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Journal of Prosthodontic Research 2023
Topics: Prosthodontics; Dental Materials; Dental Prosthesis Design; Biomimetic Materials
PubMed: 37045755
DOI: 10.2186/jpr.JPR_D_23_00081 -
Dental Materials : Official Publication... May 2024Lithium silicate-based glass ceramics have evolved as a paramount restorative material in restorative and prosthetic dentistry, exhibiting outstanding esthetic and... (Review)
Review
OBJECTIVES
Lithium silicate-based glass ceramics have evolved as a paramount restorative material in restorative and prosthetic dentistry, exhibiting outstanding esthetic and mechanical performance. Along with subtractive machining techniques, this material class has conquered the market and satisfied the patients' needs for a long-lasting, excellent, and metal-free alternative for single tooth replacements and even smaller bridgework. Despite the popularity, not much is known about the material chemistry, microstructure and terminal behaviour.
METHODS
This article combines a set of own experimental data with extensive review of data from literature and other resources. Starting at manufacturer claims on unique selling propositions, properties, and microstructural features, the aim is to validate those claims, based on glass science. Deep knowledge is mandatory for understanding the microstructure evolution during the glass ceramic process.
RESULTS
Fundamental glass characteristics have been addressed, leading to formation of time-temperature-transformation (TTT) diagrams, which are the basis for kinetic description of the glass ceramic process. Nucleation and crystallization kinetics are outlined in this contribution as well as analytical methods to describe the crystalline fraction and composition qualitatively and quantitatively. In relation to microstructure, the mechanical performance of lithium silicate-based glass ceramics has been investigated with focus on fracture strength versus fracture toughness as relevant clinical predictors.
CONCLUSION
Fracture toughness has been found to be a stronger link to initially outlined manufacturer claims, and to more precisely match ISO recommendations for clinical indications.
Topics: Ceramics; Silicates; Materials Testing; Glass; Surface Properties; Dental Materials; Crystallization; Lithium Compounds; Dental Porcelain
PubMed: 38580561
DOI: 10.1016/j.dental.2024.03.006 -
Journal of Biomedical Materials... Aug 2020Due to the excellent restoration of masticatory function, satisfaction on aesthetics and other superiorities, dental implants represent an effective method to resolve... (Review)
Review
Due to the excellent restoration of masticatory function, satisfaction on aesthetics and other superiorities, dental implants represent an effective method to resolve tooth losing and damaging. Current dental implant systems still have problems waiting to be addressed, and problems are centralized on the materials of implant bodies. This review aims to summarize major developments in the field of dental implant materials, starting with an overview on structures, procedures of dental implants and challenges of implant materials. Next, implant materials are examined in three categories, that is, metals, ceramics, and polymers, their mechanical properties, biocompatibility, and bioactivity are summarized. And as an important aspect, strategies of surface modification are also reviewed, along with some finite element analysis to guiding the research direction of implant materials. Finally, the conclusive remarks are outlined to provide an outlook on the future research directions and prospects of dental implants.
Topics: Biocompatible Materials; Dental Implants; Dental Materials; Finite Element Analysis; Humans; Materials Testing; Prosthesis Design
PubMed: 32196913
DOI: 10.1002/jbm.a.36931 -
Journal of Orthodontics Sep 2021To evaluate the colour stability of polymeric resins that could be used to 3D-print orthodontic brackets.
OBJECTIVE
To evaluate the colour stability of polymeric resins that could be used to 3D-print orthodontic brackets.
DESIGN
In vitro, laboratory study.
MATERIALS AND METHODS
Disc-shaped specimens were fabricated via 3D printing using three resins: Dental LT; Dental SG; and Clear. Five conditions were evaluated for each resin (n = 10 per treatment per resin) to assess its corresponding effect on colour and translucency: immersion in (1) red wine, (2) coffee, (3) tea and (4) distilled water (control), and (5) exposure to accelerated aging. Colour and translucency measurements were made before and after exposure using a spectrophotometer. Mean colour differences (ΔE) and changes in translucency parameter (ΔTP) were calculated for each sample using the CIEDE2000 colour difference formula.
RESULTS
Statistically significant effects of the resin material, the treatment condition and interactions effects of material and condition were observed for ΔE and ΔTP ( < 0.001). The most pronounced changes in colour (ΔE) were a result of the staining effects of wine on all three resins, ranging from 14.5 ± 0.6 to 20.8 ± 1.2. Dental LT, Dental SG and Clear resins all showed changes in colour when exposed to certain staining agents. Dental SG and Clear resins exhibited changes in colour with aging, while the colour of Dental LT resin remained stable with aging.
CONCLUSIONS
The colour changes of the resins investigated does not support their use in 3D-printed aesthetic bracket applications.
Topics: Coffee; Color; Composite Resins; Dental Materials; Humans; Materials Testing; Orthodontic Brackets; Printing, Three-Dimensional; Surface Properties
PubMed: 33719707
DOI: 10.1177/14653125211001079 -
Dental Materials : Official Publication... May 2024Functionally graded materials (FGM) with indistinct boundaries potentially eliminate the damaging stresses occurring at the interfaces. FGM applications in dental... (Review)
Review
BACKGROUND
Functionally graded materials (FGM) with indistinct boundaries potentially eliminate the damaging stresses occurring at the interfaces. FGM applications in dental ceramics have enhanced their fatigue resistance and interfacial toughness.
OBJECTIVES
This scoping review aims to map graded designs in dental ceramics, distinguish their methodological approaches with their material characteristics and properties, and understand the factors affecting the outcomes of each of the graded approaches.
METHODS
A systematic electronic search was performed with the databases MEDLINE (PubMed), Scopus, Cochrane Library, EBSCO, and Google Scholar along with a manual search.
RESULTS
About 2675 articles were initially found from all the searches with no date restriction till July 2023. After rejecting duplicates and based on exclusion criteria, about 52 articles were included.
SIGNIFICANCE
Methodological approaches in grading such as glass-infiltration and silica-infiltration have been investigated on pre-sintered zirconia. The type of infiltration and the method of infiltrate application significantly influenced the phase transformation of zirconia, its microstructure, surface hardness, fracture toughness, flexural strength, wear, and fatigue strength of graded dental zirconia. Interlayers were accommodated between metal-ceramic and veneer-core all-ceramic layers. Fractions of zirconia-porcelain and alumina-porcelain showed high bending strength and better stress distribution. The results of finite element analysis studies predicted that using 10-layered graded layers reduced the stresses at the crown-cement-dentin interface.
Topics: Ceramics; Materials Testing; Zirconium; Surface Properties; Dental Materials; Humans; Dental Stress Analysis; Hardness; Dental Porcelain; Flexural Strength
PubMed: 38438282
DOI: 10.1016/j.dental.2024.02.016 -
Methods in Molecular Biology (Clifton,... 2023Dental materials are specially fabricated materials designed for use in dentistry. A variety of materials may be used, including cements, impression, lining, and dental...
Dental materials are specially fabricated materials designed for use in dentistry. A variety of materials may be used, including cements, impression, lining, and dental restorative materials. Some of these dental materials provide temporary dressings while others are more permanent and are in contact with host tissue for prolonged periods of time. Consequently, newly developed dental materials not only require mechanical, chemical, and physical testing but also require in vitro analysis to ensure their safety and biocompatibility. The current chapter provides background on dental material characterization and a protocol for its in vitro biological testing.
Topics: In Vitro Techniques; Dental Materials
PubMed: 36418708
DOI: 10.1007/978-1-0716-2780-8_31 -
Dental Materials : Official Publication... May 2021Digital image correlation (DIC) is a non-contact image processing technique for full-field strain measurement. Although DIC has been widely used in engineering and... (Review)
Review
OBJECTIVE
Digital image correlation (DIC) is a non-contact image processing technique for full-field strain measurement. Although DIC has been widely used in engineering and biomechanical fields, it is in the spotlight only recently in dental materials. Therefore, the purpose of this review paper is introducing the working principle of the DIC technique with some modifications and providing further potential applications in various dental materials and related fields.
METHODS
The accuracy of the algorithm depending on the environmental characteristics of the DIC technique, as well as the advantages and disadvantages of strain measurement using optical measurements, have been elaborated in dental materials and related fields. Applications to those researches have been classified into the following categories: shrinkage behavior of light-cured resin composite, resin-tooth interface, mechanical properties of tooth structure, crack extension and elastic properties of dental materials, and deformation of dental restoration and prosthesis. This classification and discussion were performed using literature survey and review based on numerous papers in the international journals published over the past 20 years. The future directions for predicting the precise deformation of dental materials under various environments, as well as limitations of the DIC technique, was presented in this review.
RESULTS
The DIC technique was demonstrated as a more effective tool to measure full-field polymerization shrinkage of composite resin, even in a simulated clinical condition over the existing methods. Moreover, the DIC combined with other technologies can be useful to evaluate the mechanical behavior of material-tooth interface, dentine structure and restorative and prosthetic materials with high accuracy. Three-dimensional DIC using two cameras extended the measurement range in-plane to out-of-plane, enabling measure of the strain directly on the surface of dental restorations or prosthesis.
SIGNIFICANCE
DIC technique is a potential tool for measuring and predicting the full-field deformation/strain of dental materials and actual prostheses in diverse clinical conditions. The versatility of DIC can replace the existing complex sensor devices in those studies.
Topics: Composite Resins; Dental Materials; Dental Restoration, Permanent; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Materials Testing; Polymerization; Stress, Mechanical
PubMed: 33715864
DOI: 10.1016/j.dental.2021.02.024 -
Biotechnology and Bioengineering Dec 2021Several approaches for elimination of oral pathogens are being explored at the present time since oral diseases remain prevalent affecting approximately 3.5 billion... (Review)
Review
Several approaches for elimination of oral pathogens are being explored at the present time since oral diseases remain prevalent affecting approximately 3.5 billion people worldwide. Need for antimicrobial biomaterials in dental healthcare include but is not restricted to designing resin composites and adhesives for prevention of dental caries. Constant efforts are also being made to develop antimicrobial strategies for clearance of endodontic space prior root canal treatment and for treatment of periimplantitis and periodontitis. This article discusses various conventional and nanotechnology-based strategies to achieve antimicrobial efficacy in dental biomaterials. Recent developments in the design and synthesis of antimicrobial peptides and antifouling zwitterionic polymers to effectively lessen the risks of antimicrobial drug resistance are also outlined in this review. Further, the role of contemporary strategies such as use of smart biomaterials, ionic solvent-based biomaterials and quorum quenchers incorporated biomaterials in the elimination of dental pathogens are described in detail. Lastly, we mentioned the approach of using polymers to print custom-made three-dimensional antibacterial dental products via additive manufacturing technologies. This review provides a critical perspective on the chemical, biomimetic, and engineering strategies intended for developing antimicrobial biomaterials that have the potential to substantially improve the dental health.
Topics: Animals; Anti-Infective Agents; Antimicrobial Peptides; Biocompatible Materials; Dental Caries; Dental Materials; Humans; Mice; Nanostructures; Oral Health; Printing, Three-Dimensional
PubMed: 34599764
DOI: 10.1002/bit.27948 -
Dental Materials : Official Publication... May 2021To evaluate optical properties, and translucency and opalescence parameters of one-shaded resin-based composites.
OBJECTIVE
To evaluate optical properties, and translucency and opalescence parameters of one-shaded resin-based composites.
METHODS
Three one-shaded resin composites (OM - Omnichroma; VP - Venus Pearl; and VD - Venus Diamond) and a group-shaded resin composite (FU- Filtek Universal A2) were used. Three composite discs from each material were fabricated for each of the following thickness: 0.5, 1.0 and 2.0 mm. Diffuse reflectance was measured against white and black backgrounds using a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45°/0° geometry. Translucency parameter (TP) was calculated using ΔE and ΔE. Scattering (S) and absorption (K) coefficients and transmittance (T%) were calculated using Kubelka-Munk's equations, and a reflection spectrophotometer was used to measure the opalescence parameter (OP). Data was statistically analyzed using Kruskal-Wallis, Mann-Whitney tests, and VAF coefficient.
RESULTS
Spectral distributions of S, K and T were wavelength dependent, showing significant differences between materials of the same thickness and for different thicknesses of the same material (p < 0.001). OM showed the greatest translucency values for all thicknesses. Translucency decreased as thickness increased with statistically significant differences (p < 0.005). Values of ΔTP and ΔTP between thicknesses were above of translucency thresholds for all materials. VP and VD showed the lowest OP values.
SIGNIFICANCE
One-shaded resin-based composites showed different optical behavior than the group-shaded resin-based composite. Understanding the optical behavior of the one-shaded resin-based composites is essential to optimize their clinical performance.
Topics: Color; Composite Resins; Dental Materials; Iridescence; Light; Materials Testing
PubMed: 33658138
DOI: 10.1016/j.dental.2021.02.011 -
Operative Dentistry Nov 2021To compare the ability of two calcium-releasing restorative materials to inhibit root dentin demineralization in an artificial caries model.
OBJECTIVE
To compare the ability of two calcium-releasing restorative materials to inhibit root dentin demineralization in an artificial caries model.
METHODS AND MATERIALS
Preparations were made at the cementum-enamel junction of extracted human molars (40, n=10/material) and restored with two calcium-releasing materials (Experimental composite, Pulpdent Corporation and Cention N, Ivoclar Vivadent), a resin composite (Filtek Supreme Ultra, 3M Oral Care), and a resin-modified glass ionomer (RMGI) (Fuji II LC, GC). All materials (other than the RMGI) were used with an adhesive (Scotchbond Universal Adhesive, 3M Oral Care) in the self-etch mode, which was light cured for 10 seconds. All restorative materials were light cured in 2-mm increments for 20 seconds and then finished with a polishing disc. Teeth were incubated (37°C) for 24 hours in water. An acid-resistant varnish was painted onto the teeth around the restoration, leaving a 2-mm border of uncovered tooth. A demineralization solution composed of 0.1 M lactic acid, 3 mM Ca3(PO4)2, 0.1% thymol, and NaOH (to adjust pH=4.5), and a remineralization solution composed of 1.5 mM Ca, 0.9 mM P, and 20 mM Tris(hydroxymethyl)-aminomethane (pH=7.0) were prepared. Specimens were placed in the demineralization solution for 4 hours, followed by the remineralization solution for 20 hours and cycled daily for 30 days. The specimens were embedded, sectioned into 100-μm sections, and the interface between the restorative material and root dentin was viewed with polarized light microscopy. A line was drawn parallel with the zone of demineralization for each tooth. The area of "inhibition" (defined as the area external to the line) or "wall lesion" (defined as the area internal to the line) was measured with image evaluation software. Areas of inhibition were measured as positive values, and areas of wall lesions were measured as negative areas.
RESULTS
A one-way analysis of variance (ANOVA) found significant differences between materials for "inhibition/wall lesion" areas in root dentin (p<0.001). Tukey post hoc analysis ranked materials (μm2, mean ±SD): Fuji II LC (5412±2754) > Cention N (2768±1576) and experimental composite (1484±1585) > Filtek Supreme Ultra (-1119±1029).
CONCLUSION
The experimental composite and Cention N materials (used with an adhesive) showed net areas of inhibition greater than a reference resin composite, albeit at a lower level than a reference RMGI material (used with no adhesive).
Topics: Calcium; Composite Resins; Dental Enamel; Dental Materials; Dental Restoration, Permanent; Glass Ionomer Cements; Humans; Tooth Demineralization
PubMed: 35507898
DOI: 10.2341/20-074-L