I dunno, there's been an awful lot of controversy about carbs, sugar, fat, and cholesterol in very recent memory, and those seem pretty "core" to me.
Yes, I was already aware of the effect of food on saliva production. However, if there is more to your body than your teeth, it may be worth taking more than your dental health into consideration when making decisions about your health. It is a widely accepted fact that the feeling of fullness takes about 15-20 minutes to get to your brain. Multiple studies have suggested that eating more quickly results in eating more (because you keep eating lots while that signal is still on its way) and feeling less full long-term. This might be a valid concern for people who are worried about gaining weight. I'm reasonably sure that, in western culture, many "healthy" people have this fear. Also, saliva, rather than being merely a vehicle for tooth cleansing, also plays a role in the digestion of food. Eating quickly leaves it less time to do its job, potentially overtaxing the rest of the digestive system. Additionally, you are more likely to swallow excess air while eating quickly, and to chew less, further straining the rest of your digestive system in its attempt to absorb nutrients from the food you eat. These factors can cause indigestion... even in "healthy" people. Google "eating quickly". You won't find anything positive. Most of it will be pop-science clickbait, of course, but there'll also be stuff like this
. At any rate, when weighing your assertion against the advice of every doctor I've heard speak about the topic, I'm going to go with the latter when judging which habit is "healthy".
I would suggest that the cost, moral and financial, of purchasing an electric toothbrush, might not be dire enough to warrant such lifestyle changes, nor such a defense thereof. While lifestyle changes are certainly valuable options and deserve promotion, they are not inherently better or more virtuous than any other approach. Furthermore, neither do they preclude alternate approaches; it is entirely possible to both eat more healthily (though I still fervently dispute that eating quickly can accurately be described as "healthy" in any definition of the term that extends beyond one's molars) and to buy an electric toothbrush. Perhaps you fear that buying an electric toothbrush will induce complacency, a tendency to eat in a slatternly way in faith that the toothbrush will make up for it. I would suggest that this fear is misplaced, and ultimately irrelevant. Furthermore, if eating quickly does tend to lead to eating more, it might not even lead to any cost savings in the long run, which is, I believe, the ostensible purpose of this discussion. It might be, in short, a false economy. Regardless, it is, at the very least, incredibly off-topic.