Comparison between Zirconia Crowns versus Anterior Strip Crowns and Posterior Stainless Steel Crowns: Randomized Clinical Trial

Aim: The aim of this study is to compare two aesthetic full coronal restorations on primary maxillary central and lateral incisors and two full coronal restorations on primary posterior molars over a period of 3, 6 and 12 months. The restorations type included were Resin Composite Strip Crowns, Pre-formed Stainless Steel Crowns and pre-fabricated Primary Zirconia Crowns. Materials and Methods: Children attending the King Abdulaziz University, Faculty of Dentistry (KAUFD) clinics who needed restorations were screened for inclusion criteria till 240 teeth were recruited, 120 teeth for each group. The teeth assigned to either anterior or posterior group. Further, the posterior teeth group divided into two subgroups as one restored by SSCs (group A) and the other one restored by Zirconia crowns (group B) for primary molar teeth. On the other hand, the anterior teeth group divided also into two subgroups as group C restored with Zirconia crowns and group D restored with strip crowns. Split mouth technique were used to ensure equalizing variables for both groups in molar teeth. Randomization done using SPSS software version 20.0 (Armonk, NY; IBM Corp.). A simple descriptive statistic was used for analysis by Wilcoxon Signed-Rank test and Qui square test. Level of significance was set at (α = 0.05) and level of confidence at (95%). Results: While looking at the improvements in gingival health relative to interventions, both Zirconia and SSC showed significant changes through all time points. However, Zirconia performed better at the 3rd month with 80% compared to SSC with only 13.3% improvement with p-value<0.001 and 0.005 respectively. At 6th month, all samples under Zirconia group already improved compared to 73.3% from SSC group while, the remaining samples presented positive changes at 12th month. Similarly, Zirconia Crowns showed superiority in plaque retention compared with SSC. Regarding the anterior teeth restorations, the composite strip crowns exhibited drawback in gingival health, plaque accumulation, restoration failure, recurrent caries while it was better than Zirconia regarding attrition to the opposing dentition although it was not statistically significant. Conclusion: Although both SSC and Zirconia crowns presented an excellent choice for posterior teeth restorations, however we can conclude that Zirconia crowns performed better regarding gingival response to the material of restoration and plaque retention despite its high cost. The same was also shown in anterior teeth restorations as the Zirconia crowns present excellent esthetic result as well as better gingival health and durability.