Clinical Performance of Orthodontic Bands in the Restorative Treatment of Hypomineralised Primary Second Molars: a Randomised Clinical Trial

Hypomineralised second primary molars are more susceptible to post-eruptive enamel breakdown, carious lesions, hypersensitivity, and premature tooth loss. Although preformed stainless steel crowns have demonstrated favourable clinical performance in primary molars, orthodontic bands may represent a less invasive restorative approach for maintaining affected teeth until physiological exfoliation. However, their clinical performance in hypomineralised primary teeth has not been investigated. This parallel-group randomised clinical trial will include 30 children presenting at least one hypomineralised second primary molar with extensive post-eruptive enamel breakdown or a cavitated carious lesion requiring restorative treatment. Participants will be randomly allocated to receive either an orthodontic band cemented with glass ionomer luting cement after restoration of the cavitated lesion or a preformed stainless steel crown placed using the Hall technique. When more than one tooth is eligible, one index tooth will be randomly selected for the primary analysis. Clinical assessments will be performed immediately after treatment and at 6, 12, and 18 months. Marginal adaptation, retention, and carious lesions adjacent to the restoration margins will be assessed using modified United States Public Health Service criteria. Biofilm accumulation will be assessed using the Silness and Löe Plaque Index. Treatment acceptability will be evaluated immediately after treatment using separate questionnaires for children and caregivers. Physiological exfoliation during follow-up will be recorded separately and will not be considered treatment failure.