal torque range for the maxillary incisor is between 10.2 and 17.5 N·mm.

Background: The progression and severity of periodontitis (PD) are associated with the release of extracellular vesicles by periodontal tissue cells. However, the precise mechanisms through which exosome-related genes (ERGs) influence PD remain unclear. This study aimed to investigate the role and potential mechanisms of key exosome-related genes in PD using transcriptome profiling at the single-cell level.

Methods: The current study cited GSE16134, GSE10334, GSE171213 datasets and 19,643 ERGs. Initially, differential expression analysis, three machine learning (ML) models, gene expression analysis and receiver operating characteristic (ROC) analysis were proceeded to identify core genes. Subsequently, a core gene-based artificial neural network (ANN) model was built to evaluate the predictive power of core genes for PD. Gene set enrichment analysis (GSEA) and immunoinfiltration analysis were conducted based on core genes. To pinpoint key cell types influencing the progression of periodontal at the single-cell level, a series of single-cell analyses covering pseudo-time series analysis were accomplished. The expression verification of core genes was performed through quantitative reverse transcription polymerase chain reaction (qRT-PCR).

Results: CKAP2, IGLL5, MZB1, CXCL6, and AADACL2 served as core genes diagnosing PD. Four core gene were elevated in the PD group in addition to down-regulated AADACL2. The core gene-based-ANN model had AUC values of 0.909 in GSE16134 dataset, which exceeded AUC of each core gene, highlighting the accurately and credibly predictive performance of ANN model. GSEA revealed that ribosome was co-enriched by 5 core genes, manifesting the expression of these genes might be critical for protein structure or function. Immunoinfiltration analysis found that CKAP2, IGLL5, MZB1, and CXCL6 exhibited positive correlations with most discrepant immune cells/discrepant stromal cells, which were highly infiltrated in PD. B cells and T cells holding crucial parts in PD were identified as key cell types. Pseudo-time series analysis revealed that the expression of IGLL5 and MZB1 increased during T cell differentiation, increased and then decreased during B cell differentiation. The qRT-PCR proved the mRNA expression levels of CKAP2 and MZB1 were increased in the blood of PD patients compared to controls. But the mRNA expression levels of AADACL2 was decreased in the PD patients compared to controls. This is consistent with the trend in the amount of expression in the dataset.

Conclusion: CKAP2, IGLL5, MZB1, CXCL6 and AADACL2 were identified as core genes associated with exosomes, helping us to understand the role of these genes in PD.