Microshear bond strength of universal adhesives to enamel and dentin: an eighteen-month in vitro study

• Autor(a) principal: Garcia, Rubens Nazareno
• Data de Publicação: 2021
• Outros Autores: Araújo Neto, Vitaliano Gomes de, Silva, Camila Ribeiro, Miguel, Luiz Carlos Machado, Giannini, Marcelo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Dental Science
• Texto Completo: https://ojs.ict.unesp.br/index.php/cob/article/view/2791

Objective: The aim of this study was to evaluate the microshear bond strength of Universal adhesives to enamel anddentin after one week and eighteen months of water storage. Material and Methods: Fragments from the buccalsurfaces of 80 bovine teeth were prepared (12x5x1.0 mm) and ground to obtain flat surfaces of enamel and dentin.Samples were randomly assigned to 8 experimental groups (n=10), according to four adhesive systems (Adper SingleBond Plus/control – not a Universal adhesive/ASB; Ambar Universal/AUN; Prime&Bond Active/PBA and ScotchbondUniversal/SBU) and two water-storage times (one week and eighteen months after sample preparations). Adhesiveswere applied according to the manufacturers’ instructions and molds were positioned over bonded surfaces. A flowablecomposite was poured into the molds to fill up their internal diameter and obtain resin cylinder (1.0mm height/0.7mminternal diameter) after light-curing. Bond strength was determined using a testing machine (0.5 mm/min) and datawere statistically analyzed by two-way analysis of variance (ANOVA) and the post-hoc Tukey’s test (alpha=0.05).Failure patterns were analyzed for all resin cylinder tested. Results: For enamel, differences among adhesives wereobserved only at 18 months, in which SBU produced lower bond strength values (15.9±3.0 MPa) than the othersuniversal adhesives (AUN: 19.3±4.8 and PBA: 21.4±2.1 MPa) (p<0.05). For dentin, there were differences amongadhesives only at 7 days, with PBA showing the highest bond strength (37.4±4.9 MPa) and ASB the lowest one(19.4±3.9 MPa) (p<0.05). Enamel and dentin bond strength of all adhesives decreased significantly after 18 monthsand reduction percentage varied from 36.9 to 52.4 for enamel and from 35.1 to 62.8 for dentin. Adhesive and mixedfailures showed high incidences. Conclusion: Results suggested that adhesives presented differences among themdepending on type of hard dental tissue and evaluation time. Enamel and dentin bond strengths of control and alluniversal adhesives tested were not stable, decreasing at eighteen months.KEYWORDSHard Dental tissues; Bonding agents; Adhesion; Water storage.