Brushing Teeth on Shabbat

From Halachipedia

Brushing Teeth on Shabbat

Mimareach

The mishnah is Shabbat (73a) lists Mimachek as one of the avot melacha-scraping, removing a surface to leave a smooth remainder (sandpaper, scraping hairs off a piece of leather to make it smooth) Mimareach-smoothing not by eliminating surface, but by spreading something over the surface. [1] Rav Moshe Feinstein [2] says that it’s definitely assur to use toothpaste because of mimachek but without toothpaste its allowed just like washing the rest of your body. So seemingly, Rav moshe meant mimareach the toladah of mimachek. Maybe he actually means mimachek that you’re smoothing out your teeth by removing the plaque. Rav Soloveitchik [3] said removing dirt or plaque is certainly not mimachek just like washing dishes is permissible. Mimachek is only when you’re removing something that is part of the essence of the object itself and plaque isn’t that. So they asked him maybe you remove enamel by brushing and he said that if that were true eventually you would have no tooth left from brushing. Rav Ovadia Yosef says even paste is allowed. [4] This is based on the magen avraham (316:24) that says your allowed to smear spit on the ground, since if what your smearing gets totally absorbed, therefore its not a problem of mimareach. Similarly, toothpaste doesn’t stay there for a long time. His second proof is that the Rama (Orach Chaim 326:10) doesn’t say that the problem with using a hard soap is mimareach but instead says molid, because the soap only remains there temporarily. Rav Soloveitchik agreed to this [5] He says that even though the ads claim to coat your tooth for 24 hours he wasn’t convinced this was true. And even if it is true, an invisible coating isn’t enough to assur it. [6] The Tzitz Eliezer rules like Rav Moshe. [7] He says that its not same as magen avraham because the spit the whole purpose is to get it into the ground, but with the toothpaste there is a purpose in the smearing even if just for a minute. (Says there’s no shiur for how long it has to be there

References

  1. (Rambam Hilchot Shabbat 11:5,6)
  2. (Shu"t Iggerot Moshe Orach Chaim, 1:112)
  3. (nefesh harav 168)
  4. Shu"t Yabia Omer 4:30.
  5. Nefesh Harav 168.
  6. (Aruch Hashulchan Yoreh Deah 83:15)
  7. Shu"t Tzitz Eliezer(7:30:8).