IADR Abstract Archives
Micro-shear Bond Strength of RMGI to Silver Diamine Fluoride-treated Dentin
Objectives: We previously demonstrated that silver diamine fluoride (SDF) may affect composite bonding to sound dentin depending on the protocol and adhesive used. This study evaluated micro-shear bond strength (MSBS) of resin-modified glass ionomer (RMGI) to SDF-treated dentin using polyacrylic acid conditioning or phosphoric acid etching.
Methods: Coronal discs (2.0±0.2mm thick) prepared from 40 extracted caries-free human teeth were distributed into 4 groups (n=10). Uniform smear layers were created using #600-grit SiC paper. Dentin was pre-treated with either deionized water (DIW) or SDF 38% (Advantage Arrest) via micro-brush for 10s and rinsed after 1min for control and experimental groups respectively. After air-drying for 5s, the surfaces were treated with either polyacrylic acid (Ketac Conditioner, 3M ESPE) conditioning for 10s or phosphoric acid (Universal Etchant; 3M ESPE) etching for 15s. A layer of RMGI (Fuji II LC, GC) approximately 0.5mm in thickness was placed and light-cured. Composite cylinders (0.79mm D, 1mm H) were bonded to RMGI using Scotchbond Universal (3M ESPE) adhesive. Specimens were stored in DIW at 37°C for 24h prior to MSBS testing using the wire-loop technique. Three cylinders were tested per disc and averaged. Data were subjected to two-way ANOVA (α=0.05).
Results: MSBS data are presented in table. ANOVA suggested that none of the factors (DIW vs. SDF and conditioning vs. etching) were significant (p>0.05). Out of total 120 cylinders tested, 65 mixed failures (complex fracture involving RMGI and dentin) and 55 adhesive failures (fracture at RMGI/dentin interface) were observed under 5x magnification.
Conclusions: Bond strength of RMGI to dentin was not affected by SDF application, regardless of polyacrylic acid conditioning or phosphoric acid etching. Given that adhesive resin bonding to SDF-treated dentin is compromised, placement of RMGI may be a reliable way to improve bond strength while ensuring therapeutic effects of SDF as a caries arresting agent are achieved.
Methods: Coronal discs (2.0±0.2mm thick) prepared from 40 extracted caries-free human teeth were distributed into 4 groups (n=10). Uniform smear layers were created using #600-grit SiC paper. Dentin was pre-treated with either deionized water (DIW) or SDF 38% (Advantage Arrest) via micro-brush for 10s and rinsed after 1min for control and experimental groups respectively. After air-drying for 5s, the surfaces were treated with either polyacrylic acid (Ketac Conditioner, 3M ESPE) conditioning for 10s or phosphoric acid (Universal Etchant; 3M ESPE) etching for 15s. A layer of RMGI (Fuji II LC, GC) approximately 0.5mm in thickness was placed and light-cured. Composite cylinders (0.79mm D, 1mm H) were bonded to RMGI using Scotchbond Universal (3M ESPE) adhesive. Specimens were stored in DIW at 37°C for 24h prior to MSBS testing using the wire-loop technique. Three cylinders were tested per disc and averaged. Data were subjected to two-way ANOVA (α=0.05).
Results: MSBS data are presented in table. ANOVA suggested that none of the factors (DIW vs. SDF and conditioning vs. etching) were significant (p>0.05). Out of total 120 cylinders tested, 65 mixed failures (complex fracture involving RMGI and dentin) and 55 adhesive failures (fracture at RMGI/dentin interface) were observed under 5x magnification.
Conclusions: Bond strength of RMGI to dentin was not affected by SDF application, regardless of polyacrylic acid conditioning or phosphoric acid etching. Given that adhesive resin bonding to SDF-treated dentin is compromised, placement of RMGI may be a reliable way to improve bond strength while ensuring therapeutic effects of SDF as a caries arresting agent are achieved.