Evaluating the Effectiveness of Different Light-Cured SDF Application Techniques in Primary Teeth: An Ex Vivo Study

Abstract

Aim

This ex vivo study evaluated the effect of different light-curing 38% silver diamine fluoride (SDF) application techniques on the hardness of infected dentin, the penetration depth of SDF, and silver ion precipitation at different depths of the dentinal carious lesions.

Materials and Methods

Eighty extracted carious primary maxillary anterior teeth were randomized into four groups (N = 20). The groups were as follows: (1) “Control” with first and second applications of SDF. (2) “Test 1” with the first application of SDF and the second application of light-cured SDF. (3) “Test 2” with the first application of light-cured SDF and the second application of SDF. (4) “Test 3” with first and second applications of light-cured SDF. Dentin hardness was measured using a Vickers hardness test. Sliced samples’ images were analyzed using OmniMet software to measure the depth of SDF penetration. A scanning electron microscope (SEM) was used to perform elemental analysis using energy dispersive spectroscopy (EDS) at different lesion depths. Statistical analysis was evaluated via Welch’s ANOVA with post-hoc comparisons performed using the Games-Howell test.

Results

Welch’s ANOVA showed statistically significant differences between all groups’ mean penetration depth and hardness values (p < .001).

For all samples, the highest mean penetration depth of SDF (± standard deviations) was recorded for the “control” (225.5 ± 39.6 μm), followed by “test 1” (168.3 ± 27.8 μm), then “test 2” (96.5 ± 6.6 μm), and lastly by “test 3” (54.0 ± 11.9 μm). SDF penetrated infected, affected, and sound dentin in all samples.

On the contrary, the highest mean of dentin hardness (± standard deviations) was in “test 3” (80.0 ± 8.7 kgf/ mm2), followed by “test 2” (55.4 ± 6.6 kgf/ mm2), then by “test 1” (39.6 ± 5.5 kgf/ mm2), and then by the “control” group (23.7 ± 2.2 kgf/ mm2). In post-hoc comparisons using the Games-Howell test, the four groups had statistically significant differences in mean penetration depth and hardness (p < .001).

EDS analysis showed that oxygen, calcium, and phosphorus were the main elements detected in the center of infected, affected, and sound dentin for each specimen in all groups. Silver weight percentage for the center of infected, affected, and sound dentin in all groups ranged between 0.84% - 2%.

Conclusion

Light curing SDF after the first and second applications showed a significant increase in the hardness of infected dentin and decreased SDF penetration into sound dentin. These results might be due to the higher silver precipitation on the surface, which could indicate a higher caries arrest effect compared with the other mentioned SDF application techniques.