Physicomechanical properties of strontium and fluoride modified biodentine^TM

Abstract

Objectives: To investigate the effect of bioactive glass addition on the physicomechanical properties of Biodentine^TM. The study compares the setting time, compressive strength and radiopacity of Biodentine^TM modified by three different compositions of bioactive glasses

Design: This was an exploratory lab based quasi-experimental study

Setting: The study was conducted in the laboratory at Queen Mary, University of London Dental Physical Sciences Unit.

Materials and methods: Dental cements based on Biodentine^TM and its modifications were used in the study. Original unmodified Biodentine^TM cement was coded BO. Three bioactive glasses based on high fluoride (Q), high strontium (I) and high fluoride + strontium (H)were synthesized and 0.07g of each of the bioactive glasses added to Biodentine^TM powder to yield 3 additional types of cements which were coded BQ, BI and BH respectively. A set mass of each cement type was prepared by adding 5 drops of the liquid supplied with Biodentine^TM to the powders and triturating for 30 seconds in a 4000rpm electric amalgamator. These cements were subjected to setting time determination, compressive strength testing and radiopacity testing according to ISO 9917-1: 2007.Setting time and compressive strength were statistically analysed using T-test at 95% confidence level at a significance level of 0.05.

Results: Bioactive glass addition resulted in initial setting times of11.31+0.18, 12:22+ 0.11, 11:59+ 0.15 and 13:35+0.23 minutes for BO, BQ, BI and BH respectively. The increased setting time of BQ and BH were statistically significant. Student t-test analysis of compressive strength demonstrated statistically higher 14 day compressive strengths for BI (p=0.036) and BH (p=0004). BH cement had the highest grey scale value equivalent to 2.9mm of aluminium, which was consistent with the best radiopacity among the 4 Biodentine^TM based cements.

Conclusion: Bioactive glass addition to Biodentine^TM improved the radiographic detectability and compressive strength of the cement. This is important since current use of Biodentine^TM is limited owing to inadequate strength and detection on radiographs. However, further studies are needed to explore alternative modifications that could shorten the setting time of this cement.