Effect of aging and testing method on bond strength of CAD/CAM fiber-reinforced composite to dentin

Lucas Fracassi de Oliveira Lino; Camila Moreira Machado; Vitor Guarçoni de Paula; Hugo Alberto Vidotti; Paulo G Coelho; Ernesto Byron Benalcázar Jalkh; Thiago Amadei Pegoraro; Estevam Augusto Bonfante

doi:10.1016/j.dental.2018.08.302

Effect of aging and testing method on bond strength of CAD/CAM fiber-reinforced composite to dentin

Dent Mater. 2018 Nov;34(11):1690-1701. doi: 10.1016/j.dental.2018.08.302. Epub 2018 Sep 13.

Authors

Lucas Fracassi de Oliveira Lino¹, Camila Moreira Machado², Vitor Guarçoni de Paula³, Hugo Alberto Vidotti⁴, Paulo G Coelho⁵, Ernesto Byron Benalcázar Jalkh⁶, Thiago Amadei Pegoraro⁷, Estevam Augusto Bonfante⁸

Affiliations

¹ Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: lucas.fracassi.lino@gmail.com.
² Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: machado.camilam@gmail.com.
³ Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: vitorguarconi@gmail.com.
⁴ Departament of Prosthodontics, University Of Western São Paulo, José Bongiovani Street, 700 - Cidade Universitária, Pres. Prudente - SP, 19050-920, Brazil. Electronic address: hvidotti@gmail.com.
⁵ Department of Biomaterials, NYU College of Dentistry, Hansjörg Wyss Department of Plastic Surgery, NYU Langone Medical Center, Mechanical and Aerospace Engineering, NYU Tandon School of Engineering, 433 1st Avenue, Room 844, New York, NY 10010, United States. Electronic address: pgcoelho@nyu.edu.
⁶ Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: ernestobenalcazarj@gmail.com.
⁷ Departament of Implantology and Prosthodontics, Universidade do Sagrado Coração, Rua Irmã Arminda, 10-50, Bauru, SP, 17011-160, Brazil. Electronic address: pegthiago@gmail.com.
⁸ Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla, 9-75, Bauru, SP, 17012-901, Brazil. Electronic address: estevam.bonfante@fob.usp.br.

PMID: 30220508
DOI: 10.1016/j.dental.2018.08.302

Abstract

Objectives: To evaluate and compare the outcomes of shear (S) and microtensile (μT) bond strength tests of CAD/CAM fiber-reinforced composite (FRC) to dentin. Aging with either fatigue or thermocycling were conducted for comparison with baseline microtensile group.

Methods: CAD/CAM FRC (Trinia, Bicon LLC, Boston, USA) blocks were milled to 3-mm diameter cylinders for shear and to blocks (5×5×5mm) for μT. Sixty extracted human molars were flattened to obtain dentin surfaces and randomly divided in four groups (n=15): (1) SC: samples tested in shear 24h after bonding; (2) μTC: samples tested in μT 24h after bonding); (3) μTF: samples submitted to mechanical fatigue prior to μT test, and; (4) μTT: thermocycling prior to μT test. Bonding system was applied onto the FRC material (Cera-Resin Bond, CRB, Shofu Dental, Kyoto, Japan). A conventional three-step adhesive system (All-bond 3, Bisco, Schaumburg, USA) was use with a self-cure resin cement (C&B resin cement, Bisco, Schaumburg, USA). Bond strength tests were conducted at 0.75mm/min and data analyzed using Weibull distribution (p<0.05).

Results: Weibull contour plots showed a significantly lower characteristic strength (η) and Weibull modulus (m) for SC (η=6.9MPa and m=1.4) compared to μTC (η=20.9MPa and m=4.5). Fatigued and thermocycled μT groups presented significantly reduced characteristic strength (η=3.1MPa and η=4.1MPa, respectively) compared to μTC. Weibull modulus was significantly reduced only for SC and μTF groups compared μTC. Failure predominantly occurred at the cement/FRC interface.

Significance: FRC bonded to dentin samples presented lower Weibull modulus and characteristic bond strength when immediately tested in shear compared to microtensile. Aging through thermocycling or mechanical fatigue significantly reduced the characteristic strength in microtensile testing, with the majority of failures emerging between restoration material and cement interface.

Keywords: Bonding strength; Dentin; Dentin bonding.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Composite Resins / chemistry
Computer-Aided Design*
Dental Bonding / methods*
Dental Materials / chemistry*
Dental Stress Analysis
Dentin-Bonding Agents / chemistry*
Glass / chemistry*
Humans
In Vitro Techniques
Materials Testing
Methacrylates
Molar
Random Allocation
Resin Cements / chemistry
Surface Properties
Tensile Strength
Time Factors

Substances

All-Bond system
Composite Resins
Dental Materials
Dentin-Bonding Agents
Methacrylates
Resin Cements
fiberglass