This study evaluated the effects of different provisional luting cement removal methods on the shear bond strength (SBS) of resin cement to dentin following immediate dentin sealing (IDS) performed with two adhesive systems. A total of 168 extracted, caries-free human third molars were used, of which 144 were allocated for SBS testing and 24 for scanning electron microscopy (SEM) analysis. Specimens were assigned according to the IDS protocol (no IDS, IDS with OptiBond FL, or IDS with G2-Bond), followed by provisional cementation using an eugenol-free temporary cement. Contaminated surfaces were subsequently cleaned with a hand scaler, aluminum oxide (Al₂O₃) air abrasion, or Katana Cleaner prior to final bonding with a dual-cure resin cement. SBS was measured after 24 h of water storage, and surface morphology was evaluated by SEM at 2500× magnification. IDS significantly increased SBS under uncontaminated conditions, with G2-Bond-based IDS exhibiting higher bond strength values than specimens without IDS. However, provisional cement contamination significantly reduced SBS regardless of the cleaning method applied, and none of the tested protocols fully restored the bond strength observed in uncontaminated IDS-treated dentin. SEM analysis revealed residual cement remnants and surface alterations after cleaning, even in specimens that appeared macroscopically clean. Within the limitations of this in vitro study, IDS enhances resin–dentin bonding when contamination is avoided; however, current mechanical and chemical cleaning methods are insufficient to completely recover bond strength compromised by provisional cement contamination, highlighting the importance of preventing contamination and preserving IDS layer integrity during indirect restorative procedures.

Aims: The use of various cavity disinfectants and irrigants can influence the long-term success of restorations, thereby affecting the seal integrity of root canal treatments. This study aimed to investigate the effects of cavity cleansers and bonding protocols on the microleakage of resin-modified glass ionomer cement (RMGIC) restorations in endodontically treated teeth. Methods: Eighty extracted, non-carious maxillary first molars were used. Standardized 4×4 mm access cavities were prepared, and root canals were instrumented and obturated using the lateral condensation technique. The teeth were divided into eight groups according to the surface pretreatment protocol: no pretreatment, Cavity Conditioner, Dentin Conditioner, and Triton application, and then restored with RMGIC with and without an adhesive. After thermocycling, specimens were immersed in 0.5% basic fuchsin. Dye penetration was evaluated under a stereomicroscope (×40) using a 0–3 scoring system. Data were analyzed using ordinal logistic regression with pretreatment and bonding as fixed factors. Effect sizes were expressed as odds ratios (95% CI). Group comparisons were performed with the Kruskal–Wallis test (Holm-adjusted, α=0.05) using RStudio (v2025.09.1+401). Results: Microleakage scores varied significantly among groups (p

The durability of dental restorations against erosive and staining challenges is crucial for long-term clinical success. Therefore, this in vitro study aimed to investigate the combined effects of sequential simulated gastric acid exposure, coffee immersion, and different cleaning procedures on the surface roughness and color stability of four contemporary flowable resin composites with different filler and matrix characteristics. Ninety-six disk-shaped specimens were fabricated from four resin composites: Omnichroma Flow, G-ænial Universal Injectable, Universal Flo, and EverX Flow. Baseline surface roughness and color coordinates were recorded. Specimens were immersed in 0.06 M hydrochloric acid for 48 h to simulate gastric acid exposure and subsequently immersed in coffee solution for 24 h to simulate staining. Color measurements were performed at baseline, after sequential gastric acid–coffee exposure, and after cleaning procedures. ΔE₀ was calculated between baseline and post-exposure values, whereas ΔE₁ was calculated between post-exposure and post-cleaning values. Specimens were then allocated to three cleaning subgroups: toothbrushing (BR), water flosser (WF) and mouthrinse (MR). Final surface roughness and color changes were evaluated. Data were analyzed using mixed and factorial ANOVA tests. Sequential gastric acid–coffee exposure significantly increased surface roughness in all materials. Omnichroma Flow showed the lowest roughness values, whereas G-ænial Universal Injectable demonstrated the highest post-treatment roughness, particularly after toothbrushing. Toothbrushing generally caused greater roughness increases than other cleaning procedures. Material type significantly affected color stability, with Universal Flo showing the greatest discoloration and Omnichroma Flow the lowest color change. Surface roughness and color stability were significantly influenced by sequential gastric acid–coffee exposure and cleaning procedures in a material-dependent manner.