Are Bioactive Materials Better for Direct Restorations and Core Buildups?

Bioactive restorative materials promise something conventional composites do not: an active response at the tooth-restoration interface. Depending on the material class, that may mean fluoride release, calcium and phosphate availability, acid neutralization, or ion release intended to support remineralization. It is an appealing proposition, especially in patients who repeatedly develop caries around restorations.

But “bioactive” is a material description, not a clinical indication. For direct restorations and core buildups, the better material is still the one that fits the tooth, the patient’s caries risk, the ability to isolate, and the mechanical demands of the case.

What the evidence supports#

A recent systematic review and meta-analysis found that bioactive and smart restorative materials were associated with less secondary caries than conventional materials, with the clearest signal in glass-ionomer-based materials (Zailai et al., 2026). That is clinically relevant: recurrent caries is a major reason restorations fail.

The finding should not be read as a blanket endorsement of every product marketed as bioactive. Bioactive materials are a broad group that includes glass ionomers, resin-modified glass ionomers, giomers, alkasites, and ionic resin composites. They differ substantially in their chemistry, handling, strength, wear behavior, and the amount and durability of their ion release. A favorable result for one material class cannot automatically be transferred to another.

The clinical question is therefore not, “Is bioactive better than composite?” It is, “Which failure risk matters most in this restoration?”

Direct restorations: where bioactivity can help#

Bioactive materials are most compelling when recurrent caries risk or compromised isolation is the dominant problem.

For a patient with active caries, xerostomia, exposed root surfaces, or a history of restoration replacement because of marginal caries, an ion-releasing material can add a useful biological margin of safety. Cervical and root-surface sites are particularly relevant because they are often difficult to isolate and may have margins on dentin or cementum rather than enamel.

Giomers and other bioactive resin-based materials may also be reasonable for conservative Class I, Class II, and Class V restorations when their indicated mechanical limits match the case. In a 48-month randomized trial of non-carious cervical lesions, a giomer and a nanofilled composite both showed acceptable clinical performance, suggesting that an ion-releasing option does not necessarily require giving up predictable short-term service in the right indication (Lowenstein et al., 2025).

That does not make a bioactive material the automatic first choice for a large posterior composite. In a well-isolated, high-load restoration, bond quality, anatomy, polymerization, occlusion, and material wear resistance remain central to long-term success. Conventional direct composite has a deep evidence base and remains a dependable option when those factors favor it.

Core buildups are a different decision#

A core buildup restores form and retains the definitive restoration; it does not replace sound tooth structure or create a ferrule. The most important questions are how much tooth remains, whether a circumferential ferrule can be established, where the margins lie, whether isolation is achievable, and what forces the tooth will receive.

For that reason, no bioactive core material should be selected simply because it releases ions. A heavily compromised endodontically treated tooth under a full-coverage restoration needs a material-and-restoration plan that delivers retention, fracture resistance, seal, and an adequate ferrule. If those fundamentals are absent, a bioactive label will not compensate for them.

Bioactivity may still be valuable at the interface. In a deep carious lesion managed with selective caries removal, a three-year randomized clinical trial found comparable clinical performance for a bioactive ionic resin composite liner and a resin-modified glass-ionomer liner beneath posterior composite restorations (Ahmed et al., 2024). In a deep restoration, using an indicated liner or base beneath a durable composite core can be a more defensible strategy than relying on a bioactive bulk material to solve every problem at once.

A practical material-selection framework#

Use bioactive restorative materials when the biological challenge is real and the material's mechanical indication fits the case. They deserve serious consideration for patients at high caries risk, cervical or root-surface lesions, margins where moisture control is less predictable, and deep preparations where an ion-releasing liner or base is indicated.

Choose a conventional bonded composite when isolation is excellent and the priority is a strong, aesthetic, precisely contoured direct restoration in a load-bearing area. For a core buildup, prioritize remaining tooth structure, ferrule, retention, and the design of the definitive restoration; then choose an appropriately indicated core material.

Alkasite materials are another option in the broader bioactive category, but should be assessed by their own clinical data rather than grouped uncritically with glass ionomers or bioactive resins. A systematic review comparing alkasites with conventional materials found generally comparable clinical performance, while emphasizing the need for longer-term clinical evidence (Laporte et al., 2026).

The bottom line#

Bioactive materials are not universally better for direct restorations or core buildups. They can be better when recurrent caries risk, dentin margins, moisture-control limitations, or a deep preparation makes their ion-releasing behavior clinically useful. In mechanically demanding cases, the same basics still decide the outcome: diagnosis, isolation, preparation design, bond protocol, occlusion, and preservation of tooth structure.

The most useful approach is selective rather than ideological: use bioactivity where it solves a real biological problem, and do not let it distract from the mechanical requirements of a durable restoration.

Frequently asked questions#

Do bioactive restorative materials prevent recurrent caries?#

They may reduce secondary-caries risk, especially in higher-risk patients, but they do not eliminate the need for caries control, sound margins, and recall care. Their clinical benefit also varies by material class and indication.

Is a bioactive material better than composite for a core buildup?#

Not automatically. A core buildup should be chosen around retention, remaining tooth structure, ferrule, isolation, occlusal load, and the planned definitive restoration. Bioactivity can be a useful secondary benefit when an indicated material meets those mechanical requirements.

Can a bioactive liner be used under composite?#

Yes, when the product and clinical situation support it. In deep carious lesions, an ion-releasing liner or base beneath a conventional composite can combine interface-focused biological support with the mechanical advantages of the final composite restoration.