BMC Oral Health. 2026 Jan 12. doi: 10.1186/s12903-026-07667-2. Online ahead of print.
ABSTRACT
BACKGROUND: The Hall Technique (HT) is a minimally invasive restorative approach for managing carious primary molars, in which stainless steel crowns (SSCs) are cemented over the tooth without local anaesthesia, tooth preparation, or carious tissue removal. The aim of this study was to compare the success of the HT and the modified HT in primary molars with deep dentine caries over a 24-month follow-up period.
METHODS: This prospective longitudinal randomized controlled study included 268 primary molars with deep carious lesions. The teeth were randomly allocated into 2 study arms: HT (n = 134) and modified HT (n = 134). In the modified HT group, unlike those in the HT group, the necrotic and contaminated outermost layer of the carious lesion was removed with an excavator to soft dentine. Clinical and radiographic follow-ups were performed by a blinded evaluator after 3, 6, 12, 18, and 24 months. In addition, the 24-month treatment outcome was evaluated according to tooth group, surfaces affected by caries, preoperative pain, and SSC fit. Categorical variables were compared using Pearson chi-square, Fisher’s exact, and Fisher-Freeman-Halton tests. Success and failure rates were compared with the two-proportion z test. A p-value < 0.05 was considered statistically significant.
RESULTS: At the 24-month follow-up, there was no statistically significant difference in treatment success rates between the HT group (86.6%) and the modified HT group (92.8%) (p = 0.121). Within the HT group, teeth with insufficient SSC fit showed a significantly higher rate of major failures and a significantly lower success rate compared to those with sufficient fit (p = 0.005). In the modified HT group, first primary molars exhibited a significantly higher rate of minor failures, whereas second primary molars demonstrated a significantly higher treatment success rate (p = 0.034).
CONCLUSIONS: Both the HT and the modified HT exhibited high success rates over a 24-month follow-up period, with no statistically significant difference observed between the two methods. In the HT group, proper SSC fit is important for reducing failure rates.
TRIAL REGISTRATION: Clinical trial registration number NCT05220865, date of registration 22.01.2022.
PMID:41526924 | DOI:10.1186/s12903-026-07667-2
