# Uniquely high conversion and mechanically robust composite restorative materials for functionally elevated performance

> **NIH NIH R21** · UNIVERSITY OF COLORADO DENVER · 2023 · $441,500

## Abstract

The hydrogen bonding interactions in BisGMA and urethane dimethacrylate (UDMA) based resins provides
positive reinforcement to polymer networks that enhance overall strength. In this study, we are taking the
noncovalent interactions involving urethane functionality to an elevated level by preferentially inserting
urethane-carboxylate hydrogen bonding interactions and designing novel copolymers that reach near
quantitative conversion during a brief ambient temperature photopolymerization. The highly converted polymer
also displays extremely high modulus, strength and toughness. The proposed project will investigate the
structure-property relationships that allow this unusual combination of polymer properties to coexist while also
developing a fundamental understanding of the mechanism by which it occurs. The addition of filler to these
interesting resins will provide novel materials with substantially higher performance than existing composites.
negligible leachable free monomer and extreme mechanical strength combined with exceptional toughness.
Based on the hypothesis of a latent onset of polymeric vitrification following complete conversion, the
expectation is that polymerization stress will be quite low, which will be assessed. An unfilled polymer with
structure related to the central materials to be developed here demonstrated dramatically increased wear
resistance compared to both unfilled and filled commercial dental polymers and even out-performed a lithium
disilicate ceramic. Since the self-reinforced polymers involved here offer even greater strength, higher modulus
and more extensive toughness and resilience, we anticipate that the filled version of these materials will promote
even more impressive wear behavior. As the project progresses, biocompatibility using both direct contact and
elution testing will be in place to assure that only viable composite materials will be advanced. A mechanically
robust composite that does not leach unreacted monomer because the monomers are fully consumed during
polymer network formation has potential to mitigate the current concerns of both composite fracture and
secondary caries, which together account for the large majority of failures of resin-based composite restorations.
The pilot project proposed here will identify and validate practical candidate materials as a new class of
composite restoratives that represent a non-incremental advance in this field upon which the current and future
practice of dentistry remains so reliant. The comprehensive nature of the analytical characterization involved
here relies on previously peer-reviewed published techniques that meet the challenge of rigor.

## Key facts

- **NIH application ID:** 10646845
- **Project number:** 1R21DE032797-01
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** JEFFREY W. STANSBURY
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $441,500
- **Award type:** 1
- **Project period:** 2023-09-05 → 2026-09-04

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10646845

## Citation

> US National Institutes of Health, RePORTER application 10646845, Uniquely high conversion and mechanically robust composite restorative materials for functionally elevated performance (1R21DE032797-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10646845. Licensed CC0.

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