While the use of resin-containing materials is beneficial to the appearance of patients, these materials carry the risks of cytotoxicity and allergy. Most dental bonding technologies use primers containing the hydrophilic resins HEMA or TEGDMA. HEMA and TEGDMA have been shown to be a cause of these adverse effects due to the release of unpolymerized monomers in the surrounding tooth area, thereby triggering apoptosis or programmed cell death. Similarly, the adverse effects of bleaching agents on dental pulp and gingivae are well established. Therefore, methods for neutralizing the harmful effects of resin monomers and bleaching agents would be beneficial to current dental practices.

INNOVATION:  UCLA investigators have discovered that the presence of a confidential chemical inhibitor (CI) can inhibit HEMA, and TEGDMA-mediated apoptosis in various cell lines, including human and rat dental pulp stromal cells, immortalized human Oral Keratinocytes, human fibroblast cell line, the murine RAW 264.7 cell line, the human THP1 macrophage cell line, and the HaCaT skin keratinocyte cell line. Not only was cell death inhibited, but the presence of the CI also led to an increased viability and function of HEMA and TEGDMA treated cells. This in vitro data has been confirmed with in vivo rat models demonstrating that this CI can inhibit cell death induced by composites and bleaching systems. In addition, these rat models show the ability of this CI to restore the function of dental pulp stromal cells. The results indicate that CI prevents adverse effects mediated by HEMA, TEGDMA and bleaching agents.

POTENTIAL APPLICATIONS 

• Incorporation of CI as an additive to resin materials
• Use of CI in direct pulp-capping procedures to increase survival of the tooth
• Prophylactic application of CI to patient to prevent HEMA associated side effects
• Use of CI in deep cavity filling and tooth bleaching to minimize adverse effect to the pulp

ADVANTAGES

• Prevention of allergies and hypersensitivity in dental personnel and patients
• Improvement in healing, restoration and function of tooth and pulp

Reference: UCLA Case No. 2005-379