"It's a baby tooth, it's going to fall out anyway." We hear it almost every week, sometimes from parents, sometimes from grandma, sometimes even from other professionals. It sounds logical. And it's one of the mistakes that costs a child's smile the most, because that tooth "that's going to fall out" can stay in their mouth for six, seven, or eight more years.
It's not a minor or rare problem. According to the Epidemiological Surveillance System of Oral Pathologies (SIVEPAB) 2022, cited by researchers from the University of Guadalajara, 73.2% of children aged 2 to 5 examined in Mexico had early childhood cavities. And in the 2019 data, of the baby teeth damaged by cavities in children under 10, almost 9 out of 10 remained untreated. The phrase "it's going to fall out anyway" is, literally, in the statistics.
That's the idea I want you to take away: baby teeth are not "practice" teeth. They're the ones that prepare the ground for everything that comes next. Let me explain why and what happens when a cavity is left "because it's going to fall out anyway."
In this article
Is it worth treating a cavity in a baby tooth?
Yes, it should always be treated. A cavity in a baby tooth progresses faster than in a permanent one, can hurt, become infected, and damage the tooth coming in underneath. Also, many baby teeth stay in the mouth until age 10 or 12.
Let's start with the fact almost no one keeps in mind: not all baby teeth fall out soon. The front ones are replaced around age 6 to 8, but the baby molars, which are exactly the ones that get the most cavities, stay until age 10 or 12. If your child is 4 and has a cavity in a molar, that tooth still has to work for 6 to 8 more years.
| Diente de leche | Sale | Se cae | Tiempo en boca |
|---|---|---|---|
| Incisivos (los de enfrente) | 6 – 16 meses | 6 – 8 años | ≈ 6 años |
| Colmillos | 16 – 23 meses | 9 – 12 años | ≈ 8 a 10 años |
| Primeras muelas | 13 – 19 meses | 9 – 11 años | ≈ 8 a 9 años |
| Segundas muelas | 23 – 33 meses | 10 – 12 años | ≈ 8 a 9 años |
Now, the second reason: the enamel of baby teeth is thinner than that of permanent teeth. That means a cavity reaches the nerve faster. What today is a little brown spot can become an abscess in a few months. And young children don't always complain: many simply stop chewing on that side, eat less, or sleep worse.
That's why I don't ask you "when is it going to fall out?", but "how many more years does that tooth have to work?". It completely changes the decision. And we still haven't talked about the most important thing: what that tooth is doing for the bones of their face.
Baby teeth are the foundation of their smile
Baby teeth serve to chew, speak, maintain the space for permanent teeth and, by chewing, they stimulate the growth of the jaws so that the permanent teeth, which are larger, can fit.
Think of a house under construction. Baby teeth are the formwork: they don't stay forever, but if they're removed too early or are poorly positioned, what gets built on top comes out crooked. That's how they work:
- They stimulate the growth of the jaws. Every time your child chews, the force their teeth and muscles exert tells the bone to grow. If a molar hurts and they stop chewing on that side, that stimulus is lost.
- They hold the place. Each baby tooth "reserves" the space for the permanent one coming underneath and serves as a guide for it to come out in the correct position.
- They allow eating well. A child with cavities eats less variety and avoids hard foods like fruits, vegetables, and meat.
- They help with speech. The front teeth are involved in sounds like "s," "f," and "t."
- They protect their self-esteem. Children notice, and other children notice too.
The first point is the one most parents don't know, and it's the heart of what I always explain in the office: permanent teeth are normally larger than baby teeth. For them to fit, the jaws have to grow enough during childhood, and chewing is one of their engines. That's why we say baby teeth are just as important as permanent ones: they prepare the space for the entire adult dentition.
When that growth is missing, what we see a lot in the office appears: crowded permanent teeth, canines that have no place to come out, and bites that need orthodontics. And here's another important connection: a jaw that grows too little can also leave less space to breathe through the nose. If your child snores, I recommend reading why snoring in children isn't normal.
You've seen what healthy baby teeth do. Now let's look at what happens, step by step, when one is left with a cavity.
The domino effect of an untreated cavity
An untreated cavity advances toward the nerve, causes pain and infection, can stain or deform the permanent tooth forming underneath and, if the tooth is lost too early, causes lack of space and crooked teeth.
"If it doesn't hurt, nothing's wrong." This is the second phrase we hear the most, and the problem is that a cavity doesn't warn you until it has already advanced. This is how it usually develops when left alone:
- White or brown spot. The enamel starts losing minerals. At this stage, sometimes you don't even need to "fill it": with fluoride and habit changes it can be stopped.
- Cavity. The little hole forms. It bothers them with sweets or cold, or food gets stuck in it.
- It reaches the nerve. Pain appears, especially at night. The child sleeps poorly, is irritable, and stops eating well.
- Infection and abscess. A little "ball" of pus forms on the gum, the face can swell, and sometimes there's fever. At this point it's already an emergency.
- Damage to the permanent tooth. Right beneath each baby tooth, the permanent tooth is forming. A nearby infection can leave it with stains or enamel defects (dentists call it Turner's hypoplasia), which will stay with them for life.
- Premature loss. If the tooth has to be removed early, the neighboring teeth shift into the gap and the permanent tooth is left without space to come out.
And it's not all dental. Early childhood cavities are associated with school absences, trouble concentrating, sleep and eating disturbances. A child in pain doesn't learn the same way. The researchers from the University of Guadalajara who have studied the topic sum it up well: it's a problem that affects school, emotional well-being, and the economy of families.
With all this, where does the idea that it doesn't matter come from? From several myths that are worth dismantling one by one.
Myths we hear every week (and what's true)
The most common myths are that baby teeth don't matter, that cavities in children are hereditary and inevitable, and that you shouldn't go to the dentist until it hurts. None of them are true.
These beliefs are passed down from generation to generation and almost always come from good intentions. But each one takes away an opportunity for your child to prevent problems. Here are the ones we hear most in the office:
| Myth | Reality |
|---|---|
| «Igual se le va a caer» | Las muelas de leche se quedan hasta los 10 – 12 años y guían a los permanentes. |
| «Si no le duele, no hay caries» | La caries duele cuando ya está avanzada. Se detecta antes en revisión. |
| «Tiene dientes débiles, como su papá» | Influye la genética, pero el azúcar, la higiene y el flúor pesan mucho más. |
| «El jugo natural no hace daño» | El jugo, aunque sea natural, tiene azúcar y ácido. Mejor la fruta entera y agua. |
| «El biberón en la noche lo ayuda a dormir» | Leche o jugo toda la noche bañan los dientes de azúcar. Es una causa clásica de caries temprana. |
| «Todavía está muy chiquito para el dentista» | La primera visita se recomienda al salir el primer diente o antes de su primer año. |
| «La pasta con flúor es peligrosa para niños» | En la cantidad correcta (un granito de arroz o un chícharo, según la edad) es la mejor protección. |
| «Lo llevamos cuando ya esté grande, para que coopere» | Las primeras visitas tempranas son justo las que le enseñan a no tener miedo. |
There's one more, which isn't a myth but rather a wrong approach: thinking of the dentist only to "fix" things. With children, the most valuable thing we do is make sure we don't have to fix anything. And when treatment is needed, today there are very gentle ways to do it.
How a cavity is treated in a child (without trauma)
It depends on how advanced it is: from fluoride and sealants for initial lesions, to fillings, nerve treatment, or crowns on baby teeth. If a tooth is lost too early, a space maintainer is placed.
Many parents delay the visit because they remember their own experiences with the dentist. Today's pediatric dentistry is very different: we explain everything in words the child understands, we go at their pace, and we start with the simplest thing. The goal isn't just to heal the tooth, but for your child to want to come back.
| Etapa | Qué hacemos | Objetivo |
|---|---|---|
| Mancha blanca inicial | Barniz de flúor, ajuste de dieta e higiene | Detener y remineralizar sin «tocar» el diente |
| Muelas sanas con surcos profundos | Selladores | Prevenir que la caries empiece |
| Cavidad pequeña o mediana | Resina del color del diente | Retirar la caries y devolver la forma |
| Caries que llegó al nervio | Tratamiento del nervio del diente de leche (pulpotomía) y corona | Conservar el diente hasta su recambio natural |
| Diente que no se puede salvar | Extracción + mantenedor de espacio | Guardar el lugar del diente permanente |
Notice the last column: in almost all cases, the goal is for the baby tooth to reach its replacement date. That's what protects the growth of the jaws and the space for the permanent tooth.
En AM Dental Studio también revisamos, en cada consulta infantil, cosas que no siempre se miran: cómo está creciendo el paladar, si hay hábitos como chupón prolongado o succión de dedo, si el niño respira por la boca o si rechina los dientes. Si te preocupa esto último, tenemos una guía sobre por qué los niños rechinan los dientes. Todo forma parte de la misma boca en crecimiento.
How to prevent cavities in baby teeth from home
Brush twice a day with fluoride toothpaste (a grain of rice before age 3, a pea from 3 to 6), avoid sugary liquids in a bottle or cup between meals and at night, and take your child to the dentist from their first tooth.
Childhood cavities are largely preventable. Nothing sophisticated is needed; consistency is needed. This is the list we give families in the office:
- From the first tooth: brush it twice a day with a fluoride toothpaste amount the size of a grain of rice.
- From 3 to 6 years: the amount goes up to the size of a pea. You brush or go over it; a young child doesn't have the skill to do it alone.
- Brushing at night is the most important. After it, only water.
- No bottle with milk, formula, or juice for sleeping. If they need it to calm down, let it be with water.
- Juices and sodas, out of everyday life. Plain water as the main drink; whole fruit instead of juice.
- Less sweet "snacking." It's not just how much sugar, but how many times a day. Better dessert along with the meal than sweets spread out all afternoon.
- First dentist visit when the first tooth appears or before their first birthday, and then regular check-ups.
- Check their teeth once a week with good lighting: opaque white spots near the gum are the first sign.
"It's going to fall out anyway" is a phrase we can stop repeating. Baby teeth do go away, yes, but what they build stays forever: the size of their jaws, the place of their permanent teeth, and their relationship with the dentist. If your child has a spot, a cavity, or simply has never been for a check-up, schedule an evaluation and clear up your doubts.
Frequently Asked Questions
¿Se deben curar las caries de los dientes de leche?
Sí. Pueden doler, infectarse y dañar al diente permanente. Además, las muelas de leche permanecen en la boca hasta los 10 o 12 años.
¿A qué edad se caen las muelas de leche?
Entre los 9 y los 12 años, aproximadamente. Los dientes de enfrente se cambian antes, entre los 6 y los 8 años.
¿Una caries en un diente de leche afecta al permanente?
Puede afectarlo. Una infección cercana puede dejar manchas o defectos en el esmalte del diente permanente que se forma debajo.
¿A qué edad debe ir un niño al dentista por primera vez?
Al salir su primer diente o antes de cumplir un año. Esas primeras visitas previenen caries y le quitan el miedo al dentista.
¿Qué pasa si se pierde un diente de leche antes de tiempo?
Los dientes vecinos pueden recorrerse y quitarle espacio al permanente. Por eso se coloca un mantenedor de espacio hasta que salga.
Sources consulted
- Caries temprana de la infancia: un reto para la salud bucal (Hernández Castillo y Becerra Ruiz, CU Altos UdeG) — Revista Elementos BUAP
- Resultados SIVEPAB 2019 — Secretaría de Salud
- Use of toothpaste and toothbrushing patterns among children — CDC MMWR
This article is for informational purposes and does not replace a personalized clinical evaluation.
