No Resin Close to the Pulp

No Resin Close to the Pulp

With Professor Dr. Till Dammaschke, Professor at the Department of Periodontology and Operative Dentistry of Münster University.
 
There is now a strong awareness that certain restorative materials can be detrimental to the vitality and longevity of exposed pulp. However, many dental professionals are unaware that the pulp can be impacted by a material even when it is not in direct contact. This has led to the widespread use of cytotoxic resin-based materials¹ in indirect pulp capping, with practitioners believing that the pulp is suitably protected by the dentine layer. Here, Prof. Dr. Till Dammaschke explains why this is not the case, why resin should not be used in proximity to the pulp, and why Biodentine^® is his material of choice for success in indirect pulp capping.

The myth of the impenetrable dentine barrier

There is no shortage of evidence against resin-based materials for direct pulp capping, with the British Endodontic Society (BES) citing their cytotoxicity and poor clinical outcomes in trials.1 In contact with pulp cells, these materials have shown poor pulpal healing, poor cell viability, pain, and chronic inflammation, among other drawbacks.^2,3,4,5,6,7 As such, dental professionals are duly careful with their choice of material when the pulp is exposed, opting instead for biocompatible, bioactive materials like Biodentine^® to preserve pulp vitality.  
 
However, in indirect pulp capping, a thin layer of dentine is left over the pulpal aspect of the cavity, forming a barrier between the pulp and the restorative material. In this scenario, many practitioners will choose materials that they would never place on exposed pulp, such as resin-based composites, believing the pulp to be protected from any cytotoxic effects. Prof. Dr. Till Dammaschke believes that this is far from the case. He says:

Prof. Dr. Dammaschke notes that the myth of the impenetrable dentine barrier is incredibly persistent, even in the literature. Indeed, even in a recent 2024 in-vitro study demonstrating the cytotoxic potential of certain resin-modified materials in direct contact with the pulp, researchers still advocated for their use in indirect pulp capping.³ This, he feels, is an error, as in vitro studies confirmed that resin monomers from resin-based dental materials can diffuse through the dentinal tubules and reach the pulp chamber^8,9 even when the dentin layer is thicker than 3 mm⁸.

Biodentine^® –a material of choice for deep indirect pulp capping

Biocompatibility with the pulp tissues ^10,11**

Even when the pulp is not exposed, Prof. Dr. Dammaschke emphasises that it is essential to use a biocompatible material based on high-purity tricalcium silicate, adapted for close-to-pulp applications, such as Biodentine^®. He recently conducted research on a class of resin-modified materials that contain biomaterials like calcium silicates, which claim to combine the biocompatible properties of these materials with the fast-setting time of resins.
 
In this in vitro study using human dental pulp cells, Prof. Dr. Dammaschke and colleagues compared Biodentine^® to five resin-modified materials containing calcium silicate or calcium hydroxide. Biodentine^® was the only material to demonstrate cell viability, with the resin-based materials all showing high cytotoxicity.6 This echoed the findings of another recent in-vitro study, in which three resin-modified materials containing calcium silicate or calcium phosphate were compared to Biodentine^® and found to have a higher cytotoxic potential.³

Biodentine^®’s biocompatibility can be attributed to its high purity.^10,11** Made using patented Active Biosilicate (ABS) Technology™, it contains high quantities of pure tricalcium silicate, without the heavy metals and contaminants typically found in Portland-cement-derived calcium silicate materials.^12,13 As such, it has no cytotoxic, inflammatory, sensitising, irritant, or mutagenic effects, even with direct pulp contact. ¹⁴

Superior bioactivity^{4,10,15-17***}

Biodentine^® is a bioactive material capable of inducing dentine remineralisation, even in caries-infected dentine.18-21 It releases high quantities of calcium, silicon, hydroxyl, and carbonate ions, which diffuse into the dentine tubules and form a mineral-rich “infiltration zone” at the dentine interface.^18-21 This promotes increased mineral uptake and stimulates the formation of reactionary dentine, reinforcing the residual dentine layer and supporting pulp healing.^18-21
 
Because some of the resin-modified materials he studied also contain calcium silicate phases, they are sometimes presented as having bioactive potential. In his research, however, Prof. Dr. Dammaschke observed lower ion release and weaker mineralisation signals compared with Biodentine^®6 – findings that echoed various other studies. ^15,16
 
He adds:
 
“These materials might have calcium silicates inside, but they’re contained within a resin matrix and polymerised. With Biodentine^®, you see remineralisation and healing because of the exchange of ions between the surface and the surrounding cells. But with these resin materials, the ions you need for bioactivity remain less available because of the resin matrix. Even if the material were not cytotoxic, ion exchange would be more limited, and this reduced exchange may affect bioactivity.”

Reliable, long-lasting pulp protection

In addition to their cytotoxicity and lack of bioactivity findings reported in several studies^15,16, resin-based materials are also known to be vulnerable to shrinkage^22,23. This may affect treatment outcomes, including sealing ability, microleakage, and tooth structure integrity. It also renders these materials unsuitable for bulk-filling in deep cavities close to the pulp, with incremental layering typically needed instead²⁴.
 
With its resin-free formula, Biodentine^® is not subject to shrinkage as resin-based materials are. Biodentine^® sets via a hydration reaction, not polymerization, meaning that, unlike resin composites, its setting mechanism does not involve polymerization shrinkage. On the opposite, Biodentine^® can slightly expand in humid environments, which may contribute to improving its clinical performance²⁵. It deposits mineral tags into the dentinal tubules, using micromechanical anchorage to form a tight interface and a strong bond with the dentine surface.^17,21 The result is a tight seal with favourable marginal adaptation and reduced microleakage when Biodentine^® is used.^19,26

Biodentine^®: Prof. Dr. Dammaschke’s choice for pulp health, vitality, and longevity

Prof. Dr. Dammaschke is unwavering in his belief that resin should not be used in contact or close proximity to the pulp:
 
“Whether you’re performing indirect or direct pulp capping, the effect is the same. Resin is toxic to the pulp, and it will find its way there even if you place it over dentine.”
 
Resin-modified materials offer a fast solution that can be appealing to a busy practitioner, but Prof. Dr. Dammaschke notes that, in his experience and in the referenced studies, this convenience may come with limitations regarding pulp response and clinical outcomes.

To support favourable pulp response, whether the pulp is exposed or not, Prof. Dr. Dammaschke advocates using a biocompatible, bioactive material adapted for close-to-pulp applications, capable of supporting pulp healing.
 
In his clinical experience, Prof. Dr. Dammaschke considers Biodentine^® a top-pick for this purpose.
The first dentine replacement of its kind, combining strong mechanical and pulp therapeutic properties, Biodentine^® can be used to fill the tooth from the floor of the cavity to the crown with the Bio-Bulk Fill technique****²⁷. The bulk material creates a thick barrier between the pulpal dentine and the final composite resin enamel restoration, preventing the passage of monomers from the latter material through the dentine barrier. Moreover, the definitive restoration can be placed in the same session, allowing clinicians to combine procedural efficiency with favourable patient outcomes.

Author Biography: 

Prof. Dr. Till Dammaschke DDM

Professor at the Department of Periodontology and Operative Dentistry, Münster University, Germany.

Prof. Dr. Till Dammaschke, born in 1965, began his studies in dentistry in 1987 and passed his state examination in 1993. From 1994, he was a research assistant at the Polyclinic for Restorative Dentistry at the University of Münster. He received his doctorate in Göttingen in 1996.

In 1998, he became a senior physician, in 2007 an academic councillor, and in 2009 an academic senior councillor. After his habilitation in 2008, he was appointed adjunct professor in 2012. Since 2015, he has been head of the “Cariology and Pediatric Dentistry” department at the Polyclinic for Periodontology and Restorative Dentistry in Münster.

Prof. Dammaschke’s research focuses on the vitality maintenance of the pulp and the application of calcium silicate-based cements and sealers in endodontics. He has received numerous prizes and awards for his scientific work and is active on several scientific advisory boards, including. He is a certified member of the European Society of Endodontology (ESE).

With over 100 publications and contributions to international textbooks, such as the chapter “Vital Pulp Therapy” in Cohen’s Pathways of the Pulp, Prof. Dammaschke is one of the leading experts in his field. He has given more than 200 training lectures and has been a speaker at numerous national and international congresses.

Memberships:

• Working Group for Basic Research (AfG)
• German Society for Endodontology and Dental Traumatology (DGET)
• German Society for Dental, Oral and Maxillofacial Medicine (DGZMK)
• German Society for Restorative Dentistry (DGZ)
• German Society of Pediatric Dentistry (DGKiZ)
• European Society of Endodontology (ESE)
• Association of University Lecturers for Dental, Oral and Maxillofacial Medicine (VHZMK)

This content has an educational purpose and reflects the interpretation of the cited scientific literature. The statements appearing in quotation marks reflect Prof. Dr. Dammaschke ‘s own views and clinical experience. It does not replace the Instructions for Use.
 
The author reports no financial or professional relationships with Septodont related to this article.
 
Biodentine^® is a Medical Device regulated with applicable requirements in the United States (FDA), European Union (MDR 2017/745), or other international markets.
 
Please read the instructions for use carefully before use, especially paying close attention to warnings, precautions, and contraindications. This medical device is a regulated health product. Communication to healthcare professionals only
 
Date of creation : [April 2026]

** Biodentine^® showed the highest % of cell biocompatibility. Properties verified by preclinical studies.
*** Properties demonstrated by bo