Bond Strength and Cytotoxicity of a Universal Adhesive According to the Hybridization Strategies to Dentin

Leite, Maria Luísa de Alencar e Silva; Costa, Carlos Alberto de Souza; Duarte, Rosângela Marques; Andrade, Ana Karina Maciel de; Soares, Diana Gabriela

doi:10.1590/0103-6440201801698

Acessibilidade / Reportar erro

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

Article • Braz. Dent. J. 29 (1) • Jan-Feb 2018 • https://doi.org/10.1590/0103-6440201801698 copy

Bond Strength and Cytotoxicity of a Universal Adhesive According to the Hybridization Strategies to Dentin

Authorship SCIMAGO INSTITUTIONS RANKINGS

Abstract

This study evaluated application protocol (etch-and-rinse/ER and self-etching/SE) and dentin wettability (wet and dry) on microtensile bond strength (μTBS) and transdentinal cytotoxicity of Scotchbond^TM Universal (SU) adhesive system. The μTBS values and fracture mode were registered 24 h after adhesive system application and resin composite block build-up (n=5). For analysis of transdentinal cytotoxicity, odontoblast-like MDPC-23 cells were seeded on pulpal surface of dentin discs (0.4 mm thick) adapted to artificial pulp chambers (n=8). The adhesive system was applied to occlusal surface, followed by 24-h incubation time. Cell viability (Alamar Blue) and morphology (SEM) were assessed. Adper Single Bond 2 and Clearfil SE Bond were used as positive controls of the ER and SE application protocols, respectively. No treatment was performed on negative control (NC) group. Data were analyzed by ANOVA and Tukey’s tests (α=5%). Higher μTBS values were found for ER mode in comparison with SE protocol (p<0.05). Dentin wettability had no effect on bond strength of SU in both the ER and SE techniques (p>0.05). Most fractures involved hybrid layer and/or adhesive layer. Neither variable prevented the intense toxic effects of adhesive systems on MDPC-23 cultured cells, since intense reduction in cell viability (±88%) and severe alterations in cell morphology were observed for all groups compared to NC, with no differences among them (p>0.05). Therefore, it was concluded that application of SU following the ER protocol had better adhesive performance. However, this adhesive system featured intense transdentinal cytotoxicity to pulp cells, regardless of application protocol and dentin wettability.

Key Words:
bond strength; cytotoxicity; adhesive system; pulp cell

Adhesive system	Composition	Application protocols
Scothbond Universal	Methacryloyloxydecyl dihydrogen phosphate (MDP), dimethacrylate resins, hydroxyethylmethacrylate (HEMA), methacrylate-modified polyalkenoic acid copolymer (Vitrebond ™ Copolymer), filler, ethanol, water, initiators, silane	Etch-and-rise (ER)	A layer 37% phosphoric acid gel (Scotchbond etchant; 3M ESPE) was applied onto dentin, and kept in place for 15 s; the acidic agent was rinsed out with distilled water for 30 s.	Wet Dentin: The excess water was removed by application of a filter paper during 30 s	One layer of the adhesive system (5 μL) was actively applied onto dentin for 20 s. A slight jet of air was applied for 5 sat a distance of 10 cm. The second layer of the adhesive (5 μL) was applied and light-cured under a halogen lamp (450 mW cm², Optlux Plus, GNATUS, Brazil ) for 10 s.
Scothbond Universal		Self-etching (SE)	Dentin surface was rinsed with distilled water for 30 s.	Dry Dentin: The excess water was removed by application of a filter paper during 30 s. A constant gentle air jet was applied during 10 sonto dentin surface.
Adper Single Bond 2	Dimethacrylate resins, hydroxyethylmethacrylate (HEMA), methacrylate-modified polyalkenoic acid copolymer (Vitrebond ™ Copolymer), filler, ethanol, water, initiators	Etch-and-rise (ER)	A layer 37% phosphoric acid gel (Scotchbond etchant; 3M ESPE) was applied onto dentin, and kept in place for 15 s; the acidic agent was rinsed out with distilled water for 30 s.	Wet Dentin: The excess water was removed by application of a filter paper during 30 s	One layer of the adhesive system (5 μL) was actively applied onto dentin for 20 s. A slight jet of air was applied for 5 sat a distance of 10 cm. The second layer of the adhesive (5 μL) was applied and light-cured under a halogen lamp (450 mW cm², Optlux Plus, GNATUS, Brazil) for 10 s
Clearfil SE Bond	Primer: MDP, HEMA, hydrophilic dimethacrylate camphorquinone, N,n-dimethyl-p-toluidine, water. Bond: MDP, Bis-GMA, HEMA, hydrophobic dimethacrylate camphorquinone, N,n-dimethyl-p-toluidine, silanized colloidal silica.	Self-etching (SE)	Dentin surface was rinsed with distilled water for 30 s.	Dry Dentin: The excess water was removed by application of a filter paper during 30 s. A constant gentle air jet was applied during 10 s onto dentin surface.	One layer of the primer (5μL) was actively applied onto dentin for 20 s. A slight jet of air was applied for 5 sat a distance of 10 cm. One layer of the adhesive (5μL) was applied and light-cured under a halogen lamp (450 mW cm², Optlux Plus, GNATUS, Brazil) for 10 s

mTBS (MPa)	SU:ER/wet	SU:ER/dry	SU:SE/wet	SU:SE/dry	ASB:ER/PC	CSB:SE/PC
mTBS (MPa)	51.33±8.77* a**	51.97±9.37 a	9.7±0.97 b	16.8±4.43 b	51.19±3.72 a	22.3±8.00 b

Cell viability percentage	SU:ER/wet	SU:ER/dry	SU:SE/wet	SU:SE/dry	ASB:ER/PC	CSB:SE/PC	NC
Cell viability percentage	11.59±0.6* b**	11.63±0.65 b	11.57±0.51 b	11.98±0.58 b	11.74±0.59 b	11.80±0.73 b	100.00±16.0 a

Fundação Odontológica de Ribeirão Preto Av. do Café, S/N, 14040-904 Ribeirão Preto SP Brasil, Tel.: (55 16) 3602-3982, Fax: (55 16) 3633-0999 - Ribeirão Preto - SP - Brazil
E-mail: bdj@forp.usp.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] Correspondence: Diana Gabriela Soares, Rua Humaitá, 1680, CEP: 14801-903 Araraquara, SP, Brazil. Tel: +55-16-3301-6477. e-mail: diana_odonto@yahoo.com.br