Effect of Ageing Process and Brushing on Color Stability and Surface Roughness of Treated White Spot Lesions: An in vitro Analysis

Evaluation of resin infiltration for inhibiting initial caries progression: An in vitro study using Micro-Computed Tomographic analysis

Objective

To evaluate the changes in lesion depth and mineral density of resin infiltration-treated white spot lesions against a simulated oral environment using thermal and acidic challenges in vitro.

Materials and methods

Two enamel slabs were prepared from each buccal surface of permanent human premolars, for a total of 56 slabs. Artificial white spot lesions were induced. One specimen was treated with resin infiltration, while the other was used as an untreated control. A micro-CT was used to assess the lesion depth and mineral density of each specimen. Subsequently, all specimens were subjected to 10,000 cycles of thermocycling and pH cycling for 10 days before being re-evaluated using the micro-CT. Lesion depth and mineral density were examined and compared between before and after aging procedures within each group by the paired sample t-test. The independent samples t-test was utilized to compare lesion depth progression and percentage change of mineral density between groups.

Results

After aging, there was both a significant lesion depth progression and a mineral loss in the control and resin infiltration groups. Mean lesion depth progression was 132.88 ± 4.18 µm for the control group and 52.31 ± 4.16 µm for resin infiltration group. Percentage mineral density loss as a percentage for the control and resin infiltration groups were 16.1 ± 0.64 % and 8.83 ± 0.30 %, respectively. The resin infiltration group demonstrated a significantly lower mean lesion depth progression and percentage changes in mineral loss compared to the control group.

Conclusions

The lesion depth and mineral density changes in the resin infiltrated-treated group were lower than untreated white spot lesions after aging procedures using thermal and acidic challenges.

Clinical significance

Resin infiltration is a promising approach to inhibit the progression of white spot lesions related to the initial stage of dental caries.

Surface roughness and microhardness of enamel white spot lesions treated with different treatment methods

Objective

To analyse the surface roughness and microhardness of artificial enamel white spot lesions before and after WSL formation, after treatment (Opalsutre™ microabrasion, Sylc® bioactive glass, and ICON® resin infiltration), and after pH cycling with the help of the profilometer surface roughness tester and the digital Vickers microhardness tester.

Materials and methods

Seventy-five extracted molars were used to acquire one hundred specimens. 50 specimens were randomly assigned to five groups (n = 10) for the surface roughness study: 1) Sound group, 2) WSL group, 3) micro abrasion (MA; Opalustre, Ultradent, South Jordan, UT, USA), 4) bioactive glass 45S5 Sylc powder (Sylc; Denfotex Research Ltd, Inverkeithing, UK), and 5) ICON resin infiltration (ICON; DMG, Hamburg, Germany). An additional 25 specimens were used to obtain 50 enamel slabs for the surface microhardness study, which were also assigned to the same groups. All groups underwent a final stage of pH cycling. Surface roughness and surface microhardness measurements were performed at different stages for all groups.

Results

Regarding surface roughness, ICON significantly reduced the surface roughness compared to Opalustre and Sylc, with no significant difference between Opalustre and Sylc. In terms of surface microhardness, ICON showed the highest improvement, followed by Sylc and then Opalustre. Both surface roughness and microhardness were significantly affected by demineralization, partially improved after treatment, and then regressed significantly after pH cycling.

Conclusion

ICON resin infiltrant can be considered as a superior treatment option for improving surface roughness and microhardness, while Opalustre demonstrated relatively the poorest performance compared to the other treatment options. It is noteworthy that the pH cycling procedure had an adverse impact irrespective of the treatment option used.

Management of Enamel Defects with Resin Infiltration Techniques: Two Years Follow Up Retrospective Study

Background: Developmental Defects of Enamel (DDE) represent an aesthetic, functional, and often psychological problem, especially in young patients. Infiltrative treatment with resin (Icon-DMG, Hamburg, Germany) is a minimally invasive technique based on the infiltration of high viscosity resin inside the hypomineralized enamel, modifying its optical properties. The aim of this paper is to evaluate the clinical efficacy of superficial infiltration in the treatment of white enamel defects of the anterior sector with pre-eruptive etiology and its stability over time. Methods: Thirty-three patients affected by DDE associated with mild and moderate Molar Incisor Hypomineralization (MIH), mild and moderate fluorosis, and post-traumatic hypomineralization treated with resin infiltration were retrospectively retrieved. Results: In all cases an improvement in aesthetic appearance was achieved, and the 24-month follow-up confirmed the stability of the results. However, in the cases of traumatic hypomineralization the results were not completely satisfactory. Conclusions: The superficial infiltration technique can be considered a valid minimally invasive alternative to traditional treatment of mild or moderate fluorosis and mild MIH.