Prospective Randomized Clinical Trial of Primary Molar Crowns: 24-Month Results

Purpose: The purpose of this study was to evaluate the clinical success of a new primary zirconia molar crown compared with stainless steel crowns (55Cs). Methods: This randomized, controlled clinical trial was designed as a split-mouth study. Fifty three- to seven-year-old children were recruited to provide a total of 50 pairs of teeth requiring primary molar crowns, with each participant receiving a SSC and zirconia crown. Restorations were evaluated at six-month, 12-month, and 24-month recall appointments examining the following criteria: gingival health; estimate of extent the crown was high in occlusion; surface roughness; staining on crown surface; wear of opposing arch tooth; color match; anatomic form; marginal integrity; marginal discoloration; proximal contact area; secondary caries at crown margin; and parent/ guardian satisfaction with crown appearance. Results: The 24-month follow-up included 39 patients (78 percent). Seventy crowns (70 percent) were evaluated; of the 36 zirconia crowns and 34 SSCs, there were no failures at the 24-month evaluation. The only significant difference in the parameters evaluated was in parental satisfaction with the zirconia crown preference (P<0.05). Conclusion: Current 24-month results indicate that zirconia primary molar crowns perform similarly to an established stainless steel crown for restoration of primary molar teeth.