Tabriz University of Medical Sciences Journal of Dental Research, Dental Clinics, Dental Prospects 2008-210X 16 1 2022 05 29 In vitro comparison of microleakage with two different techniques of placing stainless steel crowns on mandibular deciduous first molar teeth with decreased mesiodistal width 35 39 10.34172/joddd.2022.006 EN Mahsa Sayadizadeh https://orcid.org/0000-0002-9140-7847 Raziyeh Shojaeipour https://orcid.org/0000-0003-4502-4754 Hamidreza Poureslami Sajad Raeisi Estabragh https://orcid.org/0000-0002-9051-4149 Maryam Sharifi Journal Article 10.34172/joddd.2022.006 2021 07 12 2022 01 03 Background. Stainless steel crowns (SSCs) of the opposing maxillary deciduous molar teeth are used in mandibular deciduous first molars with decreased proximal surfaces due to caries. However, the SSCs of maxillary deciduous molar teeth are different from those of the mandibular deciduous molars in terms of the occlusal surface morphology, the buccal margin, and the proximal surface contour. Therefore, it is possible to prepare the buccal and lingual surfaces to use the SSC of the lower deciduous molar teeth and compare microleakage. Methods. Eighty extracted mandibular deciduous first molars were randomly assigned to two groups. In the case group (BLP), the buccal (B) and lingual (L) surfaces were prepared in addition to the proximal (P) surface, and an SSC was placed on the mandibular first deciduous teeth. Only the proximal surface was prepared in the control (P) group, and the SSC of the opposing tooth (maxillary deciduous first molar teeth) was placed. After dissecting the teeth, the extent of dye penetration was measured. Results. The difference in microleakage on the buccal aspect between the case and control groups was significant (P=0.02); however, the difference in microleakage on the lingual aspect between the case and control groups was not significant (P=0.89). Conclusion. Microleakage at the buccal margin of the SSC of mandibular deciduous first molars was less than the maxillary deciduous first molar SSC, with no significant differences in the lingual margin.