In vitro investigation of microleakage and marginal fit in stainless steel crowns placed using two techniques (Conventional / Hall) techniques and cemented with different luting agents

This study was undertaken to investigate the microleakage and marginal discrepancies in stainless steel crowns placed using Conventional and Hall techniques and cemented with 3 different luting agents. 78 non-carious human primary second molars, extracted for orthodontic reasons, were randomly assigned into 2 groups (n=39/Group)with respect to the technique used to place stainless steel crowns(3M ESPE, Germany): Hall technique and Conventional technique. In each group, teeth were further subgrouped according to the material used for cementation of the crowns (n=13/Group):Conventionalglassionomercement (Ionofil, Voco, Germany); Resincement (Rely X U,3M ESPE, Germany), or polycarboxylate cement(AdhesorCarbofine,SpofaDental, CzechRepublic). Restored teeth were subjected to thermalcycling(5-55±20C, 1000X). In each subgroup,two specimens were processed for scanning electronmicroscopic (SEM) investigation, while theremaining 11 specimens were subjected to dye penetration test. The extent of microleakage and marginal fit was quantified on 4 sections perspecimenusingimageanalysis. The data were compared statistically using TwoWay Independent ANOVA and TwoWay Mixed ANOVA (p=0.05). The microleakage andmarjnal fit of theHall group was significantly inferior than those of the Conventional technique group (p<0.05). In both the Conventional and Hall groups, the resin cement (Rely XU) displayed the lowest extent of microleakage, followed by the glass ionomer and polycarboxylate cements (p<0.05). Irrespective of the crowning technique utilized, all crowns displayed significantly greater marginal opening on the buccal margins than on the lingual ones. The results of qualitative SEM investigation of marginal crown fit was compliant with those of quantitative evaluation.