Universal Adhesives Bonding Mechanisms
Universal adhesives offer a versatile and convenient option for dental practitioners, as they can simplify the bonding
process and reduce the need for multiple types of adhesives.
Even though most adhesives contain the same components, they may differ significantly, considering the proportional
amount of ingredients. Unbalanced mixtures may lead to reduced bonding effectiveness, durability, shelf life, and to phaseseparation
reactions, while a well thought-out formulation will be the key to long-term clinical success.
ProLink Universal mixture includes 10-MDP, 4-META, 2-HEMA, BisGMA / TEGDMA, MPTMS, NaF, colloidal silica,
photoinitiators and a blend of solvents.
The main challenge of bonding the tooth to restoration is that the resin matrix is hydrophobic, while the collagen on the
tooth is hydrophilic. Considering the hydrophilic nature of the tooth (especially dentin), it is logical that an adhesive
should also have a hydrophilic nature, to wet the surface and panitratethe available microstructure. A hydrophobic
polymeric layer is more insoluble and resistant to erosion and degradation by acids and other components of the oral
fluids. Thus, the ideal adhesive would have a hydrophilic nature during the placement and would become much more
hydrophobic after curing.
Smear Layer
The adhesive penetrates the inter-tubular dentin forming a resin-dentin inter-diffusion zone, and infiltrating the tubules to
form resin tags after their polymerization. This hybrid layer is an intermediate layer or a zone of the material consisting of
components of both bonding resin and dentin with collagen fibers and infiltration of resin into the etched dentin.
Cutting cavities creates a smear layer of debris that adheres tightly to dentin and fills the tubules. presence of residual
smear layer and plug particles prevents the penetration of adhesives into the dentinal tubules and results in a significant
decrease in bond strengths. ProLink Universal is able to work with the smear layer and achive excelent bonding.
