MICROTENSILE BOND STRENGTH OF FLOWABLE RESIN COMPOSITE VERSUS GLASS IONOMER CEMENT RESTORATION ON CARIOUS PRIMARY DENTIN TREATED WITH SILVER DIAMINE FLUORIDE (AN IN VITRO STUDY)

Background: Silver diamine fluoride (SDF) arrests caries but causes black staining and does not restore tooth structure.
Combining SDF with restorative materials (SMART) technique combines SDF with restorative materials to address
these limitations; however, the interaction between SDF and adhesives is not fully understood. The aim of this study to evaluate the effect of SDF on the microtensile bond strength of flowable resin composite (FRC) and glass ionomer
cement (GIC) restoration to carious-affected primary dentin.
Materials and methods: Thirty extracted carious primary molars were randomly divided into two groups (n=15 each):
Group I (FRC) and Group II (GIC) restoration. After caries removal, both groups received 38% SDF (3-minutes), rinsed for 30 s, and dried. Group I received etching (35% phosphoric acid, 15s), adhesive application, and incremental
composite placement. Group II received a cavity conditioner (10s), GIC (light-cured 20s), and a final layer of Equia™
Coat. Specimens were subjected to 500 thermocycles, sectioned into 1×1 mm beam and tested for microtensile strength using a universal testing machine. Failure modes were examined microscopically. Statistical analysis included normality tests (Shapiro-Wilk, Kolmogorov tests) and comparative tests (T-test for quantitative data, Fisher’s Exact test for qualitative data), with significance set at p≤0.05.
Results: Group I demonstrated significantly higher tensile strength compared to Group II. Regarding failure mode, the distribution difference between the two groups was statistically significant, indicating that Group I predominantly
experienced mixed failures (100%), while Group II demonstrated a combination of mixed (53.3%), adhesive (20.0%),
and cohesive (26.7%) failures.
Conclusions: Based on the findings of this study, it can be concluded that under the tested conditions, FRC
demonstrated significantly higher micro-tensile bond strength (µTBS) compared to GIC restoration after applying SDF to demineralized dentin. Flowable resin composite may offer a more predictable bonding outcome with a more
favourable failure mode.