Orthodontic Cements and Demineralization: An In Vitro Comparative Scanning Electron Microscope Study

BACKGROUND: Comparison of the demineralization potential of four luting cements, i.e. zinc phosphate, conventional glass ionomer cement (GIC), resin-modified GIC and acid modified composite resin. MATERIALS AND METHODS: This study was conducted on 75 extracted premolar teeth, which were grouped into five, each group containing 15 teeth. Groups were non-banded control, teeth cemented with the above-mentioned cements. These were incubated at 37°C for 30 days in sealable plastic containers, after which the teeth were debanded, cleaned and placed in acid gelatin solution at 37°C for 4 weeks to simulate the cariogenic solution. Then, the teeth were sectioned and examined under scanning electron microscope. The depth of the carious lesions was measured using image analysis with Digimizer software. RESULTS: The depth of the carious lesions was maximum with non-banded group, followed by zinc phosphate, acid modified composite resin, resin-modified GIC and conventional GIC. CONCLUSIONS: Among the four orthodontic banding cements compared, the enamel demineralization potential is least with conventional GIC, followed by resin-modified GIC, acid modified composite resin and zinc phosphate.