Progression of interproximal caries in the primary dentition.

While studies have addressed the diagnosis and progression of interproximal carious lesions within a primary tooth, few studies have addressed the development of proximal lesions in adjacent primary molars. The purpose of this study was to examine retrospectively the long term interproximal caries progression in primary molar teeth. Dental records of 150 children were retrospectively reviewed, 76 from a university pediatric dentistry clinic and 74 from a pediatric dentistry private practice. Out of the 387 teeth initially diagnosed with proximal caries, the combined university and private practice results for timing of the development of proximal lesions on adjacent tooth surfaces showed the following: simultaneous development-162 (41.9%); 1 to 24 months-65 (16.8%); 24 to 60 months-40 (10.3%); never-120 (31.0%). The combined results for formation of proximal caries in posterior quadrants showed that out of the 150 patients, the timing for development of additional quadrants with proximal caries was as follow: simultaneous development: 77 (51.3%); 1 to 24 months 31, (20.7%); 24 to 60 months 25, (16.7%); never 17 (11.3%). The conclusions of the study are that 69% of the primary molar teeth with proximal caries developed caries on the adjacent proximal surface and 89% of the patients who developed a proximal carious lesion on a primary molar tooth within one quadrant developed another primary molar proximal lesion in another quadrant.