To be hinest, I also find it intreresting to see Your experiment, e.g. if You will strenghten Your teeth by waiting the calcium supplement to dissolve in Your mouth. However, I figured out some obsticles.
I think, that the time the supplement dissolves is too short for the calcium to take an effect over Your teeth. Maybe You have to consider the readily dissolved supplement to stay in Your mouth.
Mineralisation of the teeth plaque leads to the development of teeth tartar. In case You try that, be sure, that You are cleaning reguralry and effective the plaque over Your teeth.
If You decide to do the experiment, after that I can't imagine how You will know, that You have actually strenghtened Your teeth. You will need an objective value, that You to use as a criterion to prove that dissolving this supplement in Your mouth strenghtens Your teeth. I can't figure out what this criterion will be. If You were in a test animal study, I would suggest electron misroscopy of the enamel of extracted teeth before and after the procedure
after the first and the last days in the experiment
Further more, I would suggest the enamel of all of the teeth to be damaged artifitially with acids
so to be seen the demineralisation effect in the enamel of the first extracted teeth and the remineralisation effect of the supplement at the end of the experiment ... but You definately are not a test animal, so the question how to detect, that this influences Your teeth is in a question.
After that, in order to isolate only the effect of the supplement, You must stop using everything, that may contribute to the calcium in Your mouth and teeth. This means, that You must stop any other food, drink or whatever You put in Your mouth, that may contain calcium. You also must have an examination of Your Vitamin D and the hormones, that influence the calcium metabolism in the body. These exams must proove, that the values are normal according to the average values for Your species - humans
and You must not take any hormones and vitamins including with the food, that have influence over the calcium metabolism.