Prevalence and factors associated with pulp stones: a systematic review with meta-analysis and meta-regression

Pulp stones are radiopaque calcified masses located within the coronal or radicular pulp tissue. They are typically asymptomatic and detected incidentally on radiographic examination. Global prevalence estimates vary widely, and methodological inconsistencies across studies hinder a comprehensive understanding of their epidemiology. Therefore, this systematic review aimed to answer the following question: "What is the global prevalence of pulp stones, and what factors are associated with their occurrence?" Aim: To systematically review and synthesize the evidence on the global prevalence of pulp stones and to identify factors associated with their occurrence.

Six electronic databases were searched up to March 2024. Data extraction included participant demographics, diagnostic methods, tooth type, and the presence of systemic diseases. Risk of bias was assessed using the JBI checklist, and prevalence was pooled using random-effects meta-analyses at individual and tooth levels. Meta-regression was performed to explore potential sources of heterogeneity, and the certainty of evidence was assessed using GRADE.

Twenty-four studies comprising 10,738 individuals and 94,416 teeth met the inclusion criteria. Pulp stones were present in 46% of individuals and 20% of teeth, with substantial heterogeneity across studies. Meta-regression identified systemic conditions and tooth type as significant contributors to prevalence variability. Individuals with both cardiovascular and renal diseases exhibited a higher prevalence (β=0.31, p=0.04), whereas those with cardiovascular diseases alone showed a lower prevalence (β=-0.33, p=0.04) than healthy participants (R2= 26.0). Risk of bias was moderate in most studies, and the overall certainty of evidence was very low.

Pulp stones are highly prevalent, and their occurrence may be influenced by systemic conditions and tooth-related factors. However, these findings are based on very-low-certainty evidence and are limited by heterogeneity and methodological inconsistencies across the included studies.