Stainless steel crowns as a restoration for permanent posterior teeth in people with special needs A retrospective study

Background. Limited information exists regarding the use of stainless steel crowns (SSCs) in permanent teeth. The objective of this retrospective cohort study was to present the long-term clinical outcomes of the SSC compared with those of amalgam and composite resin restorations and the SSC radiographic outcomes in a special-needs population. Methods. This study included 271 patients with at least 1 SSC restoration from the Mount Sinai Hospital Dentistry Clinic for Persons with Special Needs in Toronto, Ontario, Canada. A total of 2,621 posterior permanent tooth restorations were documented: 766 SSCs, 1,651 amalgam restorations, and 204 composite resin restorations. Clinical analysis included patient demographics, treatment parameters, and outcome assessments for each restoration recorded. Radiographic analysis of SSC restorations included 127 bite-wing radiographs and 118 periapical radiographs, measurement of interproximal bone loss, and assessment of periapical status using the Periapical Index Scale. Results. The 10-year survival rates for new SSC and amalgam restorations were 79.2% and 63.5%, respectively. The 91 SSC failures included 2 recementations, 33 replacements, and 56 extractions. Primary diagnoses at the time of failure included chronic periodontal disease (25) and loose or lost SSCs (24). Of the 528 failed conventional restorations that were replaced, 60% were replaced with SSCs. The mean alveolar bone loss from mesial and distal sites was 1.36 millimeters and 1.40 mm, respectively. Therefore, 93% of the sites recorded were less than 2 mm and classified as healthy. All pre-SCC and post-SSC periapical radiographs had healthy Periapical Index Scale scores (1 or 2) recorded over an average duration of 8.4 years (1-29.1 years). Conclusions. SSCs are a durable treatment option for the restoration of the posterior permanent dentition.