External and internal resin infiltration of natural proximal subsurface caries lesions: A valuable enhancement of the internal tunnel restoration.

OBJECTIVE: The aim of this ex-vivo study was to evaluate both the external and the internal penetration ability of a resin infiltrant into natural proximal and macroscopically intact white spot lesions, and to merge this approach with the internal tunnel preparation concept. METHOD AND MATERIALS: 20 premolars and 20 molars with proximal subsurface lesions (ICDAS, code 2) and respective radiographic lesion depths extending into the middle third of dentin (D2 lesions) were selected and divided into two groups. Treatment needs were confirmed using digital imaging fiber-optic transillumination and laser fluorescence. Deproteinization (NaOCl; 2%) followed, and lesions of Group 1 (control; n = 20) were etched (HCl; 15%) and externally infiltrated (Icon). Accordingly, the specimens of Group 2 (n = 20) were treated with the resin infiltrant from external; then, internal Class I tunnels were prepared, lesions were internally infiltrated (Icon), and the occlusal cavities were restored (G-ænial Flo X) after etching (H3PO4 gel; 40%). Teeth were cut perpendicular to the proximal lesion surfaces, and percentage infiltrations were analyzed using confocal laser microscopy and a dedicated image manipulation program (GIMP). RESULTS: Regarding the external infiltration, no differences between both groups were detected (P = .114; Mann-Whitney). Additional internal application of the resin infiltrant significantly increased the percentage amount of enamel lesion infiltration (P < .0001; Wilcoxon). CONCLUSION: External and internal infiltration seem to complement the internal tunnel approach, thus remediating the drawbacks of the latter by occluding and stabilizing the porous areas of the proximal caries lesion, and preserving both the marginal ridge and the proximal contact area.

Resin infiltration of deproteinised natural occlusal subsurface lesions improves initial quality of fissure sealing.

The aim of this ex vivo study was to evaluate the infiltration capability and rate of microleakage of a low-viscous resin infiltrant combined with a flowable composite resin (RI/CR) when used with deproteinised and etched occlusal subsurface lesions (International Caries Detection and Assessment System code 2). This combined treatment procedure was compared with the exclusive use of flowable composite resin (CR) for fissure sealing. Twenty premolars and 20 molars revealing non-cavitated occlusal carious lesions were randomly divided into two groups and were meticulously cleaned and deproteinised using NaOCl (2%). After etching with HCl (15%), 10 premolar and 10 molar lesions were infiltrated (Icon/DMG; rhodamine B isothiocyanate (RITC)-labelled) followed by fissure sealing (G-ænial Flo/GC; experimental group, RI/CR). In the control group (CR), the carious fissures were only sealed. Specimens were cut perpendicular to the occlusal surface and through the area of the highest demineralisation (DIAGNOdent pen, KaVo). Using confocal laser-scanning microscopy, the specimens were assessed with regard to the percentage of caries infiltration, marginal adaption and internal integrity. Within the CR group, the carious lesions were not infiltrated. Both premolar (57.9%±23.1%) and molar lesions (35.3%±22.1%) of the RI/CR group were uniformly infiltrated to a substantial extent, albeit with significant differences (P=0.034). Moreover, microleakage (n=1) and the occurrence of voids (n=2) were reduced in the RI/CR group compared with the CR group (5 and 17 specimens, respectively). The RI/CR approach increases the initial quality of fissure sealing and is recommended for the clinical control of occlusal caries.