Search Results (823)

Background: Understanding the mechanisms underlying dental pain caused by pulpitis in humans has led to the development of animal models, such as the rat, which enable the study of the mechanisms underlying inflammation; the use of these models is considered ethically justified when the anticipated scientific benefits outweigh the potential impacts on animals in the harm/benefit balance. Objective: To develop a rat model of mechanically induced pulpitis and to evaluate the potential impact on animal well-being. Methods: Pulpitis was mechanically induced in male Lewis rats (13–16 weeks, 350–400 g) which were anesthetized and endotracheally intubated. Following pulp exposure, the cavity was sealed with either amalgam (n = 10) or zinc phosphate cement (n = 10). Following recovery and return to their housing, behavioral assessments and histological evaluations using Hematoxylin and Eosin (H&E) staining were conducted in separate cohorts at two time points: 3 h and 5 days following the procedure. Results: A standardized model of mechanically induced pulpitis was established and verified clinically and by histopathological analysis, which showed evidence of the inflammatory process and revealed no statistically significant differences in the scoring of pain, discomfort, or distress, nor in the measurements of food and water consumption or body weight. Conclusions: The behavioral assessments conducted in this study supported the implementation of a safe and easily reproducible model for future research aimed at elucidating the mechanisms underlying pulp inflammation. Full article

Background: Local anesthesia is essential for most dental procedures, but its parenteral administration is often painful. Topical anesthetics are commonly used to minimize local anesthesia pain; however, commercial formulations fail to fully prevent the discomfort of local anesthetic injection. Methods: We developed and characterized a novel lidocaine and epinephrine co-loaded liquid crystalline precursor system (LCPS) for topical anesthesia. The formulation was structurally characterized using polarized light microscopy (PLM) and small-angle X-ray scattering (SAXS). Rheological behavior was assessed through continuous and oscillatory rheological analyses. Texture profile analysis, in vitro mucoadhesive force evaluation, in vitro drug release and permeation studies, and an in vivo toxicity assay using the chicken chorioallantoic membrane (CAM) model were also conducted. Results: PLM and SAXS confirmed the transition of the LCPS from a microemulsion to a lamellar liquid crystalline structure upon contact with artificial saliva. This transition enhanced formulation consistency by over 100 times and tripled mucoadhesion strength. The LCPS also provided controlled drug release, reducing permeation flow by 93% compared to the commercial formulation. Importantly, the CAM assay indicated that the LCPS exhibited similar toxicity to the commercial product. Conclusions: The developed LCPS demonstrated promising physicochemical and biological properties for topical anesthesia, including enhanced mucoadhesion, controlled drug delivery, and acceptable biocompatibility. These findings support its potential for in vivo application and future clinical use to reduce pain during dental anesthesia procedures. Full article

This study aimed to develop an innovative resin composite with anti-biofouling properties, tailored to prosthesis fabrication in dentistry using a digital light processing (DLP) 3D-printing technique. The resin composite was formulated using a blend of dental monomers, with the integration of 2-methacryloyloxylethyl phosphorylcholine (MPC) with anti-biofouling behavior and γ-MPS-treated silica-zirconia powder for simultaneous mechanical reinforcement. The overall characterization of the resin composite was carried out using various contents of MPC incorporated into the resin (0–7 wt%) for examining the rheological behavior, photopolymerization, flexural strength/modulus, microstructure and anti-biofouling efficiency. The resin composite demonstrated a significant reduction in bacterial adhesion (97.4% for E. coli and 86.5% for S. aureus) and protein adsorption (reduced OD value from 1.3 ± 0.4 to 0.8 ± 0.2) with 7 wt% of MPC incorporation, without interfering with photopolymerization to demonstrate potential suitability for 3D printing without issues (p < 0.01, and p < 0.05, respectively). The incorporation and optimization of γ-MPS-treated silica-zirconia powder (10–40 vol%) enhanced mechanical properties, leading to a reasonable flexural strength (103.4 ± 6.1 MPa) and a flexural modulus (4.3 ± 0.4 GPa) at 30 vol% (n = 6). However, a further increase to 40 vol% resulted in a reduction in flexural strength and modulus; nevertheless, the results were above ISO 10477 standards for dental materials. Full article

Aim: Pacifiers play a critical role in the early stages of craniofacial and palate development during infancy. While they provide comfort and aid in soothing, their use can also have significant impacts on the growth and function of the oral cavity. This study aimed to simulate and predict the behavior of six different types of pacifiers and their functional interaction with the tongue and palate, with the goal of understanding their potential effects on orofacial growth and development. Materials and Methods: Biomechanical analysis using Finite Element Analysis (FEA) mathematical models was employed to evaluate the behavior of six different commercial pacifiers in contact with the palate and tongue. Three-dimensional solid models of the palate and tongue were based on the mathematical framework from a 2007 publication. This allowed for a detailed investigation into how various pacifier designs interact with soft and hard oral tissues, particularly the implications on dental and skeletal development. Results: The findings of this study demonstrate that pacifiers exhibit different interactions with the oral cavity depending on their geometry. Anatomical–functional pacifiers, for instance, tend to exert lateral compressions near the palatine vault, which can influence the hard palate and contribute to changes in craniofacial growth. In contrast, other pacifiers apply compressive forces primarily in the anterior region of the palate, particularly in the premaxilla area. Furthermore, the deformation of the tongue varied significantly across different pacifier types: while some pacifiers caused the tongue to flatten, others allowed it to adapt more favorably by assuming a concave shape. These variations highlight the importance of selecting a pacifier that aligns with the natural development of both soft and hard oral tissues. Conclusions: The results of this study underscore the crucial role of pacifier geometry in shaping both the palate and the tongue. These findings suggest that pacifiers have a significant influence not only on facial bone growth but also on the stimulation of oral functions such as suction and feeding. The geometry of the pacifier affects the soft tissues (tongue and muscles) and hard tissues (palate and jaw) differently, which emphasizes the need for careful selection of pacifiers during infancy. Choosing the right pacifier is essential to avoid potential negative effects on craniofacial development and to ensure that the benefits of proper oral function are maintained. Therefore, healthcare professionals and parents should consider these biomechanical factors when introducing pacifiers to newborns. Full article

This study aimed to develop experimental filler-reinforced resin composites for vat-photopolymerization 3D printing and to evaluate the effects of filler addition on their mechanical, physicochemical, and bonding properties for dental restorative applications. Silanized nano- and/or micro-fillers were incorporated into acrylic resin monomers to formulate photocurable resins suitable for vat-photopolymerization. The rheological behavior of these liquid-state resins was assessed through viscosity measurements. Printed resin composites were fabricated and characterized for mechanical properties—including flexural strength, flexural modulus, and Vickers hardness—both before and after 8 weeks of water immersion. Physicochemical properties, such as water sorption, water solubility, and degree of conversion, were also evaluated. Additionally, shear bond strength to a resin-based luting agent was measured before and after artificial aging via thermocycling. A commercial dental CAD-CAM resin composite served as a reference material. Filler incorporation significantly improved the mechanical properties of the printed composites. The highest performance was observed in the composite containing 60 wt% micro-fillers, with a flexural strength of 168 ± 10 MPa, flexural modulus of 6.3 ± 0.4 GPa, and Vickers hardness of 63 ± 1 VHN, while the commercial CAD-CAM composite showed values of 152 ± 8 MPa, 7.9 ± 0.3 GPa, and 66 ± 2 VHN, respectively. Filler addition did not adversely affect the degree of conversion, although the relatively low conversion led to the elution of unpolymerized monomers and increased water solubility. The shear bond strength of the optimal printed composite remained stable after aging without silanization, demonstrating superior bonding performance compared with the CAD-CAM composite. These findings suggest that the developed 3D-printed resin composite is a promising candidate for dental restorative materials. Full article

Students, particularly those in the medical field, are exposed to various stressors that can affect their health-related behaviors, including smoking habits, with implications for oral health and quality of life. Background and Objectives: to analyze the relationship between smoking, oral health, perceived stress level, and self-assessed quality of life in a sample of dental students. Materials and Methods: The cross-sectional study included 338 students, who completed validated questionnaires and were clinically examined. Lifestyle was assessed using a smoking behavior questionnaire, stress levels were measured with the Student Stress Inventory (SSI), and quality of life was evaluated using the EQ-5D-5L instrument. The DMFT index was calculated to determine oral health status. Results: Among the 338 participating students, 53.8% were smokers. The lifestyle analysis revealed slightly higher average scores among non-smokers across all domains—social (3.26 vs. 3.09), attitudinal (2.75 vs. 2.97), and behavioral (3.82 vs. 3.49), but without statistically significant differences (p > 0.25). The mean DMFT score was 12.48, with no significant differences between smokers and non-smokers (p = 0.554). The SSI total score averaged 83.15, indicating a moderate level of perceived stress, again with no statistically significant differences between the groups (p > 0.05). However, slightly higher average stress scores among smokers may suggest the use of smoking as a coping mechanism. In contrast, quality of life as measured by EQ-5D-5L showed significantly worse outcomes for smokers across all five dimensions, including mobility (78.6% vs. 95.5%, p = 0.000) and self-care (93.4% vs. 100%, p = 0.001). Multivariable logistic regression identified smoking (OR = 1.935; p = 0.047) and moderate stress levels (OR = 0.258; p < 0.001) as independent predictors of oral health status. Conclusions: The results obtained suggest that smoking may function as a stress management strategy among students, supporting the relevance of integrating specific psychobehavioral interventions that address stress reduction and oral health promotion among student populations. Full article

Orthognathic surgery (OS) is a complex procedure commonly used to treat dentofacial deformities (DFDs). These conditions, related to jaw position or size and often involving malocclusion, affect approximately 15% of the population. Due to the complexity of OS, accurate planning is essential. Digital assessment using computer-aided design (CAD) and computer-aided manufacturing (CAM) tools enhances surgical predictability. However, limitations in soft tissue simulation often require surgeon input to optimize aesthetic results and minimize surgical impact. This study aimed to evaluate the accuracy of virtual surgery planning (VSP) by analyzing the relationship between planning deviations and surgical satisfaction. A single-center, retrospective study was conducted on 16 patients who underwent OS at San Pedro University Hospital of La Rioja. VSP was based on CT scans using Dolphin Imaging software (v12.0, Patterson Dental, St. Paul, MN, USA) and surgeries were guided by VSP-designed occlusal splints. Outcomes were assessed using the Orthognathic Quality of Life (OQOL) questionnaire and deviations were measured through pre- and postoperative imaging. The results showed high satisfaction scores and good overall outcomes, despite moderate deviations from the virtual plan in many cases, particularly among Class II patients. A total of 63% of patients required VSP modifications due to poor soft tissue fitting, with 72% of these being Class II DFDs. Most deviations involved less maxillary advancement than planned, while maintaining optimal occlusion. This suggests that VSP may overestimate advancement needs, especially in Class II cases. No significant differences in satisfaction were observed between patients with low (<2 mm) and high (>2 mm) deviations. These findings support the use of VSP as a valuable planning tool for OS. However, surgeon experience remains essential, especially in managing soft tissue behavior. Improvements in soft tissue prediction are needed to enhance accuracy, particularly for Class II DFDs. Full article

Temporomandibular disorders (TMDs) encompass a heterogeneous group of musculoskeletal and neuromuscular conditions affecting the temporomandibular joint (TMJ) and masticatory system. Due to academic stress and parafunctional habits, dental students may be particularly vulnerable to TMD. Objective: To determine the prevalence of TMD symptoms and their psychosocial and functional correlates among students at the Faculty of Dental Medicine, UMPh Iasi, Romania, using the diagnostic criteria for TMD (DC/TMD) self-report axis and axis II instruments. Methods: In this cross-sectional survey, 356 volunteer students (66.0% female; mean age, 22.9 ± 3.6 years) out of a total population of 1874 completed an online DC/TMD–based questionnaire. Axis I assessed orofacial pain, joint noises, and mandibular locking. Axis II instruments included the Graded Chronic Pain Scale (GCPS), Jaw Functional Limitation Scale (JFLS-20), Patient Health Questionnaire (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Oral Behaviors Checklist (OBC). Descriptive statistics summarized frequencies, means, and standard deviations; χ² tests and t-tests compared subgroups by sex; Pearson correlations explored relationships among continuous measures (α = 0.05). Results: A total of 5% of respondents reported orofacial pain in the past 30 days; 41.6% observed TMJ noises; 19.7% experienced locking episodes. Mean JFLS score was 28.3 ± 30.5, with 4.8% scoring > 80 (severe limitation). Mean PHQ-9 was 5.96 ± 5.37 (mild depression); 15.5% scored ≥ 10. Mean GAD-7 was 5.20 ± 4.95 (mild anxiety); 16.0% scored ≥ 10. Mean OBC score was 12.3 ± 8.5; 30.1% scored ≥ 16, indicating frequent parafunctional habits. Symptom prevalence was similar by sex, except temporal headache (43.4% females vs. 24.3% males; p = 0.0008). Females reported higher mean scores for pain intensity (2.09 vs. 1.55; p = 0.0013), JFLS (32.5 vs. 18.0; p < 0.001), PHQ-9 (6.43 vs. 5.16; p = 0.048), and OBC (13.9 vs. 9.7; p = 0.0014). Strong correlation was observed between PHQ-9 and GAD-7 (r = 0.74; p < 0.001); moderate correlations were observed between pain intensity and PHQ-9 (r = 0.31) or GAD-7 (r = 0.30), between JFLS and pain intensity (r = 0.33), and between OBC and PHQ-9 (r = 0.39) (all p < 0.001). Conclusions: Nearly half of dental students reported TMD symptoms, with appreciable functional limitation and psychosocial impact. Parafunctional behaviors and psychological distress were significantly associated with pain and dysfunction. These findings underscore the need for early screening, stress-management interventions, and interdisciplinary care strategies in the dental student population. Full article

Background/Objectives: The increasing clinical integration of 3D-printed definitive resins requires a comprehensive understanding of their physicochemical properties and adhesive behavior. However, there is limited evidence regarding the optimal surface treatment and bonding strategies for clear aligner composite attachments on these materials. This study aimed to characterize a 3D-printed definitive resin, evaluate the effects of surface treatments on its surface topography, and compare the shear bond strength (SBS) of the bonded attachments using different adhesive systems, both before and after thermocycling. Methods: A total of 120 rectangular specimens were fabricated from a 3D printed dental resin (Crowntec^®, SAREMCO Dental AG—Mexico City, Mexico). For physicochemical characterization, six samples underwent scanning electron microscopy/energy-dispersive spectroscopy, X-ray diffraction, and thermogravimetric analysis. To evaluate surface topography, 42 polished specimens were assigned to three groups: untreated (control), etched with 4% hydrofluoric acid (HFA), or sandblasted with 50 µm Al₂O₃ (AA). Each group was subdivided for SEM observation and surface roughness (Ra) measurement. For SBS testing, 72 additional samples received the same surface treatments and were further subdivided according to the adhesive system: Transbond™ XT Primer (TXT) or Single Bond Universal (SBU). Results: The AA group showed the highest Ra (2.21 ± 0.30 µm), followed by HFA (0.81 ± 0.20 µm) and control (0.07 ± 0.30 µm) (p < 0.001). The highest SBS was observed in the AA + SBU group, followed by AA + TXT. Conclusions: Sandblasting with Al₂O₃ particles, combined with a universal adhesive, significantly improved bond strength, suggesting a viable protocol for 3D printed definitive composites in aligner attachment applications. Full article

High-pitched noise generated by dental air turbine handpieces (ATHs) causes discomfort and anxiety, discouraging dental visits. Understanding the time-dependent noise generation mechanism associated with compressed airflow in ATHs is crucial for effective noise reduction. However, the direct investigation of airflow dynamics within ATHs is challenging. The transient-state modeling of computational fluid dynamics (CFD) simulations remains unexplored owing to the complexities of high rotational speeds and air compressibility. This study develops a novel CFD framework for transient (time-dependent) modeling under high-speed rotational conditions. Simulations were performed using a three-dimensional model reconstructed from a commercial ATH. Simulations were conducted at 320,000 rpm using a novel framework that combines the immersed boundary and building cube methods. A fine 0.025 mm mesh spacing near the ATH, combined with supercomputing resources, enabled the simulation of hundreds of millions of cells. The simulation results were validated using experimental noise measurements. The CFD simulation revealed transient airflow and aeroacoustic behavior inside and around the ATH that closely matched the prominent frequency peaks from the experimental data. This study is the first to simulate the transient airflow of ATHs. The proposed CFD model can accurately predict aeroacoustics, contributing to the future development of quieter and more efficient dental devices. Full article

Material wear significantly impacts the clinical success and longevity of dental ceramic restorations. This in vivo study aimed to assess the wear behavior of IPS Empress^® glass-ceramic inlays and onlays over 14 years, considering the influence of different antagonist materials. Fifty-four indirect restorations of 21 patients were available for comprehensive wear analysis, with complete follow-up data for up to 14 years. Three-dimensional measurements relied on digitized epoxy resin models produced immediately post-insertion (baseline) and subsequently at 2, 4, and 14 years. The occlusal region on the baseline model was delineated for comparative analysis. Three-dimensional superimpositions with models from subsequent time points were executed to assess wear in terms of average linear wear and volumetric loss. Statistical analyses were conducted in R (version 4.4.1), employing Mann–Whitney U tests (material comparisons) and Wilcoxon signed rank tests (time point comparisons), with a significance threshold of p ≤ 0.05. During the entire study period, an increase in wear was observed at each assessment interval, gradually stabilizing over time. Significant differences in substance loss were found between the follow-up time points, both for mean (−0.536 ± 0.249 mm after 14a) and integrated distance (−18,935 ± 11,711 mm³ after 14a). In addition, significantly higher wear was observed after 14 years with gold as antagonist compared to other materials (p ≤ 0.03). The wear behavior of IPS Empress^® ceramics demonstrates clinically acceptable long-term outcomes, with abrasion characteristics exhibiting stabilization over time. Full article

The design of custom abutments (CA) can affect the mechanical reliability of implant-supported restorations. The purpose of the study was to evaluate the influence of design parameters on the fatigue limit of CA and to compare optimized custom designs with the reference abutment (RA). A morse-tapered dental implant, an anatomical abutment, and a connector screw were digitalized using microcomputed tomography. A cone beam computed tomography scan was obtained from one of the authors to virtually place the implant-abutment assembly in the upper central incisor. Ten design parameters were selected according to the structural geometry of the RA and the implant planning. A reverse-engineered RA model was created in SOLIDWORKS and was modified considering a Taguchi orthogonal array to generate 36 CAs with ±20% dimensional variations. Finite element analysis was conducted in ABAQUS, and fatigue limits were estimated using Fe-safe. ANOVA (α = 0.1) identified the most influential parameters. Von Mises stress values ranged from 229 MPa to 302 MPa, and 94.4% of the CAs had a higher fatigue limit than the RA. Three parameters significantly affected the fatigue performance of the implant system. The design process of custom abutments includes critical design parameters that can be optimized for longer lifetimes of implant-abutment restorations. Full article

Hydroxyapatite (HA) has become a widely used material for bone grafting and surface modification of titanium-based orthopedic implants due to its excellent biocompatibility. Among various coating techniques, microplasma spraying (MPS) has gained significant industrial relevance. However, the clinical success of HA coatings also depends on their adhesion to the implant substrate. Achieving durable fixation and reliable biological integration of orthopedic implants remains a major challenge due to insufficient coating adhesion and limited osseointegration. This study addresses challenges in dental and orthopedic implantology by evaluating the microstructure, mechanical properties, and biological behavior of bilayer coatings composed of a zirconium (Zr) sublayer and an HA top layer, applied via MPS onto titanium alloy. Surface roughness, porosity, and adhesion were characterized, and pull-off and shear tests were used to assess mechanical performance. In vitro biocompatibility was tested using rat mesenchymal stem cells (MSCs) to model osteointegration. The results showed that the MPS-fabricated Zr–HA bilayer coatings achieved a pull-off strength of 28.0 ± 4.2 MPa and a shear strength of 32.3 ± 3.2 MPa, exceeding standard requirements. Biologically, the HA top layer promoted a 45% increase in MSC proliferation over three days compared to the uncoated titanium substrate. Antibacterial testing also revealed suppression of E. coli growth after 14 h. These findings support the potential of MPS-applied Zr-HA coatings to enhance both the mechanical integrity and biological performance of titanium-based orthopedic implants. Full article

Objective: This cross-sectional content analysis aimed to investigate how oil pulling is portrayed on YouTube Shorts, focusing on the types of speakers, claims made, and alignment with scientific evidence. The study further explored how the content may influence viewer perception, health behaviors, and the potential spread of misinformation. Methods: On 28 January 2025, a systematic search of YouTube Shorts was performed using the term “oil pulling” in incognito mode to reduce algorithmic bias. English language videos with at least 1000 views were included through purposive sampling. A total of 47 Shorts met the inclusion criteria. Data were extracted using a structured coding framework that recorded speaker type (e.g., dentist, hygienist, influencer), engagement metrics, stated benefits, oil type and regimen, the use of disclaimers or citations, and stance toward oil pulling rated on a 5-point Likert scale. Speaker background and nationality were determined through publicly available channel descriptions or linked websites, with user identities anonymized and ethical approval deemed unnecessary due to the use of publicly available content. In total, 47 videos met the inclusion criteria. Results: Of the 47 YouTube Shorts that met the inclusion criteria, most were posted by influencers rather than dental professionals. These videos predominantly encouraged oil pulling, often recommending coconut oil for 10–15 min daily and citing benefits such as reduced halitosis and improved gum health. However, a smaller subset advanced more extreme claims, including reversing cavities and remineralizing enamel. Notably, US-licensed dentists and dental hygienists tended to discourage or express skepticism toward oil pulling, assigning lower Likert scores (1 or 2) to influencers and alternative health practitioners (often 4 or 5). Conclusions: YouTube Shorts largely promote oil pulling through anecdotal and testimonial-driven content, often diverging from evidence-based dental recommendations. The findings reveal a disconnect between professional dental guidance and popular social media narratives. While some benefits like halitosis reduction may have limited support, exaggerated or misleading claims may result in improper oral hygiene practices. Greater engagement from dental professionals and improved health communication strategies are needed to counteract misinformation and reinforce oil pulling’s role, if any, as an adjunct—not a replacement—for standard oral care. Future studies should explore viewer interpretation, behavioral influence, and cross-platform content patterns to better understand the impact of short-form health videos. Full article

Background/Objectives:Titanium implant surface modifications enhance osseointegration and prevent microbial colonization, improving implant longevity. Antimicrobial coatings, particularly cerium- and bismuth-doped hydroxyapatite (CeHAp and BiHAp), have gained attention for reducing infection-related complications. This study evaluates the antimicrobial activity of CeHAp and BiHAp coatings on CpTi compared to untreated CpTi in artificial saliva at pH levels of 4.5, 6.5, and 8. Methods: Antibacterial efficacy against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Candida albicans (C. albicans) was assessed using the broth dilution method. Titanium rods coated with test compounds were incubated in inoculated nutrient broth, and microbial inhibition was determined via optical density at 600 nm. A statistical analysis was performed using the Kruskal–Wallis ANOVA test, the median and Interquartile Range were determined for the variables, and a Dwass–Steel–Critchlow–Fligner intergroup pairwise comparison was conducted. Results: The results showed that both the CeHAp and BiHAp coatings demonstrated significant antimicrobial activity against S. aureus (OD = 0.01) at pH 6.5, which was more pronounced than the activity observed against E. coli (OD = 0.05), with the difference being statistically significant (p = 0.001). The least antimicrobial activity was observed against C. albicans (0.21) at pH 8 (p = 0.001). Conclusion: These findings highlight the pH-dependent effectiveness of BiHAp and CeHAp coatings in inhibiting microbial growth. Their application on titanium implants may enhance antimicrobial properties, contributing to improved dental implant success and broader biomedical applications. Full article