I am understanding several issues here. I am going to separate them and you can choose an option.
- The blurriness. You are actually now using a 105 mm macro lens. Assuming you know how to use it, and you have tested it, for example outside of the mouth of a patient, you know how close you need to be and what "magnification".
Then "Blurriness" could mean that either you are not focusing well or that you have motion blur. If that is the case you probably need a ring flash.
If you are not focusing well either you need to practice or you need to take a look at your lens, for example, if it is autofocus.
But it can also mean that you need to practice your "macro photography skills" like holding your breath, holding the camera firmly, etc.
It can also mean that you need to understand about motion blur if you are using a slow speed, so probably you need to increase the sensitivity of your camera, increasing the ISO.
- Magnification. This is totally relative. In the photographer's world magnification is relative to the optics. Take a look at this question: What does "magnification" mean?
So in optics terms, 25x means A LOT! of magnification, and I mean a LOT.
But as you are a dentist you probably do not really mean that.
In this other question: What kind of lens to photograph a 1 mm object?
I posted this image of some sugar grains.
The optical magnification is not that great. It is less than 2x (1.8)
But if you see the image for example on a FullHD 23" monitor, at full size you can see the sugar grain of 1mm at about 11cm. This is 110 times larger.
So you need to see what is in reality what you need.
- Using a dedicated microscope. As you have been told by other answers.
It has a specific magnification, a fixed focal distance, it can be easier to clean, it's compact and probably has a built-in light, and live view, so you can use it to see in real time.