Search Results (138)

Background/Objectives: Periodontal disease, the most widespread chronic inflammatory non-communicable disease, is caused by the host-mediated inflammatory and immune responses to the bacterial biofilm. Fusobacterium nucleatum contributes to its progression and is associated with gastrointestinal cancers, including gastric cancer (GC), by promoting inflammation and immune evasion. Additionally, cathepsin K (CTSK) enhances tumor invasiveness and metastasis, playing a crucial role in GC progression. Aim: The present study was carried out to evaluate the possible association between the amount of F. nucleatum from gingival crevicular fluid and the periodontal status with the characteristics of GC. Methods: This cross-sectional study included 48 GC patients with periodontal changes, presenting to the Surgery Department in Craiova, Romania, from March 2023 to February 2024. Clinical assessments, where the number of teeth present, probing depth (PD), and bleeding on probing (BOP) were recorded, gingival crevicular fluid sampling, qPCR for Fusobacterium nucleatum, and ELISA for cathepsin K were performed. Histological analysis evaluated tumor characteristics, where tumor dimension (TD) and differentiation grade (DG) were recorded, and statistical analysis was conducted using R software. Results: Smokers presented higher PD and F. nucleatum levels than non-smokers. Gender had no impact on PD, BOP, CTSK, F. nucleatum, or TD. PD correlated with F. nucleatum, TD, and CTSK. F. nucleatum strongly correlated with CTSK and TD, and CTSK was strongly correlated with TD. Conclusions: These results suggest an association between F. nucleatum, periodontal parameters, and characteristics of GC but future studies are needed. Full article

Objective: The Staub™ Cranial system is based on defined anatomical reference points of edentulous casts that can guide the reconstruction of artificial teeth on the edentulous jaw. The aim of this study was to evaluate the validity of the Staub™ Cranial system in reconstructing the position of natural teeth in edentulous maxillae. Materials and methods: To reconstruct the original position of natural teeth, 20 fully dentate maxillary casts were produced, and 20 duplicates had all teeth eliminated. Subsequently, following the Staub™ Cranial system guidelines, an artificial teeth set-up was completed. The measured distances included the intermolar width #16–26, the intercanine width #13–23, and the incisocervical length #11. Measurements were made using the principle of stripe projection with specially developed software. Original and reproduced casts were then compared. The reproduced casts with measured distances deviating less than 5% from the mean values of control models were considered successful reconstructions. Results: The ability of the system to reconstruct the original position of lost teeth in the edentulous jaw was precise. With a narrow tolerance range of 5%, 80% of the models could be reproduced with zero or a deviation in one dimension only. Conclusions: The results of this study confirmed the efficacy of the Staub™ Cranial system to provide guidance for the customized arrangement of artificial teeth in edentulous jaws. Full article

Background/Objectives: Trauma from occlusion (TFO) is a modifying factor in periodontal disease progression, yet its morphometric impact on mandibular molars remains underexplored. The crown–root ratio (CRR), traditionally used in prosthodontic prognosis, may also serve as a diagnostic marker for structural changes in periodontally compromised teeth. This study evaluated the relationship between crown and root dimensions and clinical/radiographic parameters in mandibular first molars with TFO and developed predictive models emphasizing the role of CRR. Methods: This retrospective cross-sectional study included 99 periodontitis patients clinically and radiographically diagnosed with TFO. Digitized periapical radiographs of mandibular first molars (tooth 36 or 46) were analyzed to measure clinical and radiographic CRR, crown and root length, tooth inclination, alveolar bone loss, and root morphology. Correlation and stepwise multiple regression analyses identified predictors of crown and root length. Results: Males had significantly greater crown length (7.6 vs. 7.2 mm), root length (13.3 vs. 12.3 mm), and radiographic CRR (1.2 vs. 1.0) (p = 0.008). Clinical CRR showed a moderate positive correlation with crown length (r = 0.526) and a strong inverse correlation with root length (r = −0.735) (p < 0.001). Regression models revealed that clinical CRR, root length, and sex significantly predicted crown length (R² = 0.955), while CRR and crown length predicted root length (R² = 0.958). Conclusions: This study demonstrated that the clinical crown–root ratio (CRR) is a strong predictor of both crown and root lengths in mandibular first molars affected by trauma from occlusion (TFO) in periodontitis patients. Full article

Purpose: The study aimed to assess and compare the fracture toughness of resin-bonded fixed dental prosthesis (RBFDP) of different ceramic materials and connector parameters. Methods: Twenty extracted human incisal teeth were utilized as abutments for the RBFDP. Zirconia (Zir) and lithium disilicate (LD) were manufactured in the form of anterior cantilever RBFDPs (n = 10 per group). Each material was tested using two connector designs, with the following dimensions for height (h), base (b), and width (w): 5 (h) × 4 (b) × 1 (w) mm (n = 5), and 4 (h) × 2 (b) × 1 (w) mm (n = 5). Prostheses were computer-aided design and computer-aided manufacturing (CAD/CAM) fabricated from Zir (IPS e.max ZIRCAD prime) and LD (IPS e.max CAD). Surface pretreatment of the prosthesis was completed prior to cementation with a dual-cured resin cement (Rely-X Ultimate). The combined teeth and prostheses were subjected to thermocycling before load-to-fracture testing at 45-degrees in the center of the pontic using a universal testing machine (Shimadzu Universal Testing Machine). The types of fracture failures were observed and classified as either favorable (non-catastrophic/repairable) or unfavorable (catastrophic/non-repairable) when viewed under an electron microscope. Results: The highest fracture toughness was observed in 5 (h) × 4 (b) × 1 (w) mm for Zir, reaching 269 ± 27 N, and LD, reaching 180 ± 83 N. The lowest values were found in 4 (h) × 2 (b) × 1 (w) mm for Zir at 237 ± 52 N and LD at 116 ± 25 N. Two-way ANOVA showed the fracture strength for dimension 5 (h) × 4 (b) × 1 (w) mm was significantly higher compared to dimension 4 (h) × 2 (b) × 1 (w) mm after adjusting for the type of material (p = 0.02). One Zir sample, measuring 5 (h) × 4 (b) × 1 (w) mm, exhibited tooth fracture under applied load. Meanwhile, two LD samples of the same dimensions became decemented under load. Conclusions: RBFDPs made from Zir exhibited a pattern of higher load-to-fracture values compared to LD for all dimensions; however, this was not statistically significant. The connector parameter has a more significant influence compared to the material used to fabricate an RBFDP in the anterior region. Full article

Objective: Our aim was to investigate the oral health-related quality of life (OHRQoL) and dental care experiences of adults with Cerebral Palsy (CP). Methods: In 2023, adults with CP and their caregivers from four Australian states completed questionnaires, including the Oral Health Impact Profile-14 (OHIP-14). Non-parametric tests were conducted to analyze associations between demographic and CP-related variables and OHRQoL. Results: A total of 69 respondents participated, including n = 22 adults with CP and n = 47 caregivers of adults with CP. Most adults with CP were diagnosed with a spastic motor type (46/69, 66%), with bilateral spasticity being the most common (30/46, 65%). The mean OHIP-14 score was 10.3 ± 9.3 (mean ± SD). Nearly 70% reported challenges cleaning their teeth, over 25% lacked a dentist, more than 60% found dental exams challenging, and nearly 50% required specialized dental care. In bivariate analysis, OHIP-14 was associated with daily oral care routines (p = 0.012) and “simple dental check-up” (p = 0.017). There was a statistically significant relationship between socio-economic status and scores for the handicap dimension (p = 0.040). Higher OHIP-14 scores were associated with greater levels of impairment regarding gross motor (p = 0.199), manual functioning limitations (p = 0.001), speech (p = 0.123), and communication function scales (p = 0.319). Conclusion: Adults with CP reported challenges participating in and maintaining oral health and accessing dental care, influenced by physical, functional, and socio-economic factors. These findings indicate the need for inclusive care and strategies to support access to services. Full article

Background/Objectives: To compare the marginal integrity of sectional non-invasive laminate veneers versus sectional minimally invasive laminate veneers. Methods: A total of eighty (80) intact maxillary and mandibular frontal teeth (central incisors) were randomly divided into four groups (n = 20). Two groups received non-invasive veneers made of feldspathic porcelain (Feldspathic Non-Invasive—FNI) and lithium disilicate (Lithium Disilicate Non-Invasive—LNI) accordingly. Groups FP and LP received minimally invasive veneers manufactured by feldspathic porcelain and lithium disilicate, respectively. Following cementation, three grooves with mesio-distal orientation on the labial surface of teeth of each sample, at the incisal, middle, and cervical third, were made. Before and after artificial aging, the mesio-distal distance between the end of the groove on the tooth and the edge of each veneer was measured in micrometers (μm) employing an SEM immediately after cementation (T₀), after simulated artificial aging equivalent to four months of everyday brushing (T₁), and after twelve months of everyday brushing (2 times per day) (T₂) to identify the wear of veneers. In the same manner, the horizontal dimension of the cement layer extending from its edge till the margin of the veneer was measured for all the groups at T₀, T₁, and T₂, respectively. The statistical analysis was performed employing non-parametric Kruskal–Wallis ANOVA and Dunn’s test. Results: No significant differences from T₀ to T₁ and from T₁ to T₂, as well as from T₀ to T₂, were identified for all the groups tested. No significant differences were allocated among all groups for the dimensional changes in the cement. Conclusions: All the groups responded similarly to aging factors, regardless of the non-invasive or minimally invasive approach, or the material used to fabricate the veneers. Full article

Background/purpose: Fiber-reinforced materials are commonly used as biobases beneath indirect restorations, potentially affecting the seating and marginal accuracy of the restorations. This study intended to assess the impact of various biobase techniques on the marginal adaptation of lithium disilicate overlay restorations. Methods: Fifty sound maxillary first premolar teeth of comparable dimensions were prepared using a full-bevel overlay design (3 mm occlusal reduction) and allocated randomly to five groups as follows (n = 10): Group A, delayed dentin sealing; Group B, immediate dentin sealing using Optibond FL; Group C, immediate dentin sealing with a 1 mm flowable composite layer (Clearfil AP-X Flow); Group D, immediate dentin sealing followed by a 1 mm short-fiber-reinforced composite layer (everX Flow); and Group E, immediate dentin sealing coated with a 1 mm flowable composite layer reinforced with polyethylene Ribbond fibers. Digital impressions were obtained using a Medit i700 intraoral scanner, and the overlays were digitally designed via the Sirona inLab CAD software and milled via a four-axis milling machine. The overlays were luted with a preheated composite (Clearfil AP-X). Marginal gap assessments were conducted pre- and post-cementation via a digital microscope at 230× magnification. The data were statistically analyzed using a one-way analysis of variance and paired t-tests. Results: The one-way ANOVA disclosed no significant differences among the groups before or after cementation (p > 0.05). Conclusions: The presence or absence of fiber-reinforced biobases did not impact the marginal adaptation of the restorations; these biobases can be incorporated to optimize the mechanical behavior of indirect restorations without adversely affecting their seating accuracy. These findings suggest that fiber-reinforced and non-reinforced biobase techniques can be safely integrated into clinical adhesive protocols to enhance the mechanical performance of restorations without comprising their marginal adaptation. Full article

In this paper, we are looking for the answer to the following question: what geometric deviations do polymer gears made by 3D printing have from the theoretical geometry? From a practical point of view, the question is whether the currently installed injection-molded gear can be replaced by a 3D-printed gear. Thus, the measurements are also carried out on the sample gear and the comparison is made with this data as well. Knowing the data of the existing gear wheel, the CAD model was created, and based on this, samples of the gear were printed using various 3D printing machines. The printed gears were then subjected to geometrical analysis. During the inspection, we performed the measurement of the chordal thickness of the gear wheel using a gear tool caliper, instead of pin measurement and span measurement using a special micrometer, and 3D scanning and analysis. A surface roughness measurement was carried out as well. By conducting measurements on the injection-molded and 3D-printed samples, this research seeks to evaluate the reliability and limitations of the 3D-printed gears, providing insights into their industrial use. This study aims to determine whether 3D printing technologies can produce gears with sufficient accuracy and surface quality for practical applications. Based on the conducted analysis, general conclusions were drawn regarding the potential applicability of the 3D-printed gears. The experimental results indicate notable differences in dimensional accuracy between gears manufactured using Fused Deposition Modeling (FDM) and Selective Laser Sintering (SLS). In terms of chordal thickness measurements, FDM gears exhibited a mean relative error of 1.96 mm, whereas SLS gears showed a significantly higher average deviation of 5.64 mm. For the pin measurement, the relative error averaged 0.193 mm in the case of FDM gears, compared to 0.616 mm for SLS gears. Similarly, the span over four teeth measurements resulted in an average deviation of 0.153 mm for FDM gears, while SLS gears demonstrated a markedly higher mean error of 0.773 mm. With regard to surface roughness, it can be concluded that SLS-manufactured gears exhibit superior performance compared to FDM gears, with an average Ra value of 2.65 µm versus 9.28 µm, although their surface quality remains inferior to that of the injection-molded gear. In light of the higher relative errors observed in SLS gears compared to FDM gears, the dimensions of the theoretical model should be refined to improve the manufacturing accuracy of SLS-produced gears. Full article

Background and Objectives: CBCT images have been successfully used for CAD/CAM crown restorations; however, their use for ceramic inlay restorations remains unclear. This study aimed to evaluate the marginal and internal fit of CAD/CAM ceramic inlay restorations fabricated using intraoral scanner, model scanner, and CBCT data. Materials and Methods: Inlay preparations were performed on 11 mandibular molar typodont teeth. The teeth were scanned using an intraoral scanner, an extraoral scanner, and CBCT (0.075 mm voxel size). CBCT-generated DICOM data were converted to STL format with dedicated software. All scan data were transferred to CAD software, and a total of 33 restorations were designed. Feldspathic ceramic blocks were used for milling. Micro-CT was employed to measure marginal and internal gaps, with 60 measurement points taken from three cross-sections per sample. Data were analyzed using ANOVA and Bonferroni tests (p < 0.05). Results: CBCT exhibited greater marginal and internal gap dimensions (mean: 169.27 ± 38.64 μm), which were approximately 60–70 μm higher than those of the intraoral (97.00 ± 10.1 μm) and model scanner groups (109.67 ± 9.72 μm), exceeding clinically acceptable limits (≤120 μm) (p < 0.05). Intraoral and model scanners showed similar, clinically acceptable results. Conclusions: CBCT was less accurate for inlay restorations, likely due to their complex geometry. Nevertheless, fabrication was possible, and further research may improve its clinical applicability. Full article

This study proposes a rotational speed measurement machine based on the flux-switching principle with a 6-stator-slot/19-rotor-pole (6s/19p) topology. With a rotor shape similar to a variable reluctance sensor (VRS), the proposed machine features a simple and robust structure while ensuring the same output frequency as VRS. Additionally, compared to the conventional 12s/10p topology, the 6s/19p configuration reduces permanent magnet (PM) consumption by half while maintaining high induced voltage characteristics. A nonlinear analytical model (NAM), which incorporates the harmonic modeling (HM) technique and an iterative process, is presented. This model more accurately captures the rectangular shape of the PM and stator teeth while accounting for core saturation effects. Based on this model, the optimal dimensions of the proposed machine are investigated to achieve the best performance for speed measurement applications. A coupling FEA simulation between Ansys Maxwell and Twin Builder further analyzes the machine’s performance. Compared to a commercial product of the same size, the proposed machine achieves 31.5% higher output voltage while ensuring lower linearity errors. Moreover, superior load characteristics are observed, with a voltage drop of only 1.58% at 1500 rpm and 30 mA. The proposed machine and NAM provide an improved solution and analytical tool for speed measurement applications. Full article

Background: The treatment of head and neck cancer primarily involves surgical tumor removal combined with radiotherapy and/or chemotherapy. It often leads to significant side effects, impacting the anatomical structures of the oral cavity and resulting in major functional, esthetic, and socio-relational alterations. Case presentation: This clinical report aims to demonstrate the effectiveness of a hospital-based approach incorporating general anesthesia (GA) and computer-aided design and manufacturing (CAD/CAM) technology in the oral rehabilitation of a 58-year-old woman in remission from intraoral squamous cell carcinoma of the mandibular symphysis. The patient presented with oral pain, radiation-induced caries, reduced occlusal vertical dimension, and severely compromised teeth. Treatment Approach: The treatment plan included the removal of two non-restorable teeth, root canal treatment for the remaining teeth, and the placement of ceramic crowns and a partial removable prosthesis. Due to the complexity of the case and the patient’s limitations, the treatment was performed under GA, allowing for a staged approach. Digital technologies, including intraoral scanning and CAD-CAM, enhanced precision and patient comfort. This approach facilitated tooth preservation and minimized the number of extractions while achieving satisfactory functional and esthetic outcomes. Conclusion: The case highlights the value of GA and digital techniques in managing special-needs patients with a history of irradiated head and neck cancer. Full article

Sex identification is often challenging, especially when only skeletal remains are available. While previous research has primarily focused on skull measurements, dental traits have received less attention. This study aimed to measure the upper and lower canines, molars, and tooth rows of raccoon dogs in Lithuania to examine sexual dimorphism and analyze the correlation between different teeth and tooth row measurements. A total of 90 skulls with lower jaws of adult raccoon dogs were examined, including 55 males and 35 females. Osteometric analysis followed standard protocols, with canine measurements adapted using a method tailored to the dentition of carnivorous species. Of all the study measurements, the canine teeth demonstrated the most significant sex differences. The correlation analysis showed a strong correlation (p < 0.001) between the dimensions of the upper molars P⁴, M¹, and M². The upper tooth rows were strongly correlated (p < 0.001) with the dimensions of the P⁴ and canines. Lower molar correlations were weaker than upper ones, and lower tooth rows showed less correlation with tooth measurements. These findings indicate that molars and tooth rows are not reliable for sex determination in raccoon dogs. However, the observed sexual dimorphism in canine teeth may offer insights for future zooarchaeological and comparative anatomical studies. Full article

Space maintainers (SMs) are essential for preserving dental arch integrity after premature tooth loss. This study aimed to develop a deep learning model to predict the necessity of SMs and identify specific teeth requiring intervention. A dataset of 400 dental X-rays was preprocessed to standardize image dimensions and convert them into numerical representations for machine learning. The dataset was divided into training (80%) and testing (20%) subsets. A Convolutional Neural Network (CNN) was designed with multiple convolutional and pooling layers, followed by fully connected layers for binary classification. The model was trained using 30 epochs and evaluated with accuracy, precision, recall, F1-score, ROC AUC, and MCC. The CNN achieved 94% accuracy, with a precision of 0.93 for Class 0 (no SM needed) and 0.95 for Class 1 (SM needed). The ROC AUC was 0.94, and the MCC was 0.875, indicating strong reliability. When tested on 86 X-ray images, the model successfully identified specific teeth (showing teeth number) requiring SMs, with minimal errors. These results suggest that the proposed AI model provides high-performance predictions for SM necessity, offering a valuable decision-support tool for pediatric dentistry. Full article

The purpose of the present study was to evaluate mast cell density in squamous cell carcinoma tissues of dogs and cats to assess species differences. Skin squamous cell carcinoma tissues from dogs (n = 15: n = 10 from body sites and n = 5 nail bed specimens) and cats (n = 15, n = 10 from ears and n = 5 nasal planum specimens) were examined. Intratumoral mast cell density (IMCD), peritumoral mast cell density (PMCD) and total mast cells density (TMCD) as a sum of IMCD and PMCD were calculated from Giemsa-stained slides at high magnification in 1 mm² using an Olympus microscope (Olympus BX41, Tokyo, Japan) equipped with a digital Olympus DP72 image camera and CellSensDimension software V1.16). Both intratumoral and peritumoral tissues of the squa.mous cell carcinoma were divided into two categories: (1) loose, well-vascularized, rich in lymphocytes and plasmocytes, macrophages and neutrophils; and (2) fibrous, with few or no lymphocytes, plasmocytes, macrophages and neutrophils (the presence of neutrophils can be associated with actinic keratosis, mechanical irritation of the tumor in some anatomical areas during scratching with teeth, but, in general, neutrophils are associated with more invasive squamous cell carcinoma). In cats, a markedly higher total number of mast cells was found, and the number was also higher in intratumoral and peritumoral tissues. A similar tendency was found in both dogs and cats—a markedly higher number of mastocytes was found in both peritumoral and intratumoral loose, well-vascularized connective tissue. Conversely, lower numbers of mast cells were found in both intratumoral and peritumoral compact fibrous tissue in both animal species. Full article

Three-dimensional printing was introduced in the 1980s, though bioprinting started developing a few years later. Today, 3D bioprinting is making inroads in medical fields, including the production of biomedical supplies intended for internal use, such as biodegradable staples. Medical bioprinting enables versatility and flexibility on demand and is able to modify and individualize production using several established printing methods. A great selection of biomaterials and bioinks is available, including natural, synthetic, and mixed options; they are biocompatible and non-toxic. Many bioinks are biodegradable and they accommodate cells so upon implantation, they integrate within the new environment. Bioprinting is suitable for printing tissues using living or viable components, such as collagen scaffolding, cartilage components, and cells, and also for printing parts of structures, such as teeth, using artificial man-made materials that will become embedded in vivo. Bioprinting is an integral part of tissue engineering and regenerative medicine. The addition of newly developed smart biomaterials capable of incorporating dynamic changes in shape depending on the nature of stimuli led to the addition of the fourth dimension of time in the form of changing shape to the three static dimensions. Four-dimensional bioprinting is already making significant inroads in tissue engineering and regenerative medicine, including new ways to create dynamic tissues. Its future lies in constructing partial or whole organ generation. Full article