The aim was to evaluate the interface zone between glass hybrid (GH), high-viscosity (HV), and resin-modified (RM) glass-ionomer cements (GIC) and sound (SD) and artificially created caries-affected (ACAD) primary dentin. Occlusal cavities were prepared in 120 extracted primary molars and randomly assigned to SD or ACAD. Samples were restored with GH (Equia Forte HT-EF), HV-GIC (Equia Fill-E; Ketac Molar-KM), or RM-GIC (Fuji-II LC-FII; Photac Fill-PF) and exposed to thermal aging. Microleakage (methylene-blue) was analyzed using an optical digital microscope. The interface between dental tissues and restorative materials was analyzed using a scanning electron (SE) microscope. SE microphotographs were manually annotated for intimate contact and cracks/gaps at the material-enamel/dentin interface and analyzed using a custom Python-based algorithm to quantify the respective percentages. No microleakage was noted only in the SD group for EF (50%), FII (42%), and E (33%). All materials showed higher microleakage in ACAD than SD (p < 0.05). No continuous intimate contact between restorative material and dental tissues was observed along the entire interface. The mean proportion of intimate contact between the material and SD was EF (76%) > KM (55%) > E (38%) > FII (7%) > PF (4%), and EF (32%) > KM (24%) > E (16%) > FII (15%) > PF (0%) for ACAD (p < 0.05). Caries-induced demineralization affects the quality of the material–dentin interface. GH are likely to provide better sealing compared to the previous generations of GI materials.

Background: The aim of this ex vivo study was to compare the resistance to lateral wall failure during sequential implant site preparation using osseodensification (OD) burs and conventional rotary drills in a standardized narrow ridge model. The primary outcome was the drill diameter at first lateral wall perforation. Secondary outcomes included paired perforation occurrence at a clinically relevant diameter (4.0 mm) and perforation morphology (length and width). Methods: Twenty standardized trabecular bone blocks were prepared in a paired within-specimen design, with each block receiving two osteotomies: one prepared using conventional rotary drills and the other using OD burs. Osteotomy diameter was sequentially increased according to the manufacturers’ protocols until lateral wall perforation occurred. The drill diameter at first perforation was recorded. Perforation morphology (length and width) was quantified using high-resolution extraoral digital scanning and software-based measurements. Statistical analysis was performed using paired non-parametric tests (α = 0.05). Results: OD burs significantly delayed lateral wall perforation compared with conventional drills (median 4.30 vs. 4.00 mm; p = 0.0000171). At the 4.0 mm drill step, perforation occurred in 16/20 (80%) conventional versus 2/20 (10%) OD preparations (p = 0.0013). Perforation length was significantly greater with conventional drilling (p = 0.000681), while no significant difference was observed for perforation width (p = 0.073). Conclusions: Within the limits of this decorticated trabecular ex vivo model, OD increased resistance to lateral wall failure, delayed perforation onset, and reduced perforation length compared with conventional drilling.