The mechanical, wear, antibacterial properties and biocompatibility of injectable restorative materials under wet challenge

Yanning Chen; Xuedong Bai; Mengxiao Xu; Tianyu Zhou; Yee Man Loh; Chunjin Wang; Edmond Ho Nang Pow; James Kit Hon Tsoi

doi:10.1016/j.jdent.2024.105025

The mechanical, wear, antibacterial properties and biocompatibility of injectable restorative materials under wet challenge

J Dent. 2024 May 1:146:105025. doi: 10.1016/j.jdent.2024.105025. Online ahead of print.

Authors

Yanning Chen¹, Xuedong Bai¹, Mengxiao Xu¹, Tianyu Zhou¹, Yee Man Loh², Chunjin Wang², Edmond Ho Nang Pow³, James Kit Hon Tsoi⁴

Affiliations

¹ Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China.
² State Key Laboratory of Ultra-precision Machining Technology, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, Hong Kong, PR China.
³ Prosthodontics, Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China.
⁴ Dental Materials Science, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region, PR China. Electronic address: jkhtsoi@hku.hk.

PMID: 38697507
DOI: 10.1016/j.jdent.2024.105025

Abstract

Objectives: To evaluate the mechanical, wear, antibacterial properties, and biocompatibility of injectable composite materials.

Methods: Two injectable composite resins (GU and BI), one flowable composite resin (FS), and one flowable compomer (DF), in A2 shade, were tested. Mechanical properties were tested via three-point bending test immediately after preparation and after 1-day, 7-day, 14-day, and 30-day water storage. Under water-PMMA slurry immersion, specimens were subjected to a 3-body wear test (10,000 cycles) against stainless steel balls, while the roughness, wear depth, and volume loss were recorded. After 1-day and 3-day MC3T3-E1 cell culture, cell viability was evaluated with CCK-8 test kits, while the cell morphology was observed under CLSM and SEM. Antibacterial properties on S. mutans were assessed via CFU counting, CLSM, and SEM observation. SPSS 26.0 was used for statistical analysis (α = 0.05).

Results: The mechanical properties were material-dependent and sensitive to water storage. Flexural strength ranked GU > FS > BI > DF at all testing levels. Three nanocomposites had better wear properties than DF. No significant difference on 1-day cell viability was found, but DF showed significantly lower cell proliferation than nanocomposites on 3-day assessment. GU and FS had more favourable cell adhesion and morphology. CFU counting revealed no significant difference, while FS presented a slightly thicker biofilm and BI showed relatively lower bacteria density.

Conclusions: Injectable nanocomposites outperformed the compomer regarding mechanical properties, wear resistance, and biocompatibility. The tested materials presented comparable antibacterial behaviours. Flowable resin-based composites' performances are affected by multiple factors, and their compositions can be attributed.

Clinical significance: A profound understanding of the mechanical, wear, and biological properties of the restorative material is imperative for the clinical success of dental restorations. The current study demonstrated superior properties of highly filled injectable composite resins, which imply their wider indications and better long-term clinical performances.

Keywords: Antibacterial behaviour; Biocompatibility; Injectable composite resin; Mechanical properties; Three-body wear.