Herpes simplex virus type 1 in periapical pathoses: Systematic review and meta-analysis.

OBJECTIVES: The objective of this systematic review and meta-analysis of observational studies was to assess whether herpes simplex virus type 1 (HSV-1) can infect endodontic periapical lesions. MATERIALS AND METHODS: Studies with cross-sectional design investigating HSV-1 in periapical tissues of patients with symptomatic and asymptomatic acute and chronic apical periodontitis were searched through MEDLINE, Scopus, Embase, Web of Science, and Google Scholar. Pooled HSV-1 prevalence proportion with 95% confidence interval (95CI) in periapical lesions was assessed with both fixed-effect and random-effects models, with/without adjustment for study quality and publication bias. Result robustness was investigated through sensitivity and subgroup analyses. RESULTS: Literature search, performed twice, provided 84 items, and eight remained for the meta-analysis; globally, there were 194 patients mostly adults. The pooled HSV-1 prevalence proportions, assessed with various methods, were 6.9% (95CI, 3.8-11.3%, fixed-effect); 6.8% (95CI, 3.6-11.0%, random-effects); 8.1% (95CI, 4.4-14.5%, quality-adjusted); and 4.8% (95CI, 2.0-11.4%; adjusted for small-study effect). CONCLUSIONS: The results indicated that HSV-1 can colonize the periapical tissues of 3%-11% patients with periapical diseases. Such data do not imply a causative role of HSV-1 in disease development and advancement. Well-designed and large-sized prospective cohort studies should be added in the literature panorama.