Deep Caries Treatment: When Do Bioactive Materials Help?
Evidence-based guide to deep caries treatment: selective removal, liner use, and choosing MTA or Biodentine for vital pulp therapy.
Research
By Dr. Mahmoud H. Al-Johani
Deep Caries Treatment: When Do Bioactive Materials Help?
A practical, evidence-based update for dental professionals on selective caries removal, cavity liners, and vital pulp therapy.
Deep caries treatment is where restorative dentistry stops being routine. The radiograph looks worrying. The patient may be symptomatic, but not necessarily in pain. The remaining dentine is thin. And the question in the operatory is rarely academic:
How can we manage this lesion without turning a vital tooth into an endodontic case?
It is tempting to make the answer material-led: MTA, Biodentine, a calcium-silicate liner, a bioactive restorative material, or a newer ion-releasing product. These materials matter—but they are not the first decision.
For a vital permanent tooth with deep caries and no pulp exposure, the most consistent message from recent research is straightforward: preserve tissue, avoid unnecessary pulpal excavation, and secure an excellent coronal seal. In other words, the strategy often matters more than the liner.
When a carious pulp exposure occurs and vital pulp therapy (VPT) is indicated, the material conversation becomes more important. Even then, current evidence supports both MTA and Biodentine rather than declaring one the universal winner.
This article separates these two clinical situations and translates the evidence into a practical approach for daily restorative care.
Deep caries treatment starts with the right clinical question
“Deep caries” is often discussed as if it were one treatment category. In reality, two very different scenarios are being grouped together.
| Clinical situation | The real question | Where the evidence is most useful | |---|---|---| | Deep caries without pulp exposure | How much carious dentine should be removed? Does a liner add benefit? | Selective caries removal, cavity lining, restoration seal, and tooth survival | | Carious pulp exposure | Can pulp vitality be maintained, and which VPT material should be chosen? | Direct pulp capping, partial pulpotomy, full pulpotomy, and calcium-silicate materials |
This distinction is more than semantics. Evidence that supports Biodentine or MTA during pulpotomy does not automatically mean that every deep cavity without exposure needs a calcium-silicate liner.
Selective caries removal: the key decision in deep caries treatment
For a vital permanent tooth with a deep lesion but no exposure, the central decision is usually the excavation endpoint.
Selective caries removal aims to remove infected dentine where a seal is needed while avoiding excessive excavation near the pulp. The clinical goal is not to “leave caries behind.” It is to disrupt the lesion, preserve the pulp-dentine complex, and create conditions for a durable restoration.
A 2023 clinical guide in the British Dental Journal makes an important practical point: the peripheral seal zone must be prepared to support reliable adhesion and a tight seal, while the pulpal aspect of a deep lesion is managed conservatively. Rubber dam isolation and meticulous bonding are not optional extras; they are part of the biological treatment.
What does the five-year evidence show?
A randomized clinical trial published in Clinical Oral Investigations followed 165 deep posterior lesions in 134 patients for five years. It compared selective removal to soft dentine (SRSD), with or without calcium silicate, against selective removal to firm dentine (SRFD) with calcium silicate.
The reported five-year success rates were striking:
| Strategy | Reported five-year success | |---|---:| | Selective removal to soft dentine + calcium silicate | 100% | | Selective removal to soft dentine without calcium silicate | 94.1% | | Selective removal to firm dentine + calcium silicate | 75.8% |
The overall difference between strategies was statistically significant (P = 0.012).
The key clinical lesson is not that every case requires a calcium-silicate liner. In fact, the two SRSD groups had similarly high success. The takeaway is that excavating closer to the pulp in an effort to reach firm dentine did not improve the outcome—despite the use of calcium silicate.
That fits the direction of modern minimally invasive dentistry: preserve what is biologically valuable, remove what is necessary to control the lesion and achieve a seal, and do not confuse “more excavation” with “better treatment.”
Do bioactive materials help after selective caries removal?
The short answer is: sometimes they may be reasonable, but routine survival benefit is not yet proven.
This is the part of the conversation where marketing language can easily outpace clinical evidence. “Bioactive” may describe calcium release, apatite formation, ion exchange, or a laboratory remineralisation effect. Those properties may be valuable. But patients need clinical outcomes: maintained vitality, minimal postoperative symptoms, a durable restoration, and fewer re-interventions.
A 2025 systematic review of cavity liners in vital permanent teeth with deep caries found no consistent significant difference in clinical outcomes between restorations placed with a liner and those placed without one. The certainty of evidence was low for failure and very low for postoperative sensitivity.
A 2023 network meta-analysis reached a similar overall conclusion after selective caries removal: it did not find a statistically significant difference in pulpal vitality or failure between calcium hydroxide and alternative liners. However, only two permanent-tooth studies contributed to that analysis, so a careful reading is essential.
The honest clinical position
Current evidence does not support a blanket rule that every deep cavity needs a liner to succeed. It also does not prove that every liner is equivalent.
A more defensible position is this:
After well-executed selective caries removal, routine lining has not consistently improved clinical survival when an effective coronal seal is achieved.
A liner may still be selected for a case-specific reason—for example, when the remaining dentine is extremely thin or when the clinician has a clear biologic rationale. The point is to avoid using a material by reflex. The material should serve the treatment plan, not become the treatment plan.
When the pulp is exposed: MTA vs Biodentine for vital pulp therapy
A carious exposure changes the conversation. Once VPT is indicated, calcium-silicate materials are no longer simply “liners”; they become part of a pulp-preservation procedure.
Recent evidence is reassuring. A 2024 systematic review and network meta-analysis included 21 randomized trials of VPT biomaterials in mature permanent teeth. It found no statistically significant difference in failure odds between Biodentine and MTA at 6, 12, or 24 months.
| Follow-up | Biodentine versus MTA: odds ratio for failure | |---|---:| | 6 months | 1.09 (95% CI 0.66–1.78) | | 12 months | 1.21 (95% CI 0.74–1.96) | | 24 months | 1.47 (95% CI 0.81–2.68) |
The same analysis found that calcium-hydroxide-based materials had significantly higher failure rates than MTA at all three time points.
A separate 2024 meta-analysis of 25 randomized trials reported an overall pulpotomy success rate of 86.7% in permanent teeth with carious pulp exposure. It also found better success for MTA than calcium hydroxide in direct comparison. Evidence for Biodentine was favourable, but less precise.
What matters most in VPT?
MTA and Biodentine are both credible, evidence-supported choices. But neither material compensates for an incomplete protocol.
The essentials remain familiar:
- Sound pulpal diagnosis and thoughtful case selection
- Rubber dam isolation and asepsis
- Appropriate removal of inflamed coronal pulp tissue when indicated
- Effective haemostasis
- A material placed according to its instructions for use
- A high-quality, durable coronal seal
In practical terms, successful VPT is not a “product choice.” It is a sequence of well-controlled clinical decisions.
MTA vs Biodentine: where is the practical difference?
If clinical success is broadly similar, how should a clinician choose between MTA and Biodentine?
One useful differentiator is discoloration. In a randomized trial of mature permanent molars treated with full pulpotomy, the proportion of teeth showing discoloration at 12 months was:
| Material | Teeth with discoloration at 12 months | |---|---:| | White MTA | 87.5% | | Biodentine | 48% | | TotalFill | 53% |
Biodentine and TotalFill did not differ significantly, while white MTA was associated with significantly greater colour change.
That matters in visible teeth, thin facial walls, and cases where the patient has high aesthetic expectations. It does not mean MTA is a poor clinical material. It means that, when other factors are equal, a lower-discoloration option may make more sense.
A chairside checklist for deep caries treatment
Before reaching for a pulp liner or a VPT material, pause and ask:
- Is the pulp likely vital and capable of healing? Review symptoms, sensibility testing, radiographic findings, and restorability.
- Is this a deep lesion without exposure—or has a carious exposure occurred? The treatment pathway changes at that point.
- Can I achieve effective isolation and a durable coronal seal? If not, reassess the restorative plan before proceeding.
- Have I preserved tissue at the pulpal wall while establishing a clean peripheral seal zone? This is the core of selective caries removal.
- If VPT is indicated, am I following a complete clinical protocol rather than relying on material selection alone?
- Does the material choice fit the tooth, the aesthetic demand, the operator’s familiarity, and the final restoration plan?
Frequently asked questions
Is selective caries removal safe for deep caries in permanent teeth?
For appropriately selected vital permanent teeth, current clinical evidence supports selective caries removal as a conservative strategy that can help preserve pulp vitality and avoid unnecessary tooth removal. The peripheral seal and restoration quality are crucial.
Do I need a calcium-silicate liner in every deep cavity?
No. Current evidence does not show a consistent clinical survival advantage from routine liner placement after selective caries removal. Use a liner when there is a clear indication, not simply because the cavity is deep.
Is Biodentine better than MTA for vital pulp therapy?
Available evidence does not show a statistically significant difference in VPT failure between Biodentine and MTA through 24 months. Biodentine may be preferable where discoloration risk is a key consideration.
Is calcium hydroxide still appropriate for vital pulp therapy?
Calcium hydroxide has an important historical role, but contemporary comparative evidence in mature permanent teeth favours calcium-silicate materials such as MTA and Biodentine for VPT.
The bottom line
Deep caries treatment is not about removing every last trace of softened dentine and hoping a bioactive material will protect the pulp afterwards.
It is about making the least invasive, best-sealed, diagnosis-led intervention that gives the pulp-dentine complex the best chance to remain healthy.
For an unexposed deep lesion, let selective caries removal and coronal sealing lead the plan. When a carious exposure requires VPT, MTA and Biodentine are both evidence-supported options, with Biodentine offering an advantage when discoloration matters.
Bioactive materials can help. But in deep caries treatment, the clinical strategy comes first.
This article is for professional education and evidence discussion. Management should be individualized according to pulpal diagnosis, symptoms, restorability, isolation, radiographic findings, patient preferences, and the clinician’s judgment.
References
- Gözetici-Çil B, Çetin T, Bittar A, et al. Clinical outcomes of selective removal to soft dentin versus firm dentin for deep caries lesions: a randomized controlled trial up to 5 years. Clinical Oral Investigations. 2025;29:23. https://doi.org/10.1007/s00784-024-06109-z
- Gözetici-Çil B, Erdem-Hepşenoğlu Y, Tekin A, Özcan M. Selective removal to soft dentine or selective removal to firm dentine for deep caries lesions in permanent posterior teeth: a randomized controlled clinical trial up to 2 years. Clinical Oral Investigations. 2023;27:2125–2137. https://doi.org/10.1007/s00784-022-04815-0
- Kosan E, et al. Efficacy of different cavity liners compared to no cavity lining in managing deep caries in vital permanent teeth: a systematic review. Clinical Oral Investigations. 2025. https://doi.org/10.1007/s00784-025-06479-y
- Miotti LL, et al. Does the liner material influence pulpal vitality in deep carious cavities submitted to selective caries removal? A network meta-analysis review. Clinical Oral Investigations. 2023;27:7143–7156. https://doi.org/10.1007/s00784-023-05372-w
- Lim ZE, Duncan HF, Moorthy A, et al. Minimally invasive selective caries removal: a clinical guide. British Dental Journal. 2023;234:233–240. https://doi.org/10.1038/s41415-023-5515-4
- Komora P, et al. Comparison of bioactive material failure rates in vital pulp treatment of permanent matured teeth: a systematic review and network meta-analysis. Scientific Reports. 2024;14:18421. https://doi.org/10.1038/s41598-024-69367-7
- Li W, et al. Efficacy of pulpotomy for permanent teeth with carious pulp exposure: a systematic review and meta-analysis of randomized controlled trials. PLOS ONE. 2024;19:e0305218. https://doi.org/10.1371/journal.pone.0305218
- Taha N, et al. Coronal discoloration induced by calcium silicate-based cements used in full pulpotomy in mature permanent molars: a randomized clinical trial. Clinical Oral Investigations. 2022. https://doi.org/10.1007/s00784-022-04799-x