Pulp necrosis and crown discoloration: a systematic review and meta-analysis

Background. The association between pulp necrosis and crown discoloration in traumatized primary teeth has not been clearly determined yet. Aim. The study verified whether there is an association of pulp necrosis and crown discoloration in traumatized primary teeth through a systematic review and meta-analysis. Methods. A systematic literature search was conducted in PubMed/Medline, Lilacs/BBO, Scopus, Web of Science, Cochrane Library databases, and grey literature. A methodological quality assessment appraisal was independently conducted by two researchers. Random-effects models were employed, and heterogeneity was tested (I-2 index/P = 0.05). Results. Eight studies with low risk of bias were included in the analysis. A total of 1,494 traumatized primary teeth participated in the pooled meta-analysis. Diagnosis of pulp necrosis was evaluated in 1,414 teeth through clinical and/or radiographic analyses, and the analysis demonstrated a positive association (P = 0.0005/OR 8.37 [2.51, 27.90], I-2 = 87%). Eighty teeth were diagnosed with pulp necrosis through endodontic access, and there was no statistically significant association (P = 0.36/OR 2.46 [0.36, 16.94], I-2 = 54%). The pooled meta-analysis showed a positive association (P = 0.0003/OR 5.93 [2.24, 15.72], I-2 = 83%). Conclusion. The positive association between pulp necrosis and crown discoloration should be considered with caution once the diagnosis of pulp necrosis was performed by limited criteria.