An In Vitro Study In Microleakage Of Different Filling Materials

OBJECTIVETo observe the filling effect in type V of premolar in vitro and investigate the sealing ability of several different filling materials and the effect on microleakage by basing material, so as to supply scientific data for selecting optimal filling material in clinic.METHODSSixty cavities (type V) were prepared on buccal surface of sixty extracted premolars. Every tooth has one cavity, which the cervical wall and the incisal wall were located in enamel. They were divided into six groups randomly. Three of the six groups were filled with dental amalgam, ChemFil Superior glass ionomer and light cured composited resins P60 respectively. The fourth group were blocked by zinc phosphate and filled with amalgam, and the other two groups were blocked by Dycal and Lonosit-Baseliner respectively and filled with light cured composited resins P60. After thermocycling 60 times , the specimens were immersed in 1% solution of methylene blue. The penetrating depth of the dye was observed and taken photos under stereomicroscope at 160 magnification, and then analyzed by Photoshop and SPSS11.0 software.RESULTS1. The depth of dye penetration of the amalgam was the lowest than other two filling materials in the group filled directly with amalgam, ChemFil Superior glass ionomer and light cured composited resins P60 respectively(P<0.05), and there were no significant difference in the depth of dye penetration between ChemFil Superior glass ionomer and light cured composited resins P60(P>0.05).2.There was no significant difference in the depth of dye penetration between cavities filled by amalgam directly and ones blocked by zinc phosphate then filled with amalgam (P>0.05). And there was significant difference in the depth of dye penetration between cavities blocked by Dycal or Lonosit-Baseliner then filled with light cured composited resins P60 and ones filled by light cured composited resins P60 directly(P<0.05).3.There was no significant difference in the depth of dye penetration between cavities blocked by Dycal then filled with light cured composited resins P60 and ones blocked by Lonosit-Baseliner then filled with light cured composited resins P60 (P>0.05).4.The depth of dye penetration in incisal wall was lower than that in cervical wall significantly in the group filled with ChemFil Superior glass ionomer(P<0.05), but there was no significant difference in the depth of dye penetration between incisal wall and cervical wall in the other five groups(P>0.05).CONCLUSIONSConsiderated the microleakage of filling materials:1. The microleakage of amalgam is the lowest among the three odontal restorative materials, it is an optimal filling material for cavities. It is better to be blocked before filling by the light cured composited resins P60, select Lonosit-Baseliner or Dycal for basing.2. ChemFil Superior glass ionomer is not considerated firstly as filling material when the cervical wall of the cavities is near to the gingival.