Impact on Retrievability by Cement Variety for Implant Restorations Equipped with a Lingual Slot

ABSTRACT

PURPOSE: The purpose of this study is to measure and compare the removal torques of different cements applied in attachments of zirconia restorations on titanium (Ti) abutments fitted with retrievable cement-type slot (RCS) on the lingual side for the better retrievablity by use of a slot driver. MATERIALS AND METHODS: Three types of cements were used in the experiment: two permanent cements in RelyX™ U200 (RU) (3M ESPE) which is a resin cement and FujiCem™ (FC) (GC) which is a resin-modified glass ionomer cement, and a temporary cement in Freegenol™ temporary cement (TC) (GC). Measurements of removal torques were conducted as follows; an attached sample was fixed on the equipment customized for the experiment; a slot driver was connected to a MGT12 (Mark-10 Corp.), a torque measurement instrument; the sample had the driver fitted to its RCS and then was rotated until the it was removed; and finally, the maximum torque value was recorded. RESULT: As for the removal torque measurement results, the average values were 47.9±2.6 Ncm for RU, 43.4±1.5 Ncm for FC, and 20.9±1.0 Ncm for TC. The statistical analysis using Kruskal-Wallis test yielded the significance probability of P < 0.05 (P=0.002), which confirmed the presence of significant differences between the three groups. CONCLUSION: All three cements exhibit clinically acceptable levels of removal torque when applied to an upper zirconia implant restoration fitted with a lingual slot, with RU and FC, the two permanent cements, having the significantly higher values than that of TC, the temporary cement.