The effect of remineralization pretreatments on the enamel bond strength of demineralized and sound enamel: An in vitro study

Abstract

Background: During tooth preparation, the clinician may face a hard remineralized enamel
surrounding the cavity with unknown effects on the enamel bond strength. This study aims to
assess the effect of remineralizing pretreatments with casein phosphopeptide‑amorphous calcium
phosphate (CPP‑ACP) or CPP‑amorphous calcium fluoride phosphate (CPP‑ACFP) on the bond
strength of composite resin and sound or demineralized enamel.
Materials and Methods: This study employed an in vitro experimental factorial design. A total of
144 enamel surfaces were prepared and randomly divided into 12 groups (G1‑G12). The surfaces
of G7‑12 were demineralized to create a lesion (L), while G1‑6 were assigned to the sound (S)
enamel group. The three pretreatment protocols were CPP‑ACFP, CPP‑ACP, or no pretreatment
for a 10‑day pH‑cycling period. A composite rod was bonded to the surfaces using a self‑etch or
total‑etch bonding system. Shear force was applied, and the bond strengths of the specimens were
measured. The data were analyzed using the Kruskal–Wallis test, followed by pairwise comparisons
using Dunn’s test. The significance level for all tests was set at 0.05.
Results: The sound (S) groups (33.81 ± 8.48) showed a significantly higher bond strength than the
lesion (L) groups (25.77 ± 6.69). Among the pretreatments, CPP‑ACFP‑pretreated groups had the
highest bond strength (33.86 ± 8.87). Pairwise comparisons showed significant differences between
CPP‑ACFP‑treated demineralized enamel and control demineralized enamel in both bonding
systems (P = 0.019 and P = 0.025 for Clearfil SE and Optibond FL, respectively).
Conclusion: Pretreatment of demineralized enamel with CPP‑ACFP before using total‑etch
and self‑etch systems results in a bond strength comparable to that of sound enamel, making it
clinically acceptable.
Key Words: Composite resins, dentin‑bonding agents, shear strength, tooth remineralization

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Farzaneh Shirani: Pubmed,Google Scholar