Comparative Assessment of Different Pre-Treatment Bonding Strategies to Improve the Adhesion of Self-Adhesive Composites to Dentin

Abstract

The aim of this study is to compare the adhesive interface formed in dentin, using self-adhesive composites applied with different bonding strategies, by testing the microtensile bond strength (μTBS) and ultramorphology through the use of light microscopy. Permanent, sound human molars were randomly allocated to six experimental groups. The groups included a negative control group, where only etching was performed via EtchOnly; a positive control group where an adhesive was applied, OptiBondFL (OBFL); and an experimental group where a primer was applied using a co-curing strategy together with a composite (Primer_CoCuring). The samples were sectioned into microspecimens for μTBS (n = 8) and into 1-mm thick slabs for light microscopy using Masson’s trichrome staining protocol (n = 3). The statistical analysis included a two-way ANOVA for μTBS data and Tukey’s HSD was used as a post-hoc test (significance level of 5%; SPSS v. 26.0). The results of the μTBS revealed that the self-adhesive composite (F = 6.0, p < 0.018) and the bonding strategy (F = 444.1, p < 0.001) significantly affected the bond strength to dentin. However, their interactions were not significant (F = 1.2, p = 0.29). Etching dentin with no additional treatment revealed the lowest μTBS (VF_EtchOnly = 2.4 ± 0.8 MPa; CC_EtchOnly = 2.0 ± 0.4 MPa), which was significantly different from using a primer (VF_CoCu = 8.8 ± 0.8 MPa; CC_CoCu = 6.3 ± 1.0 MPa) or using the full adhesive (VF_OptiBondFL = 22.4 ± 0.3 MPa; CC_OptibondFL = 21.2 ± 0.4 MPa). Microscopy images revealed that the experimental Primer_CoCuring was the only group with no collagen fibers exposed to the dentin–composite interface. Overall, the use of a primer, within the limitations of this study, increased the bonding of the self-adhesive composite and provided sufficient infiltration of the collagen based on light-microscopic imaging.

Effect of varying functional monomers in experimental self-adhesive composites: polymerization kinetics, cell metabolism influence and sealing ability

“…This suggests that varying the functional monomer did not improve the sealing of the SACs, and the scores were poor for all SACs. The reason for the differences between SACs and E&R may be their poor wettability, influence of viscosity, poor hydrophilicity [62], and insufficient removal of the smear layer. It can also be derived from inadequate micromechanical retention between the restoration and tooth structures caused by the lower etching capacity of the SACs and possible lower flowability of SACs compared to dentin bonding agents [27,[63][64][65][66].…”

Sistemas autoadesivos odontológicos: uma análise abrangente

“…A revisão abrangente dessas pesquisas permite identificar as melhores práticas clínicas, destacar os materiais mais promissores e fornecer orientações baseadas em evidências para a tomada de decisões clínicas. A constante atualização e análise crítica da literatura são essenciais para acompanhar os avanços tecnológicos e melhorar a prática clínica (INGLÊS M, et al, 2022).…”

Modern Adhesive Systems and Techniques of Their Application for Direct Restoration of Hard Dental Tissues Defects

“…In a similar study, the adhesive strength of a selfadhesive composite was studied under conditions of additional use of only etching gel (I group of samples), only primer (II group) or alternate application of orthophosphoric acid, primer and adhesive (III group) on the dentin surface of samples [30]. Indicators of microtensive strength after 24 hours of artificial ageing differed significantly (p<0.05) and were 2.4+0.8 MPa, 8.8+0.8 MPa and 22.4+0.3 MPa for I, II and III groups of samples, respectively.…”

“…In other groups, on the contrary, free collagen fibres were not recorded. Instead, the formation of an organized hybrid layer with significant penetration of adhesive resins into the dentinal tubules was recorded [30].…”

“…У подібному дослідженні вивчали адгезивну міцність самоадгезивного композиту за умов додаткового використання тільки травильного гелю (І група зразків), тільки праймеру (ІІ група) або почергового нанесення ортофосфорної кислоти, праймеру та адгезиву (ІІІ група) на поверхню дентину зразків [30]. Показники мікротензивної міцності через 24 години штучного старіння відрізнялись достовірно (p<0,05) і складали 2,4+0,8 МПа, 8,8+0,8 МПа та 22,4+0,3 МПа для І, ІІ та ІІІ груп зразків, відповідно.…”