Daphne Câmara Barcellos1, Beatriz Maria Fonseca2, César Rogério Pucci3, Bruno das Neves Cavalcanti4, Erasmo De Souza Persici5, Sérgio Eduardo de Paiva Gonçalves6. 1. São José dos Campos School of Dentistry, Department of Restorative Dentistry, UNESP - Univ Estadual Paulista, São José dos Campos, SP, Brazil. 2. Clinical Research Academic Group, Institute of Science and Technology, UNESP - Univ Estadual Paulista, São José dos Campos, SP, Brazil. 3. Department of Restorative Dentistry, UNESP - Univ Estadual Paulista, São José dos Campos, SP, Brazil. 4. Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry - University of Michigan, USA. 5. Electrical System, Embraer Defense and Security, Brazil. 6. Department of Restorative Dentistry, UNESP - Univ Estadual Paulista, São José dos Campos, SP, Brazil. Electronic address: sergio@fosjc.unesp.br.
Abstract
OBJECTIVE: This study assessed a 6 month resin/dentin bond's durability and cytotoxic effect of Zn-doped model dentin adhesives. The mechanical and physicochemical properties were also tested. METHODS: A model etch-and-rinse single-bottle adhesive was formulated (55wt.% Bis-GMA, 45wt.% HEMA, 0.5wt.% CQ, 0.5wt.% DMAEMA) and Zinc methacrylate (Zn-Mt) or ZnO nanoparticles (ZnOn) were added to the model's adhesive, resulting in three groups: Group Control (control model adhesive); Group Zn-Mt (1wt.% Zn-Mt incorporated to adhesive) and Group ZnOn (1wt.% ZnOn incorporated to adhesive). The microtensile bond strength (mTBS) was assessed after 24h or 6 months in water storage. Mechanical properties (diametral tensile strength/DTS, flexural strength/FS, flexural modulus/FM, resilience modulus/RM, and compressive strength/CS) and physicochemical properties (polymerization shrinkage/PS, contact angle/CA, water sorption/WS, and water solubility/WS) were also tested. Cytotoxicity was evaluated with SRB biochemical assay. RESULTS: No significant difference in the DTS, FS, FM, CS, CA, WS, and WS were found when 1% of ZnOn or Zn-Mt was added to the model dentin adhesive. Group Zn-Mt decreased the RM of adhesive. Groups Zn-Mt and ZnOn decreased the PS of adhesives. Group ZnOn reduced the cytotoxicity of adhesive. Group ZnOn preserved mTBS after 6 months storage without degradation areas as seen by SEM analysis. SIGNIFICANCE: The 1wt.% ZnOn may preserve the integrity of the hybrid layer and may reduce cytotoxicity and polymerization shrinkage of model dentin adhesive. The addition of Zn-Mt to the adhesive had no beneficial effects.
OBJECTIVE: This study assessed a 6 month resin/dentin bond's durability and cytotoxic effect of Zn-doped model dentin adhesives. The mechanical and physicochemical properties were also tested. METHODS: A model etch-and-rinse single-bottle adhesive was formulated (55wt.% Bis-GMA, 45wt.% HEMA, 0.5wt.% CQ, 0.5wt.% DMAEMA) and Zinc methacrylate (Zn-Mt) or ZnO nanoparticles (ZnOn) were added to the model's adhesive, resulting in three groups: Group Control (control model adhesive); Group Zn-Mt (1wt.% Zn-Mt incorporated to adhesive) and Group ZnOn (1wt.% ZnOn incorporated to adhesive). The microtensile bond strength (mTBS) was assessed after 24h or 6 months in water storage. Mechanical properties (diametral tensile strength/DTS, flexural strength/FS, flexural modulus/FM, resilience modulus/RM, and compressive strength/CS) and physicochemical properties (polymerization shrinkage/PS, contact angle/CA, water sorption/WS, and water solubility/WS) were also tested. Cytotoxicity was evaluated with SRB biochemical assay. RESULTS: No significant difference in the DTS, FS, FM, CS, CA, WS, and WS were found when 1% of ZnOn or Zn-Mt was added to the model dentin adhesive. Group Zn-Mt decreased the RM of adhesive. Groups Zn-Mt and ZnOn decreased the PS of adhesives. Group ZnOn reduced the cytotoxicity of adhesive. Group ZnOn preserved mTBS after 6 months storage without degradation areas as seen by SEM analysis. SIGNIFICANCE: The 1wt.% ZnOn may preserve the integrity of the hybrid layer and may reduce cytotoxicity and polymerization shrinkage of model dentin adhesive. The addition of Zn-Mt to the adhesive had no beneficial effects.
Authors: Stephanie R Lopes; Amanda G N Matuda; Raquel P Campos; Ana Paula V P Mafetano; Ana Helena M Barnabe; Gabriela S Chagas; Daphne C Barcellos; Li-Na Niu; Franklin R Tay; Cesar R Pucci Journal: Polymers (Basel) Date: 2022-06-19 Impact factor: 4.967