Comparison of periodontal health of primary teeth restored with zirconia and stainless steel crowns: A systemic review and meta-analysis

In children, the use of stainless steel crowns to treat caries has a high success rate. However, due to the unnatural color of stainless steel crowns, it still needs to modify crown types. The present meta-analysis study aims to explore the previous articles on the comparison of stainless steel crowns and zirconia crowns. The systematic search of studies on the comparison of zirconia crowns and stainless steel crowns for primary teeth was mainly in PubMed and Cochrane database. The standardized mean differences (SMDs) of gingival health between zirconia crowns and stainless steel crowns comprised the primary outcome, and the SMDs of plaque index compared two crown treatments was treated as the secondary outcome. The meta-analysis extracted 187 papers from various databases and collected five randomized controlled trials, four comparisons on deciduous molars and one comparison on deciduous incisors. 160 children were included, ranging in age from 3-9 years old. The quantitative analysis showed a significantly lower gingival index of zirconia crowns in the primary molar group and the primary incisor group. The plaque index between two crown treatments groups was -4.51, indicating less accumulation of plaque on zirconia crown. However, the heterogeneity of included trials still need to be considered. Zirconia crowns for deciduous teeth had its advantages for gingival health. Although stainless steel crowns were more likely to have plaque deposition and gingival inflammation, zirconia crowns relatively caused the opposite tooth wearing and chipping. Therefore, the comprehensive consideration is important to choose deciduous tooth crown.