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1.
J Dent ; 93: 103278, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31945398

RESUMO

OBJECTIVE: Composite restorations are increasingly popular, but recurrent caries is a main reason for composite restoration failures. The objectives of this study were to investigate a dual strategy of combining rnc gene-deletion for Streptococcus mutans (S. mutans) with antibacterial dimethylaminohexadecyl methacrylate (DMAHDM) composite, and determine the effects of rnc gene-deletion alone, DMAHDM composite alone, and rnc-deletion plus DMAHDM composite, on biofilm growth and lactic acid production. METHODS: Parent S. mutans (UA159, ATCC 700610) and rnc-deleted S. mutans were used. DMAHDM was incorporated into a composite at mass fractions of 0%, 1.5%, and 3%. Gene expressions for biofilm formation and drug resistance were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). Biofilms were grown on composite surfaces for 2 days. Live/dead, biomass, polysaccharide, metabolic activity (MTT), colony-forming units (CFU) and lactic acid production of biofilms were evaluated. RESULTS: Compared to the parent S. mutans, the rnc-deletion technique yielded significantly less biofilm biomass, polysaccharides, metabolic activity, CFU, and lactic acid for biofilms grown on control composite (p <  0.05). With no gene modification, the biofilm CFU was decreased by 5-6 logs at 3% DMAHDM, when compared to control composite group. The dual strategy of combining rnc-deletion with 3% DMAHDM composite achieved the strongest biofilm-inhibition, with the greatest reduction in CFU by 8 logs. The combination of rnc-deletion with 3% DMAHDM composite decreased the biofilm lactic acid production by 95% (p <  0.05). CONCLUSIONS: The dual strategy of rnc-deletion plus DMAHDM composite produced synergistic effects and achieved the strongest biofilm-inhibition. This method has great potential to inhibit dental caries and is promising to reduce secondary caries and protect tooth structures.

2.
Acta Biomater ; 101: 128-140, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31629895

RESUMO

Infection is a main cause of implant failure. Early implant-related infections often occur in the first 4 weeks post-operation. Inhibiting bacterial adhesion and biofilm formation at the early stage and promoting subsequent implant osseointegration are important for implant success. Our previous studies demonstrated that dimethylaminododecyl methacrylate (DMADDM) provided dental materials with antibacterial effects. In the present study, DMADDM and hydroxyapatite (HA) are loaded on to the titanium (Ti) surface via poly dopamine (PDA) self-polymerization. This local DMADDM-delivery Ti is referred as Ti-PHD. Here we report the two-staged capability of Ti-PHD: (1) in the first stage, releasing DMADDM during the high-infection-risk initial period post-implantation for 4 weeks; (2) then in the second stage, enhancing osteogenesis and promoting osseointegration. Ti-PHD has a porous surface with higher average roughness and greater hydrophilicity than pure Ti. Its biocompatibility is verified in vitro and in vivo. During the first 4 weeks of release, both DMADDM remaining on Ti surface and DMADDM released into the soaking medium greatly reduced the adherence and growth of pathogens. This is further confirmed by the prevention of bone destruction in a rat osteomyelitis model. After releasing DMADDM for 4 weeks, Ti-PHD promotes osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) and new bone formation around the implants in vivo. This article represents the first report on the two-staged, time-dependent antibacterial and osteogenesis effects of Ti-PHD, demonstrating its potential for clinical applications to inhibit implant-associated infections. STATEMENT OF SIGNIFICANCE: The present study develops a two-staged time-dependent system for local dimethylaminododecyl methacrylate (DMADDM) delivery via Ti implant (referred to as Ti-PHD). DMADDM and hydroxyapatite (HA) are loaded on to the Ti surface with poly dopamine (PDA). Ti-PHD can release DMADDM during the high-risk period of infection in the first stage, and then promote osseointegration and new bone formation in the second stage. This bioactive and therapeutic Ti is promising to inhibit infections and enhance implant success.

3.
J Dent ; 92: 103259, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31809792

RESUMO

OBJECTIVE: Human periodontal ligament stem cells (hPDLSCs) are promising for periodontal regeneration. However, to date, there has been no report of hPDLSC differentiation into the fibrogenic lineage. There has been no report demonstrating hPDLSC differentiation into all three (osteogenic, fibrogenic and cementogenic fibrogenic) lineages in the same report. The objectives of this study were to harvest hPDLSCs from the periodontal ligaments (PDL) of the extracted human teeth, and use the same vial of hPDLSCs to differentiate into all three (osteogenic, fibrogenic and cementogenic) lineages for the first time. METHODS: hPDLSCs were harvested from PDL tissues of the extracted premolars. The ability of hPDLSCs to form bone, cementum and collagen fibers was tested in culture mediums. Gene expressions were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR). Immunofluorescence, alizarin red (ARS), Xylenol orange, picro sirius red staining (PSRS), alcian blue staining (ABS) and alkaline phosphatase (ALP) staining were evaluated. RESULTS: In osteogenic medium, hPDLSCs had high expressions of osteogenic genes (RUNX2, ALP, OPN and COL1) at 14 and 21 days (15-20 folds of that of control), and produced mineral nodules and ALP activity (5 and 10 folds those of the control). hPDLSCs in fibrogenic medium expressed high levels of PDL fibrogenic genes (COL1, COL3, FSP-1, PLAP-1 and Elastin) at 28 days (20-70 folds of control). They were stained strongly with F-actin and fibronection, and secreted PDL collagen fibers (5 folds of control). hPDLSCs in cementogenic medium showed high expressions of cementum genes (CAP, CEMP1 and BSP) at 21 days (10-15 folds of control) and synthesized mineralized cementum (50 folds via ABS, and 40 folds via ALP staining, compared to those of control). CONCLUSIONS: hPDLSCs differentiated into bone-, fiber- and cementum-forming cells, with potential for regeneration of periodontium to form the bone-PDL-cementum complex.

4.
J Dent ; 92: 103262, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31837358

RESUMO

OBJECTIVES: The objective of this study was to investigate enamel remineralization using salivary statherin protein-inspired poly(amidoamine) dendrimer (SN15-PAMAM) and adhesive containing nanoparticles of amorphous calcium phosphate (NACP) in a cyclic artificial saliva/demineralizing solution for the first time. METHODS: The enamel shear bond strengths of NACP adhesives were measured compared to commercial adhesive (Scotchbond Multi-Purpose, 3 M). Adhesive disks containing NACP were tested for calcium (Ca) and phosphorus (P) ions release. Four groups were tested: (1) enamel control, (2) enamel with NACP, (3) enamel with SN15-PAMAM, and (4) enamel with SN15-PAMAM + NACP. The specimens were treated with cyclic artificial saliva/demineralizing solution for 28 days. The remineralized enamel specimens were examined by surface and cross-sectional hardness test. RESULTS: NACP adhesive yielded a similar shear bond strength to commercial control (Scotchbond Multi-Purpose, 3 M). NACP adhesive released high levels of Ca and P ions. At 28 days, the enamel hardness of SN15-PAMAM + NACP group was 2.89 ± 0.13 GPa, significantly higher than that of control group (1.46 ± 0.10 GPa) (p < 0.05). SN15-PAMAM + NACP increased the enamel cross-sectional hardness at 28 days; at 25 µm, enamel cross-sectional hardness was 90 % higher than that of control group (p < 0.05). SIGNIFICANCE: The novel SN15-PAMAM + NACP adhesive method could achieve 90 % higher enamel remineralization of the artificial caries than the control under acid challenge for the first time. This method is promising for use after tooth cavity preparation, or as a coating on enamel with white spot lesions (WSLs) for prevention, to reduce secondary caries, prevent caries procession and protect tooth structures.

5.
Dent Mater ; 36(2): 296-309, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31839202

RESUMO

OBJECTIVES: Antibacterial quaternary ammonium monomers (QAMs) are used in resins. The rnc gene in Streptococcus mutans (S. mutans) plays a key role in resisting antibiotics. The objectives of this study were to investigate for the first time: (1) the effects of rnc deletion on S. mutans biofilms and acid production; (2) the combined effects of rnc deletion with dimethylaminohexadecyl methacrylate (DMAHDM) on biofilm-inhibition efficacy. METHODS: Parent S. mutans strain UA159 (ATCC 700610) and the rnc-deleted S. mutans were used. Bacterial growth, minimum inhibitory concentration (MIC), and minimal bactericidal concentration (MBC) were measured to analyze the bacterial susceptibility of the parent and rnc-deleted S. mutans against DMAHDM, with the gold-standard chlorhexidine (CHX) as control. Biofilm biomass, polysaccharide and lactic acid production were measured. RESULTS: The drug-susceptibility of the rnc-deleted S. mutans to DMAHDM or CHX was 2-fold higher than parent S. mutans. The drug-susceptibility did not increase after 10 passages (p < 0.05). Deleting the rnc gene increased the biofilm susceptibility to DMAHDM or CHX by 2-fold. The rnc-deletion in S. mutans reduced biofilm biomass, polysaccharide and lactic acid production, even at no drugs. DMAHDM was nearly 40 % more potent than the gold-standard CHX. The combination of rnc deletion+DMAHDM treatment achieved the greatest reduction in biofilm biomass, polysaccharide synthesis, and lactic acid production. SIGNIFICANCE: Gene modification by deleting the rnc in S. mutans reduced the biofilm growth and acid production, and the rnc deletion+DMAHDM method showed the greatest biofilm-inhibition efficacy, for the first time. The dual strategy of antibacterial monomer+bacterial gene modification shows great potential to control biofilms and inhibit caries.

6.
Int J Nanomedicine ; 14: 6937-6956, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695368

RESUMO

Oral diseases such as tooth caries, periodontal diseases, endodontic infections, etc., are prevalent worldwide. The heavy burden of oral infectious diseases and their consequences on the patients' quality of life indicates a strong need for developing effective therapies. Advanced understandings of such oral diseases, e.g., inflammatory periodontal lesions, have raised the demand for antibacterial therapeutic strategies, because these diseases are caused by viruses and bacteria. The application of antimicrobial photodynamic therapy (aPDT) on oral infectious diseases has attracted tremendous interest in the past decade. However, aPDT had a minimal effect on the viability of organized biofilms due to the hydrophobic nature of the majority of the photosensitizers (PSs). Therefore, novel nanotechnologies were rapidly developed to target the delivery of hydrophobic PSs into microorganisms for the antimicrobial performance improvement of aPDT. This review focuses on the state-of-the-art of nanomaterials applications in aPDT against oral infectious diseases. The first part of this article focuses on the cutting-edge research on the synthesis, toxicity, and therapeutic effects of various forms of nanomaterials serving as PS carriers for aPDT applications. The second part discusses nanomaterials applications for aPDT in treatments of oral diseases. These novel bioactive nanomaterials have demonstrated great potential to serve as carriers for PSs to substantially enhance the PDT therapeutic effects. Furthermore, the novel aPDT applications not only have exciting therapeutic potential to inhibit bacterial plaque-initiated oral diseases, but also have a wide applicability to other biomedical and tissue engineering applications.


Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/tratamento farmacológico , Biofilmes/efeitos dos fármacos , Boca/microbiologia , Nanoestruturas/química , Fotoquimioterapia , Antibacterianos/farmacologia , Humanos
7.
J Dent ; 91: 103220, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31678476

RESUMO

OBJECTIVES: (1) develop a CPC-metformin scaffold with hPDLSC seeding for bone tissue engineering; and (2) investigate the effects of CPC-metformin scaffold on hPDLSC proliferation, osteogenic differentiation and bone matrix mineralization for the first time. METHODS: hPDLSCs were harvested from extracted teeth. CPC scaffolds (with or without metformin) were prepared. Three groups were tested: (1) control group (growth medium); (2) osteogenic group (osteogenic medium); (3) metformin + osteogenic group (CPC-metformin scaffold, cultured in osteogenic medium). hPDLSC viability, osteogenic differentiation and mineralization were measured. SEM was used to examine cell morphology. RESULTS: After culturing for 14 days, all three groups demonstrated excellent hPDLSC attachment and viability, as shown in live-dead staining, CCK-8 assay, and SEM examinations. The osteogenic group had 3-8 folds, 5 folds and 6 folds of increases in osteogenic gene expressions, ALP activity and mineral synthesis, compared to control group. Furthermore, the metformin + osteogenic group had 3-fold to 4-fold increases over those of the osteogenic group in osteogenic gene expressions, ALP activity and mineral synthesis. CONCLUSIONS: hPDLSCs were demonstrated to be a potent cell source for bone engineering. The novel CPC-metformin-hPDLSC construct is highly promising to enhance bone repair and regeneration efficacy in dental, craniofacial and orthopedic applications.

8.
J Dent ; 90: 103214, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31629031

RESUMO

OBJECTIVES: Fluoride-containing orthodontic cements are used to combat white spot lesions (WSLs) in enamel. However, the fluoride (F) ion releases from these cements are relatively low and short-term. The objectives of this study were to develop a novel rechargeable orthodontic cement with nanoparticles of calcium fluoride (nCaF2) to provide long-term and high levels of F release, and to investigate F recharge and physical and cytotoxic properties. METHODS: The nCaF2 with a mean particle size of 58 nm were synthesized using a spray-drying method. Pyromellitic glycerol dimethacrylate (PMGDM), ethoxylated bisphenol A dimethacrylate (EBPADMA), 2-hydroxyethyl methacrylate (HEMA) and bisphenol A glycidyl dimethacrylate (BisGMA) were used to prepare the cements (denoted PE and PEHB resins). A resin-modified glass ionomer (RMGI) served as control. Enamel shear bond strength (SBS), cytotoxicity, and F ion recharge and re-release were evaluated. RESULTS: nCaF2 cements had good SBS and excellent biocompatibility that were comparable to RMGI (p > 0.1). After a recharge for 1 min, the F re-release from PEHB + 30%nCaF2 cement was 80% higher than RMGI (p < 0.05). Increasing nCaF2 content from 20% to 30% greatly increased the F ion re-release (p < 0.05). The F ion re-release of nCaF2 cements did not decrease with increasing the number of recharge and re-release cycles (p > 0.1). CONCLUSIONS: A novel F ion-rechargeable orthodontic cement containing nCaF2 was developed with clinically acceptable enamel SBS, good biocompatibility, and sustained F ion recharge and re-release that were 1.8 folds that of a commercial RMGI. CLINICAL SIGNIFICANCE: Novel rechargeable nCaF2 orthodontic cement is promising to provide the needed long-term and high levels of F ion releases to inhibit WSLs in orthodontics.

9.
J Mater Chem B ; 7(44): 6955-6971, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31617555

RESUMO

Periodontitis is a common bacteria-borne inflammatory disease that can damage the supporting structures of teeth, eventually leading to tooth loss and systemic inflammations. The present study developed novel nanoparticles (ZIF-8:Ce) by doping cerium (Ce) into zeolitic imidazolate framework-8 (ZIF-8) to simultaneously obtain antibacterial and anti-inflammatory capabilities. The objectives of this study were to: (1) develop novel ZIF-8 nanoparticles doped with different Ce/(Ce + Zn) molar ratios of 1%, 5% and 10% to combat periodontitis; (2) investigate the inhibition efficacy of different nanoparticles against biofilms of periodontal pathogens; and (3) evaluate the effects of different ZIF-8:Ce on inflammatory secretion and macrophage polarization in vitro. The results showed that Ce doping at a ratio from 1% to 10% did not compromise the regular and uniform structure of ZIF-8. ZIF-8:Ce possessed a sustained Zn2+ and Ce3+/Ce4+ release and favorable superoxide dismutase/catalase activities without cytotoxicity at a concentration below 30 µg mL-1. ZIF-8 exhibited an excellent anti-biofilm function against periodontal pathogens. Although 10% Ce doping into ZIF-8 slightly reduced the antibacterial effects, the CFU reduction still remained at approximately 2 orders of magnitude. More importantly, ZIF-8:Ce exhibited increasing anti-inflammatory effects with increasing amounts of Ce doping. In addition, ZIF-8:Ce10% exerted much better anti-inflammatory effects by inhibiting pro-inflammatory factor expression via restraining the NF-kB/p65 subunit translocation (p < 0.05). Meanwhile, ZIF-8:Ce10% elevated the polarization of the M2 phenotype of macrophages and promoted anti-inflammatory cytokine secretion. Therefore, the novel ZIF-8:Ce nanoparticles provided a unique insight into the development of effective anti-inflammatory and antibacterial platforms for treating periodontitis.

10.
Dent Mater ; 35(11): 1665-1681, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31551152

RESUMO

OBJECTIVE: Periodontal tissue destruction and tooth loss are increasingly a worldwide problem as the population ages. Periodontitis is caused by bacterial infection and biofilm plaque buildup. Therefore, the objectives of this study were to: (1) develop a near-infrared light (NIR)-triggered core-shell nanostructure of upconversion nanoparticles and TiO2 (UCNPs@TiO2), and (2) investigate its inhibitory effects via antibacterial photodynamic therapy (aPDT) against periodontitis-related pathogens. METHODS: The core ß-NaYF4:Yb3+,Tm3+ were synthesized via thermal decomposition and further modified with the TiO2 shell via a hydrothermal method. The core-shell structure and the upconversion fluorescence-induced aPDT treatment via 980nm laser were studied. Three periodontitis-related pathogens Streptococcus sanguinis (S. sanguinis), Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum) were investigated. The killing activity against planktonic bacteria was detected by a time-kill assay. Single species 4-day biofilms on dentin were tested by live/dead staining, colony-forming units (CFU), and metabolic activity. RESULTS: The hexagonal shaped UCNPs@TiO2 had an average diameter of 39.7nm. UCNPs@TiO2 nanoparticles had positively charged (+12.4mV) surface and were biocompatible and non-cytotoxic. Under the excitation of NIR light (980nm), the core NaYF4:Yb3+,Tm3+ UCNPs could emit intense ultraviolet (UV) light, which further triggered the aPDT function of the shell TiO2 via energy transfer, thereby realizing the remarkable antibacterial effects against planktons and biofilms of periodontitis-associated pathogens. NIR-triggered UCNPs@TiO2 achieved much greater reduction in biofilms than control (p<0.05). Biofilm CFU was reduced by 3-4 orders of magnitude via NIR-triggered aPDT, which is significantly greater than that of negative control and commercial aPDT control groups. The killing efficacy of UCNPs@TiO2-based aPDT against the three species was ranked to be: S. sanguinis

Assuntos
Periodontite , Fotoquimioterapia , Biofilmes , Humanos , Nanotecnologia , Periodonto
11.
J Dent ; 89: 103193, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31476321

RESUMO

OBJECTIVES: The remineralization of dentin at a bonded interface would help to strengthen the bonded interface and inhibit secondary caries, and would prolong the longevity of restoration. The aim of this study was to investigate the remineralization of demineralized human dentin in a dental biofilm environment via an adhesive containing nanoparticles of amorphous calcium phosphate (NACP). METHODS: Dentin demineralization was promoted by subjecting samples to a Streptococcus mutans acidic biofilm for 24 h. Samples were divided into a control group, a commercial fluoride-releasing adhesive group, and an NACP adhesive group. All samples were subjected to a remineralization protocol consisting of 4-h exposure per 24-h period in brain heart infusion broth plus 1% sucrose (BHIS) followed by immersion in artificial saliva for the remaining period. The pH of BHIS after 4-h immersion was measured every other day. After 10 days, the biofilm was assessed for colony-forming unit (CFU) count, lactic acid production, live/dead staining, and calcium and phosphate content. The mineral changes in the demineralized dentin samples were analyzed by transverse microradiography, hardness measurement, X-ray diffraction characterization, and scanning electron microscopy. RESULTS: The NACP adhesive achieved acid neutralization, decreased biofilm CFU count, decreased biofilm lactic acid production, and increased biofilm calcium and phosphate content (P < 0.05). The NACP adhesive group had higher remineralization value than the commercial fluoride-releasing adhesive group (P < 0.05). CONCLUSIONS: The NACP adhesive was effective in remineralizing dentin lesions in a biofilm model. Its ability to protect bond interface, inhibit secondary caries, and prolong the longevity of restoration is promising. CLINICAL SIGNIFICANCE: Using NACP-containing adhesives could be recommended because of the protective ability of its hybrid layer even under a biofilm-challenged environment.

12.
Mater Sci Eng C Mater Biol Appl ; 104: 109955, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500064

RESUMO

Calcium phosphate cement (CPC), functionalized with iron oxide nanoparticles (IONP), is of great promise to promote osteoinduction and new bone formation. In this work, the IONP powder was added into the CPC powder to fabricate CPC + IONP scaffolds and the effects of the novel composite on bone matrix formation and osteogenesis of human dental pulp stem cells (hDPSCs) were explored. A series of CPC + IONP magnetic scaffolds with different IONP contents (1%, 3% and 6%) were fabricated using 5% chitosan solution as the cement liquid. Western blotting and RT-PCR were used to analyze the signaling pathway. The IONP incorporation substantially enhanced the performance of CPC + IONP, with increases in both mechanical strength and cellular activities. The IONP addition greatly promoted the osteogenesis of hDPSCs, elevating the ALP activity, the expression of osteogenic marker genes and bone matrix formation with 1.5-2-fold increases. The 3% IONP incorporation showed the most enhancement among all groups. Activation of the extracellular signal-related kinases WNT/ß-catenin in DPSCs was observed, and this activation was attenuated by the WNT inhibitor DKK1. The results indicated that the osteogenic behavior of hDPSCs was likely driven by CPC + IONP via the WNT signaling pathway. In conclusion, incorporate IONP into CPC scaffold remarkably enhanced the spreading, osteogenic differentiation and bone mineral synthesis of stem cell. Therefore, this method had great potential for bone tissue engineering. The novel CPC + IONP composite scaffolds with stem cells are promising to provide an innovative strategy to enhance bone regenerative therapies.


Assuntos
Cimentos para Ossos/química , Cimentos para Ossos/farmacologia , Fosfatos de Cálcio/química , Compostos Férricos/química , Nanopartículas/química , Osteogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Regeneração Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Quitosana/química , Cimentos Dentários/química , Polpa Dentária/efeitos dos fármacos , Polpa Dentária/metabolismo , Humanos , Células-Tronco/metabolismo , Engenharia Tecidual/métodos , Tecidos Suporte/química , Proteínas Wnt/metabolismo , beta Catenina/metabolismo
13.
Dent Mater ; 35(10): 1479-1489, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31387742

RESUMO

OBJECTIVES: Root canal re-infection and weakening of roots are two main challenges in endodontics. The objectives of the study were: (1) to develop a novel root canal sealer containing dimethylaminohexadecyl methacrylate (DMAHDM), nanoparticles of silver (NAg), and nanoparticles of amorphous calcium phosphate (NACP), and (2) to investigate the effects on the physical, anti-biofilm, remineralizing ions, and hardness of human dentin for the first time. METHODS: Methacrylate-resin dual-cured root canal sealer contained 5% DMAHDM, 0.15% NAg, and NACP at 10%, 20% and 30% mass fractions. The flow, film thickness, and Ca and P ions release were investigated. The effects of NACP on radicular dentin hardness after treatment with sodium hypochlorite (NaOCL) and ethylenediaminetetraacetic acid (EDTA) were assessed. Antibacterial properties were measured against Enterococcus faecalis (E. faecalis)-impregnated dentin blocks; colony-forming units (CFU) and live/dead assays were measured. RESULTS: Incorporating DMAHDM, NAg and NACP did not adversely influence the flow and film thickness properties. Sealer with 30% NACP neutralized the acid and increased the solution pH (p<0.05). Sealer containing 30% NACP regenerated dentin minerals lost due to NaOCL and EDTA treatment, and increased the dentin hardness to match that of sound dentin (p>0.1). Incorporating 5% DMAHDM and 0.15% NAg reduced biofilm CFU of E. faecalis-impregnated dentin blocks by nearly 3 logs when compared control group (p<0.05). SIGNIFICANCE: The novel therapeutic root canal sealer with triple bioactive agents of DMAHDM, NAg and NACP neutralized acid, raised the pH, regenerated dentin minerals, increased root dentin hardness, and reduced dentin-block-impregnated biofilm CFU by 3 logs. This new sealer with highly desirable antibacterial and remineralization properties are promising to increase the success rate of endodontic therapy and strengthen the tooth root structures.


Assuntos
Cavidade Pulpar , Prata , Antibacterianos , Bactérias , Biofilmes , Fosfatos de Cálcio , Cimentos Dentários , Dentina , Dureza , Humanos , Metacrilatos , Raiz Dentária
14.
Sci Rep ; 9(1): 12463, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462657

RESUMO

Persisting apical periodontitis is a primary reason for multiple intervention in root canal. Persisting bacteria in root canal is related with the persisting infection. Despite the advancement in treatment strategies the persisting infection is a major challenge for endodontist. Here we tested two newly developed quaternary ammonium methacrylates (QAMs) against endodontic bacteria and their biofilms. Their antibacterial and antibiofilm efficiency were compared with chlorhexidine (CHX) and sodium hypochlorite (NaOCl). We measured the MIC, MBC and MBIC of DMADDM and DMAHDM respectively. We also detected the ratio of live/dead bacteria and bacterial composition in the biofilms treated by DMADDM and DMAHDM. We found that DMADDM and DMAHDM could inhibit the growth of bacteria and biofilms formation. The result showed that novel QAMs were remarkably efficient than CHX against biofilms. In addition, we found that Streptococcus gordonii (S. gordonii) and Enterococcus faecalis (E. faecalis) were frequent isolates after treatment with antimicrobial compounds.

15.
J Dent ; 89: 103172, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31326528

RESUMO

OBJECTIVES: The objectives of this study were to develop a resin-modified glass ionomer containing nanoparticles of calcium fluoride (nCaF2) and dimethylaminohexadecyl methacrylate (DMAHDM) for the first time and investigate the antibacterial and remineralization properties. METHODS: nCaF2 was synthesized using a spray-drying method and characterized using a transmission electron microscope. Twenty weight percentage (wt%) nCaF2 and 3 wt% DMAHDM were incorporated into a RMGI (GC Ortho LC). Enamel shear bond strength (SBS) and cytotoxicity were determined. Fluoride (F) and calcium (Ca) ion releases were assessed. Biofilm live/dead staining, metabolic activity, polysaccharide and lactic production, and colony-forming units (CFU) were evaluated. The remineralization ability was determined by measuring the effects of cements on enamel surface hardness and lesion depth. RESULTS: Incorporating 20 wt% nCaF2 and 3 wt% DMAHDM did not compromise the SBS (p > 0.1). The decrease of pH from 7.0 to 4.0 significantly increased the F and Ca ion releases. The new cement greatly reduced the metabolic activity, polysaccharide and lactic acid productions, and lowered the biofilm CFU by 3 log, compared to commercial control (p < 0.05). The new cement increased the enamel hardness by 56% and decreased the lesion depth by 43%, compared to control (p < 0.05). The cell viability at 7 days against the new cement extracts was 82.2% of that of the negative control in culture medium without any extracts. CONCLUSIONS: The novel orthodontic cement containing nCaF2 and DMAHDM achieved much stronger antibacterial and remineralization capabilities and greater enamel hardness than the commercial control did, without compromising the orthodontic bracket-enamel SBS and biocompatibility. CLINICAL SIGNIFICANCE: The novel bioactive and nanostructured orthodontic cement is promising to inhibit enamel demineralization, white spot lesions and caries in orthodontic treatments.

16.
Int J Mol Sci ; 20(14)2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31315225

RESUMO

Cariogenic oral biofilms are strongly linked to dental caries around dental sealants. Quaternary ammonium monomers copolymerized with dental resin systems have been increasingly explored for modulation of biofilm growth. Here, we investigated the effect of dimethylaminohexadecyl methacrylate (DMAHDM) on the cariogenic pathogenicity of Streptococcus mutans (S. mutans) biofilms. DMAHDM at 5 mass% was incorporated into a parental formulation containing 20 mass% nanoparticles of amorphous calcium phosphate (NACP). S. mutans biofilms were grown on the formulations, and biofilm inhibition and virulence properties were assessed. The tolerances to acid stress and hydrogen peroxide stress were also evaluated. Our findings suggest that incorporating 5% DMAHDM into 20% NACP-containing sealants (1) imparts a detrimental biological effect on S. mutans by reducing colony-forming unit counts, metabolic activity and exopolysaccharide synthesis; and (2) reduces overall acid production and tolerance to oxygen stress, two major virulence factors of this microorganism. These results provide a perspective on the value of integrating bioactive restorative materials with traditional caries management approaches in clinical practice. Contact-killing strategies via dental materials aiming to prevent or at least reduce high numbers of cariogenic bacteria may be a promising approach to decrease caries in patients at high risk.


Assuntos
Antibacterianos/farmacologia , Biofilmes , Cimentos Dentários/química , Metacrilatos/farmacologia , Streptococcus mutans/efeitos dos fármacos , Ácidos/farmacologia , Antibacterianos/química , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Peróxido de Hidrogênio/farmacologia , Metacrilatos/química , Streptococcus mutans/patogenicidade , Streptococcus mutans/fisiologia
17.
Sci Rep ; 9(1): 10632, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337813

RESUMO

Persistent apical periodontitis, mainly caused by microorganisms infections, represents a critical challenge for endodontists. Dimethylaminododecyl methacrylate (DMADDM) is a well-studied and potent antibacterial agent used in various studies described in the literature. The aim of this study is to develop a novel antibacterial root canal sealer by incorporating DMADDM into EndoREZ and investigate the properties of the resulting material. Different mass fractions (0, 1.25%, 2.5%, and 5%) of DMADDM were incorporated into EndoREZ and the cytotoxicity, apical sealing ability and solubility of the resulting material were evaluated. Furthermore, a direct contact test, determination of colony-forming units, a crystal violet assay, scanning electronic microscopy and live/dead bacteria staining were performed to evaluate the antibacterial effect of the sealer to multispecies bacteria (Enterococcus faecalis, Streptococcus gordonii, Actinomyces naeslundii, and Lactobacillus acidophilus), in planktonic cells or biofilms. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction were carried out to assess the composition of the multispecies biofilms. No difference on the cytotoxicity, apical sealing ability and solubility between sealers containing DMADDM (1.25%, 2.5%) and EndoREZ (0%) could be determined. However, when the mass fraction of DMADDM increased to 5%, significantly different properties were found compared to the 0% (p < 0.05) group. Moreover, incorporating DMADDM into the sealer could greatly improve the antibacterial properties of EndoREZ. In addition, the composition ratio of E. faecalis could be decreased in multispecies microecology in sealers containing DMADDM. Therefore, a EndoREZ sealer material containing DMADDM could be considered useful in clinical applications for preventing and treating persistent apical periodontitis.

18.
Nanomedicine ; 21: 102069, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31351236

RESUMO

The objectives of this study were to incorporate iron oxide nanoparticles (IONPs) into calcium phosphate cement (CPC) to enhance bone engineering, and to investigate the effects of IONPs as a liquid or powder on stem cells using IONP-CPC scaffold for the first time. IONP-CPCs were prepared by adding 1% IONPs as liquid or powder. Human dental pulp stem cells (hDPSCs) were seeded. Subcutaneous implantation in mice was investigated. IONP-CPCs had better cell spreading, and greater ALP activity and bone mineral synthesis, than CPC control. Subcutaneous implantation for 6 weeks showed good biocompatibility for all groups. In conclusion, incorporating IONPs in liquid or powder form both substantially enhanced hDPSCs on IONP-CPC scaffold and exhibited excellent biocompatibility. IONP incorporation as a liquid was better than IONP powder in promoting osteogenic differentiation of hDPSCs. Incorporating IONPs and chitosan lactate together in CPC enhanced osteogenesis of hDPSCs more than using either alone.

19.
Acta Biomater ; 94: 627-643, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31212111

RESUMO

Peri-implantitis is the most common risk factor for dental implant failure. Nanostructured ceria (nano-CeO2) has anti-inflammatory and antibacterial functions, and different shapes of ceria enclosed by specific crystal planes could be an effective approach to enhance intrinsic catalysis. In the present study, the authors developed a novel implant surface-modification strategy by coating different shapes of nano-CeO2 onto titanium (Ti) surfaces to enhance their antibacterial and anti-inflammatory properties. The objectives of the study were to: (1) develop novel Ti surfaces modified with different shapes of nano-CeO2 (nanorod, nanocube and nano-octahedron) for peri-implantitis prevention; (2) investigate and compare the inhibition efficacy of different shapes of CeO2-modified surfaces against biofilms of peri-implantitis-related pathogens; and (3) evaluate the different CeO2-modified surfaces on cell inflammatory response in vitro and in vivo. The results showed that nanorod CeO2-modified Ti had more bacteria attachment of Streptococcus sanguinis in the early stage, compared with other CeO2-modified Ti (p < 0.05). They all exhibited similarly substantial CFU reductions against peri-implantitis-related biofilms (p > 0.1). Nanocube and nano-octahedron CeO2-modified Ti exerted much better anti-inflammatory effects and ROS-scavenging ability than nanorod CeO2in vitro (p < 0.05). In vivo, the mean mRNA expression of TNF-α, IL-6 and IL-1ß in the tissues around Ti was decreased by the three shapes of nano-CeO2; nano-octahedron CeO2 showed the strongest anti-inflammatory effect among all groups (p < 0.05). In conclusion, all three types of CeO2-modified Ti exerted equally strong antibacterial properties; nano-octahedron CeO2-modified Ti had the best anti-inflammatory effect. Therefore, CeO2-modified Ti surfaces are highly promising for enhancing antimicrobial functions for dental implants. Novel nano-octahedron CeO2 coating on Ti had great therapeutic potential for alleviating and eliminating peri-implantitis. STATEMENT OF SIGNIFICANCE: Peri-implantitis is the most common risk factor for dental implant failure. Nanostructured ceria (nano-CeO2) has anti-inflammatory and antibacterial functions, and different shapes of ceria enclosed by specific crystal planes could be an effective approach to enhance intrinsic catalysis. In the present study, we developed a novel implant surface-modification strategy by coating different shapes of nano-CeO2 onto titanium surfaces to enhance their antibacterial and anti-inflammatory properties for dental implants. In addition, we found that the nano-octahedron CeO2 coating on titanium would have great therapeutic potential for alleviating and eliminating peri-implantitis.

20.
Cells ; 8(6)2019 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-31167434

RESUMO

Periodontitis is a prevalent infectious disease worldwide, causing the damage of periodontal support tissues, which can eventually lead to tooth loss. The goal of periodontal treatment is to control the infections and reconstruct the structure and function of periodontal tissues including cementum, periodontal ligament (PDL) fibers, and bone. The regeneration of these three types of tissues, including the re-formation of the oriented PDL fibers to be attached firmly to the new cementum and alveolar bone, remains a major challenge. This article represents the first systematic review on the cutting-edge researches on the regeneration of all three types of periodontal tissues and the simultaneous regeneration of the entire bone-PDL-cementum complex, via stem cells, bio-printing, gene therapy, and layered bio-mimetic technologies. This article primarily includes bone regeneration; PDL regeneration; cementum regeneration; endogenous cell-homing and host-mobilized stem cells; 3D bio-printing and generation of the oriented PDL fibers; gene therapy-based approaches for periodontal regeneration; regenerating the bone-PDL-cementum complex via layered materials and cells. These novel developments in stem cell technology and bioactive and bio-mimetic scaffolds are highly promising to substantially enhance the periodontal regeneration including both hard and soft tissues, with applicability to other therapies in the oral and maxillofacial region.


Assuntos
Cemento Dentário/fisiologia , Ligamento Periodontal/fisiologia , Regeneração/fisiologia , Células-Tronco/metabolismo , Terapia Genética , Humanos , Periodontite/patologia , Periodontite/terapia , Transplante de Células-Tronco , Células-Tronco/citologia , Engenharia Tecidual , Tecidos Suporte/química
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