Filling or inlay: which is the better solution for a damaged tooth?

Especially for larger defects in the back teeth, an inlay can be an interesting alternative to a direct filling. At the same time, scientific studies show that an inlay does not automatically last longer or offer better medical results. What matters includes the size of the defect, the remaining tooth structure, the material used, the load on the tooth and the quality of the treatment.

What is a conventional dental filling?

With a conventional filling, the diseased tooth structure is first removed. The filling material is then placed directly into the tooth, where it is shaped and cured.

Today, tooth-coloured composites and various self-adhesive materials are used in particular. Amalgam no longer plays a regular role in Germany. Since 1 January 2025, new rules for statutory health insurance care have applied to back teeth; under certain conditions, self-adhesive materials or bulk-fill composites are used.

The great advantage of a direct filling: it can be placed in a single appointment and usually does not require a dental technician. In addition – depending on the defect – relatively little healthy tooth structure has to be sacrificed.

What is an inlay?

An inlay, by contrast, is a custom-made filling. It is not modelled directly in the tooth but fabricated outside the mouth – traditionally in a dental laboratory or, increasingly, digitally using CAD/CAM technology – and then fitted into the prepared tooth.

Inlays are mainly used for larger defects in the back teeth, when a simple filling no longer offers the desired stability but the tooth still has enough healthy structure.

Depending on the extent, it may also be called an onlay or overlay. These additionally cover the cusps or larger parts of the chewing surface.

Which materials are available?

Composite

Composite is a tooth-coloured, resin-based material reinforced with glass or ceramic particles. It can be placed directly into the tooth and allows highly aesthetic results.

Its advantages are its comparatively low invasiveness, good aesthetics and the ability to treat smaller defects relatively easily.

Ceramic

Ceramic inlays are among the most popular indirect restorations. They are colour-stable, tooth-coloured and can be fabricated with great precision.

Ceramic is particularly suitable when aesthetics are important or when a larger defect needs to be reconstructed.

Gold

Gold is less aesthetic but has excellent mechanical properties. The KZBV (National Association of Statutory Health Insurance Dentists in Germany) describes gold inlays as a particularly durable restoration for back teeth. Gold is comparatively soft and can therefore be gentle on the opposing teeth.

For patients who value maximum aesthetics, however, gold plays a much smaller role today than it used to.

Which is better: filling or inlay?

There is no one-size-fits-all answer. For small and medium-sized defects, a direct composite filling is often the more conservative solution. For larger defects, an inlay or – if cusps need to be protected – an onlay can be appropriate.

The scientific evidence is interesting here: a systematic review and meta-analysis of randomised trials found no statistically significant difference in the longevity of direct and indirect composite inlays after five and eleven years respectively. However, the authors emphasise that the number of high-quality long-term studies is limited.

Another systematic review also concluded that the available studies are not sufficient to generally favour either a direct or an indirect restoration.

This means: an inlay is not automatically the “better” filling. Rather, its advantages lie in certain clinical situations – especially with larger defects and when a precise reconstruction fabricated outside the mouth makes sense.

Durability: how long does an inlay last?

The lifespan depends heavily on the material, the tooth, the load and oral hygiene. Blanket statements such as “inlays last 20 years” should therefore be treated with caution.

Very interesting long-term data come, for example, from a retrospective study by the Medical University of Innsbruck, which examined 547 back teeth with ceramic inlays and onlays. The estimated survival rate of the inlays was around 96.8% after ten years and 89.6% after twelve years.

For ceramic onlays, a systematic review shows medium-term survival rates of around 91 to 100 percent after two to five years. In studies with more than five years of follow-up, the figures ranged between 71 and 98.5 percent. Fractures were cited as the most common cause of failure.

Direct composite fillings can also function for many years. Their durability depends, among other things, on the size and position of the filling, caries risk, oral hygiene, bruxism and the quality of the workmanship.

How much does a filling or an inlay cost?

Prices vary considerably between Germany, Austria and Croatia.

Germany

Patients with statutory health insurance generally receive a medically necessary standard filling at no additional cost. Anyone who wants a more elaborate restoration, such as a particular composite restoration or an inlay, must pay the additional costs or the private service themselves in line with the individual agreement.

For a ceramic inlay, the private costs – depending on the dentist, size, material and laboratory – are often in the range of several hundred euros (between €450 for single-surface inlays and €950 for multi-surface inlays).

Austria

The 2026 Autonomous Fee Guidelines (AHR) of the Austrian Dental Chamber, for example, give guide values for cast gold inlays of €625 for a single-surface, €762 for a two-surface and €902 for a three-surface or multi-surface inlay. For composite fillings in the back teeth, they list €139, €201 and €262 for single-, two- and multi-surface restorations respectively.

A dental practice in Graz quotes a guide price for inlays and onlays starting at around €500 per tooth.

Croatia

In Croatia, prices are often significantly lower. Currently published price lists from clinics in Zagreb show, for example, composite fillings from around €55–70 and ceramic inlays at around €230–330.

An international clinic comparison site currently lists prices for inlays and onlays in Zagreb starting at around €212; specific offers from different clinics range, for example, from around €212 to just under €400.

This can make Croatia attractive in terms of price, especially for larger treatments. However, price should not be the only consideration: what matters are the qualifications of the treatment team, the materials used, diagnostics, warranty conditions and the organisation of follow-up care.

Rough price comparison

The table is for guidance only. An individual cost estimate may differ considerably depending on the tooth, material, laboratory, diagnostics and scope of treatment. In addition, the Austrian AHR are fee guidelines and not a binding price list for each individual practice.

What does the health insurance fund (ÖGK) pay?

Statutory health insurance funds in Austria generally classify inlays as a private service or special treatment. They usually only cover a small subsidy equivalent to a simple standard filling. You have to pay the difference (your own contribution) yourself. If you have private supplementary dental insurance, the costs will be reimbursed partially or in full, depending on your plan.

What does inlay treatment involve?

The process depends on whether the inlay is made conventionally in a laboratory or digitally on site at the practice.

Typically, an examination is carried out first, including X-ray diagnostics if medically necessary. The decay or damaged tooth structure is then removed.

For a conventional laboratory inlay, the tooth is then prepared and an impression or digital scan is taken. A temporary restoration can be placed until the final restoration is ready. The inlay is custom-made in the laboratory.

At the second appointment, the fit is checked. Colour, contact points and bite are assessed. The inlay is then permanently fixed – in the case of ceramic, usually with adhesive bonding.

Modern CAD/CAM procedures can partly shorten this process, because scanning, design and fabrication can all take place directly at the practice.

What do patients say?

Patient experiences are, of course, not scientific studies – but they can show which factors patients consider important in a treatment.

International review platforms feature numerous positive testimonials from patients who were treated in Croatia. They frequently mention not only the treatment itself but, in particular, transparent costs, personal care, fast communication and support with travel and accommodation.

A published testimonial from a patient at Dental Adria, for example, explicitly describes a combination of root canal treatment, inlay and composite filling and, besides the price, particularly highlights the care received during treatment.

Such testimonials should, however, always be seen in context: a positive review does not prove the medical quality of an individual treatment. For patients, independent diagnostics, comprehensible treatment planning and clear arrangements for aftercare and possible complications are therefore more important than star ratings alone.

Here is the direct comparison at a glance:

When is which better – filling or inlay?

• Choose a filling if the cavity is small. For minimal defects, an inlay would be unnecessary effort, as an inlay often even requires slightly more healthy tooth structure to be ground away so that the restoration has sufficient hold.
• Choose an inlay if a large part of the chewing surface or the tooth wall is already affected. A normal filling may eventually break or start to leak under high chewing pressure. An inlay stabilises the remaining tooth much better and protects it in the long term from needing a crown.

The decision should not be made on the basis of “an inlay is higher quality, so it must be better”.

For a small defect, a high-quality direct filling is often the more minimally invasive and more economical solution. For larger defects, an inlay or onlay can offer advantages in terms of shape, fit and reconstruction.

At the same time, scientific studies show that direct and indirect composite restorations can achieve comparable long-term results when properly indicated. There are also convincing long-term clinical data for ceramic inlays and onlays, especially when the indication is carefully assessed and the work is carefully carried out.

Anyone comparing Germany, Austria and Croatia should therefore not look at price alone. An affordable treatment is only truly good value if the diagnostics, material quality, treatment outcome, warranty and aftercare are right.

The most important question is therefore not: “Which is cheaper – a filling or an inlay?”

But rather: “Which restoration will preserve my tooth with as little loss of tooth structure as possible, functionally and reliably in the long term?”

This is exactly the decision that should be made together with the treating dentist after an examination and individual assessment.