Success rates of Hall technique crowns in primary molars: a retrospective pilot study

The purpose of this retrospective observational study was to assess success rates, both clinical and radiographic, of stainless steel crowns (SSCs) placed on primary molars using the Hall technique. A retrospective analysis was performed on recorded data of patients with any primary molar treated with an SSC that was placed using the Hall technique at the University of Iowa College of Dentistry during 2011-2015. The primary outcome measure was the success or failure of the SSCs placed with the Hall technique. These outcomes were categorized as either clinical and radiographic success or failure. Clinical failure was defined as the need for pulp therapy or extraction following crown placement. Radiographic failure was defined as the presence of any pathological condition-including external or internal root resorption, bifurcation radiolucency, widened periodontal ligament, or ectopic eruption of permanent first molar adjacent to the Hall crown-following crown placement. Records indicated that 100 boys received a total of 179 crowns (61.1% of all Hall crowns placed), and 64 girls received 114 crowns. The mean age of the patients was 5.1 years (SD, 2.4 years). Of 293 SSCs included in the study, 180 received at least 1 follow-up examination after a mean of 9.9 months (SD, 6.5 months). At the first follow-up visit, 178 (98.9%) of 180 SSCs placed using the Hall technique were clinically successful. Of 87 crowns with radiographs available, 85 (97.7%) were radiographically successful. At the second follow-up visit (after a mean of 20.1 months), 74 of 76 (97.4%) were rated as clinically successful, and 37 of 39 (94.9%) were radiographically successful. Results of this study provide evidence of high clinical and radiographic success rates for SSCs placed on primary molars with the Hall technique.