Interdental spacing and caries in the primary dentition
Related Experiment Video
Updated: Sep 26, 2026

Impact of Common Fruit Juices and Toothbrushing on the Discoloration of Primary Teeth
Published on: March 27, 2026
John J Warren1, Rebecca L Slayton, Takuro Yonezu
1Department of Preventive and Community Dentistry, University of Iowa, Iowa City, Iowa, USA. john-warren@uiowa.edu
Purpose:
This study assessed the relationship between interdental spacing patterns and caries experience in the primary dentition.
Methods:
Caries examinations were conducted amoung 356 children 4 to 6 years of age. At the time of the examinations, alginate impressions were obtained and poured in yellow stone. From the stone casts, each interdental area was categorized as: (1) space > 1 mm, (2) space < 1 mm, (3) no space, teeth in contact, or (4) no space, teeth overlapped. These categories were collapsed into presence or absence of space for each interdental site, and counted for each individual. Analyses assessed the relationships between interdental spacing and caries experience with separate analyses for anterior spacing, posterior spacing and total spacing.
Results:
Children with more total interdental spaces had less decay experience and less untreated decay than children with fewer interdental spaces, and children with more molar spacing had less molar decay experience; however, these relationships were weak. Correlation analyses demonstrated significant relationships between number of decayed surfaces and total number of interdental spaces (r=-0.11, P=.04) and number of molar sites with interdental spaces (r=-0.13, P=.02). Multivariate analyses revealed the total number of interproximal spaces to be weakly associated with interproximal caries experience, but that fluoride exposure was a much stronger predictor.
Conclusions:
Absence of interdental spaces is weakly associated with greater decay experience in the primary dentition.
Related Concept Videos
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.
Development of the Oral Microbiota
The Oral Microbiota