University of Groningen
Quaternary ammonium compounds to prevent oral biofilm formation
Miura Sugii, Mari
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Publisher's PDF, also known as Version of record
Publication date: 2019
Link to publication in University of Groningen/UMCG research database
Citation for published version (APA):
Miura Sugii, M. (2019). Quaternary ammonium compounds to prevent oral biofilm formation.
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Summary
Samenvatting
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SUMMARY
Bacterial contamination is an everlasting human problem. Specially, bacteria organized into biofilms can lead to serious and costly problems for society in many different aspects. Chapter 1 gives a brief overview of biofilm formation and associated problems. We made clear why it is difficult to fight biofilms, introducing materials with antimicrobial activity for biomedical application as a good strategy to address the problem. In this context, quaternary ammonium compounds (QAC) came into sight to efficiently endow materials with antimicrobial capability, either by release or by contact-active mechanism.
In this regard, Chapter 2 focuses on quaternary ammonium-containing antimicrobial materials. Considering oral biofilms, bacterial colonization and settlement is one of the driving factors for caries disease. Recently prevention efforts have been aimed at the development of materials with antimicrobial activity, either by incorporating the antimicrobial agent in the matrix or by modifying material surfaces. For the incorporated antimicrobial agent, there is burst release of the antimicrobial followed by much lower releasing rates over time. This chapter reviews the literature about modifications promoted on the surface by organosilane compounds or methacrylate monomers containing quaternary ammonium as the functional group for biomedical and dental application.
In Chapter 3 the antibiofilm effect of an iodide quaternary ammonium methacryloxy silicate (IQAMS) in Transbond XT Light Cure Adhesive resin used for braces cementation was evaluated. Fourier Transform Infrared spectroscopy confirmed IQAMS formation and scanning electron microscopy (SEM) coupled to energy-dispersive X-ray spectroscopy revealed that in the coating, the quaternary ammonium groups from IQAMS were homogeneously dispersed throughout the surface. When incorporated, the composite material presented homogeneous dispersion throughout the resin. Assays with Streptococcus mutans demonstrated enhanced antibiofilm effect for the IQAMS coated resin, with much lower colony-forming units (CFU), in contrast to incorporated IQAMS. Such a difference was assigned to low availability of quaternary ammonium groups at the surface of the resin after lightcuring process, hindering its antibiofilm effect. Additionally, the incorporation of IQAMS led to slight decrease in ultimate bond strength and shear bond strength, in comparison to the commercial resin. Thus, the synthesized
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IQAMS displays great potential only as antibiofilm coating or sealant to prevent oral infections in brackets during orthodontic treatment.
In Chapter 4 we further investigated quaternary ammonium containing materials for dental application. As adequate brushing is hindered by cemented orthodontic devices, bacterial biofilm growth on device surfaces and surrounding areas is a common issue. To address this problem, polyhydroxyurethane (PHU) coatings containing quaternary ammonium salt (QAS) were developed for application on stainless steel devices. Two hybrid polyhydroxyurethane were designed and a quaternary ammonium salt was bound by a sol-gel process. Materials syntheses and coating preparation were successfully achieved as confirmed by FTIR-ATR, NMR, XPS, and GIXS. The coatings exhibited strong S. mutans killing by leaching of antimicrobial QAS as well as contact-killing upon bacterial contact with the coatings. Unfortunately, the leachate containing QAS also showed high levels of cytotoxicity on fibroblast L929. Two treatments were used to reduce this cytotoxic effect, a short-duration (2 h) ion exchange with sodium phosphate and an extensive (3 days) washing with demineralized water. None of the treatments affected the antimicrobial properties of the coatings. In contrast to ion exchange, washing for 3 days did decrease the cytotoxicity after remaining in medium for 7 days. In conclusion, PHU-QAS coating when washed is a reliable approach to render stainless steel antimicrobial properties.
Based on the good performance of coatings containing QAC, Chapter 5 focused on the incorporation of QAC into a commercial dental sealant, conceived to be applied as coating on the surface of restorations. The objective of this study was to evaluate a commercial surface sealant with respect to its mechanical resistance to abrasion by brushing and its antimicrobial potential when a QAC was added. Brushing cycles, SEM and S. mutans biofilm formation were performed comparing 4 surfaces: restorative composite resin Z350 XT, the resin with BisCover surface sealant, the resin with a QAC coating and the resin with BisCover surface sealant containing QAC. The morphology of the brushed and non-brushed surfaces was qualitatively compared by SEM and their antimicrobial potential measured by biofilm formation and CFU/cm2. The antimicrobial activity of QAC
was similar in its pure form, applied as a coating or inserted into BisCover surface sealant. Antimicrobial activity was diminished by brushing for the equivalent time of 2.5 months but CFU/cm2 of QAC coating remained statistically different from
SUMMARY
Bacterial contamination is an everlasting human problem. Specially, bacteria organized into biofilms can lead to serious and costly problems for society in many different aspects. Chapter 1 gives a brief overview of biofilm formation and associated problems. We made clear why it is difficult to fight biofilms, introducing materials with antimicrobial activity for biomedical application as a good strategy to address the problem. In this context, quaternary ammonium compounds (QAC) came into sight to efficiently endow materials with antimicrobial capability, either by release or by contact-active mechanism.
In this regard, Chapter 2 focuses on quaternary ammonium-containing antimicrobial materials. Considering oral biofilms, bacterial colonization and settlement is one of the driving factors for caries disease. Recently prevention efforts have been aimed at the development of materials with antimicrobial activity, either by incorporating the antimicrobial agent in the matrix or by modifying material surfaces. For the incorporated antimicrobial agent, there is burst release of the antimicrobial followed by much lower releasing rates over time. This chapter reviews the literature about modifications promoted on the surface by organosilane compounds or methacrylate monomers containing quaternary ammonium as the functional group for biomedical and dental application.
In Chapter 3 the antibiofilm effect of an iodide quaternary ammonium methacryloxy silicate (IQAMS) in Transbond XT Light Cure Adhesive resin used for braces cementation was evaluated. Fourier Transform Infrared spectroscopy confirmed IQAMS formation and scanning electron microscopy (SEM) coupled to energy-dispersive X-ray spectroscopy revealed that in the coating, the quaternary ammonium groups from IQAMS were homogeneously dispersed throughout the surface. When incorporated, the composite material presented homogeneous
IQAMS displays great potential only as antibiofilm coating or sealant to prevent oral infections in brackets during orthodontic treatment.
In Chapter 4 we further investigated quaternary ammonium containing materials for dental application. As adequate brushing is hindered by cemented orthodontic devices, bacterial biofilm growth on device surfaces and surrounding areas is a common issue. To address this problem, polyhydroxyurethane (PHU) coatings containing quaternary ammonium salt (QAS) were developed for application on stainless steel devices. Two hybrid polyhydroxyurethane were designed and a quaternary ammonium salt was bound by a sol-gel process. Materials syntheses and coating preparation were successfully achieved as confirmed by FTIR-ATR, NMR, XPS, and GIXS. The coatings exhibited strong S. mutans killing by leaching of antimicrobial QAS as well as contact-killing upon bacterial contact with the coatings. Unfortunately, the leachate containing QAS also showed high levels of cytotoxicity on fibroblast L929. Two treatments were used to reduce this cytotoxic effect, a short-duration (2 h) ion exchange with sodium phosphate and an extensive (3 days) washing with demineralized water. None of the treatments affected the antimicrobial properties of the coatings. In contrast to ion exchange, washing for 3 days did decrease the cytotoxicity after remaining in medium for 7 days. In conclusion, PHU-QAS coating when washed is a reliable approach to render stainless steel antimicrobial properties.
Based on the good performance of coatings containing QAC, Chapter 5 focused on the incorporation of QAC into a commercial dental sealant, conceived to be applied as coating on the surface of restorations. The objective of this study was to evaluate a commercial surface sealant with respect to its mechanical resistance to abrasion by brushing and its antimicrobial potential when a QAC was added. Brushing cycles, SEM and S. mutans biofilm formation were performed comparing 4 surfaces: restorative composite resin Z350 XT, the resin with BisCover surface sealant, the resin with a QAC coating and the resin with BisCover surface
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the other surfaces. SEM images evidenced that BisCover containing QAC better maintained surface characteristics facing brushing abrasion forces.
Chapter 6 discussed all the previous chapters highlighting changes in
approach and materials among studies explaining the rationale behind the modifications. Also, aspects that can still be explored such as cytotoxicity and bacterial resistance to QAC are pointed out as future perspectives for research on the field.
the other surfaces. SEM images evidenced that BisCover containing QAC better maintained surface characteristics facing brushing abrasion forces.
Chapter 6 discussed all the previous chapters highlighting changes in
approach and materials among studies explaining the rationale behind the modifications. Also, aspects that can still be explored such as cytotoxicity and bacterial resistance to QAC are pointed out as future perspectives for research on the field.
