Benefits of Nonthermal Atmospheric Plasma Treatment on Dentin Adhesion

Autor(es)

Ayres, A. P. ^{[1, 2]} ; Freitas, P. H. ^[3] ; De Munck, J. ^{[1, 2]} ; Vananroye, A. ^[4] ; Clasen, C. ^[4] ; dos Santos Dias, C. T. ^[5] ; Giannini, M. ^[6] ; Van Meerbeek, B. ^{[1, 2]}

Afiliação do(s) autor(es)

^[1] Univ Leuven, KU Leuven, Dept Oral Hlth Sci, BIOMAT, Leuven - Belgium

^[2] Univ Hosp Leuven, UZ Leuven, Dent, Leuven - Belgium

^[3] Univ Manitoba, Fac Hlth Sci, Coll Dent, Dept Restorat Dent, Winnipeg, MB - Canada

^[4] Univ Leuven, KU Leuven, Chem Engn Dept, Soft Matter Rheol & Technol, Leuven - Belgium

^[5] Univ Sao Paulo, Luiz de Queiroz Coll Agr, Exact Sci Dept, Piracicaba, SP - Brazil

^[6] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Restorat Dent, Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Operative Dentistry; v. 43, n. 6, p. E288-E299, NOV-DEC 2018.
• Citações Web of Science: 0

Resumo

Objectives: This study aimed to evaluate the influence of two nonthermal atmospheric plasma (NTAP) application times and two storage times on the microtensile bond strength (mu TBS) to dentin. The influence of NTAP on the mechanical properties of the dentin-resin interface was studied by analyzing nanohardness (NH) and Young's modulus (YM). Water contact angles of pretreated dentin and hydroxyapatite blocks were also measured to assess possible alterations in the surface hydrophilicity upon NTAP. Methods and Materials: Forty-eight human molars were used in a split-tooth design (n=8). Midcoronal exposed dentin was flattened by a 600-grit SiC paper. One-half of each dentin surface received phosphoric acid conditioning, while the other half was covered with a metallic barrier and remained unetched. Afterward, NTAP was applied on the entire dentin surface (etched or not) for 10 or 30 seconds. The control groups did not receive NTAP treatment. Scotchbond Universal (SBU; 3M ESPE) and a resin-based composite were applied to dentin following the manufacturer's instructions. After 24 hours of water storage at 37 degrees C, the specimens were sectioned perpendicular to the interface to obtain approximately six specimens or bonded beams (approximately 0.9 mm(2) in cross-sectional area) representing the etch-and-rinse (ER) approach and another six specimens representing the self-etch (SE) approach. Half of the mu TBS specimens were immediately loaded until failure, while the other half were first stored in deionized water for two years. Three other bonded teeth were selected from each group (n=3) for NH and YM evaluation. Water contact-angle analysis was conducted using a CAM200 (KSV Nima) goniometer. Droplet images of dentin and hydroxyapatite surfaces with or without 10 or 30 seconds of plasma treatment were captured at different water-deposition times (5 to 55 seconds). Results: Two-way analysis of variance revealed significant differences in mu TBS of SBU to dentin after two years of water storage in the SE approach, without differences among treatments. After two years of water aging, the ER control and ER NTAP 10-second groups showed lower mu TBS means compared with the ER NTAP 30-second treated group. Nonthermal atmospheric plasma resulted in higher NH and YM for the hybrid layer. The influence of plasma treatment in hydrophilicity was more evident in the hydroxyapatite samples. Dentin hydrophilicity increased slightly after 10 seconds of NTAP, but the difference was higher when the plasma was used for 30 seconds. Conclusions: Dentin NTAP treatment for 30 seconds contributed to higher mu TBS after two years of water storage in the ER approach, while no difference was observed among treatments in the SE evaluation. This result might be correlated to the increase in nanohardness and Young's modulus of the hybrid layer and to better adhesive infiltration, since dentin hydrophilicity was also improved. Although some effects were observed using NTAP for 10 seconds, the results suggest that 30 seconds is the most indicated treatment time. (AU)

• Processo FAPESP: 13/15952-7 - Efeito da aplicação de plasma de argônio na superfície dentinária e na adesão do material restaurador
• Beneficiário: Ana Paula Almeida Ayres
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 15/05939-9 - Influência do plasma atmosférico não térmico na interface resina-dentina
• Beneficiário: Ana Paula Almeida Ayres
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado