# Magnesium-organophosphate bone adhesives repurposed as endodontic cements for dental applications

## TL;DR

Researchers explored new dental cements made from magnesium and organophosphates, originally designed for bone adhesives, finding them promising for temporary dental restorations due to their strong bonding and sealing properties.

## Contribution

The study introduces magnesium-organophosphate cements as a novel class of resorbable materials for endodontic applications.

## Key findings

- The OPLS + TMP ∙ xH₂O formulation showed significantly higher shear bond strength to dentin compared to Cavit™.
- The TMP ∙ xH₂O + OPLS formulation demonstrated favorable sealing behavior and structural integrity.
- The tested cements are promising candidates for temporary restorations in non-retentive cavities.

## Abstract

This study investigated novel mineral-organic cements based on magnesium and organophosphates, originally developed as resorbable bone adhesives. The aim was to evaluate this new class of materials in a dental context, focusing on their suitability as temporary restorative materials in endodontic treatments.

Two thermally treated trimagnesium phosphate hydrates (Mg₃(PO₄)₂ ∙ xH₂O and Mg₃(PO₄)₂ ∙ 22H₂O (cattiite)) were each combined with two organophosphates (phosphoserine (OPLS) and sodium phytate (Na-IP6)), resulting in four adhesive formulations. These were compared with a commonly used material for temporary restorations (Cavit™) and a reference adhesive (TTCP + OPLS) regarding mechanical strength, sealing ability (methylene blue penetration) on bovine teeth, and structural integrity.

Shear bond strength to dental hard tissues was significantly higher for the new cements compared to Cavit™, particularly for the OPLS + TMP ∙ xH₂O formulation (4.35 ± 0.71 MPa vs. 0.29 ± 0.16 MPa; initially on dentin). pH and temperature during setting remained within clinical limits. TMP ∙ xH₂O + OPLS also showed the favorable sealing behavior, while Cavit™ performed similarly. Porosimetry, SEM and micro-CT supported the favorable profile of this formulation.

The combination of 400 °C sintered TMP ∙ xH₂O and OPLS proved most suitable in terms of handling, stability, and sealing. This system are promising candidates for temporary restorations, particularly in non-retentive cavities.

The tested cements may serve as novel resorbable, adhesive alternatives for temporary restorations. Future applications could include pulp capping or perforation repair.

The online version contains supplementary material available at 10.1007/s00784-026-06743-9.