Dental Materials Research Articles

Contrast-Enhanced Micro-CT Imaging of Murine Mandibles: A Multi-Method Approach for Simultaneous Hard and Soft Tissue Analysis.

To develop and evaluate a novel multi-method micro-computed tomography (μCT) imaging protocol for enhanced visualization of both hard and soft tissues in murine mandibles, addressing the limitations of traditional imaging techniques in dental research. We employed a contrast-enhanced (CE) μCT imaging technique using Lugol's iodine as a contrast agent to visualize the intricate structures of murine mandibles. The protocol involved the combination of conventional μCT imaging as well as CE-μCT, including decalcification with EDTA, allowing for simultaneous assessment of hard and soft tissues. The method is compared with standard imaging modalities, and the ability to visualize detailed anatomical features is discussed. The CE-μCT imaging technique provided superior visualization of murine mandibular structures, including dental pulp, periodontal ligaments and the surrounding soft tissues, along with conventional μCT imaging of alveolar bone and teeth. This method revealed detailed anatomical features with high specificity and contrast, surpassing traditional imaging approaches. Our findings demonstrate the potential of CE-μCT imaging with Lugol's iodine as a powerful tool for dental research. This technique offers a comprehensive view of the murine mandible, facilitating advanced studies in tissue engineering, dental pathology and the development of dental materials.

Nanotechnology In Prosthodontics

Nanotechnology is rapidly transforming the field of medicine, offering new and innovative solutions to some of the most complex challenges in healthcare. At its core, nanotechnology involves manipulating and engineering materials at the nanometer scale, where unique physical, chemical, and biological properties emerge. In medicine, this ability to work at such a small scale opens the door to revolutionary advancements, such as targeted drug delivery systems, improved diagnostic tools, regenerative medicine, and even nanoscale surgery. Nanotechnology in prosthodontics represents a transformative approach to dental restoration and rehabilitation, enhancing the precision and effectiveness. Commonly used dental materials, despite their limitations in physical and biological properties, have not been replaced but can instead be enhanced with nanomaterials to improve their inherent qualities while remaining cost-effective. The current article focuses on the nanomaterials utilized in prosthodontics

Optimizing the microstructure, mechanical, and optical properties of recycled zirconia for dental applications

Efficient recycling of dental zirconia residues from computer-aided design/manufacturing processes is crucial for sustainable development in dentistry. This study employed ball milling to modify recycled zirconia powder (RZP). Initial RZP and ball-milled RZP (RZP-BM) were pre-sintered at 1000–1150 °C and then final sintered at 1500 °C. Initial RZP had irregular shapes, while RZP-BM showed finer and more uniform morphology, higher packing density, and improved de-agglomeration after 6 h of ball milling. For pre-sintered zirconia, RZP-BM samples achieved properties comparable with commercial zirconia at 1100 °C, whereas initial RZP required 1150 °C. For final sintered zirconia, initial RZP samples exhibited lower Vickers microhardness, density, strength, and transmittance, with numerous defects in its microstructure. RZP-BM samples showed significant improvement in mechanical and optical properties, comparable with commercial zirconia. This study establishes a viable approach for recycling dental zirconia residues, enhancing its properties for potential reuse as dental materials.

Research on Textured Polishing Wheel (TPW) patterns for polishing dental ceramic materials in anhydrous environments

Abstract Dental ceramics commonly utilize high-hardness fused silica materials for the fabrication of inlays, crowns, and artificial dental implants, with their processing efficiency and surface roughness (Ra) directly influencing manufacturing costs and product quality. This study presents the development of a Textured Polishing Wheel (TPW) featuring three distinct surface patterns (spiral, linear, and radial), achieved through single-point diamond and pulsed laser processing techniques. It investigates the effects of these patterns on the removal rate and surface roughness (Ra) of dental ceramics during the polishing process. Results indicate that while TPW demonstrates comparable material removal depth to non-textured polishing wheels, it marginally increases surface roughness (Ra). Moreover, TPW significantly reduces burning and wear on the wheel surface during polishing. Pulsed laser ablation of TPW leads to further improvement in surface roughness, thereby enhancing the processing of dental ceramics. Experimental findings highlight the superior performance of spiral TPW, achieving a material removal rate of 4.2 μm/h and a surface roughness (Ra) of approximately 2.2 nm , thus meeting the manufacturing and functional requirements of dental ceramics.

Effect of denture materials on substructures for implant-supported overdenture

Effect of denture materials on substructures for implant-supported overdenture

The Integration of Gold Nanoparticles into Dental Biomaterials as a Novel Approach for Clinical Advancement: A Narrative Review.

Gold nanoparticles (AuNPs) have gained significant attention in the biomedical field owing to their versatile properties. AuNPs can be customized by modifying their size, shape and surface characteristics. In recent years, extensive research has explored the integration of AuNPs into various dental materials, including titanium, polymethylmethacrylate (PMMA) and resin composites. This review aims to summarize the advancements in the application of modified AuNPs in dental materials and to assess their effects on related cellular processes in the dental field. Relevant articles published in English on AuNPs in association with dental materials were identified through a systematic search of the PubMed/MEDLINE, Embase, Scopus and ScienceDirect databases from January 2014 to April 2024. Future prospects for the utilization of AuNPs in the field of dentistry are surveyed.

Antimicrobial Activity of Metal Oxide Nanoparticles

A broad range of gram positive and gram negative bacteria have been demonstrated to be effectively suppressed in growth by Metal Oxide Nanoparticles (MONPs), suggesting that these particles may be useful in the fight against antibiotic resistance. The antibacterial characteristics of MONPs, including those of silver, zinc, titanium, zirconia, iron, copper, magnesium, and cobalt oxide are widely recognized. The use of these nanoparticles made of synthetic and natural materials in dentistry is developing quickly, has been included in a variety of dental materials and has assisted in the treatment of oral disorders as well as the removal of biofilms and smear layers. The reader will gain up-to-date knowledge on MONPs, their modes of action, and their significance in endodontics in this review.

Reinforcing dental restoration material PMMA with SS 316L nanoparticles for mechanical performance analysis

Reinforcing dental restoration material PMMA with SS 316L nanoparticles for mechanical performance analysis

Interactive Online Modules for Dental Education: A Practical Example of Gagne’s Nine Events of Instruction

Effective and engaging learning experiences are crucial in dental education, especially in the field of dental materials science, as previous approaches were largely through didactic teaching. Interactive online modules have emerged as valuable supplemental tools to enhance dental education. It offers interactive elements, promotes active learning, and provides an immersive, self-paced learning environment. This article highlights the use of Gagne’s Nine Events of Instruction as a practical framework to design and implement interactive online modules in the dental materials science curriculum. Gagne’s model provides a structured approach to instructional design, improving students’ engagement and their learning process. The development of interactive online modules follows Gagne’s model, including gaining attention, informing students of objectives, stimulating the recall of prior knowledge, presenting new material, providing guidance, eliciting performance, providing feedback, assessing performance, and enhancing retention and transfer. Students’ perceptions and feedback can be evaluated at the end of the online modules. In short, this article provides a systematic approach to the design and implementation of interactive online modules, ultimately improving the educational outcomes for dental and other health profession students.

Approach for evaluating the effectiveness of ex vivo root canal instrumentation using microtomography

Endodontic treatment of a tooth involves effective elimination of the infectious process localized in the tooth cavity and root canals. The process of root canal treatment is carried out using specialized rotary instruments (files). In this paper, an approach is proposed for evaluating the effectiveness of root canal treatment using the ProTaper Next file system ex vivo using computed X-ray microtomography and VGSTUDIO MAX 3.5 software. This approach involves comparison of three-dimensional tooth models before and after the endodontic instrumentation procedure, segmentation, calculation of the root canal volume using software according to a specially developed protocol, as well as a study of their microgeometry. As an example of using the approach, a study of the features of root canal instrumentation of two- and three-rooted human molars is presented. The developed approach demonstrated high effectiveness in the process of examining human teeth, while the endodontic procedure was effective for both two- and three-rooted molars in terms of removing the internal biological content of the canals, which indicates the reliability of the applied method. The developed approach can be applied to evaluate the effectiveness of liquid dental materials and antibacterial solutions used during endodontic treatment of teeth.

Analyzing the Educational Needs of Dental Hygiene Students Using the Borich Needs Assessment and Locus for Focus Models

Objective: This study aimed to develop a standard for a practice-based curriculum that reflects the needs of dental hygiene students’ clinical practice education and to provide basic data that can contribute to improving dental hygienists’ competence in clinical practice. Methods: A survey of 132 dental hygiene students from selected universities was conducted. The Borich Needs Assessment model and The Locus for Focus models were used to evaluate the students’ educational needs for clinical practice content. Results: The highest level of present educational needs was for ‘fluoride application,’ while the greatest requirement was for ‘preparing surgical dental treatment’. Using The Locus for Focus model, 33 items in the first quadrant were identified as common to the Borich Needs Assessment priorities. These items include ‘dental insurance claims’, ‘patient reception’, ‘dental materials counseling’, ‘making a temporary crown’, ‘setting a temporary crown’, ‘document management’ and ‘prepare of dental emergencies’. Conclusions: The analysis of the clinical practice needs of dental hygiene students identified the needs for practice-oriented education. These findings suggest that future curriculum revisions should reflect not only the needs of students, but also the perspectives of educators and clinical dental hygienists.

Current Updates in Implant Dentistry Materials

Background: Permanent tooth loss without replacement results in impaired chewing function, aesthetics, phonetics, and balance of the masticatory organs which can lead to more complex dental and oral health problems. Dental implants are the best treatment alternative today to restore masticatory function, aesthetics, and phonetics more perfectly. The use of implants allows tooth replacement that resembles the patient's previous natural teeth, both in terms of aesthetics and comfort. Until now, many types of materials have been studied and applied as dental implant materials. Objective: This review aims to analyze the latest developments regarding materials used for dental implants. Methods: A literature search was conducted on the PubMed, ScienceDirect, Cochrane, and Scopus databases until December 2023 using predetermined keywords and the results were limited to articles published in 2018-2023 with full-text open-access. Conclusion: The selection of ideal implant material for patients can be adjusted to the patient's needs taking into account the physical, mechanical, and biocompatibility properties of the material.

Depth of Cure, Surface Characteristics, Hardness, and Brushing Wear of 4 Direct Restorative Materials in Paediatric Dentistry

Aim: The study aimed to compare the depth of cure, hardness, surface roughness, and wear resistance of four restorative materials used in pediatric dentistry: FUJI IX GP FAST, RivaSilver, SDR flow+, and Vertise Flow. Materials and Methods: The depth of cure was measured per ISO 4049 standards using a digital caliper, with 15 samples of each material. Hardness was evaluated using a Vickers indenter under a 10 N load for 20 s. Surface roughness was assessed before and after acid exposure using an optical profilometer according to ISO 4288. Brushing wear resistance was analyzed by subjecting samples to 20 and 60 min of brushing, followed by roughness measurements. Statistical analysis was performed using independent sample t-tests to determine the significance of differences between the materials, with p-values < 0.05 considered significant. Results: SDR flow+ exhibited the highest depth of cure with an average of 3.5 mm (±0.2 mm), significantly higher than Vertise Flow at 2.8 mm (±0.3 mm) (p < 0.001). Hardness testing revealed SDR flow+ had the highest average hardness (85 HV ± 4 HV), while Vertise Flow had the lowest (72 HV ± 5 HV) (p < 0.001). Surface roughness increased significantly after acid exposure for RivaSilver (from 1.2 μm ± 0.12 μm to 1.6 μm ± 0.15 μm, p = 0.007) and for SDR flow+ (from 0.85 μm ± 0.08 μm to 1.3 μm ± 0.14 μm, p = 0.001). Brushing wear resistance was highest in RivaSilver (Ra increase from 1.2 μm to 1.4 μm ± 0.11 μm) and lowest in FUJI IX GP FAST (Ra increase from 1.5 μm to 1.9 μm ± 0.15 μm, p < 0.001). Conclusions: The study demonstrates significant differences in performance among the tested materials. SDR flow+ showed a superior depth of cure and hardness, making it suitable for high-stress applications. However, all materials displayed increased surface roughness following acid exposure and brushing, with FUJI IX GP FAST showing the highest wear. These findings highlight the need to select restorative materials based on the specific clinical demands of pediatric patients, considering both their mechanical properties and resistance to wear and acid.

Biomechanical behaviour of tilted abutment after fixed partial denture restoration of CAD/CAM materials

BackgroundFailure to restore missing teeth in time can easily lead to the mesial tilting of the distal abutment teeth. However, a fixed partial denture (FPD) can improve stress conduction and distribution and prevent periodontal injuries. In these more complex cases, it is necessary to consider various factors comprehensively to improve conventional treatment planning and achieve better results.MethodsWe selected a patient with a missing first molar and a mesial inclination of the second molar, leaving inadequate space or bone mass for implant denture restoration, necessitating an FPD for restoration. Three-dimensional finite element analysis (3D-FEA) combined with photoelastic analysis were used to explore how the inclination angle (0 ‒ 30°) and different dental restoration materials (zirconia, lithium disilicate, polymer-infiltrated ceramic network, and resin composite) affect the biomechanical behaviour of FPD‒abutments‒periodontal tissue complex.ResultsThe stress was easily concentrated in the FPD connectors, enamel shoulder collar, periapical area, and root bifurcation. The stress on FPD and the periodontal ligament (PDL) of the second premolar increased with an increase in the elastic modulus of FPD, with an opposite trend in the abutments, the alveolar bone, and the PDL of the second molar. The stress on the FPD and alveolar bone increased with increased inclination angle of the distal abutment. The stress on two abutments and their PDL were positively correlated with the inclination angle in two stages; however, when the inclination angle > 12°, the second premolar and its PDL showed a negative correlation.ConclusionsFPDs can be used for restoration within 24° of distal abutment inclination, but protecting the abutments (< 12° especially) and the periodontal tissue (> 12° especially) must be taken seriously. For this purpose, an FPD material with higher strength is recommended.

Biocompatibility and Enamel Remineralization Potential of Titanium-Doped Phosphate Glasses With/Without Diode Laser Irradiation

This study investigates the biocompatibility and enamel remineralization potential of titanium-doped phosphate glasses (TDPG), third-generation materials with promising applications in dentistry. The biocompatibility of TDPG paste and its components (TDPG powder and polyacrylic acid liquid) was assessed using human gingival fibroblast cells (hGF) and human dental pulp stem cells (hDPSC). Cell attachment and viability were examined at 1, 3, and 7 days, comparing results with Nupro® Prophy paste and Teethmate, commonly used desensitizers, and positive control cells in normal tissue culture medium. Furthermore, the remineralization potential of these glasses with or without the use of diode laser irradiation on white spot lesions in enamel was explored at 12- and 21-days using Raman Spectroscopy and Field Emission Scanning Electron Microscopy (FESEM). The remineralization potential of TDPG was compared with Nupro® Prophy paste and Teethmate. Furthermore, both sound and demineralized enamel were also used as other controls.Results indicated that cells exposed to TDPG extracts displayed similar morphology and viability to positive control cells. While all tested pastes did not show remineralizing action after 12 days, Nupro® Prophy and Teethmate exhibited such action after 21 days. However, laser application enhanced remineralization potential for all pastes at both time points, with TDPG showing comparable results to Nupro® Prophy paste and significantly higher potential than Teethmate when used with laser at 21 days.In summary, this study reveals the biocompatibility and enhanced remineralization potential of TDPG when combined with diode laser irradiation. These findings signify innovative strides in dental materials and treatment modalities, offering new possibilities for advanced dental applications.

Synthesis and characterization of the dental adhesive monomer 10-MDP

Many studies have demonstrated the excellent performance of 10-MDP (10-methacryloyloxydecyl dihydrogen phosphate) as a functional monomer for dental adhesive materials and as a primer for ceramic surfaces. Although adhesive performance is affected by the purity level of 10-MDP, this parameter is rarely described, and possible byproducts have been suggested in the literature, but have not been identified to date. The present study aims to present an accessible 10-MDP synthesis strategy with easily handled reagents and address the characterization challenges, especially in identifying byproducts. 10-MDP was synthesized from 10-hydroxydecyl methacrylate and phosphorus pentoxide in acetone. The final product was characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (FTIR) and mass spectrometry MALDITOF/TOF. The main chemical groups associated with 10-MDP were identified by 1H, 31P, and 13C NMR analyses. Only mass spectrometry analyses (MALDITOF/TOF) could identify the presence of dimers as byproducts. Its proposed chemical structure indicates that the dimers were formed by the reaction between the phosphate ester groups and others formed by the reaction of the methacrylic group of 10-MDP molecules. Careful adjustment of the synthesis conditions to reduce the formation of these byproducts is also described. The results indicate that the characterization of 10-MDP batches as raw materials is an important task because, depending on the byproduct present, its ability to polymerize or acid etching capacity may be compromised.

Effect of Hydrogen Peroxide-Based Bleaching Agents on the Color Dimensions and Surface Roughness of Different Milled Restorative Dental Materials.

To compare the color dimensions, color discrepancies (ΔE00), and surface roughness of milled materials before and after application of a bleaching agent. A total of 10 extracted molars were obtained. Each tooth was cut in transverse sections to create disks (3-mm thick, 10-mm diameter; control group). Disk specimens of eight materials (n &#61; 10 per group) were fabricated: polymethyl methacrylate (PMMA) interim material (PMMA-Telio group), two resin nanoceramics (RNC-Ultimate group and RNC-Cerasmart group), two hybrid ceramics (HC-Shofu group and HC-Enamic group), lithium disilicate (LD-Emax group), zirconia-reinforced glass ceramic (ZGC-Suprinity group), and zirconia (Zr-InCeram group). Color measurements were obtained using a spectrophotometer before and after applying 35% hydrogen peroxide-based bleaching agent. Pre- and postbleaching surface roughness (Sa) analyses were completed using a profilometer. Significant L*, a*, b*, and ΔE00 value differences were found (P < .05). Color discrepancies (ΔE00) ranged from 0.30 ± 0.14 to 4.82 ± 0.10. The highest color discrepancies were measured on the PMMA-Telio group, while the lowest color discrepancies were computed for ZGC-Suprinity, RNCUltimate, and RNC-Cerasmart. Significant surface roughness differences were found (P < .05). The largest increase of surface roughness values between the pre- and postbleaching measurements was obtained in the PMMA-Telio group with a mean ΔSa value of 4.73 ± 3.02, while the largest decrease of surface roughness values between the pre- and postbleaching measurements was obtained in the Zr-InCeram group with a mean ΔSa value of -1.58 ± 0.10. The milled materials showed significant pre- and postbleaching color and surface roughness discrepancies.

Synergistic effects of bacteria, enzymes, and cyclic mechanical stresses on the bond strength of composite restorations

Predicting how tooth and dental material bonds perform in the mouth requires a deep understanding of degrading factors. Yet, this understanding is incomplete, leading to significant uncertainties in designing and evaluating new dental adhesives. The durability of dental bonding interfaces in the oral microenvironment is compromised by bacterial acids, salivary enzymes, and masticatory fatigue. These factors degrade the bond between dental resins and tooth surfaces, making the strength of these bonds difficult to predict. Traditionally studied separately, a combined kinetic analysis of these interactions could enhance our understanding and improvement of dental adhesive durability. To address this issue, we developed and validated an original model to evaluate the bond strength of dental restorations using realistic environments that consider the different mechanical, chemical, and biological degradative challenges working simultaneously: bacteria, salivary esterases, and cyclic loading. We herein describe a comprehensive investigation on dissociating the factors that degrade the bond strength of dental restorations. Our results showed that cariogenic bacteria are the number one factor contributing to the degradation of the bonded interface, followed by cyclic loading and salivary esterases. When tested in combinatorial mode, negative and positive synergies towards the degradation of the interface were observed. Masticatory loads (i.e., cycling loading) enhanced the lactic acid bacterial production and the area occupied by the biofilm at the bonding interface, resulting in more damage at the interface and a reduction of 73 % in bond strength compared to no-degraded samples. Salivary enzymes also produced bond degradation caused by changes in the chemical composition of the resin/adhesive. However, the degradation rates are slowed compared to the bacteria and cyclic loading. These results demonstrate that our synergetic model could guide the design of new dental adhesives for biological applications without laborious trial-and-error experimentation.

Synthesis and Application of Silver Nanoparticles for Caries Management: A Review.

Silver nanoparticles have unique physical, chemical, and biological properties that make them attractive for medical applications. They have gained attention in dentistry for their potential use in caries management. This study reviews the different synthesis methods of silver nanoparticles and the application of them for caries management. Silver nanoparticles are tiny silver and are typically less than 100 nanometres in size. They have a high surface area-to-volume ratio, making them highly reactive and allowing them to interact with bacteria and other materials at the molecular level. Silver nanoparticles have low toxicity and biocompatibility. Researchers have employed various methods to synthesise silver nanoparticles, including chemical, physical, and biological methods. By controlling the process, silver nanoparticles have defined sizes, shapes, and surface properties for wide use. Silver nanoparticles exhibit strong antibacterial properties, capable of inhibiting a broad range of bacteria, including antibiotic-resistant strains. They inhibit the growth of cariogenic bacteria, such as Streptococcus mutans. They can disrupt bacterial cell membranes, interfere with enzyme activity, and inhibit bacterial replication. Silver nanoparticles can inhibit biofilm formation, reducing the risk of caries development. Additionally, nano silver fluoride prevents dental caries by promoting tooth remineralisation. They can interact with the tooth structure and enhance the deposition of hydroxyapatite, aiding in repairing early-stage carious lesions. Silver nanoparticles can also be incorporated into dental restorative materials such as composite resins and glass ionomer cements. The incorporation can enhance the material's antibacterial properties, reducing the risk of secondary caries and improving the longevity of the restoration.

Repeatability of different mobile phone applications for color measurement in dentistry.

To assess the repeatability of various color-measuring mobile phone applications (MPAs) on dental materials in clinically relevant shades in 1-mm thickness. A benchtop spectrophotometer was used as a reference instrument. Seven MPAs were used: Color Analysis, Color Analyzer-Iro Shirabe, Color Grab, and Colorimeter from Android, and Color Analyzer-Iro Shirabe, ColorMeter RGB, and Optishade from iOS. Color measurements were performed on 1-mm thickness slices of CAD-CAM materials, Vita Enamic shades 1M2, 2M2, 3M2, 4M2, and Vitablocs Mark II shades A1C, A2C, A3C, A4C (n=10, for a total 80 specimens). The specimens were measured at three time periods, Day 0, Day 1, and Day 7, and three measurements were made on each day, to mimic short-, medium-, and long-term repeatability. The color differences were analyzed using the CIEDE2000 formula, with the corresponding color difference (ΔE00), and mean color difference from the mean (MCDM00). One-way ANOVA, Repeated measures ANOVA, and Paired sample t-tests were used for statistical analysis. Optishade from iOS showed the lowest mean color difference among the MPAs (ΔE00=0.2 (SD 0.1), 0.3 (SD 0.2), and 0.2 (SD 0.1) at Day 0, 1, and 7, respectively, and ΔE00=0.5 (SD 0.3) for all three periods Days 0-1, 0-7, and 1-7). Material-dependent variations in the repeatability of color measurements were observed. There was a statistically significant difference among color measurements using MPAs and a spectrophotometer, among the MPAs, and materials. The spectrophotometer exhibited the highest repeatability across the tested time periods. The iOS Optishade showed the highest repeatability among the MPAs.