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Koshering Utensils for Pesach – Dental Fixatures


This week’s article will provide a halachic overview of the issues that involve dental prosthesis – medical devices used to restore dental defects – false teeth, fillings, crowns, or implants. Since the mouth is the most prominent place that should seemingly require cleaning before Pesach, do these apparatuses require cleaning or koshering? And if so, what kind? What is the difference between dishes and teeth? Pesach is associated with multiple customs. What is the source for the custom of not eating sharp foods on Pesach? Is this an obligation? Why are some people careful not to eat boiling hot foods on Pesach? Who should not consume chometz an entire day before Pesach? Of this and more in the coming article.


One of the most astounding creations in our body is our teeth. They grind; they chew; they are the first stop for digestion. And they flash white when you smile! While certainly no substitute for the real thing, false teeth can also do the job. Since people lose their teeth for a variety of reasons, medical science has found ways of supplementing lost teeth to enable chewing and to remedy the aesthetic damage caused by missing teeth. As early as the 7th century BC, Etruscans in northern Italy made partial dentures out of human (dead or alive) or other animal teeth fastened together with gold bands. Later, materials such as beeswax, animal bone or porcelain were used to construct dentures. Other materials utilized were ivory, rubber or even gold. Today, dentures are made of acrylics.

By the end of the 18th century, use of dentures became so widespread that a halachic debate arose revolving around two basic questions: must one have two sets of teeth, one for dairy and another fore meat? And what happens with the teeth on Pesach? Do the dentures need koshering, and how?

During the course of the halachic debate, rabbonim answered why natural teeth don’t require any form of koshering – halacha clearly states that one is permitted to eat boiling meat right after drinking hot milk. Why don’t natural teeth absorb flavor of the foods we eat?

Absorbing Flavors

The poskim mention several reasons why natural teeth don’t absorb food flavors. While most reasons apply also to dentures, one doesn’t. As a result, the poskim regard them differently.

The Beis Yitzchak (YD I, 43:12) writes that a living organ doesn’t absorb flavor. Therefore, a limb of a living animal that fell into boiling milk and was removed doesn’t absorb dairy flavor as long as the animal is still living, and consumption will not be forbidden once slaughtered. Here we learn of a rule: natural teeth don’t absorb flavors. Presumably, though, dentures do. However, the Beis Yitzchak refutes this assumption since even natural teeth are not fully alive, and there must be other reasons that apply even for dentures.


Dentures are viewed leniently for the same reasons that natural teeth do not absorb flavor. The following is a short summery of them. But first, some basic rules:

In order for a utensil to absorb flavor, the temperature of the forbidden food (chometz\meat\milk) must be yad soledes bo. Contemporary poskim debated what this temperature is. While some sources titrate it at 45 degrees Celsius, Rabbi Shlomo Zalman Auerbach proved it could not be less than 47 degrees Celsius and the Chazon Ish measured it at 49 degrees Celsius.

Additionally, for flavor to be absorbed in teeth hot food must be consumed directly from the pot in which it was cooked (kli rishon). Chometz flavor on Pesach is judges more stringently, and halacha forbids even flavor of chometz that was absorbed in a kli shieni.

The reasons to rule dentures leniently that are the same for natural teeth:

  1. By the time food comes in contact with teeth, both natural or synthetic, it is less than yad soledes bo and cannot be absorbed (Beis Yitzchak YD, I 43:12; Maharsham volume I, chapter 197; She’elat Shalom 195).
  2. People don’t usually drink or eat directly from a pot (Beis Ha’otzar chapter 39; She’elat Shalom 195, and others). Drinking from a cup that was warmed in a microwave will be discussed further on.
  3. Food does not remain next to the teeth very long. Even if the food is at the temperature of yad soledes bo, it does not remain so hot for more than a few seconds (Maharsham I 197; Beis Ha’otzar chapter 39). This leniency follows the Radvaz (volume I, chapter 223) and Chamudei Daniel (Ta’arovos, chapter 1:34) who maintain that absorption of prohibited flavors occurs only if the forbidden element remains in place for some time. If it only remains in place for a few seconds, there’s no harm done. However, the Ohr Chadash (95:9) and Pri Megadim (introduction) maintain that absorption occurs immediately.
  4. Dentures are made of non-absorbent materials (Beis Ha’otzar 39 and others). While lechatchila we are stringent with newly invented substances, here we can be lenient due to a combination of reasons, one of which is the fact that medical scientists produce dentures from non-absorbent materials in order to prevent decay and infection. Along with the fact that people cannot eat without their dentures it becomes a sha’as hadchak, and dentures can be seen as non-absorbent.
  5. The temperature of the mouth and the enzymes in the saliva were created by Hashem in order to break up food particles. It does the same for food particles on dentures (She’elat Shalom 195, mention in Darchei Teshuva YD chapter 89:11 and in Kaf Hachaim ibid, footnote 22). The Minchas Shlomo (volumes 2-3 chapter 60:30) sees this reason as the main reason for leniency.
  6. While the Beis Yitzchak (YD I chapter 43:12) writes that for Pesach there could have been reason to do hag’ala on natural teeth, since it is impossible, it is unnecessary. Dentures, however, if easily koshered, hag’ala is recommended because they do touch boiling chometz.

Early Halachic Rulings

Rabbi Avraham Palagi, Rav of Izmir (Pada Et Avraham, ma’arechet 40:1) notes a dispute between the sages of Tveria on the issue. The Sdei Chemed (volume 5, Chametz U’matza chapter 4:24) notes a dispute between his colleagues: Rabbi Avraham Mattiya Chalfan (Beis Ha’otzar 39) sees dentures as natural teeth because of the material it is made of, and because the food does not remain near it at yad soledes bo temperature for long. Rabbi Moshe Mishel Shmuel Shapira (Beis H’Otzar, Or Tzadikim chapter 3:2) though argues that dentures should be immersed in boiling water for Pesach for the following reasons:

  1. People consume food or beverages at temperatures that would forbid dishes had the food been forbidden, or directly from the vessel used to warm the food. Additionally, one may eat a boiling chunk of food, which according to he Maharshal doesn’t cool off even when transferred to another utensil.
  2. When eating sharp foods teeth expel the flavor that was absorbed. Therefore, when one eats matzah together with horseradish for maror (which is sharp), the flavor of the chometz he ate before Pesach will be discharged into his food resulting in eating chometz along with matzah.
  3. The Shulchan Aruch mentions the Jewish custom to scrape out the walls near the stove, despite not being the mainstream halacha. Therefore, there’s no reason not to kosher dentures.
  4. Koshering them is not difficult, therefore, there’s no reason not to.

The Maharsham writes that despite the possibility of refuting every one of the reasons to be lenient, since there are a combination of reasons, it is possible to be lenient.

The Drachei Teshuva (YD chapter 89:11) notes that he discussed the issue with a denture manufacturer in Vienna who told him that dentures (at the time) were produced from non-absorbent substance to prevent rot and danger of infection. While the Darchei Teshuva maintains that it is not required, preferably one should have separate sets for meat, dairy, and Pesach.

The Kaf Hachaim (YD 89:22) maintains that koshering dentures is unnecessary because food is not yad soledes bo and dentures are made of non-absorbent substances.

Rabbi Dovid Hoffman (Melamed L’holil, volume I, OC 93) summarizes all the opinions on the matter and rules that since dentures are ruined in boiling water, and since it is permitted, one need not be stringent.

Contemporary Poskim

Rabbi Tzvi Pesach Frank (cited in Tzitz Eliezer volume 9 chapter 25:5) rules that dentures should be cleaned with alcohol for Pesach.

The Shevet Halevi (volume I, 148); Rav Ovadia Yosef (Yechave Da’at volume I, chapter 8); and Rabbi Ben Tzion Aba Shaul (Ohr Letzion volume III chapter 10:15) rule leniently where dentures may be ruined because all the presumptions that demand koshering are not m’ikar hadin. Therefore, since they may be ruined there is no need to be scrupulous.

Rabbi Moshe Sternbuch (Teshuvos V’hanhagos volume II, chapter 211:7) writes that it is proper to be scrupulous and refrain from eating hot chometz with dentures 24 hours before Pesach and then to pour over them boiling water directly from a kli rishon. However, when Erev Pesach falls on Shabbos one is not obligated to eat a cold Shabbos meal (and cancel the mitzva of oneg Shabbos). One should, however, try not to eat boiling hot chometz. This appears to also be Rabbi Shlomo Zalman Auerbach’s opinion (Minchas Shlomo volume 2-3 chapter 50).

Touching Boiling Chometz

Rav Ovadia Yosef notes that the Ben Ish Chai (Bo, shana 2, footnote 5) defines yad soledes bo as the temperature one can ingest. Rav Moshe Feinstein (Igros Moshe OC I:5) rules that one can drink hot milk and then eat meat because yad soledes bo food cannot enter one’s mouth. Therefore, between dairy and meat one should clean his dentures just as he would clean his natural teeth.

On the other hand, Rabbi Shlomo Zalman Auerbach (Minchas Shlomo volumes 2-3 chapter 3) writes that this rule is not carved in stone: some people can drink or eat things that are yad soledes bo. Therefore, the main reason for leniency with dentures is the mouth’s internal temperature that ruins all flavors absorbed.

As mentioned earlier, the debate is not about the facts but about the definition of yad soledes bo. Halachic authorities who define it in the higher temperatures have a lower chance of people eating or drinking at that temperature. Those who see it as the lower temperatures have more room for scrupulousness. It remains, though, that even according to the Minchas Shlomo, one who never ingests too-hot food, and especially one who is sensitive to heat can certainly be lenient with his dentures.

Eating From the Pot

Early commentaries debate if a person eats directly from a pot or not, and if so, perhaps his mouth becomes a kli sheini.

This discussion is relevant for people who eat or drink microwaved food or beverages. The Shevet Halevi and Rav Ovadia Yosef note that most people don’t eat directly from pots, and even if they do drink microwaved foods and beverages, they don’t usually pour it directly on their teeth – they sip it with their lips. This would make the contact with teeth a kli shlishi which the Mishna Brura (451: 10) regards leniently even for Pesach. Those who see teeth as a kli shieni (due to eating boiling hot microwaved foods on the plate on which they were warmed) can be scrupulous for Pesach, but it is considered a chumra, not the mainstream halacha.

Review of Approaches

The Tzitz Eliezer (Part 9, chapter 25:10) summarizes the six different approaches to dentures in halacha:

1) Mainstream halacha requires one to rub and wash dentures well.

2) Some require immersion in boiling water.

3) Others require soaking in cold water for 3 days, changing the water every 24 hours (applicable only for people with more than one set of dentures or who can live without them for 3 days).

4) Some maintain that one should pouring boiling water on them directly from a pot.

5) Some are scrupulous not to eat chometz, and at least not hot chometz, for 24 hours proper to koshering.

6) The most scrupulous prepare another set of dentures for Pesach, as well as for meat and dairy.

Rabbi Shlomo Zalman Auerbach (Minchas Shlomo volumes 2-3 chapter 50) and others recommend refraining from consuming sharp foods on Pesach.

Crowns and Fillings

Halacha sees crowns, gold or silver teeth, and fillings as equal to dentures. However, with these even those who are scrupulous with dentures must rely on the lenient opinions. The scrupulous are careful not to eat hot food 24 hours before Pesach, and before the last time for eating chametz drink something as hot as they are used to drinking. Some are scrupulous not to eat sharp vegetables, but where refraining from it would cancel the joy of Yom Tov, or for the mitzva of eating maror, one need not exercise scrupulousness.


Mainstream halacha sees dentures, crowns, gold and silver teeth or fillings as being non-absorbent substances and therefore do not require koshering. Where it is not difficult, and when erev Pesach is not on Shabbos, the above-mentioned procedures can be employed, provided it is not at the price of other things and where there is no risk to the fixtures. Customarily, poskim are not strict with dentures or dental fixtures with issurim other than Pesach and only discuss chometz because the prohibition of chometz is more severe than others.



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