Advisory Committee Chair
John O Burgess
Advisory Committee Members
Nathaniel C Lawson
Date of Award
Degree Name by School
Master of Science in Dentistry (MScD) School of Dentistry
Introduction : Dental caries is one of the most prevalent chronic diseases 1. Unfortunately, there have been numerous failures with the treatment rendered, the materials used and how they are used. One significant cause for dental restoration failure is secondary caries and the need to replace the existing restoration. It has been reported that more than half of the restorations placed have been replaced because of recurrent caries. New materials and techniques have been developed to enhance adhesives in dentistry and improve the bonded interface however that interface still remains the weakest component of composite restorations. Marginal degradation and the inert nature of resin restoration have led to the introduction of bioactive materials which promote hydroxyapatite formation. Materials and Methods: Experimental (Activa 2), Fuji LC II (positive control) and Filtek Supreme Ultra (negative control). Firstly, measurement of fluoride release in deionized water from these materials were recorded with ion electrode at 24 hours, 1 week, 1 and 3-month intervals. Secondly, fluoride recharge was measured after 3 months storage in deionized water. Measurement of recharge was measured 2 days after storage. Thirdly, gloss developed during polishing was measured using a glossmeter. Fourth, hydroxyapatite formation was measured using 3 samples of each material placing them in phosphate buffered saline solution for 21 days. Sections from specimens were examined with the scanning electron microscope (SEM). Fifth, wear test was conducted by mounting 8 specimens in a UAB wear machine. Human premolar teeth were collected, and the lingual cusp was refined using a cone shaped bur to act as an antagonist. After 400,000 wear cycles the volumetric wear was measured for the teeth with non-contact profilometer (Proscan). The data obtained was analyzed using an ANOVA (wear, gloss), repeated ANOVA (fluoride release & fluoride recharge) and post-hoc Tukey statistical tests. Results: Fluoride release, fluoride recharge, gloss and hydroxyapatite formation from Activa 2 was not significantly (P>.05) different from Filtek Supreme Ultra. The wear of Activa 2 was significantly different (P<.05) than Filtek Supreme Ultra. Fuji II LC produced significantly greater (P<.05) fluoride recharge, fluoride release and hydroxyapatite formation compared to Active 2 and Filtek Supreme. However, Fuji II LC had significantly (P>.05) less wear and gloss compared to Activa 2 and Filtek Supreme Ultra. Conclusion: There were no statistically significant differences between Activa 2 and Filtek Supreme Ultra material in gloss, hydroxyapatite, fluoride release and fluoride recharge there were statistical significant in the wear. There were statistical significant between Fuji II LC and the two other materials in all other tests.
Badahman, Mohammed, "Bioactive Materials: Ion Release & Recharge, Wear, Gloss & Hydroxyapatite Formation" (2019). All ETDs from UAB. 1074.