In Vitro Penetration of Adhesives into Proximal White-Spot Caries Lesions

Adhesives have shown in vivo efficacy for sealing incipient proximal lesions in young adults and in vitro deeper penetration then sealants.

Objective: To determine which adhesive: Excite Ivoclar-Vivadent (E), Prime&Bond-NT Dentsply (PB) and Single-Bond-2 3M-ESPE (SB), achieves deeper penetration within early proximal lesions.

Methods: One hundred and sixteen recently extracted premolar-teeth with ICDAS-lesions type white-opacity-on-wet-surface (WSL) were selected out of 420 with proximal initial-caries lesions. Teeth were randomly assigned to one of three groups: -E, -PB, -SB. Then they were placed on plaster 1.2 mm apart from another tooth and lesions were sealed with previous addition of methyl-blue dye to adhesives using the technique described by Martignon et al. 250-micron longitudinal sections were obtained and digital pictures were taken under stereomicroscopy. Measurements of enamel width at lesion's location; maximum lesion's depth; and maximum adhesive penetration's depth were conducted using the Dpx View Pro EE EF Delta Pix software. Covering of the lesion with material was also assessed. The Kruskal-Wallis Test was used to explore significant differences between groups regarding percentage of depth penetration and the Spearman Correlation was used to explore linear correlations between variables (p-value <0.05).

Results: The 116 lesions were located in: outer-third -19%; middle-third -51%; inner-third -30%. No significant differences (p=0.38) of lesion's depth were observed between groups. All lesions were covered with material. Average penetration depth of material within the lesion was 81.17% (697.9µ±412.3µ) with the following results for each group: SB-80.45% (612.3µ±354.1µ); E-88.36% (785.8µ±393.3µ); PB-76.09% (693.3µ±471.6µ)) (p=0.05). Finally, there was a general significant linear correlation (63.5%) between lesion depth and adhesive penetration (p-value<0.0001).

Conclusion: This study confirms the ability of adhesives to penetrate proximal WSL on natural teeth in a depth greater than 80%. These results encourage their novel use on proximal initial lesions.