A filling is the most common restorative procedure in dentistry and, for most people, the least dramatic. Yet it is also where a lot of quiet confusion lives. Should you choose white or silver? Does that old metal filling need to come out? Why did one dentist suggest three fillings and another suggest a crown? If you live in Medellín or are here long enough to need one, this guide explains how fillings work, what the material choice actually involves and how to keep a small repair small.
What a filling actually fixes
Tooth decay starts when acids produced by bacteria dissolve the mineral of the enamel. Early, the damage may be limited to the outer surface and sometimes can be monitored or managed without drilling. Once decay breaks through into the softer dentine underneath, it tends to spread faster, and the usual answer is to remove the damaged tissue and seal the space with a restorative material. That sealed repair is the filling.
Fillings are also used for reasons other than decay: a chipped edge, a worn notch near the gumline, or replacing a previous restoration that has cracked or started to leak. Asking "what is this filling for?" is a reasonable first question, because the answer shapes everything else.
The materials you are likely to hear about
In Medellín, as in most places, the large majority of new fillings are tooth-coloured. You will hear them called resinas in Spanish. But it is worth knowing the full menu, because each material has a job it does well.
| Material | Where it tends to be used | Trade-offs to ask about |
|---|---|---|
| Composite resin (tooth-coloured) | Front and back teeth, small to moderate cavities | Technique-sensitive; needs a dry field; very large composites on heavy-biting teeth may wear or fracture |
| Glass ionomer | Root surfaces, areas near the gum, some children's teeth, temporary repairs | Releases fluoride, but generally less wear-resistant than composite |
| Amalgam (metal) | Back teeth, larger cavities, situations hard to keep dry | Durable and economical, but contains mercury; less commonly chosen today |
| Inlay or onlay (lab-made ceramic or resin) | Larger cavities where a direct filling would be weak but a crown is more than needed | Two visits, laboratory cost, needs adequate remaining tooth |
What the FDA says about amalgam
Expats from the United States sometimes arrive worried about the metal fillings they already have. The U.S. Food and Drug Administration describes amalgam as a mix of liquid mercury and a powdered alloy of silver, tin and copper, and notes that it is durable and the least expensive option (FDA, content current as of 2021). The agency says the available evidence does not show harm in the general population from the low levels of mercury vapour these fillings release, but it encourages non-amalgam materials, when the dentist considers them appropriate, for groups it considers potentially more susceptible. Those groups include pregnant and nursing women, women planning a pregnancy, children (especially under six), people with pre-existing neurological disease or impaired kidney function, and people with a known sensitivity to the metals involved.
Just as important for this guide: the FDA does not recommend removing amalgam fillings that are in good condition unless a health professional considers it medically necessary. Removing a sound filling sacrifices healthy tooth structure and briefly increases vapour exposure. If a clinic in any country suggests replacing every metal filling in your mouth purely because it is metal, that is a moment to slow down and ask why.
When an old filling really needs replacing
Fillings do not last forever, but age alone is not a diagnosis. These are the kinds of findings that usually justify a replacement:
- New decay around or beneath the edges of the filling
- A visible crack in the filling or in the tooth next to it
- A gap or step at the margin where food and plaque collect
- A piece of the filling has broken off
- Persistent sensitivity or pain that the dentist links to the restoration
And these, on their own, usually do not:
- The filling is old
- The filling is dark or a different colour from the tooth
- It is a metal filling and you would simply prefer white (a valid cosmetic choice, but a choice, not a necessity)
Ask the dentist to show you the problem on an intraoral photo or X-ray. Most clinics in Medellín use small cameras or digital radiographs, and seeing the shadow under an old filling makes the decision much easier to understand.
Filling, inlay or crown: why two dentists might disagree
When a cavity is large, dentists weigh how much healthy tooth will remain once the decay is removed. A tooth with thin, unsupported walls can split under chewing forces, and covering it with an onlay or crown may protect it. A tooth with strong remaining walls can often be restored with a direct filling, which removes less structure and costs less.
That is a judgment call, and reasonable dentists land in different places. If one plan says "crown" and another says "large composite", ask each dentist the same three questions:
- How much natural tooth will remain after the decay is removed?
- What is the risk of the tooth cracking if we choose the smaller option?
- If the smaller option fails, what would we do next, and would that be harder than doing the larger option now?
Their answers tell you far more than the price difference does. Our second-opinion guide covers how to put two plans side by side.
What the appointment usually involves
A typical filling visit
Composite fillings are bonded in layers and hardened with a curing light, so the tooth needs to stay dry. You may have a small rubber sheet (a dental dam) placed around the tooth to isolate it. It can feel odd, but it is a sign of careful technique, not a cause for concern.
The bite check at the end matters more than people think. A filling that sits even slightly high can make the tooth sore for days. If your bite feels "off" once the numbness wears off, contact the clinic and ask for an adjustment. It is usually a quick fix.
Questions to ask before anyone starts drilling
The last question is the one people forget. Sometimes decay reaches closer to the nerve than the X-ray suggested. The dentist may then recommend a protective liner, a temporary filling while the tooth settles, or, if the nerve is involved, discuss root canal treatment. Agreeing in advance how you want to be consulted if the plan changes mid-appointment avoids surprises in the chair.
Reading a filling quote
Fillings are often priced by the number of surfaces involved and the material, so two quotes can look very different for what sounds like "one filling". A small filling on the chewing surface of a molar is a different job from a large filling that wraps around three surfaces and rebuilds a corner. When you compare, check that each quote names the tooth, the surfaces and the material, and whether it includes anaesthetic, any X-ray and a follow-up bite adjustment.
| What the quote should show | Why it matters |
|---|---|
| Tooth number and position | Prevents confusion and lets you compare plans tooth by tooth |
| Number of surfaces | Larger fillings take longer and may be priced differently |
| Material | Composite, glass ionomer and amalgam behave and cost differently |
| Whether it replaces an old filling | Removing old material can add time and reveal hidden decay |
| What happens if the decay is deep | Liners, temporaries or referral for a root canal may change the plan |
After the filling
Expect the numbness to last a few hours. Avoid chewing hard food on that side until sensation returns, mostly so you do not bite your cheek or tongue. Mild sensitivity to cold for a short period afterwards is common with deeper fillings; worsening pain, throbbing or pain that keeps you awake is not something to wait out, and you should contact the clinic.
Keep a note of which teeth were filled, the material and the date. If you later see a dentist in another country, that information saves time and avoids an unnecessary replacement of perfectly good work.
Keeping small problems small
The cheapest filling is the one you never need. Regular check-ups catch decay early, when a filling is small and simple. Between visits, fluoride toothpaste, cleaning between teeth and limiting how often you snack on sugary or acidic foods all lower the odds of new cavities. Medellín's fruit juices and tinto with sugar are part of the pleasure of living here; sipping them slowly all day is what gives decay the most time to work.
Have a treatment plan or quote already?
Send the actual document, tooth numbers and any recent dental images you have. We can help you organize the questions to ask Medellín clinics and compare what is included. We do not diagnose or select treatment for you.
Frequently asked questions
Are tooth-coloured fillings always better than amalgam?
Not always. Composite is the usual choice for appearance and conservative preparation, but amalgam can still be useful in some situations. The dentist should explain why one material suits a particular tooth.
Should I replace my old metal fillings while I am in Medellín?
Only if there is a specific problem such as decay, cracking or a broken edge, or if you choose to for cosmetic reasons knowing the trade-off. The FDA does not recommend removing amalgam fillings in good condition without a medical reason.
How can I tell if a dentist is recommending too many fillings?
Ask to see each cavity on an X-ray or photo and ask whether any could be monitored. If the plan still seems large, a second opinion with the same images is reasonable.
Why is my filled tooth sensitive to cold?
Short-lived cold sensitivity is common after deeper fillings. A high bite, worsening pain or throbbing is different and should be checked by the dentist who placed the filling.
What is a dental dam and why did my dentist use one?
It is a thin sheet that isolates the tooth being treated, keeping it dry and protecting your airway from debris. It is a mark of careful technique, particularly for bonded fillings.
Sources and verification
Medical / dental disclaimer: Dental Medellin publishes general educational and travel-planning information. It does not diagnose, prescribe, or create a clinician-patient relationship. Treatment suitability, timing, medications, imaging and emergency decisions must be made by qualified clinicians who know your history and have examined you. If you have trouble breathing or swallowing, major facial trauma, uncontrolled bleeding, or severe rapidly spreading swelling, seek urgent local medical care.