# Effect of Pre-Conditioning Temperature and Method of Curing on the Shear Bond Strength of Dual-Cure Composite Cements to Dentin

## TL;DR

This study examines how temperature and curing methods affect the bond strength of dental cements to teeth, finding that some cements are more stable at higher temperatures.

## Contribution

The study reveals how pre-conditioning temperature and curing methods influence the shear bond strength of dual-cure composite cements to dentin.

## Key findings

- Dual-cured cements showed higher bond strength at 25 °C compared to 50 °C.
- MaxCem Elite demonstrated the best resistance to temperature changes.
- Cements with benzoyl peroxide (BPO) showed better stability at different temperatures.

## Abstract

Dual-cure composite cements are an important element of modern dental prosthetics, enabling a stable and long-lasting bond between prosthetic restorations and tooth tissues. Thanks to the combined mechanism of chemical- and light-curing polymerization, they are characterized by high clinical versatility. Despite their wide application, the impact of storage/pre-conditioning temperature on the mechanical properties of dual-cure composite cements remains unclear. The study evaluated the shear bond strength (SBS) of the bond between four dual cements—Bifix Hybrid Abutment (VOCO GmbH, Cuxhaven, Germany), MaxCem Elite (Kerr Corporation, Orange, CA, USA), EnaCem HF (Micerium, Avegno, Italy), and Multilink Automix (Ivoclar Vivadent, Schaan, Lichtenstein)—and dentin depending on their storage temperature (25 °C or 50 °C) and curing method. The tests were carried out on extracted human permanent teeth. The cements were divided into two temperature groups—stored for 7 days at 25 °C or stored for 7 days at 50 °C—and then each of these two temperature groups was divided into two groups—light- and chemically cured (dual-cured, LC) and chemically cured only (CC). Dual-cured cements showed higher shear bond strength at 25 °C. Storage at 50 °C lowered the SBS values, especially for the purely chemically bound cements. LC Bifix Hybrid Abutment achieved the highest SBS at 25 °C, but at 50 °C its properties deteriorated. EnaCem HF showed higher strength at a lower temperature; MaxCem Elite was stable at both temperatures, whereas Multilink Automix showed lower SBS at 50 °C. The study showed that the chemical composition of cements, especially the presence of a benzoyl peroxide (BPO) initiating system, can play a key role in their SBS when bonded to teeth tissue and stability at different storage temperatures. MaxCem Elite showed the best resistance to temperature changes—it achieved the highest temperature stability in both temperature groups.