217 research outputs found
Class I Gap-formation in Highly-viscous Glass-ionomer Restorations: Delayed vs Immediate Polishing
This in vitro study evaluated the effects of delayed versus immediate polishing to permit maturation of interfacial gap-formation around highly viscous conventional glass-ionomer cement (HV-GIC) in Class I restorations, together with determining the associated mechanical properties. Cavity preparations were made on the occlusal surfaces of premolars. Three HV-GICs (Fuji IX GP, GlasIonomer FX-II and Ketac Molar) and one conventional glass-ionomer cement (C-GIC, Fuji II, as a control) were studied, with specimen subgroups (n=10) for each property measured. After polishing, either immediately (six minutes) after setting or after 24 hours storage, the restored teeth were sectioned in a mesiodistal direction through the center of the model Class I restorations. The presence or absence of interfacial-gaps was measured at 1000Ă magnification at 14 points (each 0.5-mm apart) along the cavity restoration interface (n=10; total points measured per group = 140). Marginal gaps were similarly measured in Teflon molds as swelling data, together with shear-bond-strength to enamel and dentin, flexural strength and moduli. For three HV-GICs and one C-GIC, significant differences (p<0.05) in gap-incidence were observed between polishing immediately and after one-day storage. In the former case, 80â100 gaps were found. In the latter case, only 9â21 gaps were observed. For all materials, their shear-bond-strengths, flexural strength and moduli increased significantly after 24-hour storage.</p
Class I Gap-formation in Highly-viscous Glass-ionomer Restorations: Delayed vs Immediate Polishing
This in vitro study evaluated the effects of delayed versus immediate polishing to permit maturation of interfacial gap-formation around highly viscous conventional glass-ionomer cement (HV-GIC) in Class I restorations, together with determining the associated mechanical properties. Cavity preparations were made on the occlusal surfaces of premolars. Three HV-GICs (Fuji IX GP, GlasIonomer FX-II and Ketac Molar) and one conventional glass-ionomer cement (C-GIC, Fuji II, as a control) were studied, with specimen subgroups (n=10) for each property measured. After polishing, either immediately (six minutes) after setting or after 24 hours storage, the restored teeth were sectioned in a mesiodistal direction through the center of the model Class I restorations. The presence or absence of interfacial-gaps was measured at 1000Ă magnification at 14 points (each 0.5-mm apart) along the cavity restoration interface (n=10; total points measured per group = 140). Marginal gaps were similarly measured in Teflon molds as swelling data, together with shear-bond-strength to enamel and dentin, flexural strength and moduli. For three HV-GICs and one C-GIC, significant differences (p<0.05) in gap-incidence were observed between polishing immediately and after one-day storage. In the former case, 80â100 gaps were found. In the latter case, only 9â21 gaps were observed. For all materials, their shear-bond-strengths, flexural strength and moduli increased significantly after 24-hour storage.</p
Preliminary fabrication and characterization of electron beam melted Tiâ6Alâ4V customized dental implant
The current study was aimed to fabricate customized root form dental implant using
additive manufacturing technique for the replacement of missing teeth. The root form dental
implant was designed using GeomagicTM and MagicsTM, the designed implant was directly manufactured
by layering technique using ARCAM A2TM electron beam melting system by employing medical
grade Tiâ6Alâ4V alloy powder. Furthermore, the fabricated implant was characterized in terms
of certain clinically important parameters such as surface microstructure, surface topography,
chemical purity and internal porosity. Results confirmed that, fabrication of customized dental implants using additive rapid manufacturing technology offers an attractive method to produce
extremely pure form of customized titanium dental implants, the rough and porous surface texture
obtained is expected to provide better initial implant stabilization and superior osseointegration
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