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International Journal of Molecular... Dec 2023The dental material industry is rapidly developing resin-based composites (RBCs), which find widespread use in a variety of clinical settings. As such, their... (Review)
Review
The dental material industry is rapidly developing resin-based composites (RBCs), which find widespread use in a variety of clinical settings. As such, their biocompatibility has gained increasing interest. This literature review presents a summary of research into the cytotoxicity of methacrylate-based composites published from 2017 to 2023. Subject to analysis were 14 in vitro studies on human and murine cell lines. Cytotoxicity in the included studies was measured via MTT assay, LDH assay, and WST-1 assay. The QUIN Risk of Bias Tool was performed to validate the included studies. Included studies (based entirely on the results of in vitro studies) provide evidence of dose- and time-dependent cytotoxicity of dental resin-based composites. Oxidative stress and the depletion of cellular glutathione (GSH) were suggested as reasons for cytotoxicity. Induction of apoptosis by RBCs was indicated. While composites remain the golden standard of dental restorative materials, their potential cytotoxicity cannot be ignored due to direct long-term exposure. Further in vitro investigations and clinical trials are required to understand the molecular mechanism of cytotoxicity and produce novel materials with improved safety profiles.
Topics: Humans; Animals; Mice; Apoptosis; Biological Assay; Cell Line; Dental Materials; Glutathione
PubMed: 38203323
DOI: 10.3390/ijms25010152 -
Operative Dentistry May 2024
Topics: Humans; Dentistry, Operative; Dental Materials
PubMed: 38807320
DOI: 10.2341/1559-2863-49-3-245 -
Journal of Chromatography. A Nov 2018Since 2011, the World Health Organization has encouraged a global phase-down of the use of dental amalgam and actively supported the use of alternative, resin-based...
Since 2011, the World Health Organization has encouraged a global phase-down of the use of dental amalgam and actively supported the use of alternative, resin-based dental materials. The resins consist of (meth)acrylate monomers derived from Bisphenol A (BPA), such as Bisphenol A glycidyl methacrylate (BisGMA) and Bisphenol A ethoxylate methacrylate (BisEMA) or triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA) which lack the BPA backbone. Besides monomers, other compounds such as photoinitiators and stabilizing agents can be present in the dental resin matrices. The current study consists in the development of an analytical method for the separation and identification of dental material components using LC-QTOF-MS. The developed method was applied on several dental material ingredients, unpolymerized composite resins, and a common dental sealant. The acquired high resolution accurate-mass data was analyzed using suspect screening with an in-house developed library. Next to the main components, various isomers and impurities related to the production of the main component have been detected and identified in the dental material ingredients. In total, 39 chemicals have been identified in the analyzed dental materials. On average 15 chemicals have been identified. Major components, such as BisEMA, BisGMA and TEGDMA were identified although they were not always stated in the material safety data sheets. Minor components included photoinitiators, such as ethyl 4-dimethyl aminobenzoate (EDMAB) and (meth)acrylates impurities originating from production of main ingredients.
Topics: Chromatography, Liquid; Composite Resins; Dental Materials; Mass Spectrometry; Materials Testing; Pit and Fissure Sealants
PubMed: 30266234
DOI: 10.1016/j.chroma.2018.09.039 -
The Journal of Prosthetic Dentistry Apr 2019Electron backscatter radiation from dental materials can contribute to soft tissue injury in patients undergoing head and neck radiation therapy.
STATEMENT OF PROBLEM
Electron backscatter radiation from dental materials can contribute to soft tissue injury in patients undergoing head and neck radiation therapy.
PURPOSE
The dose enhancement from the materials used for prosthodontic restoration of the dentition has not been well quantified. This study reports the magnitude of backscatter dose from the contemporary dental materials lithium disilicate and zirconia as compared with high-noble alloy and investigates the role of a spacer material in mitigating this effect.
MATERIAL AND METHODS
Three flat slabs of dental materials high-noble alloy, lithium disilicate, and zirconia with thicknesses of 1.5 and 3 mm were irradiated with 6-MV photons from a clinical linear accelerator. Measurements were made using a thin-window parallel-plate ionization chamber placed at 0, 1, 3, and 5 mm from the material. One millimeter of poly(methyl methacrylate) or thermoplastic material was used to cover the dental material and measure the effect on the adjacent dose enhancement.
RESULTS
Dose enhancements between 8% and 50% were recorded adjacent to the dental restoration materials. The largest enhancements occurred for the material of the highest density, the high-noble alloy. Dose enhancement was substantially lower for lithium disilicate (8%) and zirconia (30%). The thickness of the restoration material did not significantly affect dose enhancement. The dose enhancement decreased with distance from the material, dropping to <10% for all materials at 3 mm.
CONCLUSIONS
Contemporary dental restorations enhance the backscatter dose. The presence of dental restorations may warrant the use of a stent to create separation from these materials as this can mitigate the effect.
Topics: Dental Alloys; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Humans; Materials Testing; Radiation Dosage; Zirconium
PubMed: 30580980
DOI: 10.1016/j.prosdent.2018.07.012 -
Journal of Prosthodontics : Official... Apr 2023To measure the flexural strength and Weibull characteristics of aged and nonaged printed interim dental material fabricated with different layer thickness. (Comparative Study)
Comparative Study
PURPOSE
To measure the flexural strength and Weibull characteristics of aged and nonaged printed interim dental material fabricated with different layer thickness.
MATERIAL AND METHODS
Bars (25×2×2 mm) were additively fabricated by using a polymer printer (Asiga Max) and an interim resin (Nexdent C&B MFH). Specimens were fabricated with the same printing parameters and postprocessing procedures, but with 7 different layer thickness: 50 (control or 50-G group), 10 (10-G group), 25 (25-G group), 75 (75-G group), 100 (100-G group), 125 (125-G group), and 150 μm (150-G group). Two subgroups were created: nonaged and aged subgroups (n = 10). A universal testing machine was selected to measure flexural strength. Two-parameter Weibull distribution values were computed. Two-way ANOVA and Tukey tests were selected for statistical evaluation of the data (α = 0.05).
RESULTS
Artificial aging methods (p < 0.001) were a significant predictor of the flexural strength computed. Aged specimens acquired less flexural strength than nonaged specimens. The Weibull distribution obtained the highest shape for nonaged 50-G and 75-G group specimens compared with those of other nonaged groups, while the Weibull distribution showed the highest shape for aged 125-G specimens.
CONCLUSIONS
The flexural strength of the additively fabricated interim material examined was not influenced by the layer thickness at which the specimens were fabricated; however, artificial aging techniques reduced its flexural strength. Aged specimens presented lower Weibull distribution values compared with nonaged specimens, except for the 125-G specimens.
Topics: Flexural Strength; Dental Materials; Materials Testing; Surface Properties; Stress, Mechanical; Printing, Three-Dimensional; Polymerization; Polymers
PubMed: 35924435
DOI: 10.1111/jopr.13582 -
Journal of the American Dental... Jan 2021Zirconia is a relatively new dental material used for indirect dental restorations. Little is known about how dental practitioners are using this material in their...
BACKGROUND
Zirconia is a relatively new dental material used for indirect dental restorations. Little is known about how dental practitioners are using this material in their practice.
METHODS
A survey on zirconia restorations was developed and administered electronically through e-mail communications to the American Dental Association Clinical Evaluators (ACE) Panel on August 31, 2020. Reminders were sent to nonrespondents, and the survey closed 2 weeks after the launch date.
RESULTS
When using zirconia for a restoration, respondents choose it to restore natural teeth (99%) more often than implants (76%). Almost all respondents (98%) use it for posterior crowns, whereas approximately two-thirds (61%) use it for anterior crowns. Restoration removal or replacement and shade matching and translucency were the top 2 cited disadvantages of zirconia, whereas most of the respondents (57%) cited flexural strength or fracture resistance as the biggest advantage. Fine diamonds and ceramic polishers are used most often to polish and adjust zirconia restorations, whereas coarse diamond rotary instruments and those made specifically for zirconia are most frequently used for removing these restorations. Compared with metal ceramic restorations, more than 50% of respondents experience debonding more often with zirconia restorations.
CONCLUSIONS
Dentists recognize the favorable fracture resistance and flexural strength properties of zirconia, and most use similar techniques when adjusting and removing this material. Removing these restorations and shade matching are a struggle for many.
PRACTICAL IMPLICATIONS
Dentists may benefit from tips on the best methods to remove, shade match, and adhesively bond zirconia restorations.
Topics: American Dental Association; Ceramics; Crowns; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Dental Restoration Failure; Dental Stress Analysis; Dentists; Humans; Professional Role; Surveys and Questionnaires; United States; Zirconium
PubMed: 33250170
DOI: 10.1016/j.adaj.2020.10.012 -
Compendium of Continuing Education in... Sep 2022The clinical application of modern bioceramics is no longer limited only to prosthetic restorations. Zirconia is also successfully used as a dental implant material,...
The clinical application of modern bioceramics is no longer limited only to prosthetic restorations. Zirconia is also successfully used as a dental implant material, enabling a metal-free restoration concept in most cases. The demand for such metal-free solutions is steadily rising mainly because of patients' increased health awareness. With the development of new materials, microrough surfaces, and improved treatment protocols, implants made of zirconium dioxide are already achieving results comparable to those of titanium. This advancement will enable clinicians to leverage the clinical advantages of ceramic implants in daily practice as an additional reliable treatment alternative to titanium implants. However, to successfully use ceramic implants, practitioners should have knowledge of the background of zirconium dioxide material and its particular features in clinical application, as presented in this overview article.
Topics: Ceramics; Dental Implants; Dental Materials; Dental Prosthesis Design; Dental Restoration Failure; Humans; Titanium; Zirconium
PubMed: 36170627
DOI: No ID Found -
Dental Materials : Official Publication... Jan 2023Different types of direct-placement dental materials are used for the restoration of structure, function and aesthetics of teeth. The aim of this research investigation...
OBJECTIVES
Different types of direct-placement dental materials are used for the restoration of structure, function and aesthetics of teeth. The aim of this research investigation is to determine, through a comparative cradle-to-gate life cycle assessment, the environmental impacts of three direct-placement dental restorative materials (DRMs) and their associated packaging.
METHODS
Three direct-placement dental materials; dental amalgam, resin-based composite (RBC) and glass polyalkenoate cements (GIC) are assessed using primary data from a manufacturer (SDI Limited, Australia). The functional unit consisted of 'one dental restoration' of each restorative system under investigation: 1.14 g of dental amalgam; 0.25 g of RBC (plus the adhesive = 0.10 g); and 0.54 g of GIC. The system boundary per restoration included the raw materials and their associated packaging materials for each DRM together with the processing steps for both the materials and packaging. The environmental impacts were assessed using an Egalitarian approach under the ReCiPe method using Umberto software and the Ecoinvent database. Nine different impact categories were used to compare the environmental performance of these materials.
RESULTS
Dental amalgam had the highest impact across most of the categories, but RBC had the highest Global Warming Potential. The highest sources of the environmental impacts for each restorative material were: Amalgam, derived from material use; RBC, derived from energy use in processing material and packaging material; GIC, derived from material and energy use for packaging.
SIGNIFICANCE
Less intensive energy sources or more sustainable packaging materials can potentially reduce the impacts associated with RBC and GIC thus making them suitable alternatives to dental amalgam.
Topics: Animals; Dental Restoration, Permanent; Dental Amalgam; Dental Materials; Glass Ionomer Cements; Life Cycle Stages; Composite Resins
PubMed: 36428112
DOI: 10.1016/j.dental.2022.11.007 -
American Journal of Dentistry Aug 2023To evaluate and compare the effects of different scaling and polishing techniques on the surface roughness of four different restorative materials.
PURPOSE
To evaluate and compare the effects of different scaling and polishing techniques on the surface roughness of four different restorative materials.
METHODS
72 specimens were prepared, molded to a size of 8.0 by 2.0 mm, and cured according to the manufacturers' instructions. The specimens were stored at 37°C for 24 hours and then thermocycled for 5,000 cycles (from 55°C to 5°C) to simulate 6 months of clinical use. Surface roughness (Ra/average and Rz/max-overall heights) was calculated using a stylus profilometer by subtracting the simulated treatments of hand scaling, ultrasonic scaling, and air polishing from the baseline measurements. The difference in Ra and Rz data were compared independently for each measurement using a two-way ANOVA on Ranks and the Holm-Sidak test, with α< 0.05 used to determine significance.
RESULTS
Irrespective of the scaling or polishing technique employed, flowable bulk fill demonstrated the lowest Ra and Rz values. Hand scaling exhibited the highest roughness and variability among the other techniques, regardless of the materials tested (P< 0.001). Air polishing with glycine resulted in the lowest roughness values across all tested materials, with the exception of the tested bioactive restorative material group.
CLINICAL SIGNIFICANCE
Regarding surface roughness, air polishing with glycine may be an effective and safe intervention for periodontal maintenance of subgingival restorations compared to the other tested scaling methods.
Topics: Dental Scaling; Analysis of Variance; Dental Materials; Glycine; Ultrasonics
PubMed: 37587032
DOI: No ID Found -
Clinical Oral Investigations Mar 2022The aims of this study are (i) to propose specific selection criteria related to NiTi instruments for dental practitioners and (ii) to objectively assess the NiTi...
OBJECTIVES
The aims of this study are (i) to propose specific selection criteria related to NiTi instruments for dental practitioners and (ii) to objectively assess the NiTi instruments.
MATERIALS AND METHODS
The steps of the methodology are as follows: Step 1: "Delphi method" was employed to reach a consensus on criteria defined according to the literature review and a group of panelists. Step 2: "Smart pairwise comparisons" were employed to rank the proposed criteria. Step 3: "Borda voting" was employed to determine the weights of the proposed criteria. Step 4: To determine assessment scores, "Simple Additive Weighting" was employed. Step 5: Reliability and validity checks were made by "simulation."
RESULTS
Specific criteria classified under dimensions were proposed and weighted for the NiTi instrument assessment. In this context, an assessment model was proposed and validated.
CONCLUSIONS
The proposed assessment model for NiTi instruments could aid to make the decision-making process as systematic, transparent, and reproducible as possible not only for dental practitioners but also for healthcare professionals. Also, this proposed model can represent a reference framework for further MCDM studies which can rank or classify materials in medical science.
CLINICAL RELEVANCE
The model proposed in this study can be used to aid decision-making in clinical practice by means assessing the NiTi instrumentation system alternatives for practitioners.
Topics: Dental Alloys; Dental Instruments; Dental Materials; Dentists; Equipment Design; Humans; Materials Testing; Nickel; Professional Role; Reproducibility of Results; Root Canal Preparation; Titanium
PubMed: 34750681
DOI: 10.1007/s00784-021-04234-7