DFT-based investigation of polyetherketoneketone materials for surface modification for dental implants.

BACKGROUND: Polyetherketoneketone (PEKK) is a high-performance thermoplastic polymer with unique structural and mechanical properties that make it a promising candidate for surface modification of dental implants. This study was conducted to investigate the feasibility of PEKK for this purpose using the Cambridge Serial Total Energy Package (CASTEP) code based on density functional theory (DFT). METHODS: This study examined the ground state energy, structural properties, thermodynamic behavior, cohesive energy, refractive index, stress analysis, mechanical properties, and anisotropic behavior of PEKK. RESULTS: This study found that PEKK has a complex crystal structure with an orthorhombic unit cell shape, triclinic lattice type, and a centered structure. It also has a 2D layered structure owing to the presence of carbonyl groups, which provides a large surface area for interaction with biological tissues. Thermodynamic analysis showed that PEKK exhibited bond elongation and structural changes at 380 °C, indicating thermal degradation. The cohesive energy of PEKK was calculated to be - 440 eV, indicating its stability and structural integrity. PEKK has a complex refractive index, with real and imaginary components that affect its optical properties. Stress analysis showed that PEKK is resistant to shear deformation and has high hydrostatic stress, which contributes to its stability and biocompatibility. CONCLUSION: The mechanical properties of PEKK, including its high stiffness, resistance to volume change under pressure, and ability to accommodate natural movements, make it suitable for surface modification of dental implants.

In silico assessment of biocompatibility and toxicity: molecular docking and dynamics simulation of PMMA-based dental materials for interim prosthetic restorations.

AIM: This study aimed to comprehensively assess the biocompatibility and toxicity profiles of poly(methyl methacrylate) (PMMA) and its monomeric unit, methyl methacrylate (MMA), crucial components in dental materials for interim prosthetic restorations. METHODOLOGY: Molecular docking was employed to predict the binding affinities, energetics, and steric features of MMA and PMMA with selected receptors involved in bone metabolism and tissue development, including RANKL, Fibronectin, BMP9, NOTCH2, and other related receptors. The HADDOCK standalone version was utilized for docking calculations, employing a Lamarckian genetic algorithm to explore the conformational space of ligand-receptor interactions. Furthermore, molecular dynamics (MD) simulations over 100 nanoseconds were conducted using the GROMACS package to evaluate dynamic actions and structural stability. The LigandScout was utilized for pharmacophore modeling, which employs a shape-based screening approach to identify potential ligand binding sites on protein targets. RESULTS: The molecular docking studies elucidated promising interactions between PMMA and MMA with key biomolecular targets relevant to dental applications. MD simulation results provided strong evidence supporting the structural stability of PMMA complexes over time. Pharmacophore modeling highlighted the significance of carbonyl and hydroxyl groups as pharmacophoric features, indicating compounds with favorable biocompatibility profiles. CONCLUSION: This study underscores the potential of PMMA in dental applications, emphasizing its structural stability, molecular interactions, and safety considerations. These findings lay a foundation for future advancements in dental biomaterials, guiding the design and optimization of materials for enhanced biocompatibility. Future directions include experimental validation of computational findings and the development of PMMA-based dental materials with improved biocompatibility and clinical performance.

The association between genetic factors and temporomandibular disorders: A systematic literature review.

OBJECTIVE: This study aimed to investigate the correlation between genetic factors and the occurrence and progression of temporomandibular disorders (TMDs) using a comprehensive review and meta-analysis. DESIGN: A comprehensive search was conducted using the ScienceDirect, PubMed, Cochrane Library, Dimensions, and Emerald databases. A reviewer selected the study using modified PICO criteria, considering human subjects with TMDs, comparing different genetic factors among TMD and non-TMD patients, and reporting TMD signs and symptoms as outcomes. The methodological standards of the eligible papers were assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Non-randomized Experimental Investigations. Information was collected methodically and examined. RESULTS: The electronic database search yielded 851 articles, 19 of which were included in this study. The data analysis showed a significant influence of genetic factors, such as polymorphisms and gene differences, on the development of TMD signs and symptoms, such as myofascial pain, chronic pain, and disc displacement. In addition, gene polymorphism significantly influenced TMD development, with an odds ratio of 2.46 (1.93-3.14) and p of 0.00001. CONCLUSIONS: Genetic factors significantly influenced TMD signs and symptoms, and genetic polymorphisms significantly influenced TMD onset and progression. Further research should be conducted in diverse settings with larger sample sizes to verify and validate these findings.

Comparative efficacy of photobiomodulation on osseointegration in dental implants: A systematic review and meta-analysis.

AIM: This study aimed to assess the effectiveness of photobiomodulation therapy (PBM) in enhancing bone integration with dental implants. METHOD: PubMed, ScienceDirect, the Cochrane Library, Scopus, and Google Scholar were searched. Studies assessing PBM effectiveness with defined intervention/control groups were included, while those lacking specified laser types, involving severe maxillofacial defects or surgery, and not reporting outcomes related to dental implant osseointegration post-PBM therapy were excluded. The studies' risk of bias was assessed using Robvis for randomized controlled trials (RCTs) and ROBINS-I for non-RCTs. The meta-analysis was conducted utilizing a random-effects model at a significance level of 0.01. RESULTS: The study reviewed 26 papers involving 571 patients undergoing dental implant procedures with PBM/Low-Level Laser Therapy (LLLT) or placebo/control. Implant stability quotients (ISQ) analysis showed a non-significant difference (p = 0.06, mean difference: 1.02, 95 % CI: 0.28 to 1.75, I2=28 %), while the Periotest method indicated significant improvement in stability (p < 0.01, mean difference: -0.51, 95 % CI: -0.78 to -0.24, I2=71 %). PBM resulted in a significant bone density increase (p < 0.01, mean difference: 26, 95 % CI: 6.93 to 45.06, I2=91 %), but marginal bone loss showed no significant difference (p = 0.11, mean difference: 0.00, 95 % CI: -0.06 to 0.05, I2=45 %). Implant survival rate did not significantly differ (p = 0.73, mean difference: 1.56, 95 % CI: 0.38 to 6.46, I2=0 %). Most studies raised concerns regarding randomization. CONCLUSION: PBM could improve implant stability, as assessed with Periotest, and increase bone density, enhancing osseointegration. However, implant stability assessed with ISQ, marginal bone loss, and implant survival rate were comparable between the study groups.

Impact of 3D imaging techniques and virtual patients on the accuracy of planning and surgical placement of dental implants: A systematic review.

Aim: The integration of advanced technologies, including three-dimensional (3D) imaging modalities and virtual simulations, has significantly influenced contemporary approaches to preoperative planning in implant dentistry. Through a meticulous analysis of relevant studies, this review synthesizes findings related to accuracy outcomes in implant placement facilitated by 3D imaging in virtual patients. Methods: A comprehensive literature search was conducted across relevant databases to identify relevant studies published to date. The inclusion criteria were studies utilizing 3D imaging techniques, virtual patients, and those focusing on the accuracy of dental implant planning and surgical placement. The selected studies were critically appraised for their methodological quality. Results: After a rigorous analysis, 21 relevant articles were included out of 3021 articles. This study demonstrates the versatility and applicability of these technologies in both in vitro and in vivo settings. Integrating Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM), cone bean computed tomography (CBCT), and advanced 3D reconstruction methodologies showcases a trend toward enhanced precision in implant planning and placement. Notably, the evaluation parameters varied, encompassing distances, discrepancies, and deviations in the implant placement. The ongoing integration of systems such as dynamic navigation systems, augmented reality, and sophisticated software platforms shows a promising trajectory for the continued refinement of virtual reality applications in dental implantology, providing valuable insights for future research and clinical implementation. Moreover, using stereolithographic surgical guides, virtual planning with CBCT data, and 3D-printed templates consistently demonstrates enhanced precision in dental implant placement compared to traditional methods. Conclusion: The synthesis of the available evidence underscores the substantial positive impact of 3D imaging techniques and virtual patients on dental implant planning and surgical placement accuracy. Utilizing these technologies contributes to a more personalized and precise approach that enhances overall treatment outcomes. Future research directions and potential refinements to the application of these technologies in clinical practice should be discussed.

Dental biomaterials redefined: molecular docking and dynamics-driven dental resin composite optimization.

BACKGROUND: Dental resin-based composites are widely recognized for their aesthetic appeal and adhesive properties, which make them integral to modern restorative dentistry. Despite their advantages, adhesion and biomechanical performance challenges persist, necessitating innovative strategies for improvement. This study addressed the challenges associated with adhesion and biomechanical properties in dental resin-based composites by employing molecular docking and dynamics simulation. METHODS: Molecular docking assesses the binding energies and provides valuable insights into the interactions between monomers, fillers, and coupling agents. This investigation prioritizes SiO2 and TRIS, considering their consistent influence. Molecular dynamics simulations, executed with the Forcite module and COMPASS II force field, extend the analysis to the mechanical properties of dental composite complexes. The simulations encompassed energy minimization, controlled NVT and NPT ensemble simulations, and equilibration stages. Notably, the molecular dynamics simulations spanned a duration of 50 ns. RESULTS: SiO2 and TRIS consistently emerged as influential components, showcasing their versatility in promoting solid interactions. A correlation matrix underscores the significant roles of van der Waals and desolvation energies in determining the overall binding energy. Molecular dynamics simulations provide in-depth insights into the mechanical properties of dental composite complexes. HEMA-SiO2-TRIS excelled in stiffness, BisGMA-SiO2-TRIS prevailed in terms of flexural strength, and EBPADMA-SiO2-TRIS offered a balanced combination of mechanical properties. CONCLUSION: These findings provide valuable insights into optimizing dental composites tailored to diverse clinical requirements. While EBPADMA-SiO2-TRIS demonstrates distinct strengths, this study emphasizes the need for further research. Future investigations should validate the computational findings experimentally and assess the material's response to dynamic environmental factors.

Mapping the research landscape of nanoparticles and their use in denture base resins: a bibliometric analysis.

BACKGROUND: Nanoparticles are increasingly used in dentistry for various applications, including enhancing the mechanical properties of denture base resins. This study aimed to comprehensively review and analyze the research landscape of nanoparticles and their effect on the flexural strength of denture base resins to identify key research areas and trends and to highlight the importance of collaboration between authors and institutions. METHODS: A Bibliometric Analysis was conducted using the Keywords "Nanoparticle*" AND "Denture*" OR "CAD/CAM." The literature search from the WOS database was restricted to the publication years 2011 to 2022. RESULTS: Key findings encompass an increase in research publications but a decline in citations. Saudi Arabia, China, and Iraq led this research, with specific institutions excelling. Notable journals with high impact factors were identified. Authorship patterns show variations in citation impact. Additionally, keyword analysis revealed that current research trends offer insights into influential authors and their networks. CONCLUSIONS: The analysis of nanoparticles and denture base resins reveals a dynamic and evolving landscape that emphasizes the importance of collaboration, staying current with research trends, and conducting high-quality research in this ever-evolving domain.

Quantum mechanical analysis of yttrium-stabilized zirconia and alumina: implications for mechanical performance of esthetic crowns.

BACKGROUND: Yttrium-stabilized zirconia (YSZ) and alumina are the most commonly used dental esthetic crown materials. This study aimed to provide detailed information on the comparison between yttrium-stabilized zirconia (YSZ) and alumina, the two materials most often used for esthetic crowns in dentistry. METHODOLOGY: The ground-state energy of the materials was calculated using the Cambridge Serial Total Energy Package (CASTEP) code, which employs a first-principles method based on density functional theory (DFT). The electronic exchange-correlation energy was evaluated using the generalized gradient approximation (GGA) within the Perdew (Burke) Ernzerhof scheme. RESULTS: Optimization of the geometries and investigation of the optical properties, dynamic stability, band structures, refractive indices, and mechanical properties of these materials contribute to a holistic understanding of these materials. Geometric optimization of YSZ provides important insights into its dynamic stability based on observations of its crystal structure and polyhedral geometry, which show stable configurations. Alumina exhibits a distinctive charge, kinetic, and potential (CKP) geometry, which contributes to its interesting structural framework and molecular-level stability. The optical properties of alumina were evaluated using pseudo-atomic computations, demonstrating its responsiveness to external stimuli. The refractive indices, reflectance, and dielectric functions indicate that the transmission of light by alumina depends on numerous factors that are essential for the optical performance of alumina as a material for esthetic crowns. The band structures of both the materials were explored, and the band gap of alumina was determined to be 5.853 eV. In addition, the band structure describes electronic transitions that influence the conductivity and optical properties of a material. The stability of alumina can be deduced from its bandgap, an essential property that determines its use as a dental material. Refractive indices are vital optical properties of esthetic crown materials. Therefore, the ability to understand their refractive-index graphs explains their transparency and color distortion through how the material responds to light..The regulated absorption characteristics exhibited by YSZ render it a highly attractive option for the development of esthetic crowns, as it guarantees minimal color distortion. CONCLUSION: The acceptability of materials for esthetic crowns is strongly determined by mechanical properties such as elastic stiffness constants, Young's modulus, and shear modulus. YSZ is a highly durable material for dental applications, owing to its superior mechanical strength.

The effectiveness of botulinum toxin for temporomandibular disorders: A systematic review and meta-analysis.

OBJECTIVE: The current body of research on utilizing botulinum toxin (BTX) to manage temporomandibular disorders (TMDs) has not yet yielded definitive conclusions. The primary objective of this study was to determine the effectiveness of BTX in pain reduction for TMDs compared to placebo and other treatments. The secondary outcomes evaluated were adverse events, maximum mouth opening, bruxism events, and maximum occlusal force. MATERIALS AND METHODS: A literature search was performed on PubMed, Dimension Publication, Scopus, and Google Scholar. The RoB 2 tool was used for quality assessment. The mean differences in pain scores were estimated to measure the effect of BTX on pain reduction. For adverse events, the risk ratio for the incidence of side effects was calculated. RESULTS: Two hundred and sixty non-duplicate articles were identified; however, only 14 RCTS were included in this review. The total study population included 395 patients. The overall risk of bias showed a low to moderate quality of evidence. Results from 6 studies were reported only narratively; four studies were used for meta-analysis on pain reduction, and five were used for meta-analysis on adverse events. The control used in the meta-analysis was placebo injections. Results of the meta-analysis for pain reduction were statistically insignificant for the BTX group with mean differences at MD = -1.71 (95% CI, -2.87 to -0.5) at one month, -1.53 (95% CI, -2.80 to -0.27) at three months, and -1.33 (95% CI, -2.74 to 0.77) at six months. This showed that BTX treatment was not significantly better than placebo for a reduction in pain scores at 1, 3, and 6 months. Regarding safety, the placebo group showed a relative risk of 1.34 (95%CI, 0.48-6.78) and 1.17 (95%CI, 0.54-3.88) at 1 and 3 months respectively. However, the risks were not statistically significant. There was also no difference in the effectiveness of BTX compared to placebo and other treatments for maximum mouth opening, bruxism events, and maximum occlusal force. CONCLUSION: BTX was not associated with better outcomes in terms of pain reduction, adverse events, maximum mouth opening, bruxism events, and maximum occlusal force. More high-quality RCTs are needed to better understand this topic.

Finite element analysis of stress distribution on residual root structure in socket shield procedure following immediate dental implant placement: an in vitro study.

BACKGROUND: The success of implants in the socket shield technique relies on stress experienced by root fragments within the socket. Although there is no consensus on optimal root fragment thickness, varying thicknesses and dynamic implant placement induce stress in various directions and degrees. This study aimed to assess biomechanical response and stress distribution across different root fragment thicknesses in the socket shield procedure. METHODS: This in vitro study was conducted to assess and compare the stress distribution on residual root structures of varying thicknesses positioned within the labial aspect of the maxillary incisor socket during immediate implant placement of standard dimensions. The procedure involved applying an insertional torque of 40 Ncm, and the analysis was conducted using finite element analysis software. RESULTS: Utilizing the Numerical Technique with Abaqus software for explicit dynamics, von Mises stress and principal strain were analyzed on the root structure and bone under nonlinear contact conditions during implant torque application. For Model A, a loading torque of 40 Ncm was applied vertically on the implant, along with a horizontal force of 20 N on the root structure and bone. Results indicated maximum stress of 12.68 MPa on the root structure with a thickness of 0.5 mm and 5.61 MPa on the bone, with principal strains of 6.82E-03 and 4.10E-03, respectively. In Model B, with a root structure thickness of 1.0 mm, the maximum stress increased to 19.70 MPa, while the bone stress rose to 9.51 MPa, with principal strains of 1.03E-02 and 6.09E-03. Model C, with a root structure thickness of 1.5 mm, exhibited a maximum stress of 21.58 MPa on the root and 10.12 MPa on the bone, with principal strains of 1.16E-02 and 6.10E-03. Lastly, in Model D, with a root structure thickness of 2.0 mm, the maximum stress on the root structure and bone escalated to 28.74 MPa and 11.38 MPa, respectively, with principal strains of 1.55E-02 and 8.31E-03. CONCLUSIONS: As the thickness of the shield increases (ranging from 0.5 to 2 mm) in socket shield procedures with immediate implant placement, both stress on the root fragment and bone and principal micro-strain escalate. However, employing a shield thickness within the range of 0.5 to 2 mm does not lead to any adverse stress generation on the residual root fragment. However, for enhanced safety, it is recommended to restrict the maximum diameter and extension of the root fragment to 1.5 mm when considering implant sizes and socket diameter for the socket shield technique.

Assessment of hearing performance of dental technicians due to the professional noise exposure.

BACKGROUND: Some of the noise-intensive processes in dental laboratories include the finishing of crowns, bridges, and removable partial dentures; blowing out workpieces with steam and compressed air; and deflating casting rings. High sound pressure levels are also present in dental vibrators, polishing equipment, and sandblasters. The aim of this study was to Evaluation of the effect of noise production in dental technology laboratory on dental technician hearing capacity. METHODS: For this cross-sectional study, a total of 120 dental technicians were chosen. Otoscopic evaluation and the Weber test were used to establish if they had sensorineural or transmission hearing loss at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz, respectively. Then an OAER (objective auditory evoked response) and PTA (clinical aurimeter) test were administered (Neurosoft, Russia). The whole procedure was carried out by an audiologist and an ENT specialist. RESULTS: The PTA results showed that the patient had mild hearing impairment overall, with the loss being more severe in the left ear than in the right. The OAE test results revealed that in-ear of the left side, 84.5% of subjects passed and 15.5% of subjects struggled and were referred to an ear specialist, whereas in the right ear, 82.7% of subjects passed and 17.3% struggled and were referred to an ear specialist. According to this study, in a right-handed study participant, the ear on the left side is more vulnerable than the right side. Differences in the mean hearing threshold at 4000 and 6000 Hz in the left ear were statistically significant in the groups of workers with eleven to fifteen years of practical experience and twenty-one to twenty-five years of practical experience, respectively (Minervini, et al. J Clin Med 12:2652, 2023). CONCLUSIONS: A statistically meaningful threshold shift from 4000 to 6000 Hz is observed as the working experience grows, and this is suggestive of sensorineural hearing impairment brought on by the noisy dental environment.