In vitro cuspal deflection and microleakage of maxillary premolars restored with novel low-shrink dental composites

摘要: Summary Objectives : The development of novel low-shrink resin-based composites (RBCs) may offer a potential reduction in polymerisation shrinkage stresses generated at the tooth/restoration interface compared with current methacrylate RBCs. In vitro cuspal deflection and microleakage meiso-occlusal-distal (MOD) cavities restored experimental oxirane silorane (EXL596 H1) (Z100 Filtek™ Z250) RBCs were assessed. Methods Standardised pre-molar MOD prepared ( n =10) each material. flexure buccal palatal cusps was recorded 0.1 h following irradiation utilising differential transformer gauge. Each tooth subjected to thermocycling regime sections assessed 24 h immersion 0.2% fuschin dye. degree conversion (DC) RBC material also using Fourier transform infra-red (FTIR) spectroscopy 0.1, 0.5, 1, 4, 24 48 h post-irradiation. Results A total observed for EXL596 (2.5±0.9 μm) H1 (6.0±1.8 μm) Z100 (20.0±4.7 μm) Z250 (16.5±3.3 μm) 0.1 h. displayed significantly higher than any other exhibited non-significant decreased Z250, respectively. DC 0.5 1 h. Significance ‘living’ associated decrease suggest magnitude stress interface. has provided information on cure rate cationic free-radical mechanisms, inadequate marginal seal would preclude its use as dental restorative. be advantageous terms integrity placement. However, difference between only present modest decreases deleterious effects stress.