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العنوان
Biological, Mechanical and Physical Evaluation of Glass Ionomer Functionalized with Two Different Chlorohexidine Derivatives :
المؤلف
Hasan, Shaimaa Mortada AbdEllah.
هيئة الاعداد
باحث / شيماء مرتضى عبد اللاه حسن
مشرف / دينا أحمد الرفاعى
مشرف / محمد محمود قنديل
مناقش / دينا أحمد الرفاعى
تاريخ النشر
2021.
عدد الصفحات
183 p. :
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
Dentistry (miscellaneous)
تاريخ الإجازة
1/1/2021
مكان الإجازة
جامعة عين شمس - كلية طب الأسنان - علم المواد الحيوية
الفهرس
Only 14 pages are availabe for public view

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from 178

Abstract

The main objective of this study was to investigate the effectiveness of adding chlorhexidine derivatives (digluconate and hexametaphosphate) using glass ionomer cement (GIC) with modified concentration (0.25%, 0.75%, 1.5%) as a restorative material in the treatment for secondary caries.
Another objective of this study is to test the local and general effects of chlorhexidine in the GIC, chlorhexidine digluconate and chlorhexidine hexametaphosphate when mixed with GIC with different conc. at different time periods 7 days, 3months and 6 months.
Antibacterial effect was tested by agar diffusion against oral bacteria streptococcus mutans and lactobacillus acidophilus that are the main cause of dental caries. Differences in inhibition zones at these time points were used to investigate the antimicrobial effect of the two restorations over the 6-month period.
In addition, fluoride release and chlorhexidine release were tested in the laboratory to assess the time duration of the release over a period of 6 months to reassure release over this period.
Compressive strength was tested after adding chlorhexidine to glass ionomer with different concentrations after 7 days and 6 months’ storage period. Also, initial setting time was measured.
Glass ionomer cement is the most common restorative materials used in the atraumatic restorative treatment (ART) approach due to adhesion and esthetic properties. Hence the oral cavity is one of the most challenging environments, glass ionomer cement is subjected to a lot of challenges that might deteriorate their physical and mechanical properties.
Among the agents, the addition of chlorhexidine has showed a significant increase in antimicrobial activity with minimal effects on the mechanical properties of GIC. This modified GIC was more effective in delivering a greater and longer lasting anti-biofilm activity compared to conventional GIC, with no adverse effects on setting time or physical and bonding properties of the material.
Specimens from each type of glass ionomer cement were prepared and divided into two main groups according to the type of chlorhexidine salt added either digluconate or hexametaphosphate. Then each group was further subdivided into subgroups according to the concentrations of the chlorhexidine (0.25%, 0.75%, and 1.5%) and time interval (7 days, 3 months and 6 months).
Results of the antibacterial test showed that chlorhexidine hexametaphosphate caused the greatest bacterial reduction at its highest concentration over the period of 6 months while chlorhexidine digluconate caused bacterial reduction over 3 months’ period only for both streptococcus mutans and lactobacillus acidophilus.
Results of chlorhexidine release test showed that chlorhexidine hexametaphosphate has substantive release of chlorhexidine over 6 months, while chlorhexidine digluconate show less release for only
3 months.
Results of fluoride release test showed that the highest result was from unmodified GIC specimens followed by chlorhexidine digluconate. Chlorhexidine hexametaphosphate showed the lowest fluoride release.
Results of compressive strength showed that adding CHX to glass ionomer lowered the compressive strength. Compressive strength increased for all groups after 6 months.
Results of setting time showed that it prolonged after mixing glass ionomer with higher concentrations of both chlorhexidine derivatives. Setting time was higher in chlorhexidine hexametaphosphate specimens than in chlorhexidine digluconate specimens.
Conclusions:
Within the limitations of the current study, the following could be concluded:
1. The incorporation of CHX into ChemFil Superior glass ionomer cement has the ability to provide a long-term antimicrobial effect on S. mutans and L. acidophilus.
2. The substantivity of CHX release from glass ionomer is dependent on the molecule attached to in the cement; either digluconate or hexametaphosphate.
3. Fluoride release of GIC decreases by adding CHX and with the increase of its concentration. This is considered a major problem that can make glass ionomer lose its characteristic feature for being anticariogenic
4. Addition of CHX to glass ionomer cement ChemFil superior can deteriorate its short term compressive strength. However, the compressive strength increases by time, regaining its strength at 6 months.
5. Addition of CHX to glass ionomer cement ChemFil superior increases its setting time.
Recommendations for further directions:
Within the limitations of this study, the GIC modified with CHX was investigated in vitro for biological examinations, some physical and mechanical properties. However, further studies for managing the decreased fluoride release are necessary. It’s challenge that must be dealt with, in order not to deprive glass ionomer its anticariogenic property. Also, another route that should be cut in future researches is the compressive strength of glass ionomer modified with chlorohexidine.
A three month testing, as well as, one year or longer duration testing are needed to have a full scientific information regarding the compressive strength of glass ionomer modified with chlorohexidine.
Surface mechanical properties are crucial factors that can be further studied.