Vegetarian diet and its possible influence on dental health: A systematic literature review.

Objectives: People following a vegetarian diet could be more prone to oral health problems than people following a nonvegetarian diet. The aim of this systematic review was to examine the possible impacts of following a vegetarian diet on dental hard tissues, focusing on caries development, dental erosion and number of natural teeth.

Methods: PubMed, EMBASE, Web of Science and CINAHL were searched systematically up until 17 April 2019. Original studies comparing dental health (exclusively focusing on dental hard tissues) in vegetarians and nonvegetarians were selected. Study characteristics and outcome data were extracted, and the quality of the studies was assessed using the Newcastle-Ottawa Scale. When a dental health characteristic was reported in three or more papers in a comparable way, a meta-analysis was performed.

Results: Twenty-one papers reporting on 18 studies were included in this review. In meta-analyses, the vegetarian diet was associated with a higher risk for dental erosion (odds ratio: 2.40 [95% confidence interval: 1.24, 4.66]; P = .009) and a lower decayed, missing and filled teeth (DMFT) score (mean difference: -0.15 [95% confidence interval: -0.29, -0.02]; P = .023), although the quality of most included studies was poor and the findings for DMFT score became insignificant when only studies on adults were included in the meta-analysis. A meta-analysis for the other dental characteristics was not possible due to the limited number of eligible studies. There was inconsistent evidence for a link between following a vegetarian diet and dental caries or the number of natural teeth.

Conclusions: Within the limitations of the present study, the findings suggest that following a vegetarian diet may be associated with a greater risk of dental erosion.