Biological Mechanisms Associated with Pulp Necrosis and Sickle Cell Anemia

Objectives: This cohort study was conducted to investigate the biological mechanisms underlying the association between asymptomatic pulp necrosis (APN) in subjects with healthy teeth and sickle cell anemia (SCA).
Methods: This study was conducted in two phases, a retrospective and a prospective. The retrospective phase (2010–2011) included 113 subjects with SCA aged >16 years with at least one healthy tooth and with no history of paresthesia of the inferior alveolar nerve in the past 6 months, dental trauma, or periodontal disease. In the prospective phase (2015–2016), 7 subjects died and 25 could not be contacted. A total of 59 new participants were included, resulting in a total sample of 140 subjects, including 125 without APN and 15 with APN. A theoretical model was built to explore the following three biological mechanisms involved in the association between APN and SCA: increase in the number of sickle cell crises in the previous year (No. SCCs/year), lower percentage of blood oxygen saturation (SpO₂) in the body, and comorbidities (CoM). The theoretical model for testing the causal association was analyzed by structural equation modeling. The prevalence rates of variables between the groups with and without APN were compared by the Student’s t-test or the Fisher’s exact. The level of significance for all analyses was 5%.
Results: APN was associated with the presence of CoM (SFL=1.115; p=0.032). However, this association was not mediated by the No. SCCs/year (SFL=0.127; p=0.596) or by the body SpO₂ (SFL=−0.102; p=0.485). The prevalence rates of osteoarticular lesions (p=0.009) and death (p<0.001) were significantly higher in subjects with APN.
Conclusions: CoM, primarily osteoarticular lesions, increase the prevalence of APN in the healthy teeth of subjects with SCA. APN can be considered as an indicator of the lethality of SCA.