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Journal of Biomedical Materials... Nov 2019Nearly 100 million of the 170 million composite and amalgam restorations placed annually in the United States are replacements for failed restorations. The primary... (Review)
Review
Nearly 100 million of the 170 million composite and amalgam restorations placed annually in the United States are replacements for failed restorations. The primary reason both composite and amalgam restorations fail is recurrent decay, for which composite restorations experience a 2.0-3.5-fold increase compared to amalgam. Recurrent decay is a pernicious problem-the standard treatment is replacement of defective composites with larger restorations that will also fail, initiating a cycle of ever-larger restorations that can lead to root canals, and eventually, to tooth loss. Unlike amalgam, composite lacks the inherent capability to seal discrepancies at the restorative material/tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal the interface, but the adhesive degrades, which can breach the composite/tooth margin. Bacteria and bacterial by-products such as acids and enzymes infiltrate the marginal gaps and the composite's inability to increase the interfacial pH facilitates cariogenic and aciduric bacterial outgrowth. Together, these characteristics encourage recurrent decay, pulpal damage, and composite failure. This review article examines key biological and physicochemical interactions involved in the failure of composite restorations and discusses innovative strategies to mitigate the negative effects of pathogens at the adhesive/dentin interface. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2466-2475, 2019.
Topics: Adhesives; Dental Materials; Dental Restoration, Permanent; Dentin; Humans
PubMed: 30895695
DOI: 10.1002/jbm.b.34358 -
Molecules (Basel, Switzerland) Feb 2021The aim of this study was to investigate and understand bacterial adhesion to different dental material surfaces like amalgam, Chromasit, an Co-Cr alloy, an IPS InLine...
The aim of this study was to investigate and understand bacterial adhesion to different dental material surfaces like amalgam, Chromasit, an Co-Cr alloy, an IPS InLine ceramic, yttrium stabilized tetragonal polycrystalline zirconia (TPZ), a resin-based composite, an Au-Pt alloy, and a tooth. For all materials, the surface roughness was assessed by profilometry, the surface hydrophobicity was determined by tensiometry, and the zeta potential was measured by electrokinetic phenomena. The arithmetic average roughness was the lowest for the TPZ ceramic (R = 0.23 µm ± 0.02 µm), while the highest value was observed for the Au-Pt alloy (R = 0.356 µm ± 0.075 µm). The hydrophobicity was the lowest on the TPZ ceramic and the highest on the Co-Cr alloy. All measured streaming potentials were negative. The most important cause of tooth caries is the bacterium , which was chosen for this study. The bacterial adhesion to all material surfaces was determined by scanning electron microscopy. We showed that the lowest bacterial extent was on the amalgam, whereas the greatest extent was on tooth surfaces. In general, measurements showed that surface properties like roughness, hydrophobicity and charge have a significant influence on bacterial adhesion extent. Therefore, dental material development should focus on improving surface characteristics to reduce the risk of secondary caries.
Topics: Alloys; Bacterial Adhesion; Ceramics; Composite Resins; Dental Amalgam; Humans; Hydrophobic and Hydrophilic Interactions; Materials Testing; Methacrylates; Microscopy, Electron, Scanning; Particle Size; Streptococcus mutans; Surface Properties; Urethane
PubMed: 33670043
DOI: 10.3390/molecules26041152 -
Journal of the Mechanical Behavior of... Jul 2020The interest in ceramic dental implants made of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) or alumina toughened zirconia (ATZ) has increased in recent...
OBJECTIVES
The interest in ceramic dental implants made of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) or alumina toughened zirconia (ATZ) has increased in recent years. However, in the light of aging, corrosion, and potential impurities of zirconia ceramics, the material composition of these implants and the associated term "metal-free" is persistently questioned. Thus, the present study aimed to conduct an elemental analysis of commercial zirconia dental implants to specify their elemental composition and to identify contaminants.
METHODS
Nine commercial zirconia dental implant systems and corresponding material samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES).
RESULTS
While the elemental composition was dominated by the main components Zr, Y and Al (in ATZ samples), all investigated samples contained impurities with Hf and contamination with alkali and alkali earth elements (Na, K, Mg, Ca), essential trace elements (e.g. Fe, Cu, Zn) but also potentially noxious metal elements (e.g. Ni, Cr). Furthermore, ultra-trace level contamination with the radionuclides U-238 and Th-232 was found in the majority of samples.
SIGNIFICANCE
The results indicate that, although all the investigated Y-TZP and ATZ dental implants meet the currently relevant ISO standards and manufacturer's specifications, from an elemental point of view, they are not devoid of metals. Due to the lack of a universal definition and thresholds for the term "metal-free", the question of whether the examined zirconia dental implants can be holistically classified as "metal-free" or not remains a controversial, philosophical one.
Topics: Ceramics; Dental Implants; Dental Materials; Materials Testing; Uranium; Yttrium; Zirconium
PubMed: 32364951
DOI: 10.1016/j.jmbbm.2020.103759 -
Journal of Prosthodontic Research Jan 2023Various oral rehabilitation approaches are available for severely worn dentition. However, evidence-based guidelines for permanent treatment are limited. This review...
PURPOSE
Various oral rehabilitation approaches are available for severely worn dentition. However, evidence-based guidelines for permanent treatment are limited. This review aims to investigate clinical observational findings and compare in-vitro outcomes of thin and ultrathin occlusal veneers using different materials and approaches.
METHODS
An electronic search of online databases, such as PubMed (MEDLINE), BioMed Central (BMC), Cochrane, and Scopus, was performed for the 2009 - Jun 2021 period, following the PRISMA 2020 criteria. The reports sought for retrieval were all the articles evaluating the clinical outcomes of permanent full-mouth rehabilitation, and all in-vitro records that investigated and compared fracture strength, survival rate, and modes of failure of ultrathin (0.3 - 0.6 mm), thin (0.5 - 0.8 mm), and thick (0.8-1.5 mm) occlusal veneer restorations, with regard to the available indirect restorative materials. The Newcastle Ottawa risk of bias criteria was used to judge the clinical studies and a modified consort statement was used for the evaluation of in-vitro studies. The data of the included studies were extracted and grouped based on the similarity of the outcomes and study protocols. Data heterogeneity determined the qualitative and quantitative grouping of the results.
RESULTS
Two clinical and 17 in-vitro studies were included. Data exhibited heterogeneity within the materials, variables, testing protocols and observation periods. Therefore, only qualitative synthesis of the results was feasible. Clinically used 1 mm lithium disilicate overlays and ultrathin one-step no-prep polymer infiltrated ceramic network (PICN) occlusal veneers exhibited very high success and survival rates. The analysis of in-vitro studies exhibited variable survival rates and fracture load values, based on materials, thickness, and restorative approaches used.
CONCLUSIONS
Within the limitations of this systematic review, it can be concluded that the clinical outcomes of thin and ultrathin occlusal veneers/overlays are auspicious. In-vitro experimental results support the usage of the thin and ultrathin occlusal veneers.
Topics: Survival Rate; Materials Testing; Dental Veneers; Dental Porcelain; Ceramics; Dental Materials; Dental Stress Analysis; Computer-Aided Design
PubMed: 35545532
DOI: 10.2186/jpr.JPR_D_21_00270 -
BMC Oral Health May 2023This study aimed to evaluate the surface hardness (VHN) and biaxial flexural strength (BFS) of dual-cured bulk-fill restorative materials after solvent storage.
BACKGROUND
This study aimed to evaluate the surface hardness (VHN) and biaxial flexural strength (BFS) of dual-cured bulk-fill restorative materials after solvent storage.
METHODS
Two dual-cured bulk-fill composites (Surefil One® and Activa™ Bioactive), a light-cured bulk-fill composite (Filtek One Bulk-Fill) and a resin-modified glass ionomer (Fuji II LC) were investigated. Surefil One and Activa were used in the dual-cure mode, all materials were handled according to manufacturer's instructions. For VHN determination, 12 specimens were prepared from each material and measured after 1 h (baseline), 1 d, 7 d and 30 d of storage in either water or 75% ethanol-water. For BFS test, 120 specimens were prepared (n = 30/material) and stored in water for either 1, 7 or 30 d before testing. Repeated measures MANOVA, two-way and one-way ANOVA followed by the Tukey post hoc test (p ≤ 0.05) were used to analyze the data.
RESULTS
Filtek One had the highest VHN, while Activa had the lowest. All materials exhibited a significant increase in VHN after 1d of storage in water, except for Surefil One. After 30 d of storage, VHN increased significantly in water except for Activa, while ethanol storage caused a significant time-dependent reduction in all tested materials (p ≤ 0.05). Filtek One showed the highest BFS values (p ≤ 0.05). All the materials, except for Fuji II LC, exhibited no significant differences between 1 and 30 d BFS measurements (p > 0.05).
CONCLUSIONS
Dual-cured materials had significantly lower VHN and BFS compared to the light-cured bulk-fill material. The low results of Activa VHN and Surefil One BFS, indicate that these materials should not be recommended in posterior stress-bearing areas.
Topics: Humans; Hardness; Flexural Strength; Solvents; Materials Testing; Dental Materials; Composite Resins; Ethanol; Water
PubMed: 37208664
DOI: 10.1186/s12903-023-03047-2 -
Dental Materials : Official Publication... Dec 2022This study investigated potential variations in polymerisation of light- and dual-cured (LC and DC) resin cements photoactivated through four CAD/CAM restorative...
OBJECTIVES
This study investigated potential variations in polymerisation of light- and dual-cured (LC and DC) resin cements photoactivated through four CAD/CAM restorative materials as a function of substrate thickness.
METHODS
Four CAD/CAM materials [two resin composites CeraSmart (CS) and Grandio Blocs (GB); a polymer infiltrated ceramic Vita Enamic (VE) and a feldspathic ceramic Vita Mark II (VM)], with five thicknesses (0.5, 1, 1.5, 2, and 2.5 mm) were prepared and their optical characteristics measured. 1 mm discs of LC and DC resin cement (Variolink® Esthetic, Ivoclar AG) were photoactivated through each specimen thickness. After 1 h post-cure, polymerisation efficiency was determined by degree of conversion (DC%) and Martens hardness (H). Interactions between materials, thicknesses and properties were analysed by linear regressions, two-way ANOVA and one-way ANOVA followed by post hoc multiple comparisons (α = 0.05).
RESULTS
All substrates of 0.5- and 1.0-mm thickness transmitted sufficiently high peak irradiances at around 455 nm: (I = 588-819 mW/cm) with translucency parameter TP = 21.14 - 10.7; ranked: CS> GB = VM> VE. However, increasing the substrate thickness (1.5-2.5 mm) reduced energy delivery to the luting cements (4 - 2.8 J/cm). Consequently, as their thicknesses increased beyond 1.5 mm, H of the cement discs differed significantly between the substrates. But there were only slight reduction of DC% in LC cements and DC cement discs were not affected.
SIGNIFICANCE
Photoactivating light-cured Ivocerin™ containing cement through feldspathic ceramics and polymer-infiltrated ceramics achieved greater early hardness results than dual-cured type, irrespective of substrate thickness (0.5 - 2.5 mm). However, only 0.5 and 1 mm-thick resin composites showed similar outcome (LC>DC). Therefore, for cases requiring early hardness development, appropriate cement selection for each substrate material is recommended.
Topics: Resin Cements; Esthetics, Dental; Computer-Aided Design; Polymerization; Glass Ionomer Cements; Dental Cements; Dental Materials; Bone Cements; Polymers
PubMed: 36443106
DOI: 10.1016/j.dental.2022.11.016 -
Colloids and Surfaces. B, Biointerfaces Jun 2020Dental materials are susceptible to dental plaque formation, which increases the risk of biofilm-associated oral diseases. Physical-chemical properties of dental...
Dental materials are susceptible to dental plaque formation, which increases the risk of biofilm-associated oral diseases. Physical-chemical properties of dental material surfaces can affect salivary pellicle formation and bacteria attachment, but relationships between these properties have been understudied. We aimed to assess the effects of surface properties and adsorbed salivary pellicle on Streptococcus gordonii adhesion to traditional dental materials. Adsorption of salivary pellicle from one donor on gold, stainless steel, alumina and zirconia was monitored with a quartz crystal microbalance with dissipation monitoring (QCM-D). Surfaces were characterized by X-ray photoelectron spectroscopy, atomic force microscopy and water contact angles measurement before and after pellicle adsorption. Visualization and quantification of Live/Dead stained bacteria and scanning electron microscopy were used to study S. gordonii attachment to materials with and without pellicle. The work of adhesion between surfaces and bacteria was also determined. Adsorption kinetics and the final thickness of pellicle formed on the four materials were similar. Pellicle deposition on all materials increased surface hydrophilicity, surface energy and work of adhesion with bacteria. Surfaces with pellicle had significantly more attached bacteria than surfaces without pellicle, but the physical-chemical properties of the dental material did not significantly alter bacteria attachment. Our findings suggested that the critical factor increasing S. gordonii attachment was the salivary pellicle formed on dental materials. This is attributed to increased work of adhesion between bacteria and substrates with pellicle. New dental materials should be designed for controlling bacteria attachment by tuning thickness, composition and structure of the adsorbed salivary pellicle.
Topics: Adsorption; Anti-Bacterial Agents; Chemistry, Physical; Dental Materials; Dental Pellicle; Humans; Microbial Sensitivity Tests; Particle Size; Streptococcus gordonii; Surface Properties
PubMed: 32172164
DOI: 10.1016/j.colsurfb.2020.110938 -
Dental Materials Journal Dec 2020Silicon nitride (SiN) is one of the promising ceramics for dental restoration due to providing significant benefits during the application. This study aimed to...
Silicon nitride (SiN) is one of the promising ceramics for dental restoration due to providing significant benefits during the application. This study aimed to investigate the potential use of SiN for all-ceramic dental restorations by characterizing some critical properties as color shade, mechanical resistance, shear-bond strength and radiolucency. For our study, porous SiN ceramic was produced by partial sintering process with limited amounts of sintering additives and low temperature. A commercial ZrO ceramic was prepared according to manufacturer's instructions and results were compared with SiN. SiN is an attractive ceramic for dental applications with good mechanical properties even in porous form, it has additional advantages over the conventional ceramics used as restorative material, such as, inherent antibacterial/anti-infective activity, radiolucency, and lower hardness. It is expected that SiN will become popular in dental applications as well.
Topics: Ceramics; Dental Materials; Dental Porcelain; Materials Testing; Silicon Compounds; Surface Properties
PubMed: 33028788
DOI: 10.4012/dmj.2020-134 -
BMC Oral Health Nov 2023The successful integration of resin-based dental adhesives significantly impacts restorative dentistry, providing efficient and aesthetically pleasing caries treatments....
BACKGROUND
The successful integration of resin-based dental adhesives significantly impacts restorative dentistry, providing efficient and aesthetically pleasing caries treatments. Among various adhesives, one-step self-etching adhesives (1-SEAs) have gained popularity due to their simplicity and short application time. However, concerns have been raised regarding their bonding performance and marginal adaptation characteristics, which differ from two-step self-etching adhesives (2-SEAs) and three-step etch-and-rinse adhesives. Additionally, light-cured bonding materials may encounter challenges in deep cavities and inaccessible areas, necessitating extended light irradiation time. Autocured bonding materials are a potential solution, but limited comparative studies have been conducted on their performance.
METHODS
In this in vitro study, we evaluated a new autocured universal bonding material (Bondmer Lightless 2) and compared the results with recent light-cured bonding materials. Microshear bond strength (μSBS) tests were performed on 25 human molars using five different combinations of adhesives and composite resins: Bondmer Lightless 2 with Estelite Bulk Fill Flow (BE group), Bondmer Lightless 2 with a prototype composite resin (BO group), Prime&Bond Universal with SDR flow + (PS group), Scotchbond Universal with Filtek Bulk Fill (SF group), and G-Premio Bond with Gracefil BulkFlo (GG group). The bond strengths and failure modes were assessed using a universal testing machine and scanning electron microscope (SEM), respectively. Marginal adaptation was evaluated using swept-source optical coherence tomography (SS-OCT) and confocal laser scanning microscopy (CLSM) on 40 sound bovine maxillary incisors.
RESULTS
The μSBS test showed no significant differences in bond strength among the tested groups. Most failure modes were observed at the bond interface between the adhesive and the dentin. The autocured bonding material demonstrated significantly higher marginal adaptation (SI%) than PS, SF, and GG. The CLSM images corresponded with gaps observed in the SS-OCT images, indicating improved marginal sealing in the autocured group.
CONCLUSIONS
The new autocured universal bonding material exhibited comparable bond strength to a conventional light-cured material while demonstrating a superior marginal adaptation level. This finding suggested that the autocured material could be a valuable alternative, especially when extended light irradiation would pose a challenge. Further clinical studies would be warranted to evaluate the performance of the autocured bonding material in actual restorative dental practice.
Topics: Animals; Cattle; Humans; Dental Cements; Dental Bonding; Composite Resins; Dental Materials; Resin Cements; Dentin; Materials Testing; Tensile Strength
PubMed: 38012568
DOI: 10.1186/s12903-023-03645-0 -
Clinical Oral Investigations Feb 2022The aim of the study was to evaluate the influence of filler content, degradation media and time on the mechanical properties of different dental composites after in...
OBJECTIVE
The aim of the study was to evaluate the influence of filler content, degradation media and time on the mechanical properties of different dental composites after in vitro aging.
MATERIALS AND METHODS
Specimens (1 mm) of three commercially available composites (GrandioSO®, Arabesk Top®, Arabesk Flow®) with respect to their filler content were stored in artificial aging media: artificial saliva, ethanol (60%), lactic acid (pH 5) and citric acid (pH 5). Parameters (Vickers microhardness, compressive strength, elastic modulus, water sorption and solubility) were determined in their initial state (control group, n = 3 for microhardness, n = 5 for the other parameters) and after 14, 30, 90 and 180 days (n = 3 for microhardness, n = 5 for the other parameters for each composite group, time point and media). Specimens were also characterized with dynamic-mechanical-thermal analysis (compression tests, F = ± 7 N; f = 0.5 Hz, 1 Hz and 3.3 Hz; t = 0-170 °C).
RESULTS
Incorporation of fillers with more than 80 w% leads to significantly better mechanical properties under static and dynamic compression tests and a better water sorption behavior, even after chemical degradation. The influence of degradation media and time is of subordinate importance for chemical degradation.
CONCLUSION
Although the investigated composites have a similar matrix, they showed different degradation behavior. Since dentine and enamel occur only in small layer thickness, a test specimen geometry with very small dimensions is recommended for direct comparison. Moreover, the use of compression tests to determine the mechanical parameters for the development of structure-compatible and functionally adapted composites makes sense as an additional standard. Clinical relevance Preferential use of highly filled composites for occlusal fillings is recommended.
Topics: Composite Resins; Dental Materials; Elastic Modulus; Hardness; Materials Testing; Saliva, Artificial; Stress, Mechanical; Surface Properties
PubMed: 34453210
DOI: 10.1007/s00784-021-04122-0