Filler Mixed Into Adhesives Does Not Necessarily Improve Their Mechanical Properties

C Tang; B Mercelis; F Zhang; C Mocquot; K Nakanishi; K Yoshihara; M Peumans; B Van Meerbeek

doi:10.2341/23-106-L

Filler Mixed Into Adhesives Does Not Necessarily Improve Their Mechanical Properties

Oper Dent. 2024 May 1;49(3):311-324. doi: 10.2341/23-106-L.

Authors

C Tang¹, B Mercelis², F Zhang³, C Mocquot⁴, K Nakanishi⁵, K Yoshihara⁶, M Peumans⁷, B Van Meerbeek⁸

Affiliations

¹ Chuliang Tang, KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT, Biomaterials Research Group & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium.
² Ben Mercelis, KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT, Biomaterials Research Group & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium.
³ Fei Zhang, KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT, Biomaterials Research Group & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium; KU Leuven (University of Leuven), Department of Materials Engineering, Leuven, Belgium; 3Université Lyon 1, Laboratoire des Multimatériaux et Interfaces, Villeurbanne, France.
⁴ Caroline Mocquot, Université Lyon 1, Laboratoire des Multimatériaux et Interfaces, Villeurbanne, France; Université Paris Cité, Faculté dentaire, Hôpital Rothschild, Assistance Publique-Hôpitaux de Paris, Paris, France.
⁵ Ko Nakanishi, KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT, Biomaterials Research Group & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium; Hokkaido University, Faculty of Dental Medicine, Department of Biomaterials and Bioengineering, Sapporo, Japan.
⁶ Kumiko Yoshihara, National Institute of Advanced Industrial Science and Technology (AIST), Health and Medical Research Institute, Kagawa, Japan; Okayama University, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Department of Pathology & Experimental Medicine, Okayama, Japan.
⁷ Marleen Peumans, KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT, Biomaterials Research Group & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium.
⁸ *Bart Van Meerbeek, KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT, Biomaterials Research Group & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium.

PMID: 38632849
DOI: 10.2341/23-106-L

Abstract

Objectives: To investigate the influence of filler type/loading on the micro-tensile fracture strength (μTFS) of adhesive resins, as measured 'immediately' upon preparation and after 1-week water storage ('water-stored').

Methods: The morphology and particle-size distribution of three filler particles, referred to as 'Glass-S' (Esschem Europe), 'BioUnion' (GC), and 'CPC_Mont', were correlatively characterized by SEM, TEM, and particle-size analysis. These filler particles were incorporated into an unfilled adhesive resin ('BZF-29unfilled', GC) in different concentrations to measure the 'immediate' μTFS. After 1-week water storage, the 'water-stored' μTFS of the experimental particle-filled adhesive resins with the most optimum filler loading, specific for each filler type, was measured. In addition, the immediate and water-stored μTFS of the adhesive resins of three experimental two-step universal adhesives based on the same resin matrix but varying for filler type/loading, coded as 'BZF-21' (containing silica and bioglass), 'BZF-29' (containing solely silica), and 'BZF-29_hv' (highly viscous with a higher silica loading than BZF-29), and of the adhesive resins of the gold-standard adhesives OptiBond FL ('Opti-FL', Kerr) and Clearfil SE Bond 2 ('C-SE2', Kuraray Noritake) was measured along with that of BZF-29unfilled (GC) serving as control/reference. Statistics involved one-way and two-way ANOVA followed by post-hoc multiple comparisons (α<0.05).

Results: Glass-S, BioUnion, and CPC_Mont represent irregular fillers with an average particle size of 8.5-9.9 μm. Adding filler to BZF-29unfilled decreased μTFS regardless of filler type/loading. One-week water storage reduced μTFS of all adhesive resins except BZF-21, with the largest reduction in μTFS recorded for BZF-29unfilled. Among the three filler types, the μTFS of the 30 wt% Glass-S and 20 wt% BioUnion filled adhesive resin was not significantly different from the μTFS of BZF-29unfilled upon water storage.

Conclusions: Adding filler particles into adhesive resin did not enhance its micro-tensile fracture strength but appeared to render it less sensitive to water storage as compared to the unfilled adhesive resin investigated.

MeSH terms

Composite Resins / chemistry
Dental Cements / chemistry
Dental Stress Analysis
Humans
Materials Testing*
Microscopy, Electron, Scanning
Particle Size
Resin Cements / chemistry
Surface Properties
Tensile Strength*

Substances

Resin Cements
Composite Resins
Dental Cements