Considering they "brush" their teeth by chewing a branch, definitely not.
Considering they spend the whole day in the labyrinth and only return home in the evening, and they don't have convenient Warp spell at their disposal, pretty certain that they do.
I'm sure mc could make some kinda makeshift toothpaste if he can make soap
If not just rinse out with either baking soda or like chew mint while using toothpick/some kinda string for floss but it doesn't come up (imagine if "healing" spells worked on cavities but usually most isekai foods aren't too chemical or sugary[tho did actually find a cola manhwa one haha])
And yeah I doubt many ppl ask/question other daily life stuff otherwise
If mc was more business oriented he prolly could sell the soap to the landlord lady they got the house from but I imagine they're not short on money with MCs exp bonus making those crystals change color faster
Would've expected one of their "day offs" to have some restaurant date to see what the local foods are like and buy more ingredients to do their own versions depending but dun expect creativity beyond tavern food if one piece of bread was meant to be for the whole day (maybe a hollowed out bread bowl with soup inside lol)
Altho mc himself is prolly more interested in commissioning sexy clothes/lingerie from a tailor lol