Comparative Study Of Marginal Microleakage About Inlays

OBJECTIVE: Microleakage is the tiny gap that difficult to detect with the naked eye between the tooth hard tissue and the prosthesis, Micro- leakage can lead to secondary caries, loosening of prosthesis, such as falling or even negative consequences endodontics, is one of the factors to repair the failure, with serious harm . There are two purposes of this experiment, first using the same kinds of adhesive bonding of the six kinds of different inlay materials, to observe the edge of microleakage. The other is the selection of alloys with two kinds of inlay cement bonding, to observe the edge of microleakage .METHODS: 50 freshly extracted human premolars were prepared for MOD cavity .The teeth were randomly assigned to 10 expermental groups 5 of each: Groups 1~4: gold inlay, Ag-Pd alloy inlay, Co-Cr alloy inlay, Ni-Cr alloy inlay, with 3MESPE RelyXTM Luting Cement separately. Group 5~6: ceramic inlay , composite resigns inlay with 3MESPE RelyXTM Luting Cement separately. Groups 7~10: gold inlay, Ag-Pd alloy inlay, Co-Cr alloy inlay, Ni-Cr alloy inlay with glass ionomer cement (Medical Devices Co. Ltd. Shanghai Dental Material Factory)separately. In each group by the inlay on the restored teeth, from the outside edge of 1mm holes evenly coating a two-tier polish, root canal system closed with self-curing resin. After thermal cycling (x500, 5℃~55℃),the teeth were immersed in 5g/L basic fuchjion solution for 24 hours and were sectioned twice longitudinally, Section polished with sandpaper, then measured the depth of dye along with the tooth and inlay under the microscope .Every tooth were observed four sections, each section measuring 6, the average check.RESULTS: With the same cement 3MESPE RelyXTM Luting Ce- ment , among the alloy inlays, gold inlay show perfect adaption, the microleakage value were the smallest, Ag-Pd alloy inlay second, and Co-Cr alloy inlay again, and Ni-Cr alloy inlay were a maximum of marginal gap formation . Among the non-alloy cast inlays, ceramiac inlay displayed less microleakage than composite resigns inlay .Among the Six kinds of material inlays, the microleakage had a significant difference (P <0.05), for LSD-t further comparison, the differences in microleakage were signi- ficantly (P <0.05).Alloy inlay cemented by 3MESPE RelyXTM Luting Cement and glass ionomer cement (Medical Devices Co. Ltd. Shanghai Dental Material Factory), the microleakage of gold inlay with 3MESPE RelyXTM Luting Cement were less than the microleakage with glass ionomer cement. the microleakage of Ag-Pd alloy inlay with 3MESPE RelyXTM Luting Cement were less than the microleakage with glass ionomer cement. the micro- leakage of Co-Cr alloy inlay with 3MESPE RelyXTM Luting Cement were less than the microleakage with glass ionomer cement. the micro- leakage of Ni-Cr alloy inlay with 3MESPE RelyXTM Luting Cement were less than the microleakage with glass ionomer cement. Therefore, the microleakage of the same kinds of materials inlay with 3MESPE RelyXTM Luting Cement is less than with glass ionomer cement. the microleakage of the same inlay material with two cement material was a significant difference (P <0.05).CONCLUSION: gold inlay, Ceramic inlay, Ag-Pd alloy inlay, Co-Cr alloy inlays ,composite resigns inlay could meet the need of clinical restoration. Ni-Cr alloy inlay should be used with better cements. The effect of 3MESPE RelyXTM Luting Cement on avoiding microleakage is superior to glass ionomer cement.