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.

Attenuation of orthodontically induced inflammatory root resorption by using low-intensity pulsed ultrasound as a therapeutic modality- a systematic review.

Ultrasound is an effective tool for both diagnostic and therapeutic applications. As an imaging tool, ultrasound has mostly been used for real-time noninvasive diagnostic imaging. As ultrasound propagates through a material, a reflected radio-frequency (RF) signal is generated when encountering a mismatch in acoustic impedance. While traditionally recognized for its diagnostic imaging capabilities, the application of ultrasound has broadened to encompass therapeutic interventions, most notably in the form of Low-Intensity Pulsed Ultrasound (LIPUS). Low-Intensity Pulsed Ultrasound (LIPUS) is a form of mechanical energy transmitted transcutaneously by high-frequency acoustic pressure waves. The intensity of LIPUS (30 mW/cm2) is within the range of ultrasound intensities used for diagnostic purposes (1-50 mW/cm2) and is regarded as non-thermal, non-destructive, permeating living tissues and triggering a cascade of biochemical responses at the cellular level. The LIPUS device produces a 200 µs burst of 1.5 MHz acoustic sine waves, that repeats at a modulation frequency of 1 kHz and provides a peak pressure of 30 mW/cm2. Low-intensity pulsed ultrasound (LIPUS) forms one of the currently available non-invasive healing-enhancing devices besides electro-stimulation (pulsed electro-magnetic field, PEMF). This modality has been leveraged to enhance drug delivery, expedite injury recovery, improve muscle mobility, alleviate joint stiffness and muscle pain, and enhance bone fracture healing. Although LIPUS has been embraced within various medical disciplines, its integration into standard dental practices is still in its nascent stages, signifying an unexplored frontier with potentially transformative implications. Low-intensity pulsed ultrasound (LIPUS) has emerged as an attractive adjuvant therapy in various dental procedures, such as orthodontic treatment and maxillary sinus augmentation. Its appeal lies in its simplicity and non-invasive nature, positioning LIPUS as a promising avenue for clinical innovation. One particular area of interest is orthodontically induced inflammatory root resorption (OIIRR), an oftenunavoidable outcome of the orthodontic intervention, resulting in the permanent loss of root structure. Notably, OIIRR is the second most common form of root resorption (RR), surpassed only by root resorption related to pulpal infection. Given the high prevalence and potential long-term consequences of OIIRR, this literature review seeks to evaluate the efficacy of LIPUS as a therapeutic approach, with an emphasis on assessing its capacity to reduce the severity of OIIRR to a level of clinical significance. To conduct this systematic review, a comprehensive automated literature search was executed across multiple databases, including MEDLINE, Embase, PsycINFO, Web of Knowledge, Scopus, CINAHL, LILACS, SciELO, Cochrane, PubMed, trials registries, 3ie, and Google Scholar. Both forward and backward citation tracking was employed, encompassing studies published from database inception through January 2009 to April 2023. The review focused on randomized controlled trials (RCTs) that specifically evaluated the effects of low-intensity pulsed ultrasound therapy on orthodontically induced inflammatory root resorption (OIIRR), without restrictions of publication date. A stringent selection criterion was applied, and only studies demonstrating high levels of statistical significance were included. Ultimately, fourteen studies met the inclusion criteria and were subjected to further analysis. The overall quality of the included randomized controlled trials (RCTs) was rigorously assessed utilizing the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. This analysis revealed certain methodological limitations that posed challenges in drawing definitive conclusions from the available evidence. Despite these constraints, the review offers invaluable insights that can inform and guide future research. Specifically, it delineates recommendations for targeted populations, necessary interventions, appropriate outcome measures, suitable study designs, and essential infrastructure to facilitate further investigations. The synthesis of these insights aims to enhance the development and application of low-intensity pulsed ultrasound therapy within the field of dentistry, thereby contributing to improved patient outcomes.

Comparative analysis of different types of occlusal splints for the management of sleep bruxism: a systematic review.

BACKGROUND: Sleep bruxism is a prevalent condition in dentistry practice, characterized by involuntary grinding or clenching of the teeth during sleep. Several therapies, including occlusal splints, have been used to manage sleep bruxism and temporomandibular disorders, including occlusal splints. This study aimed to compare the effectiveness of different occlusal splints in managing sleep bruxism. METHODS: The PICO framework encompasses the characterization of the population, intervention, comparison, and pertinent outcomes. A comprehensive and systematic literature review was conducted on PubMed, Scopus, and Google Scholar to identify grey literature. The search specifically targeted scientific studies published before September 20, 2023. The Cochrane Collaboration Risk of Bias Tool assessed the accuracy of the included Randomized Control Trials (RCTs). The modified Newcastle-Ottawa Scale assessed non-randomized studies. Data were systematically extracted, synthesized, and reported thematically. RESULTS: Out of the total of 808 articles that were evaluated, only 15 articles were found to meet the specified inclusion criteria. Adjustable splints, such as full-occlusion biofeedback splints, were more effective in reducing sleep bruxism episodes, improving patient-reported symptoms, and enhancing overall well-being. The impact of different occlusal sprints on electromyographic activity varies, and potential adverse effects should be considered individually. CONCLUSIONS: This review provides valuable insights into the effectiveness of occlusal splints in managing sleep bruxism. The results of this study indicate that occlusal splint therapy is a viable treatment approach for sleep bruxism.

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.

The flexural strength of 3D-printed provisional restorations fabricated with different resins: a systematic review and meta-analysis.

BACKGROUND: Three-dimensional (3D) printing technology has revolutionized dentistry, particularly in fabricating provisional restorations. This systematic review and meta-analysis aimed to thoroughly evaluate the flexural strength of provisional restorations produced using 3D printing while considering the impact of different resin materials. METHODS: A systematic search was conducted across major databases (ScienceDirect, PubMed, Web of Sciences, Google Scholar, and Scopus) to identify relevant studies published to date. The inclusion criteria included studies evaluating the flexural strength of 3D-printed provisional restorations using different resins. Data extraction and quality assessment were performed using the CONSORT scale, and a meta-analysis was conducted using RevMan 5.4 to pool results. RESULTS: Of the 1914 initially identified research articles, only 13, published between January 2016 and November 2023, were included after screening. Notably, Digital Light Processing (DLP) has emerged as the predominant 3D printing technique, while stereolithography (SLA), Fused Deposition Modeling (FDM), and mono-liquid crystal displays (LCD) have also been recognized. Various printed resins have been utilized in different techniques, including acrylic, composite resins, and methacrylate oligomer-based materials. Regarding flexural strength, polymerization played a pivotal role for resins used in 3D or conventional/milled resins, revealing significant variations in the study. For instance, SLA-3D and DLP Acrylate photopolymers displayed distinct strengths, along with DLP bisacrylic, milled PMMA, and conventional PMMA. The subsequent meta-analysis indicated a significant difference in flexure strength, with a pooled Mean Difference (MD) of - 1.25 (95% CI - 16.98 - 14.47; P < 0.00001) and a high I2 value of 99%, highlighting substantial heterogeneity among the studies. CONCLUSIONS: This study provides a comprehensive overview of the flexural strength of 3D-printed provisional restorations fabricated using different resins. However, further research is recommended to explore additional factors influencing flexural strength and refine the recommendations for enhancing the performance of 3D-printed provisional restorations in clinical applications.

Evaluation of the effect of chemical disinfection and ultraviolet disinfection on the dimensional stability of polyether impression material: an in-vitro study.

BACKGROUND: Various methods, chemical and physical, disinfect dental impressions. Common chemicals include 1% Sodium Hypochlorite and 2% glutaraldehyde, while UV radiation is a prevalent physical method. Few studies compare their effects on dimensional stability in polyether impressions. This study aims to assess such stability using different disinfection methods. Therefore, this study was planned to evaluate the dimensional stability of polyether impression material using different disinfection methods. METHODS: This in vitro study compared the effects of chemical disinfectants (1% Sodium Hypochlorite and 2% glutaraldehyde) and UV irradiation on the dimensional stability of polyether impression material. Groups A, B, C, and D, each with ten samples (N = 10), were studied. Group A was untreated (control). Group B was treated with 2% glutaraldehyde for 20 min, Group C with 1% Sodium Hypochlorite for 20 min, and Group D with UV rays for 20 min. A pilot milling machine drill was used to make four parallel holes labeled A, B, C, and D in the anterior and premolar regions from right to left. After sequential drilling, four implant analogs were positioned using a surveyor for accuracy. Ten open-tray polyether impressions were made and treated as described in the groups, followed by pouring the corresponding casts. Distortion values for each disinfection method were measured using a coordinate measuring machine capable of recording on the X- and Y-axes. RESULTS: A comprehensive analysis was conducted using the one-way ANOVA test for distinct groups labeled A, B, C, and D, revealing significant differences in the mean distances for X1, X2, X4, X5, and X6 among the groups, with p-values ranging from 0.001 to 0.000. However, no significant differences were observed in X3. Notably, mean distances for the Y variables exhibited substantial differences among the groups, emphasizing parameter variations, with p-values ranging from 0.000 to 0.033. The results compared the four groups using the one-way ANOVA test, revealing statistically significant distance differences for most X and Y variables, except for X3 and Y4. Similarly, post-hoc Tukey's tests provided specific pairwise comparisons, underlining the distinctions between group C and the others in the mean and deviation distances for various variables on both the X- and Y-axes. CONCLUSIONS: This study found that disinfection with 1% sodium hypochlorite or UV rays for 20 min maintained dimensional stability in polyether impressions.

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.

Clinical Trial to Assess Physiology and Activity of Masticatory Muscles of Complete Denture Wearer Following Vitamin D Intervention.

Background and Objectives: Little information is available on the role of Vitamin D as a micro-nutrient deficiency with masticatory muscle efficiency and its effect on the function of removable prosthesis. The aim of this study was to evaluate the role of vitamin D on masticatory muscle activity among completely edentulous patients and its effect on the retention of removable complete dentures (RCDs). Materials and Methods: A non-randomized clinical control trial was conducted on completely edentulous patients (60.53 ± 7.01 years) in the Indian population between 2017 and 2019. Subjects were evaluated for temporomandibular disorders according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Serum Vitamin D (S Vit D) levels, Ultrasonography (USG), and surface Electromyography (sEMG) readings of the masseter muscle were recorded at enrolment (Level 0), after 3 months of Vitamin D therapy (Level 3), and after consecutive 3 months of maintenance therapy, i.e., after 6 months from baseline (Level 6). The fabrication of new RCDs was done for all after the enrolment, and the retention of RCDs was assessed by asking a question regarding denture retention and asking respondents to mark their satisfaction on a 5-point Likert scale. Data were analysed using ANOVA, Paired'-test and Pearson correlation coefficients. A p-value less than 0.05 indicated a statistically significant association. Results: Between enrolment and a six-month follow-up, S Vit D levels showed an increase from 16.03 ± 5.68 ng/mL to 31.35 ± 9.28 ng/mL, showing an increase of 15.32 ± 9.38 ng/mL (95.57% rise). Statistically significant values were observed for USG and sEMG. Conclusions: Results showed that S Vit D affects masticatory muscle activity by improving its thickness and boosting its tonicity. Healthy muscles assist in the retention of RCDs, consequently aiding in mastication, speech, and phonetics, hence improving patient satisfaction. Clinical implication: Acknowledging the fact that the prevalence of Vitamin D deficiency is worldwide. We suggest Vitamin D therapy as a nutritional intervention among the elderly completely edentulous population, following dietary counselling, and consider Vitamin D therapy to be an adjunct to nutritional counselling for improving masticatory muscle activity and efficiency, which aids in RCD retention and stability. Consequently, improving oral health-related quality of life for individuals.

Variations in the Compressive Strength of a Die Stone with Three Different Sulfates at Eight Different Concentrations: An In Vitro Study.

AIM: The present study aimed to evaluate the alteration in the compressive strength (CS) of the die stone with three different sulfate salt additives, each at eight various concentrations. MATERIALS AND METHODS: The specimens were prepared at specific dimensions (length: 2.5 cm and diameter: 2.5 cm) divided into three test groups based on the type of sulfate additives used [potassium sulfate (K2SO4), zinc sulfate (ZnSO4·H2O), and manganese sulfate (MnSO4·H2O)] and one control group, without any additives. Again, each group was divided into eight subgroups based on concentration of sulfates (ranging from 0.2% to 4%). A total of 375 specimens were tested. CS (in MPa) was evaluated after 72 hours of drying time, using an universal testing machine. STATISTICAL ANALYSIS: A one-way analysis of variance (ANOVA) was used for intergroup comparisons. Individual comparisons were done using the post hoc Tukey HSD analysis. RESULTS: All the three additives at all the concentrations have shown an inferior resistance to compressive forces when compared to the standard specimen. However, the least mean CS was observed at 0.8% of MnSO4 (10.95 MPa) and the highest was at 1% K2SO4 (25.28%). A highly significant difference (p < 0.001) was observed among the concentrations in all the three groups (K2SO4, MnSO4, and ZnSO4 groups) and F values were derived as 69.84, 24.29, and 130.52, respectively. At each concentration, comparisons between the groups have shown a significant difference (p < 0.05) at almost all concentrations. CONCLUSION: The CS of die stone is shown to be decreased with an increase in all three types of sulfate additives when compared to the control specimen. CLINICAL SIGNIFICANCE: Die stone is an often used gypsum material in the field of dentistry. Compressive strength of the die stone is crucial in prosthetic dentistry; chemical additives such as sulfate salts may increase the CS such that the die stone can withstand clinical and laboratory handling forces. How to cite this article: Vyas R, Vaddamanu SK, Gurumurthy V, et al. Variations in the Compressive Strength of a Die Stone with Three Different Sulfates at Eight Different Concentrations: An In Vitro Study. J Contemp Dent Pract 2019;20(11):1297-1306.

An esthetic modification of a nasal conformer.

Facial contractures caused by burns can collapse the nasal aperture and lead to airway obstruction. Management in such situations requires surgical and prosthetic intervention. Prosthetically, although a nasal conformer is the treatment of choice, even a well-fabricated nasal conformer may be esthetically unappealing and require an aid for enhanced retention. Expensive implant-aided conformers are not always a viable option. This article introduces a technique for fabricating a nasal conformer that is both esthetically appealing and cost-effective. The technique is illustrated by the treatment of a 12-year-old girl who presented with a history of burn injuries leading to nasal contracture that was effectively managed with this concept.

Assessment of Fracture Resistance Capacity of Different Core Materials with Porcelain Fused to Metal Crown: An in vitro Study.

Aim: The aim of the study was to evaluate the capacity to resist fracture in different core buildup materials with porcelain fused to metal (PFM) crown. Materials and methods: Totally, 45 mandibular single rooted first premolars were collected, which were sound along with similar shape and size. The teeth were sectioned at 15 mm above the root apex sparing the sound tooth structure. The teeth were endodontically treated with the crown-down technique using nickel-titanium (NiTi) instrumentation. The specimens were randomized into three groups as per the core materials used and were labeled accordingly. Group I consisted of dual-cured composite resin, group II consisted of glass ionomer reinforced with resin, and group III consisted of Miracle mix. Universal loading machine is used for measuring the compres-sive load applied to fracture the tooth. Results: The mean value of compressive strength was maximum in the dual cured composite resin (598.42 ± 22.64) followed by glass ionomer reinforced with resin (478.88 ± 26.74) and Miracle mix (442.16 ± 30.10). The results showed a significant difference statistically within the core materials used with p < 0.05. The results from the Tukey's post hoc test of multiple comparisons between dual-cured composite resin vs glass ionomer reinforced with resin, dual-cured composite resin vs Miracle mix, and glass ionomer reinforced with resin vs Miracle mix showed a highly statistical difference with p < 0.05, which is significant. Conclusion: This in vitro study showed that the dual-cured composite resin had maximum resistance to fracture compared with other core buildup materials on teeth which were endodonti-cally treated. Clinical significance: Restoration of a tooth which is structurally compromised is a tricky job for all the dentists. Restoring it with a proper core buildup material with adequate fracture resistance makes the tooth structure stable. The core material should be able to resist all types of occlusal forces and to distribute it equally within the tooth structure. Keywords: Core buildup, Crowns, Endodontically treated teeth, Fracture resistance.

A Lab-Based Study to Assess the Surface Roughness of Various Investments: An Original Research.

Introduction: Surface roughness of the crowns is dependent on the pattern material used for the making as well as the procedure of investing. The study was aimed to examine the impact of various pattern materials and investment procedures on the surface roughness of nickel-chromium alloy raw castings. Materials and Methods: An in-vitro study was piloted at a tertiary care hospital. Eighty samples of inlay wax and pattern resin were divided equally. They were invested in phosphate-bonded investment material and kept under normal atmospheric pressure as well as invested under a pressure of 3 bars. The surface roughness was calculated with a Profilometer. The values obtained were compared using statistical tools keeping P < 0.05 as significant. Results: Lowest surface roughness was seen for the wax pattern invested under positive pressure. While the highest was seen for the resin patterns invested at room pressure. A significant variance between the wax 1 and wax 2 (P < 0.01); as well as between the wax 2 vs. Resin 2 specimens (P < 0.01) was noted. Conclusions: Wax patterns can be suggested as the material and method of choice because they showed the least amount of surface roughness when placed under pressure. Resin patterns when invested under pressure can also be suggested as an alternate as they also exhibited similar surface roughness as that of the wax.

Analysis of modified palatal surface for better speech in edentulous patients: A clinico-analytical study.

BACKGROUND: Phonetics with mechanics and aesthetics are considered cardinal factors contributing to the success of complete dentures. OBJECTIVE: The aim of the current study was to evaluate the changes in speech in complete denture patients with and without palatal surface changes. METHODS: The data collected for the study involved completely edentulous Patients (n= 80). Patients were divided into two groups. Group A: Up to 50 years (n= 40); Group B: Above 50 years (n= 40) (including male and female). Each group was further divided into four subgroups for speech analysis-without dentures (A1/B1); with conventional dentures (A2/B2); dentures with a palatogram (A3/B3) and dentures with palate sandblasted (A4/B4). The speech sounds of all patients were evaluated for pitch and intensity using a spectrophotogram (Praat software) and Likert scale. The data so obtained from the quantitative and qualitative analysis were statistically analysed through one-way ANOVA, unpaired student's t-test, and Pearson correlation coefficient. Qualitative analysis was done with the Mann-Whitney U test. RESULTS: The maximum mean value of the pitch and intensity in Groups A and B was subgroup A3 (Palatogram) 190.37 ± 21.50 and 77.07 ± 7.58, B3 (Palatogram) 190.87 ± 24.36 and 75.33 ± 8.12. When comparing Groups A [A1, A2, A3, A4] and B [B1, B2, B3, B4] on the basis of pitch and intensity, a statistically insignificant value was found. No changes in speech sounds (pitch and intensity) were observed in terms of age. Both quantitative and qualitative analysis results showed that speech sounds in the patients with palatogram, had the highest pitch and intensity and were most clear to the listener and there were statistically significant differences from other groups. CONCLUSION: Speech was better in palatogram-based dentures in comparison to a sandblasted denture, conventional denture and without denture in terms of qualitative and quantitative analysis. The physiologic nature of the palatogram fabrication technique produces the palatal part of the denture more compatible with the tongue, thus producing better speech.

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.

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.

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.

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.

Exploring Technological Progress in Three-Dimensional Imaging for Root Canal Treatments: A Systematic Review.

INTRODUCTION AND AIMS: Root canal therapy is a crucial aspect of endodontic treatment aimed at preserving natural dentition. Over the years, advancements in three-dimensional (3D) technology have revolutionized diagnosis and treatment planning. Different 3D technologies are used in dental care, such as cone-beam computed tomography (CBCT), which ensures 3D slice visualization, root canal microanatomy, and dynamic navigation throughout the pulp cavity. By exploring the latest technological progress in this field, we seek to understand how these innovations are enhancing precision, efficiency, and patient outcomes, shedding light on the benefits and potential impact of 3D imaging in improving root canal procedures. METHODS: Literature was searched from different databases, including PubMed, ScienceDirect, The Cochrane Library, Scopus, and Google Scholar. Inclusion criteria involved studies on 3D technology in root canal therapy with comparison groups, including RCTs and non-RCTs. Excluded studies lacked 3D imaging advancements, a control group, or were review articles or case studies. Quality assessment utilized QUIN for in vitro studies and ROBINS-I for non-RCTs to evaluate the studies' validity. RESULTS: According to the PRISMA guidelines, among 5015 initial articles, 16 were included. CBCT was the most used 3D imaging technique for root imaging followed by micro-computed tomography (MCT) and limited CBCT (LCBCT) imaging methods. 2D radiographs and 2D histological methods and clearing techniques were the most common comparative modalities. Overall, 3D imaging streamlined dental treatment as clinicians could visualize much clearer and higher-quality images. Different resolutions and voxel sizes were applied to improve imaging quality. CONCLUSION: Three-dimensional imaging, especially CBCT, improves root canal treatments by providing superior image quality. CBCT outperforms other techniques like MCT and LCBCT, enhancing clarity. Varying resolutions and voxel sizes optimize the effectiveness of 3D imaging in root canal therapy. CLINICAL RELEVANCE: The advancements in 3D imaging technology, particularly CBCT, have significantly enhanced the diagnosis and treatment planning for root canal therapy. CBCT provides detailed insights into intricate root canal anatomy, improving diagnostic accuracy.

The impact of virtual reality simulation on dental education: A systematic review of learning outcomes and student engagement.

PURPOSE: Virtual reality (VR) simulations have been increasingly employed to train dental students prior to clinical practice. According to the literature, blended learning designs in the form of VR simulations can be utilized by both dental students and instructors to provide quality education. They can also save time and improve motor skills before students enter clinical stages. Therefore, this study was designed to review the importance of available VR simulators and their impact on student learning and outcomes. METHOD: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed to review the literature systematically, and different databases such as PubMed, ScienceDirect, Cochrane Library, Scopus, and Google Scholar were searched (up to December 2023) for relevant articles using keywords: "virtual reality," "virtual reality simulators," "virtual reality simulation," and "dental education." The Mixed Methods Appraisal Tool was used to assess the study quality. RESULTS: After a comprehensive literature search, 1477 research articles were identified, of which 16 were included in the present study. In terms of students' learning outcomes, engagement, and optimal approach, a significant improvement was observed compared to conventional training methods, specifically in their knowledge, performance, confidence, and psychomotor skills. CONCLUSION: The findings suggest that VR simulators enhance the overall learning abilities of dental students and should be regarded as an integral component of the current curriculum. However, it is important to recognize that VR simulators cannot fully substitute traditional training methods; rather, they can effectively complement them.

Challenges of E-Learning: Behavioral Intention of Academicians to Use E-Learning during COVID-19 Crisis.

The COVID-19 crisis demanded that all educational activities should be performed virtually to follow social distancing guidelines. Therefore, there was a need to perform a research study to assess the effects of external factors on the perceived usefulness, ease of use of e-learning, and the further effect of these perceptions on attitude and intent to use e-learning by using the technology acceptance model (TAM) among academicians at higher education institutions in the Kingdom of Saudi Arabia. METHODS: A cross-sectional study was conducted, and data were collected from 263 academicians across Saudi Arabia through an online survey questionnaire using a non-probability purposive sampling technique and analyzed and tested using the SPSS and Smart PLS software. RESULTS: This study found that self-efficacy was positively associated with perceived usefulness at ß = 0.143 and p < 0.05, but it had no association with perceived ease of use at ß = 0.057 at p > 0.05. System accessibility had a significant and positive relationship with perceived usefulness and perceived ease of use at ß = 0.283, ß = 0.247, and p < 0.01, respectively. Self-efficacy had a positive effect on perceived usefulness, whereas the subjective norm had no relationship with perceived usefulness and perceived ease of use at ß = -0.065 and ß = -0.012 at p > 0.05, respectively. Perceived ease of use and perceived usefulness were positively related to attitude towards use, which has a significant influence on intention to use e-learning. CONCLUSION: Perceived ease of application is the most significant factor (ß = 0.556) in developing the attitude among academicians to practice e-learning, followed by perceived usefulness (ß = 0.262). Moreover, it can be concluded that system accessibility has a stronger influence on developing perception among academicians about the expediency and ease of application of e-learning than self-efficacy.