Objective To assess the microleakage of Class V restorations made with two resin-modified glass ionomer cements （RMGICs） and two polyacid-modified composite resins （PMCRs）. Methods Restorations of the four materia...Objective To assess the microleakage of Class V restorations made with two resin-modified glass ionomer cements （RMGICs） and two polyacid-modified composite resins （PMCRs）. Methods Restorations of the four materials （ GC Fuji Ⅱ LC, Vitremer^TM, Dyract AP and F2000^TM ） were placed in facial Class V cavity preparations in forty noncarious human molar teeth. Teeth were randomly assigned to 4 experimental groups of 10 teeth each. After thermal cycling（ ×20, 5 -55℃ ） , the interface between dentin and restorations was spattercoated with gold and observed under scanning electron microscopy （SEM）. Then the square and average width of margin gaps of central 1/3 interface were recorded with image analysis software. Results The data indicated no significant differences between all the restorative materials for both occlusal and gingival margins. Further analysis revealed there were statistically significant differences between occlusal margins and gingival margins for VitremerTM and Dyract AP, respectively. Conclusion None of the tested materials guaranteed margins free of microleakage. Resin-modified glass ionomer cements showed similar margin gaps to the polyacid-modified composite resins tested.展开更多
To evaluate the retention properties of the novel ‘C＇-shaped molar bands at a laboratory level. Resin-modified glass ionomer cement（RMGIC） was used as a luting agent for the novel C-shaped molar band. The mechanic...To evaluate the retention properties of the novel ‘C＇-shaped molar bands at a laboratory level. Resin-modified glass ionomer cement（RMGIC） was used as a luting agent for the novel C-shaped molar band. The mechanical properties of the band were examined and the retention performance was characterized in the mesial, distal and vertical directions. A clinical trial was conducted using a spilt-mouth design on 50 patients. The novel C-shaped molar bands fit most molars without a repeated try-in process.The use of both nanoHA coating and RMGIC enhanced the tensile（8.00 ± 1.8 MPa） and shear strengths（27.17 ± 8.6 MPa） of the molar bands, leading to high retention in vertical, mesial and distal directions（ p 〈 0.001）. In clinical trials, the C-shaped molar bands had a failure rate（15%） comparable to that of traditional bands, and 93% of the failed bands demonstrated an adhesive remnant index score of 0, corroborating the observation that no luting agent residue remained on the tooth surface in most cases. The novel C-shaped molar bands appear to be a promising appliance that requires further clinical investigations, and may be used effectively in orthodontics.展开更多
文摘Objective To assess the microleakage of Class V restorations made with two resin-modified glass ionomer cements （RMGICs） and two polyacid-modified composite resins （PMCRs）. Methods Restorations of the four materials （ GC Fuji Ⅱ LC, Vitremer^TM, Dyract AP and F2000^TM ） were placed in facial Class V cavity preparations in forty noncarious human molar teeth. Teeth were randomly assigned to 4 experimental groups of 10 teeth each. After thermal cycling（ ×20, 5 -55℃ ） , the interface between dentin and restorations was spattercoated with gold and observed under scanning electron microscopy （SEM）. Then the square and average width of margin gaps of central 1/3 interface were recorded with image analysis software. Results The data indicated no significant differences between all the restorative materials for both occlusal and gingival margins. Further analysis revealed there were statistically significant differences between occlusal margins and gingival margins for VitremerTM and Dyract AP, respectively. Conclusion None of the tested materials guaranteed margins free of microleakage. Resin-modified glass ionomer cements showed similar margin gaps to the polyacid-modified composite resins tested.
基金Funded by Department of Education,National Natural Science Foundation of China(No.81170960)Heilongjiang Province(No.11531204)+1 种基金Department of Health,Heilongjiang Province(No.2006-123)Youth Foundation of the Second Affiliated Hospital of Harbin Medical University(No.QN2006-13)
文摘To evaluate the retention properties of the novel ‘C＇-shaped molar bands at a laboratory level. Resin-modified glass ionomer cement（RMGIC） was used as a luting agent for the novel C-shaped molar band. The mechanical properties of the band were examined and the retention performance was characterized in the mesial, distal and vertical directions. A clinical trial was conducted using a spilt-mouth design on 50 patients. The novel C-shaped molar bands fit most molars without a repeated try-in process.The use of both nanoHA coating and RMGIC enhanced the tensile（8.00 ± 1.8 MPa） and shear strengths（27.17 ± 8.6 MPa） of the molar bands, leading to high retention in vertical, mesial and distal directions（ p 〈 0.001）. In clinical trials, the C-shaped molar bands had a failure rate（15%） comparable to that of traditional bands, and 93% of the failed bands demonstrated an adhesive remnant index score of 0, corroborating the observation that no luting agent residue remained on the tooth surface in most cases. The novel C-shaped molar bands appear to be a promising appliance that requires further clinical investigations, and may be used effectively in orthodontics.
