Dental Sealants: What They Are and Why the Dental Voucher Covers Them
There is a question that often comes up during appointments with school-age children: if the tooth does not yet have decay, why intervene? The answer lies in the shape of permanent molars, which usually erupt at around the age of six with grooves so narrow that no toothbrush bristle can reach inside them.
Dental sealants are designed to solve this anatomical problem. The fact that they are included in Portugal’s National Oral Health Promotion Programme also says a great deal about the difference between the cost of applying a sealant and the cost of treating the decay it can help prevent.
What Are Dental Sealants?
A dental sealant is a fluid material applied to the chewing surface of the back teeth. It fills the grooves and fissures and creates a physical barrier between the enamel and bacteria. Once hardened, it forms a smooth layer that helps prevent plaque from accumulating in the deepest and most inaccessible areas of the tooth. It is not a filling. No tooth tissue is removed, no drill is used and no anaesthetic is required. It is a preventive procedure applied to a healthy tooth precisely to help keep it healthy.
Why Are Molars the Most Vulnerable Teeth?
The chewing surface of a molar is not flat. It contains a system of grooves and fissures which, under a microscope, can be narrower than a single toothbrush bristle. In some cases, the fissure is deep and shaped rather like an hourglass, with a very narrow opening at the surface and a wider space underneath.
In these circumstances, brushing cleans the surrounding surface but not the inside of the groove. Bacterial plaque can settle there and remain protected from the toothbrush, saliva and, to a large extent, fluoride.
It is therefore no coincidence that many cavities in children and teenagers develop on these surfaces rather than on the smooth surfaces of the teeth. The first permanent molars are also exposed for longer because they usually erupt at around the age of six, often without parents realising that they are permanent teeth, as they appear behind the baby teeth without any tooth falling out beforehand.
How Are Sealants Applied?
The procedure takes only a few minutes per tooth and is painless. It begins with cleaning the tooth surface, followed by the application of an etching gel that makes the enamel microscopically rougher to improve adhesion. After the area has been thoroughly rinsed and dried, the sealant is applied and hardened using a curing light. The bite is then checked and adjusted if necessary.
The most important step for a successful result is isolation. The tooth surface needs to be completely dry at the time of application, which can be the main technical challenge in a child who finds it difficult to remain still or cooperate. If saliva contaminates the area, adhesion may be compromised and the sealant may come away within a few months.
No anaesthetic is required at any stage, which can make this a good first treatment experience for children who feel anxious in a dental setting.
At What Age Are Sealants Applied?
The ideal time is shortly after the tooth has fully erupted, when the chewing surface is completely accessible and decay has not yet had time to develop. In practice, this usually corresponds to two main periods: around six to seven years of age for the first permanent molars, and around eleven to thirteen for the second molars and premolars.
Premolars and baby teeth with particularly deep grooves may also be sealed, depending on the child’s individual risk of tooth decay.
Applying a sealant too early, while the tooth is still partially covered by gum tissue, can compromise isolation and durability. Applying it too late may mean that an early carious lesion is already present, which changes the treatment approach.
Dental Sealants and the Dental Voucher
Portugal’s National Oral Health Promotion Programme, managed by the Directorate-General of Health and commonly known through its Cheque Dentista, or Dental Voucher, includes the application of fissure sealants for school-age children through a specific voucher intended for this purpose.
Access is usually arranged through the school or family doctor, and the voucher can be used with a dentist participating in the programme, chosen by the family from the list of contracted professionals.
The public health reasoning behind this funding is straightforward: the cost of applying a sealant is only a fraction of the cost of treating the decay it can help prevent, without even considering the discomfort for the child or the fact that, once a filling has been placed, it may require maintenance or replacement over the course of a lifetime.
A tooth sealed at the right time may never need restorative treatment. Eligibility criteria, age groups covered and the number of vouchers available are updated periodically, so it is always worth confirming the current rules with the family doctor, the school or the dentist before assuming what is or is not covered.
How Long Do Sealants Last and What Maintenance Do They Require?
A well-applied sealant can remain effective for several years, although it will naturally wear down with chewing and may fracture or become partially detached, particularly during the first year. For this reason, applying a sealant does not eliminate the need for follow-up.
During routine dental appointments, the dentist checks whether the sealant is still intact and reapplies it when necessary. This is a quick procedure. A partially lost sealant that is not replaced may even create an additional plaque-retentive area, which is why regular checks are important.
Do Sealants Replace Brushing?
No, and it is important that parents understand this clearly. A sealant protects one specific surface: the chewing surface. The side surfaces, the areas in contact with neighbouring teeth and the area along the gumline remain exposed and still depend entirely on brushing and interdental cleaning.
A child with sealants but poor oral hygiene may simply develop decay on other surfaces.
Likewise, sealants do not replace controlling sugar intake, particularly how frequently sugary foods and drinks are consumed throughout the day, which has a major influence on the risk of tooth decay. We have brought together in another article on the blog the oral hygiene habits that can make a difference from an early age.
Sealants and Fluoride: Different Roles
The two work in a complementary rather than competing way. Fluoride strengthens enamel and supports remineralisation, with greater effectiveness on the smooth surfaces of the teeth, where it can reach more easily. A sealant creates a physical barrier over the surfaces where fluoride is less able to act precisely because those areas are difficult to reach. They therefore address different types of risk.
In children at higher risk of tooth decay, the two approaches are often combined: sealants on the molars and periodic fluoride varnish applications at the dental practice.
In another article on the blog, we explain the role of fluoride on the teeth, the most common myths surrounding it and the appropriate amounts according to age.
Dental Sealants in Adults
Sealants are less commonly used in adults, but there are clear indications.
They may be considered for adults with deep grooves and no existing decay, a high history of carious lesions, dry mouth caused by medication or greater difficulty maintaining oral hygiene because of limited mobility. The decision depends on the individual risk assessment and the condition of the tooth surface, rather than age alone.
When to Book an Assessment
If you have a child aged around six or seven, it is worth arranging an appointment to check whether the first permanent molars have erupted and whether they are suitable for sealants.
The opportunity can be relatively brief and is often missed precisely because no baby tooth falls out to signal the eruption of these molars.
During an assessment, the dentist can evaluate the child’s risk of tooth decay, identify which teeth may benefit from sealants and confirm whether the child falls within the current Cheque Dentista eligibility criteria.
