Preparation of a novel anti shrinking agent (SOC DA) and its evaluation in dental resins

2013 ◽  
Vol 1609 ◽  
Author(s):  
Ricardo Acosta Ortiz ◽  
Luis Alberto Reyna Medina ◽  
María Lydia Berlanga Duarte ◽  
Aida Esmeralda Garcia Valdez

AbstractIn this work is discussed the synthesis of a novel antishrinking agent (SOC DA) and the evaluation of its performance in an acrylic dental resin. SOC DA was photopolymerized in conjunction with the components of a conventional acrylic resin, which includes a mixture of diacrylate monomers [glycerolate bisphenol A dimethacrylate (BIS-GMA) / Urethane dimethacrylate (UDMA) / triethyleneglycol dimethacrylate (TEGDMA)] in 50/30/20 molar ratio). SOC DA was added in a range between 5.0-20.0 mol % with respect to the total amount of moles of the acrylic monomers. It was found that increasing concentrations of SOC DA, promoted higher conversions of the dimethacrylate monomers without decreasing the photopolymerization rate of the acrylate monomers. The study of the effect of SOC DA on the mechanical properties of the dental composite filled with 70 % of silicon dioxide, revealed that the presence of the antishrinking agent improved both the compressive and the flexural strength of the dental materials. Besides, it was found that by using the SOC DA at 20%, the shrinkage was reduced 52%, compared with the same formulation without SOC DA.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2727
Author(s):  
Agata Szczesio-Wlodarczyk ◽  
Monika Domarecka ◽  
Karolina Kopacz ◽  
Jerzy Sokolowski ◽  
Kinga Bociong

Most of the dental materials available on the market are still based on traditional monomers such as bisphenol A-glycidyl methacrylate (Bis-GMA), urethane dimethacrylate (UDMA), triethyleneglycol dimethacrylate (TEGDMA), and ethoxylated bisphenol-A dimethacrylate (Bis-EMA). The interactions that arise in the monomer mixture and the characteristics of the resulting polymer network are the most important factors, which define the final properties of dental materials. The use of three different monomers in proper proportions may create a strong polymer matrix. In this paper, fourteen resin materials, based on urethane dimethacrylate with different co-monomers such as Bis-GMA or Bis-EMA, were evaluated. TEGDMA was used as the diluting monomer. The flexural strength (FS), diametral tensile strength (DTS), and hardness (HV) were determined. The impacts of material composition on the water absorption and dissolution were evaluated as well. The highest FS was 89.5 MPa, while the lowest was 69.7 MPa. The median DTS for the tested materials was found to range from 20 to 30 MPa. The hardness of the tested materials ranged from 14 to 16 HV. UDMA/TEGDMA matrices were characterized by the highest adsorption values. The overall results indicated that changes in the materials’ properties are not strictly proportional to the material’s compositional changes. The matrices showed good properties when the composite contained an equal mixture of Bis-GMA/Bis-EMA and UDMA or the content of the UDMA monomer was higher.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 470
Author(s):  
Andrea Kowalska ◽  
Jerzy Sokolowski ◽  
Kinga Bociong

The presented paper concerns current knowledge of commercial and alternative photoinitiator systems used in dentistry. It discusses alternative and commercial photoinitiators and focuses on mechanisms of polymerization process, in vitro measurement methods and factors influencing the degree of conversion and hardness of dental resins. PubMed, Academia.edu, Google Scholar, Elsevier, ResearchGate and Mendeley, analysis from 1985 to 2020 were searched electronically with appropriate keywords. Over 60 articles were chosen based on relevance to this review. Dental light-cured composites are the most common filling used in dentistry, but every photoinitiator system requires proper light-curing system with suitable spectrum of light. Alternation of photoinitiator might cause changing the values of biomechanical properties such as: degree of conversion, hardness, biocompatibility. This review contains comparison of biomechanical properties of dental composites including different photosensitizers among other: camphorquinone, phenanthrenequinone, benzophenone and 1-phenyl-1,2 propanedione, trimethylbenzoyl-diphenylphosphine oxide, benzoyl peroxide. The major aim of this article was to point out alternative photoinitiators which would compensate the disadvantages of camphorquinone such as: yellow staining or poor biocompatibility and also would have mechanical properties as satisfactory as camphorquinone. Research showed there is not an adequate photoinitiator which can be as sufficient as camphorquinone (CQ), but alternative photosensitizers like: benzoyl germanium or novel acylphosphine oxide photoinitiators used synergistically with CQ are able to improve aesthetic properties and degree of conversion of dental resin.


2017 ◽  
Vol 752 ◽  
pp. 3-10
Author(s):  
Timea Gherman ◽  
Marioara Moldovan ◽  
Miuţa Filip ◽  
Trifoi Ancuța ◽  
Maria Râpă ◽  
...  

In this study urethane dimethacrylate (UDMA) based dental resin materials were synthesized. Urethane methacrylate oligomers (UDMO) were synthesized via a radical chain growth polymerization mechanism using polyethylene glycol (PEG) in order to improve the mechanical properties, without adding a solvent in the reaction medium. The structure of the new monomer and oligomer were confirmed by FT-IR and 1H-NMR spectra. The results of FT-IR analysis indicated that the addition of PEG as plasticizer in the urethane methacrylate dental material in the adequate molar ratio (isophorone diisocyanate : HEM (2-hydroxyethyl methacrylate) : PEG = 2:2:1) improve the isocyanate double bond consumption. The Elastic strength (MPa) and Young’s Modulus of bending (MPa) were measured using a three-point bending set up. Urethane dimethacrylate monomer without PEG was used as control group. The results showed that PEG containing UDMO resins had lower Young’s Modulus: 2984 MPa and 2537 MPa (for 40s irradiation time) and Elastic strenght: 77 MPa and 51 MPa than UDMA derived resin: 3270 MPa respectively 90 MPa for all irradiation times (20 and 40 seconds).


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 425
Author(s):  
Ericles Otávio Santos ◽  
Pedro Lima Emmerich Oliveira ◽  
Thaís Pereira de Mello ◽  
André Luis Souza dos Santos ◽  
Carlos Nelson Elias ◽  
...  

The wide application of additive manufacturing in dentistry implies the further investigation into oral micro-organism adhesion and biofilm formation on vat-photopolymerization (VP) dental resins. The surface characteristics and microbiological analysis of a VP dental resin, printed at resolutions of 50 μm (EG-50) and 100 μm (EG-100), were evaluated against an auto-polymerizing acrylic resin (CG). Samples were evaluated using a scanning electron microscope, a scanning white-light interferometer, and analyzed for Candida albicans (CA) and Streptococcus mutans (SM) biofilm, as well as antifungal and antimicrobial activity. EG-50 and EG-100 exhibited more irregular surfaces and statistically higher mean (Ra) and root-mean-square (rms) roughness (EG-50-Ra: 2.96 ± 0.32 µm; rms: 4.05 ± 0.43 µm / EG-100-Ra: 3.76 ± 0.58 µm; rms: 4.79 ± 0.74 µm) compared to the CG (Ra: 0.52 ± 0.36 µm; rms: 0.84 ± 0.54 µm) (p < 0.05). The biomass and extracellular matrix production by CA and SM and the metabolic activity of SM were significantly decreased in EG-50 and EG-100 compared to CG (p < 0.05). CA and SM growth was inhibited by the pure unpolymerized VP resin (48 h). EG-50 and EG-100 recorded a greater irregularity, higher surface roughness, and decreased CA and SM biofilm formation over the CG.


2018 ◽  
Vol 19 (11) ◽  
pp. 3443 ◽  
Author(s):  
Mary Melo ◽  
Michael Weir ◽  
Vanara Passos ◽  
Juliana Rolim ◽  
Christopher Lynch ◽  
...  

Cariogenic oral biofilms cause recurrent dental caries around composite restorations, resulting in unprosperous oral health and expensive restorative treatment. Quaternary ammonium monomers that can be copolymerized with dental resin systems have been explored for the modulation of dental plaque biofilm growth over dental composite surfaces. Here, for the first time, we investigated the effect of bis(2-methacryloyloxyethyl) dimethylammonium bromide (QADM) on human overlying mature oral biofilms grown intra-orally in human participants for 7–14 days. Seventeen volunteers wore palatal devices containing composite specimens containing 10% by mass of QADM or a control composite without QADM. After 7 and 14 days, the adherent biofilms were collected to determine bacterial counts via colony-forming unit (CFU) counts. Biofilm viability, chronological changes, and percentage coverage were also determined through live/dead staining. QADM composites caused a significant inhibition of Streptococcus mutans biofilm formation for up to seven days. No difference in the CFU values were found for the 14-day period. Our findings suggest that: (1) QADM composites were successful in inhibiting 1–3-day biofilms in the oral environment in vivo; (2) QADM significantly reduced the portion of the S. mutans group; and (3) stronger antibiofilm activity is required for the control of mature long-term cariogenic biofilms. Contact-killing strategies using dental materials aimed at preventing or at least reducing high numbers of cariogenic bacteria seem to be a promising approach in patients at high risk of the recurrence of dental caries around composites.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 882 ◽  
Author(s):  
Agata Szczesio-Wlodarczyk ◽  
Jerzy Sokolowski ◽  
Joanna Kleczewska ◽  
Kinga Bociong

The paper reviews the environmental factors affecting ageing processes, and the degradation of resins, filler, and the filler-matrix interface. It discusses the current methods of testing materials in vitro. A review of literature was conducted with the main sources being PubMed. ScienceDirect, Mendeley, and Google Scholar were used as other resources. Studies were selected based on relevance, with a preference given to recent research. The ageing process is an inherent element of the use of resin composites in the oral environment, which is very complex and changes dynamically. The hydrolysis of dental resins is accelerated by some substances (enzymes, acids). Bonds formed between coupling agent and inorganic filler are prone to hydrolysis. Methods for prediction of long-term behaviour are not included in composite standards. Given the very complex chemical composition of the oral environment, ageing tests based on water can only provide a limited view of the clinical performance of biomaterial. Systems that can reproduce dynamic changes in stress (thermal cycling, fatigue tests) are better able to mimic clinical conditions and could be extremely valuable in predicting dental composite clinical performance. It is essential to identify procedure to determine the ageing process of dental materials.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1054
Author(s):  
Zbigniew Raszewski ◽  
Danuta Nowakowska ◽  
Wlodzimierz Wieckiewicz ◽  
Agnieszka Nowakowska-Toporowska

Background: Oral hygiene is essential for maintaining residual dentition of partial denture wearers. The dental material should positively affect the oral environment. Fluoride-releasing dental materials help to inhibit microbial colonization and formation of plaque as well as to initiate the remineralization process in the early cavity area. Aim: To evaluate fluoride ion release and recharge capacity, sorption, and solubility of polymethyl methacrylate (PMMA) dental resin modified with bioactive glass addition. Materials and methods: Two bioactive glass materials (5 wt% Kavitan, 10 wt% Kavitan, and 10 wt% Fritex) and pure 10 wt% NaF were added to dental acrylic resin. After polymerization of the modified resins, the release levels of fluoride anions were measured based on color complex formation by using a spectrophotometer after 7, 14, 28, and 35 days of storage in distilled water at 37 °C. Subsequently, specimens were brushed with a fluoride-containing tooth paste on each side for 30 s, and the fluoride recharge and release potential was investigated after 1, 7, and 14 days. Sorption and solubility after 7 days of storage in distilled water was also investigated. Results: The acrylic resins with addition of 10% bioactive glass materials released fluoride ions for over 4 weeks (from 0.14 to 2.27 µg/cm2). The amount of fluoride ions released from the PMMA resin with addition of 10 wt% Fritex glass was higher than that from the resin with addition of 10 wt% Kavitan. The acrylic resin containing 10 wt% NaF released a high amount of ions over a period of 1 week (1.58 µg/cm2), but the amount of released ions decreased rapidly after 14 days of storage. For specimens containing 5 wt% Kavitan glass, the ion-releasing capacity also lasted only for 14 days. Fluoride ion rechargeable properties were observed for the PMMA resin modified with addition of 10 wt% Fritex glass. The ion release levels after recharge ranged from 0.32 to 0.48 µg/cm2. Sorption values ranged from 10.23 μm/mm3 for unmodified PMMA resin to 12.11 μm/mm3 for specimens modified with 10 wt% Kavitan glass. No significant differences were found regarding solubility levels after 7 days. Conclusions: The addition of 10 wt% Fritex and 10 wt% Kavitan bioactive glass materials to heat-cured acrylic resin may improve its material properties, with bioactive fluoride ion release ability lasting for over 4 weeks. The resin modified with 10 wt% Fritex glass could absorb fluoride ions from the toothpaste solution and then effectively release them. Addition of fluoride releasing fillers have a small effect on sorption and solubility increase of the modified PMMA resin. Clinical significance: The addition of bioactive glass may be promising in the development of the novel bioactive heat-cured denture base resin.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1682
Author(s):  
Alexandros K. Nikolaidis ◽  
Elisabeth A. Koulaouzidou ◽  
Christos Gogos ◽  
Dimitris S. Achilias

Diverse approaches dealing with the reinforcement of dental composite resins with quaternary ammonium compounds (QAC) have been previously reported. This work aims to investigate the physicochemical and mechanical performance of dental resins containing silica nanofillers with novel QAC. Different types of quaternary ammonium silane compounds (QASiC) were initially synthesized and characterized with proton nuclear magnetic resonance (1H-NMR) and Fourier transform infrared (FTIR) spectroscopy. Silica nanoparticles were surface modified with the above QASiC and the structure of silanized products (S.QASiC) was confirmed by means of FTIR and thermogravimetric analysis. The obtained S.QASiC were then incorporated into methacrylate based dental resins. Scanning electron microscopy images revealed a satisfactory dispersion of silica nanoclusters for most of the synthesized nanocomposites. Curing kinetics disclosed a rise in both the autoacceleration effect and degree of conversion mainly induced by shorter QASiC molecules. Polymerization shrinkage was found to be influenced by the particular type of S.QASiC. The flexural modulus and strength of composites were increased by 74% and 19%, while their compressive strength enhancement reached up to 19% by adding 22 wt% S.QASiC nanoparticles. These findings might contribute to the proper design of multifunctional dental materials able to meet the contemporary challenges in clinical practice.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1442
Author(s):  
Kumiko Yoshihara ◽  
Noriyuki Nagaoka ◽  
Aya Umeno ◽  
Akinari Sonoda ◽  
Hideki Obika ◽  
...  

Several dental materials contain silver for antibacterial effect, however the effect is relatively low. The reason for the lower antibacterial efficacy of silver is considered to be the fact that silver ions bind to chloride ions in saliva. To develop new effective silver antibacterial agents that can be useful in the mouth, we synthesized two novel amino acid (methionine or histidine)–silver complexes (Met or His–Ag) loaded with montmorillonite (Mont) and analyzed their antibacterial efficacy. At first the complexes were characterized using nuclear magnetic resonance (NMR), and amino acid–Ag complex-loaded Mont (amino acid–Ag–Mont) were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The antibacterial efficacy of these materials in dental acrylic resin was then investigated by bacterial growth measurement using a spectrophotometer. As controls, commercially available silver-loaded zeolite and silver-zirconium phosphate were also tested. Dental acrylic resin incorporating His–Ag–Mont strongly inhibited Streptococcus mutans growth. This was explained by the fact that His-Ag complex revealed the highest amounts of silver ions in the presence of chloride. The structure of the amino acid–Ag complexes affected the silver ion presence in chloride and the antibacterial efficacy. His–Ag–Mont might be used as antibacterial agents for dental materials.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Li Cao ◽  
Junling Wu ◽  
Qiang Zhang ◽  
Bashayer Baras ◽  
Ghalia Bhadila ◽  
...  

Orthodontic treatment is increasingly popular as people worldwide seek esthetics and better quality of life. In orthodontic treatment, complex appliances and retainers are placed in the patients’ mouths for at least one year, which often lead to biofilm plaque accumulation. This in turn increases the caries-inducing bacteria, decreases the pH of the retained plaque on an enamel surface, and causes white spot lesions (WSLs) in enamel. This article reviews the cutting-edge research on a new class of bioactive and therapeutic dental resins, cements, and adhesives that can inhibit biofilms and protect tooth structures. The novel approaches include the use of protein-repellent and anticaries polymeric dental cements containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and dimethylaminododecyl methacrylate (DMAHDM); multifunctional resins that can inhibit enamel demineralization; protein-repellent and self-etching adhesives to greatly reduce oral biofilm growth; and novel polymethyl methacrylate resins to suppress oral biofilms and acid production. These new materials could reduce biofilm attachment, raise local biofilm pH, and facilitate the remineralization to protect the teeth. This novel class of dental resin with dual benefits of antibacterial and protein-repellent capabilities has the potential for a wide range of dental and biomedical applications to inhibit bacterial infection and protect the tissues.


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