Daalen, E. van (Elleke) (2019) Evaluatie van methoden om de contactdoding van composiet met quaternair ammonium te bepalen. thesis, Dentistry.
Full text available on request.Abstract
Introduction. Diseases like caries and persistent apical periodontitis threaten oral health. Streptococcus mutans and Enterococcus faecalis are important factors in causing these diseases. These diseases can be eliminated by means of a dental treatment, but return regularly. Antibacterial materials are already used in a composite or root canal filling to prevent secondary caries and persistent apical periodontitis. These materials have short term antibacterial properties. An antibacterial material with long term antibacterial properties is Quaternary Ammonium (QA). Antibacterial composites containing QA are well studied materials in in vitro and in vivo research and kills bacteria upon contact, called ‘contact�killing’. In vitro research results are hard to interpret because most-used methods to determine efficacies of contact-killing have never been compared. Most used methods are: 1) ‘American Society for Testing and Materials’ (ASTM) 2) bacterial spray 3) ‘Japanese Industrial Standards’ (JIS Z) 4) modified JIS and 5) Petrifilm®. These five methods have been used in this study. The importance to identify the most appropriate method is high. With an appropriate method, more valid research can be done to evaluate antibacterial materials. As a result, diseases like SC and PPA can be eliminated. The research question of this study is: ‘What is the most suitable method to test the in vitro contact-killing of composite with QA on S. mutans and E. faecalis?’. Research material and method. These five methods were applied to the bacteria S. mutans and E. faecalis. The antibacterial material is composite with QA and the control group composite without QA. The experiments were executed in triplicate. Results. The methods JIS Z and Petrifilm® demonstrate a significant higher contact-killing of S. mutans and E. faecalis for composite with QA than composite without QA. The methods ASTM and bacterial spray show no significant difference between composite with QA and without QA. The method modified JIS shows a significant higher contact-killing of E. faecalis for composite with QA than composiet without QA assuming equality of variances. Modified JIS shows no significant difference in contact-killing of S. mutans and E. faecalis between composite with and without QA assuming no equality of variances. All methods illustrate a low contact-killing for composite without QA. The method modified JIS even shows growth of the bacteria E. faecalis in the control group. The results of modified JIS are not consistent upon repetition. Discussion. Based on these results the methods JIS Z and Petrifilm® appear to be the most suitable methods to determine contact-killing of QA with S. mutans and E. faecalis. Petrifilm® seems to be the most preferred method, because this method is easier to execute than JIS Z. Further optimization and standardization of the methods is necessary to make a final judgment. More research is needed to confirm the results of this research to enable a better evaluation of these different methods for antibacterial research.
| Item Type: | Thesis (UNSPECIFIED) |
|---|---|
| Supervisor name: | Lagemaat, dr. M. van de and Ren, prof. dr. Y. |
| Faculty: | Medical Sciences |
| Date Deposited: | 23 Nov 2021 13:45 |
| Last Modified: | 23 Nov 2021 13:45 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/2842 |
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