Editorial

3 pages, 171 KiB

Open AccessEditorial

Bacterial Interactions with Dental and Medical Materials

by Mary Anne Melo

J. Funct. Biomater. 2020, 11(4), 83; https://doi.org/10.3390/jfb11040083 - 23 Nov 2020

Cited by 4 | Viewed by 1859

Fundamental scientific understanding of oral diseases associated with tissue-contacting dental and medical devices is primordial to facilitate pathways for their translation to clinical use [...] Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

Research

Jump to: Editorial, Review

16 pages, 1380 KiB

Open AccessArticle

Novel Orthodontic Cement Comprising Unique Imidazolium-Based Polymerizable Antibacterial Monomers

by Hui Lu and Xiaoming Jin

J. Funct. Biomater. 2020, 11(4), 75; https://doi.org/10.3390/jfb11040075 - 17 Oct 2020

Cited by 3 | Viewed by 2748

Abstract

White spot lesions (WSLs) can develop quickly and compromise the successful outcome of the orthodontic treatment. Orthodontic bonding cement with the capability to prevent or mitigate WSLs could be beneficial, especially for patients with high risk of caries. This study explored novel mono- [...] Read more.

White spot lesions (WSLs) can develop quickly and compromise the successful outcome of the orthodontic treatment. Orthodontic bonding cement with the capability to prevent or mitigate WSLs could be beneficial, especially for patients with high risk of caries. This study explored novel mono- and di-imidazolium-based polymerizable antibacterial monomers and evaluated orthodontic cement compositions comprising such novel monomers. Their antibacterial potentials, mechanical properties, and shear bond strength (SBS) to bovine enamel were investigated. Statistical tests were applied to SBS and mechanical tests (one-way ANOVA and Tukey’s test). For antibacterial resins C (ABR-C) and E (ABR-E), their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against cariogenic Streptococcus mutans bacterial strain UA159 were found to be 4 μg/mL and 8 μg /mL, respectively. The loss of dry mass from completely demineralized dentin beams in buffer solutions pre-dipped into ABR-C and ABR-E resins is much less than that in control buffer (artificial saliva) only. For unfilled resins comprising up to 12 wt % ABR-C, no significant decreases in flexural strength or modulus were observed. For experimental cements incorporating 1–4 wt % ABR-C, there was no drastic compromise to the SBS to enamel except for 3 wt % ABR-C. Furthermore, their SBS was all comparable to the commercially available orthodontic cements. The ISO-22196 antimicrobial test against S. aureus showed significant levels of antibacterial effects—up to over 5 logs of microorganism reduction exhibited by ABR-C-containing experimental cements. The imidazolium-based polymerizable monomers could be utilized to functionalize orthodontic bonding cement with steady antibacterial activity and develop a potential strategy to counteract WSLs. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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17 pages, 4203 KiB

Open AccessEditor’s ChoiceArticle

Electrospun Scaffolds Containing Silver-Doped Hydroxyapatite with Antimicrobial Properties for Applications in Orthopedic and Dental Bone Surgery

by Thomas E. Paterson, Rui Shi, Jingjing Tian, Caroline J. Harrison, Mailys De Sousa Mendes, Paul V. Hatton, Zhou Li and Ilida Ortega

J. Funct. Biomater. 2020, 11(3), 58; https://doi.org/10.3390/jfb11030058 - 14 Aug 2020

Cited by 27 | Viewed by 3967

Abstract

Preventing the development of osteomyelitis while enhancing bone regeneration is challenging, with relatively little progress to date in translating promising technologies to the clinic. Nanoscale hydroxyapatite (nHA) has been employed as a bone graft substitute, and recent work has shown that it may [...] Read more.

Preventing the development of osteomyelitis while enhancing bone regeneration is challenging, with relatively little progress to date in translating promising technologies to the clinic. Nanoscale hydroxyapatite (nHA) has been employed as a bone graft substitute, and recent work has shown that it may be modified with silver to introduce antimicrobial activity against known pathogens. The aim of this study was to incorporate silver-doped nHA into electrospun scaffolds for applications in bone repair. Silver-doped nHA was produced using a modified, rapid mixing, wet precipitation method at 2, 5, 10 mol.% silver. The silver-doped nHA was added at 20 wt.% to a polycaprolactone solution for electrospinning. Bacteria studies demonstrated reduced bacterial presence, with Escherichia coli and Staphylococcus aureus undetectable after 96 h of exposure. Mesenchymal stem cells (MSCs) were used to study both toxicity and osteogenicity of the scaffolds using PrestoBlue^® and alkaline phosphatase (ALP) assays. Innovative silver nHA scaffolds significantly reduced E. coli and S. aureus bacterial populations while maintaining cytocompatibility with mammalian cells and enhancing the differentiation of MSCs into osteoblasts. It was concluded that silver-doped nHA containing scaffolds have the potential to act as an antimicrobial device while supporting bone tissue healing for applications in orthopedic and dental bone surgery. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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17 pages, 5424 KiB

Open AccessArticle

Novel CaF₂ Nanocomposites with Antibacterial Function and Fluoride and Calcium Ion Release to Inhibit Oral Biofilm and Protect Teeth

by Heba Mitwalli, Abdulrahman A. Balhaddad, Rashed AlSahafi, Thomas W. Oates, Mary Anne S. Melo, Hockin H. K. Xu and Michael D. Weir

J. Funct. Biomater. 2020, 11(3), 56; https://doi.org/10.3390/jfb11030056 - 01 Aug 2020

Cited by 38 | Viewed by 4158

Abstract

(1) Background: The objective of this study was to develop a novel dental nanocomposite containing dimethylaminohexadecyl methacrylate (DMAHDM), 2-methacryloyloxyethyl phosphorylcholine (MPC), and nanoparticles of calcium fluoride (nCaF₂) for preventing recurrent caries via antibacterial, protein repellent and fluoride releasing capabilities. (2) Methods: [...] Read more.

(1) Background: The objective of this study was to develop a novel dental nanocomposite containing dimethylaminohexadecyl methacrylate (DMAHDM), 2-methacryloyloxyethyl phosphorylcholine (MPC), and nanoparticles of calcium fluoride (nCaF₂) for preventing recurrent caries via antibacterial, protein repellent and fluoride releasing capabilities. (2) Methods: Composites were made by adding 3% MPC, 3% DMAHDM and 15% nCaF₂ into bisphenol A glycidyl dimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) (denoted BT). Calcium and fluoride ion releases were evaluated. Biofilms of human saliva were assessed. (3) Results: nCaF₂+DMAHDM+MPC composite had the lowest biofilm colony forming units (CFU) and the greatest ion release; however, its mechanical properties were lower than commercial control composite (p < 0.05). nCaF₂+DMAHDM composite had similarly potent biofilm reduction, with mechanical properties matching commercial control composite (p > 0.05). Fluoride and calcium ion releases from nCaF₂+DMAHDM were much more than commercial composite. Biofilm CFU on composite was reduced by 4 logs (n = 9, p < 0.05). Biofilm metabolic activity and lactic acid were also substantially reduced by nCaF₂+DMAHDM, compared to commercial control composite (p < 0.05). (4) Conclusions: The novel nanocomposite nCaF₂+DMAHDM achieved strong antibacterial and ion release capabilities, without compromising the mechanical properties. This bioactive nanocomposite is promising to reduce biofilm acid production, inhibit recurrent caries, and increase restoration longevity. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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13 pages, 3382 KiB

Open AccessArticle

Effect of Novel Antibacterial Composites on Bacterial Biofilms

by Rayan B. Yaghmoor, Wendy Xia, Paul Ashley, Elaine Allan and Anne M. Young

J. Funct. Biomater. 2020, 11(3), 55; https://doi.org/10.3390/jfb11030055 - 01 Aug 2020

Cited by 18 | Viewed by 3537

Abstract

Continuing cariogenic bacterial growth demineralizing dentine beneath a composite filling is the most common cause of tooth restoration failure. Novel composites with antibacterial polylysine (PLS) (0, 4, 6, or 8 wt%) in its filler phase were therefore produced. Remineralising monocalcium phosphate was also [...] Read more.

Continuing cariogenic bacterial growth demineralizing dentine beneath a composite filling is the most common cause of tooth restoration failure. Novel composites with antibacterial polylysine (PLS) (0, 4, 6, or 8 wt%) in its filler phase were therefore produced. Remineralising monocalcium phosphate was also included at double the PLS weight. Antibacterial studies involved set composite disc placement in 1% sucrose-supplemented broth containing Streptococcus mutans (UA159). Relative surface bacterial biofilm mass (n = 4) after 24 h was determined by crystal violet-binding. Live/dead bacteria and biofilm thickness (n = 3) were assessed using confocal laser scanning microscopy (CLSM). To understand results and model possible in vivo benefits, cumulative PLS release from discs into water (n = 3) was determined by a ninhydrin assay. Results showed biofilm mass and thickness decreased linearly by 28% and 33%, respectively, upon increasing PLS from 0% to 8%. With 4, 6, and 8 wt% PLS, respectively, biofilm dead bacterial percentages and PLS release at 24 h were 20%, 60%, and 80% and 85, 163, and 241 μg/disc. Furthermore, initial PLS release was proportional to the square root of time and levelled after 1, 2, and 3 months at 13%, 28%, and 42%. This suggested diffusion controlled release from water-exposed composite surface layers of 65, 140, and 210 μm thickness, respectively. In conclusion, increasing PLS release initially in any gaps under the restoration to kill residual bacteria or longer-term following composite/tooth interface damage might help prevent recurrent caries. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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10 pages, 2089 KiB

Open AccessArticle

Early Polylysine Release from Dental Composites and Its Effects on Planktonic Streptococcus mutans Growth

by Nikos N. Lygidakis, Elaine Allan, Wendy Xia, Paul F. Ashley and Anne M. Young

J. Funct. Biomater. 2020, 11(3), 53; https://doi.org/10.3390/jfb11030053 - 27 Jul 2020

Cited by 8 | Viewed by 2657

Abstract

The study aim was to assess the effect of incorporating polylysine (PLS) filler at different mass fractions (0.5, 1 and 2 wt%) on PLS release and Streptococcus mutans planktonic growth. Composite containing PLS mass and volume change and PLS release upon water immersion [...] Read more.

The study aim was to assess the effect of incorporating polylysine (PLS) filler at different mass fractions (0.5, 1 and 2 wt%) on PLS release and Streptococcus mutans planktonic growth. Composite containing PLS mass and volume change and PLS release upon water immersion were assessed gravimetrically and via high-performance liquid chromatography (HPLC), respectively. Disc effects on bacterial counts in broth initially containing 8 × 10⁵ versus 8 × 10⁶ CFU/mL Streptococcus mutans UA159 were determined after 24 h. Survival of sedimented bacteria after 72 h was determined following LIVE/DEAD staining of composite surfaces using confocal microscopy. Water sorption-induced mass change at two months increased from 0.7 to 1.7% with increasing PLS concentration. Average volume increases were 2.3% at two months whilst polylysine release levelled at 4% at 3 weeks irrespective of composite PLS level. Early percentage PLS release, however, was faster with higher composite content. With 0.5, 1 and 2% polylysine initially in the composite filler phase, 24-h PLS release into 1 mL of water yielded 8, 25 and 93 ppm respectively. With initial bacterial counts of 8 × 10⁵ CFU/mL, this PLS release reduced 24-h bacterial counts from 10⁹ down to 10⁸, 10⁷ and 10² CFU/mL respectively. With a high initial inoculum, 24-h bacterial counts were 10⁹ with 0, 0.5 or 1% PLS and 10⁷ with 2% PLS. As the PLS composite content was raised, the ratio of dead to live sedimented bacteria increased. The antibacterial action of the experimental composites could reduce residual bacteria remaining following minimally invasive tooth restorations. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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11 pages, 3497 KiB

Open AccessEditor’s ChoiceArticle

Time-Transient Effects of Silver and Copper in the Porous Titanium Dioxide Layer on Antibacterial Properties

by Masaya Shimabukuro, Akari Hiji, Tomoyo Manaka, Kosuke Nozaki, Peng Chen, Maki Ashida, Yusuke Tsutsumi, Akiko Nagai and Takao Hanawa

J. Funct. Biomater. 2020, 11(2), 44; https://doi.org/10.3390/jfb11020044 - 22 Jun 2020

Cited by 18 | Viewed by 3670

Abstract

Recently, silver (Ag) and copper (Cu) have been incorporated into a titanium (Ti) surface to realize their antibacterial property. This study investigated both the durability of the antibacterial effect and the surface change of the Ag- and Cu-incorporated porous titanium dioxide (TiO₂ [...] Read more.

Recently, silver (Ag) and copper (Cu) have been incorporated into a titanium (Ti) surface to realize their antibacterial property. This study investigated both the durability of the antibacterial effect and the surface change of the Ag- and Cu-incorporated porous titanium dioxide (TiO₂) layer. Ag- and Cu-incorporated TiO₂ layers were formed by micro-arc oxidation (MAO) treatment using the electrolyte with Ag and Cu ions. Ag- and Cu-incorporated specimens were incubated in saline during a period of 0–28 days. The changes in both the concentrations and chemical states of the Ag and Cu were characterized using X-ray photoelectron spectroscopy (XPS). The durability of the antibacterial effects against Escherichia coli (E. coli) were evaluated by the international organization for standardization (ISO) method. As a result, the Ag- and Cu-incorporated porous TiO₂ layers were formed on a Ti surface by MAO. The chemical state of Ag changed from Ag₂O to metallic Ag, whilst that of Cu did not change by incubation in saline for up to 28 days. Cu existed as a stable Cu₂O compound in the TiO₂ layer during the 28 days of incubation in saline. The concentrations of Ag and Cu were dramatically decreased by incubation for up to 7 days, and remained a slight amount until 28 days. The antibacterial effect of Ag-incorporated specimens diminished, and that of Cu was maintained even after incubation in saline. Our study suggests the importance of the time-transient effects of Ag and Cu on develop their antibacterial effects. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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19 pages, 5990 KiB

Open AccessArticle

CaSiO₃-HAp Structural Bioceramic by Sol-Gel and SPS-RS Techniques: Bacteria Test Assessment

by Evgeniy Papynov, Oleg Shichalin, Igor Buravlev, Anton Belov, Arseniy Portnyagin, Vitaliy Mayorov, Evgeniy Merkulov, Taisiya Kaidalova, Yulia Skurikhina, Vyacheslav Turkutyukov, Alexander Fedorets and Vladimir Apanasevich

J. Funct. Biomater. 2020, 11(2), 41; https://doi.org/10.3390/jfb11020041 - 12 Jun 2020

Cited by 8 | Viewed by 3375

Abstract

The article presents an original way of getting porous and mechanically strong CaSiO₃-HAp ceramics, which is highly desirable for bone-ceramic implants in bone restoration surgery. The method combines wet and solid-phase approaches of inorganic synthesis: sol-gel (template) technology to produce the [...] Read more.

The article presents an original way of getting porous and mechanically strong CaSiO₃-HAp ceramics, which is highly desirable for bone-ceramic implants in bone restoration surgery. The method combines wet and solid-phase approaches of inorganic synthesis: sol-gel (template) technology to produce the amorphous xonotlite (Ca₆Si₆O₁₇·2OH) as the raw material, followed by its spark plasma sintering–reactive synthesis (SPS-RS) into ceramics. Formation of both crystalline wollastonite (CaSiO₃) and hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂) occurs “in situ” under SPS conditions, which is the main novelty of the method, due to combining the solid-phase transitions of the amorphous xonotlite with the chemical reaction within the powder mixture between CaO and CaHPO₄. Formation of pristine HAp and its composite derivative with wollastonite was studied by means of TGA and XRD with the temperatures of the “in situ” interactions also determined. A facile route to tailor a macroporous structure is suggested, with polymer (siloxane-acrylate latex) and carbon (fibers and powder) fillers being used as the pore-forming templates. Microbial tests were carried out to reveal the morphological features of the bacterial film Pseudomonas aeruginosa that formed on the surface of the ceramics, depending on the content of HAp (0, 20, and 50 wt%). Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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11 pages, 4239 KiB

Open AccessArticle

In Vitro Study on the Effect of a New Bioactive Desensitizer on Dentin Tubule Sealing and Bonding

by Minh N. Luong, Laurie Huang, Daniel C. N. Chan and Alireza Sadr

J. Funct. Biomater. 2020, 11(2), 38; https://doi.org/10.3390/jfb11020038 - 02 Jun 2020

Cited by 7 | Viewed by 4428

Abstract

Bioactive mineral-based dentin desensitizers that can quickly and effectively seal dentinal tubules and promote dentin mineralization are desired. This in vitro study evaluated a novel nanohydroxyapatite-based desensitizer, Predicta (PBD, Parkell), and its effect on bond strength of dental adhesives. Human dentin discs (2-mm [...] Read more.

Bioactive mineral-based dentin desensitizers that can quickly and effectively seal dentinal tubules and promote dentin mineralization are desired. This in vitro study evaluated a novel nanohydroxyapatite-based desensitizer, Predicta (PBD, Parkell), and its effect on bond strength of dental adhesives. Human dentin discs (2-mm thick) were subjected to 0.5 M EDTA to remove the smear layer and expose tubules, treated with PBD, and processed for surface and cross-sectional SEM examination before and after immersion in simulated body fluid (SBF) for four weeks (ISO 23317-2014). The effects of two dental desensitizers on the microshear bond strength of a universal adhesive and a two-step self-etch system were compared. SEM showed coverage and penetration of nanoparticles in wide tubules on the PBD-treated dentin at the baseline. After four weeks in SBF, untreated dentin showed amorphous mineral deposits while PBD-treated dentin disclosed a highly mineralized structure integrated with dentin. Desensitizers significantly reduced microshear bond strength test (MSBS) of adhesives by 15–20% on average, depending on the bonding protocol. In conclusion, PBD demonstrated effective immediate tubules sealing capability and promoted mineral crystal growth over dentin and into the tubules during SBF-storage. For bonding to desensitizer-treated dentin, a two-step self-etching adhesive or universal bond with phosphoric acid pretreatment are recommended. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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10 pages, 2998 KiB

Open AccessCommunication

Towards the Development of a Novel Ex Ovo Model of Infection to Pre-Screen Biomaterials Intended for Treating Chronic Wounds

by Elena García-Gareta, Justyna Binkowska, Nupur Kohli and Vaibhav Sharma

J. Funct. Biomater. 2020, 11(2), 37; https://doi.org/10.3390/jfb11020037 - 02 Jun 2020

Cited by 8 | Viewed by 3565

Abstract

This communication reports preliminary data towards the development of a live ex vivo model of persistent infection that is based on the chick embryo chorioallantoic membrane (CAM), which can be used for pre-screening biomaterials with antimicrobial properties for their antimicrobial and angiogenic potential. [...] Read more.

This communication reports preliminary data towards the development of a live ex vivo model of persistent infection that is based on the chick embryo chorioallantoic membrane (CAM), which can be used for pre-screening biomaterials with antimicrobial properties for their antimicrobial and angiogenic potential. Our results showed that it was possible to infect chicken embryos with Staphylococcus aureus, one of the main types of bacteria found in the persistent infection associated with chronic wounds, and maintain the embryos’ survival for up to 48 h. Survival of the embryos varied with the dose of bacteria inoculum and with the use and time of streptomycin application after infection. In infected yet viable embryos, the blood vessels network of the CAM was maintained with minimal disruption. Microbiological tests could confirm embryo infection, but quantification was difficult. By publishing these preliminary results, we hope that not only our group but others within the scientific community further this research towards the establishment of biomimetic and reproducible ex vivo models of persistent infection. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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17 pages, 3556 KiB

Open AccessArticle

Substituted Nano-Hydroxyapatite Toothpastes Reduce Biofilm Formation on Enamel and Resin-Based Composite Surfaces

by Andrei C. Ionescu, Gloria Cazzaniga, Marco Ottobelli, Franklin Garcia-Godoy and Eugenio Brambilla

J. Funct. Biomater. 2020, 11(2), 36; https://doi.org/10.3390/jfb11020036 - 01 Jun 2020

Cited by 22 | Viewed by 4478

Abstract

Background: Toothpastes containing nano-hydroxyapatite (n-HAp) substituted with metal ions provide calcium and phosphate ions to dental hard tissues, reducing demineralization, and promoting remineralization. Few data are available about the effect of these bioactive compounds on oral microbiota. Methods: This in vitro [...] Read more.

Background: Toothpastes containing nano-hydroxyapatite (n-HAp) substituted with metal ions provide calcium and phosphate ions to dental hard tissues, reducing demineralization, and promoting remineralization. Few data are available about the effect of these bioactive compounds on oral microbiota. Methods: This in vitro study evaluated the influence of two commercially-available substituted n-HAp-based toothpastes (α: Zn-carbonate substituted n-HAp; β: F, Mg, Sr-carbonate substituted n-HAp) on early colonization (EC, 12 h) and biofilm formation (BF, 24 h) by oral microbiota. Controls were brushed with distilled water. Artificial oral microcosm and Streptococcus mutans biofilms were developed using human enamel and a resin-based composite (RBC) as adherence surfaces. Two test setups, a shaking multiwell plate and a modified drip-flow reactor (MDFR), were used to simulate clinical conditions during the night (low salivary flow and clearance) and daytime, respectively. Energy-dispersive X-ray spectrometry (EDS) was used to evaluate specimens’ surfaces after toothpaste treatment. Fluoride release from β toothpaste was evaluated. Viable adherent biomass was quantified by MTT assay, and biofilms’ morphology was highlighted using confocal microscopy. Results: EDS showed the presence of remnants from the tested toothpastes on both adherence surfaces. β toothpaste showed significantly lower EC and BF compared to control using the artificial oral microcosm model, while α toothpaste showed lower EC and BF compared to control, but higher EC and BF compared to β toothpaste. The effect shown by β toothpaste was, to a minimal extent, due to fluoride release. Interestingly, this result was seen on both adherence surfaces, meaning that the tested toothpastes significantly influenced EC and BF even on RBC surfaces. Furthermore, the effect of toothpaste treatments was higher after 12 h than 24 h, suggesting that toothbrushing twice a day is more effective than brushing once. Conclusions: The efficacy of these treatments in reducing microbial colonization of RBC surfaces may represent a promising possibility in the prevention of secondary caries. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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13 pages, 6437 KiB

Open AccessArticle

Anti-Bacterial Properties and Biocompatibility of Novel SiC Coating for Dental Ceramic

by Samira Esteves Afonso Camargo, Azeem S. Mohiuddeen, Chaker Fares, Jessica L. Partain, Patrick H. Carey IV, Fan Ren, Shu-Min Hsu, Arthur E. Clark and Josephine F. Esquivel-Upshaw

J. Funct. Biomater. 2020, 11(2), 33; https://doi.org/10.3390/jfb11020033 - 20 May 2020

Cited by 21 | Viewed by 4645

Abstract

A 200 nm plasma-enhanced chemical vapor-deposited SiC was used as a coating on dental ceramics to improve anti-bacterial properties for the applications of dental prosthesis. A thin SiO₂ (20 nm) in the same system was deposited first, prior to SiC deposition, to [...] Read more.

A 200 nm plasma-enhanced chemical vapor-deposited SiC was used as a coating on dental ceramics to improve anti-bacterial properties for the applications of dental prosthesis. A thin SiO₂ (20 nm) in the same system was deposited first, prior to SiC deposition, to improve the adhesion between SiC to dental ceramic. Silane and methane were the precursors for SiC deposition, and the SiO₂ deposition employed silane and nitrous oxide as the precursors. SiC antimicrobial activity was evaluated on the proliferation of biofilm, Streptococcus sanguinis, and Streptococcus mutans on SiC-coated and uncoated dental ceramics for 24 h. The ceramic coating with SiC exhibited a biofilm coverage of 16.9%, whereas uncoated samples demonstrated a significantly higher biofilm coverage of 91.8%, measured with fluorescence and scanning electron microscopic images. The cytotoxicity of the SiC coating was evaluated using human periodontal ligament fibroblasts (HPdLF) by CellTiter-BlueCell viability assay. After 24 h of HPdLF cultivation, no obvious cytotoxicity was observed on the SiC coating and control group; both sets of samples exhibited similar cell adhesion and proliferation. SiC coating on a ceramic demonstrated antimicrobial activity without inducing cytotoxic effects. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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13 pages, 2231 KiB

Open AccessArticle

Myristyltrimethylammonium Bromide (MYTAB) as a Cationic Surface Agent to Inhibit Streptococcus mutans Grown over Dental Resins: An In Vitro Study

by Paola Andrea Mena Silva, Isadora Martini Garcia, Julia Nunes, Fernanda Visioli, Vicente Castelo Branco Leitune, Mary Anne Melo and Fabrício Mezzomo Collares

J. Funct. Biomater. 2020, 11(1), 9; https://doi.org/10.3390/jfb11010009 - 15 Feb 2020

Cited by 16 | Viewed by 4460

Abstract

This in vitro study evaluated the effect of myristyltrimethylammonium bromide (MYTAB) on the physical, chemical, and biological properties of an experimental dental resin. The resin was formulated with dental dimetacrylate monomers and a photoinitiator/co-initiator system. MYTAB was added at 0.5 (G_0.5%), [...] Read more.

This in vitro study evaluated the effect of myristyltrimethylammonium bromide (MYTAB) on the physical, chemical, and biological properties of an experimental dental resin. The resin was formulated with dental dimetacrylate monomers and a photoinitiator/co-initiator system. MYTAB was added at 0.5 (G_0.5%), 1 (G_1%), and 2 (G_2%) wt %, and one group remained without MYTAB and was used as the control (G_Ctrl). The resins were analyzed for the polymerization kinetics, degree of conversion, ultimate tensile strength (UTS), antibacterial activity against Streptococcus mutans, and cytotoxicity against human keratinocytes. Changes in the polymerization kinetics profiling were observed, and the degree of conversion ranged from 57.36% (±2.50%) for G_2% to 61.88% (±1.91%) for G_0.5%, without a statistically significant difference among groups (p > 0.05). The UTS values ranged from 32.85 (±6.08) MPa for G_0.5% to 35.12 (±5.74) MPa for G_Ctrl (p > 0.05). MYTAB groups showed antibacterial activity against biofilm formation from 0.5 wt % (p < 0.05) and against planktonic bacteria from 1 wt % (p < 0.05). The higher the MYTAB concentration, the higher the cytotoxic effect, without differences between G_Ctrl e G_0.5% (p > 0.05). In conclusion, the addition of 0.5 wt % of MYTAB did not alter the physical and chemical properties of the dental resin and provided antibacterial activity without cytotoxic effect. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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9 pages, 1869 KiB

Open AccessArticle

Cerium Dioxide Particles to Tune Radiopacity of Dental Adhesives: Microstructural and Physico-Chemical Evaluation

by Isadora Martini Garcia, Vicente Castelo Branco Leitune, Antonio Shigueaki Takimi, Carlos Pérez Bergmann, Susana Maria Werner Samuel, Mary Anne Melo and Fabrício Mezzomo Collares

J. Funct. Biomater. 2020, 11(1), 7; https://doi.org/10.3390/jfb11010007 - 11 Feb 2020

Cited by 13 | Viewed by 4281

Abstract

The insufficient radiopacity of dental adhesives applied under composite restorations makes the radiographic diagnosis of recurrent caries challenging. Consequently, the misdiagnosis may lead to unnecessary replacement of restorations. The aims of this study were to formulate experimental dental adhesives containing cerium dioxide (CeO [...] Read more.

The insufficient radiopacity of dental adhesives applied under composite restorations makes the radiographic diagnosis of recurrent caries challenging. Consequently, the misdiagnosis may lead to unnecessary replacement of restorations. The aims of this study were to formulate experimental dental adhesives containing cerium dioxide (CeO₂) and investigate the effects of different loadings of CeO₂ on their radiopacity and degree of conversion for the first time. CeO₂ was characterized by X-ray diffraction analysis, Fourier transforms infrared spectroscopy, and laser diffraction for particle size analysis. Experimental dental adhesives were formulated with CeO₂ as the inorganic filler with loadings ranging from 0.36 to 5.76 vol.%. The unfilled adhesive was used as a control. The studied adhesives were evaluated for dispersion of CeO₂ in the polymerized samples_, degree of conversion, and radiopacity. CeO₂ presented a monoclinic crystalline phase, peaks related to Ce-O bonding, and an average particle size of around 16 µm. CeO₂ was dispersed in the adhesive, and the addition of these particles increased the adhesives’ radiopacity (p < 0.05). There was a significant decrease in the degree of conversion with CeO₂ loadings higher than 1.44 vol.%. However, all materials showed a similar degree of conversion in comparison to commercially available adhesives. CeO₂ particles were investigated for the first time as a promising compound to improve the radiopacity of the dental adhesives. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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17 pages, 3720 KiB

Open AccessArticle

Physicochemical, Mechanical, and Antimicrobial Properties of Novel Dental Polymers Containing Quaternary Ammonium and Trimethoxysilyl Functionalities

by Diane R. Bienek, Anthony A. Giuseppetti, Stanislav A. Frukhtbeyn, Rochelle D. Hiers, Fernando L. Esteban Florez, Sharukh S. Khajotia and Drago Skrtic

J. Funct. Biomater. 2020, 11(1), 1; https://doi.org/10.3390/jfb11010001 - 18 Dec 2019

Cited by 4 | Viewed by 4405

Abstract

The aims of this study were to evaluate the physicochemical and mechanical properties, antimicrobial (AM) functionality, and cytotoxic potential of novel dental polymers containing quaternary ammonium and trimethoxysilyl functionalities (e.g., N-(2-(methacryloyloxy)ethyl)-N,N-dimethyl-3-(trimethoxysilyl)propan-1-aminium iodide (AM_sil1) and N-(2-(methacryloyloxy)ethyl)-N, [...] Read more.

The aims of this study were to evaluate the physicochemical and mechanical properties, antimicrobial (AM) functionality, and cytotoxic potential of novel dental polymers containing quaternary ammonium and trimethoxysilyl functionalities (e.g., N-(2-(methacryloyloxy)ethyl)-N,N-dimethyl-3-(trimethoxysilyl)propan-1-aminium iodide (AM_sil1) and N-(2-(methacryloyloxy)ethyl)-N,N-dimethyl-11-(trimethoxysilyl)undecan-1-aminium bromide (AM_sil2)). AM_sil1 or AM_sil2 were incorporated into light-cured (camphorquinone + ethyl-4-N,N-dimethylamino benzoate) urethane dimethacrylate (UDMA)/polyethylene glycol-extended UDMA/ethyl 2-(hydroxymethyl)acrylate (EHMA) resins (hereafter, UPE resin) at 10 or 20 mass %. Cytotoxic potential was assessed by measuring viability and metabolic activity of immortalized mouse connective tissue and human gingival fibroblasts in direct contact with monomers. AM_sil–UPE resins were evaluated for wettability by contact angle measurements and degree of vinyl conversion (DVC) by near infra-red spectroscopy analyses. Mechanical property evaluations entailed flexural strength (FS) and elastic modulus (E) testing of copolymer specimens. The AM properties were assessed using Streptococcus mutans (planktonic and biofilm forms) and Porphyromonas gingivalis biofilm. Neither AM_sil exhibited significant toxicity in direct contact with cells at biologically relevant concentrations. Addition of AM_sils made the UPE resin more hydrophilic. DVC values for the AM_sil–UPE copolymers were 2–31% lower than that attained in the UPE resin control. The mechanical properties (FS and E) of AM_sil–UPE specimens were reduced (11–57%) compared to the control. Compared to UPE resin, AM_sil1–UPE and AM_sil2–UPE (10% mass) copolymers reduced S. mutans biofilm 4.7- and 1.7-fold, respectively (p ≤ 0.005). Although not statistically different, P. gingivalis biofilm biomass on AM_sil1–UPE and AM AM_sil2–UPE copolymer disks were lower (71% and 85%, respectively) than that observed with a commercial AM dental material. In conclusion, the AM function of new monomers is not inundated by their toxicity towards cells. Despite the reduction in mechanical properties of the AM_sil–UPE copolymers, AM_sil2 is a good candidate for incorporation into multifunctional composites due to the favorable overall hydrophilicity of the resins and the satisfactory DVC values attained upon light polymerization of AM_sil-containing UDMA/PEG-U/EHMA copolymers. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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16 pages, 1845 KiB

Open AccessFeature PaperArticle

Understanding the Role of Shape and Composition of Star-Shaped Polymers and their Ability to Both Bind and Prevent Bacteria Attachment on Oral Relevant Surfaces

by Hamid Mortazavian, Guillaume A. Picquet, Jānis Lejnieks, Lynette A. Zaidel, Carl P. Myers and Kenichi Kuroda

J. Funct. Biomater. 2019, 10(4), 56; https://doi.org/10.3390/jfb10040056 - 17 Dec 2019

Cited by 9 | Viewed by 4880

Abstract

In this study, we have prepared a series of 4- and 6-arm star-shaped polymers with varying molecular weight and hydrophobicity in order to provide insight into the role and relationship that shape and composition have on the binding and protecting of oral relevant [...] Read more.

In this study, we have prepared a series of 4- and 6-arm star-shaped polymers with varying molecular weight and hydrophobicity in order to provide insight into the role and relationship that shape and composition have on the binding and protecting of oral relevant surfaces (hydroxyapatite, HAP) from bacteria colonization. Star-shaped acrylic acid polymers were prepared by free-radical polymerization in the presence of chain transfer agents with thiol groups, and their binding to the HAP surfaces and subsequent bacteria repulsion was measured. We observed that binding was dependent on both polymer shape and hydrophobicity (star vs. linear), but their relative efficacy to reduce oral bacteria attachment from surfaces was dependent on their hydrophobicity only. We further measured the macroscopic effects of these materials to modify the mucin-coated HAP surfaces through contact angle experiments; the degree of angle change was dependent on the relative hydrophobicity of the materials suggesting future in vivo efficacy. The results from this study highlight that star-shaped polymers represent a new material platform for the development of dental applications to control bacterial adhesion which can lead to tooth decay, with various compositional and structural aspects of materials being vital to effectively design oral care products. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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Review

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13 pages, 1209 KiB

Open AccessReview

Use of Protein Repellents to Enhance the Antimicrobial Functionality of Quaternary Ammonium Containing Dental Materials

by Leopoldo Torres Jr and Diane R. Bienek

J. Funct. Biomater. 2020, 11(3), 54; https://doi.org/10.3390/jfb11030054 - 01 Aug 2020

Cited by 5 | Viewed by 4835

Abstract

An advancement in preventing secondary caries has been the incorporation of quaternary ammonium containing (QAC) compounds into a composite resin mixture. The permanent positive charge on the monomers allows for electrostatic-based killing of bacteria. Spontaneous adsorption of salivary proteins onto restorations dampens the [...] Read more.

An advancement in preventing secondary caries has been the incorporation of quaternary ammonium containing (QAC) compounds into a composite resin mixture. The permanent positive charge on the monomers allows for electrostatic-based killing of bacteria. Spontaneous adsorption of salivary proteins onto restorations dampens the antimicrobial capabilities of QAC compounds. Protein-repellent monomers can work with QAC restorations to achieve the technology’s full potential. We discuss the theory behind macromolecular adsorption, direct and indirect characterization methods, and advances of protein repellent dental materials. The translation of protein adsorption to microbial colonization is covered, and the concerns and fallbacks of the state-of-the-art protein-resistant monomers are addressed. Last, we present new and exciting avenues for protein repellent monomer design that have yet to be explored in dental materials. Full article

(This article belongs to the Special Issue Bacterial Interactions with Dental and Medical Materials)

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