Moist vs over‐dried etched dentin: FE‐SEM/TEM and bond strength evaluation of resin‐dentin interfaces produced by universal adhesives

Abstract

Objective: To evaluate the influence of the degree of dentin moisture on interfacial ultramorphology and bond strength (μTBS) of universal adhesives. Materials and Methods: Futurabond U (FBU), Scotchbond Universal (SBU), AdheseUniversal (ADU), and Prime&Bond active (PBA) were used. After acid-etching, moist or over-dried dentin surfaces were tested. Teeth were restored for scanning and transmission electron microscopy (n = 3) and μTBS evaluation (n = 5). μTBS results were analyzed by two-way ANOVA and Tukey.Results: For moist dentin, a well-formed hybrid layer (HL) was observed. However, when applied to over-dried dentin, remarkable differences were observed. Defects, gaps, and reduced HL thickness were observed mainly for ADU and FBU. When applied to wet dentin, μTBS values were similar for all adhesives, except for FBU, which was significantly lower. When applied to over-dried dentin, PBA presented the highest μTBS values, followed by SBU, ADU, and FBU. ADU presented significantly lower μTBS when applied to over-dried dentin.Conclusion: PBA, SBU, and FBU μTBS values were not sensitive to the degree of moisture.Even though application to over-dried dentin revealed defects, gaps and reduced HL thickness for SBU, ADU, and FBU, μTBS analysis only revealed a significant reduction for ADU.Clinical Significance: Universal adhesives can be applied in either self-etching or etch-and-rinse mode. However, clinicians are not aware which universal adhesives should be strictly applied on a moist dentin for bonding in the etch-and-rinse mode. K E Y W O R D S dentin, hybrid layer, microtensile bond strength, SEM, TEM, universal adhesives

Effect of Intraoral Humidity on Dentin Bond Strength of Two Universal Adhesives: An In Vitro Preliminary Study

“…Furthermore, it is possible that the solvent (isopropanol) present in this adhesive may facilitate adhesive distribution in between collagen fibers, even in a higher RH condition [49]. A previous study denoted that the isopropanol solvent re-expands the collapsed collagen network, and the low-viscosity resin mixture may sufficiently infiltrate the inter-fibrillar spaces, hence making a suitable HL when affected on both over-dried and moist demineralized dentinal surface [50]. Another potential explanation of the findings obtained was that other variances in the composition, such as the initiators, percentage of water content, presence/absence of different functional monomers, for example, 10-MDP, among others, might be involved in the bonding performance to dentin [50,51].…”

“…A previous study denoted that the isopropanol solvent re-expands the collapsed collagen network, and the low-viscosity resin mixture may sufficiently infiltrate the inter-fibrillar spaces, hence making a suitable HL when affected on both over-dried and moist demineralized dentinal surface [50]. Another potential explanation of the findings obtained was that other variances in the composition, such as the initiators, percentage of water content, presence/absence of different functional monomers, for example, 10-MDP, among others, might be involved in the bonding performance to dentin [50,51]. Although the manufacturers do not state the detailed percentage of each constituent inside adhesive systems, it is probable that the presence of diverse percentages of the 10-MDP monomer can influence the vulnerability of the adhesive to the degradation process [52].…”

Reinforced Universal Adhesive by Ribose Crosslinker: A Novel Strategy in Adhesive Dentistry

“…In this study, resin-dentin interface of the specimens was analyzed for morphological stability. Prime&Bond active TM with pH-2.5 [55] was used in this study in a self-etch strategy. The hybrid layer is thin (0.5-1.5 µm for mild or moderate self-etch adhesives) compared to that which can be formed after phosphoric acid etching, which is more acidic (5 µm for etch-and-rinse adhesives) [56].…”

A importância do tratamento transdisciplinar para lesão cervical não cariosa e hipersensibilidade dental e sua influência na qualidade de vida: relato de caso

“…Não há consenso sobre o melhor método de aplicação do condicionamento ácido e do adesivo para restaurações (Kumagai, Hirata, Pereira & Reis, 2020). Um dos fatores críticos para o sucesso é a inserção de incrementos de resina composta.…”