The success of Preformed Metal Crowns in Primary Molars using the Hall Technique Versus the Conventional Method: A Retrospective Study in a Postgraduate Setting

Abstract

Preformed metal crowns (PMCs) have been used conventionally for decades in managing multi-surface carious primary molars in children. However, the Hall Technique (HT) is a controversial novel method, used in the United Kingdom (UK) since 2006. The HT was introduced in the United Arab Emirates (UAE) in 2014. The aim of this study was to evaluate the clinical and radiographic success of conventional and HT PMCs in a pediatric dentistry postgraduate dental setting in Dubai, UAE. A retrospective study, using HBMCDM (MBRU) pediatric dentistry patients’ electronic case-notes and radiographic images, was carried out on a random sample of carious primary molars treated with either conventional or HT PMCs (from 1st July 2014 to 1st March 2017) to assess for clinical and radiographic success/failure. A Kaplan-Meier curve was used to assess PMC survival. 187 PMCs (110 HT and 77 conventional) in 65 children (34 females and 31 males) at six, 12 and 18 months were assessed for success or failure. The success rate of the HT-PMC at 6 months, 12 and 18 months was (100%, 99.1% and 98.8% respectively) while the success rate of the conventional –PMCs for the same period was (98.7%, 96.1% and 95.2% respectively), both were comparable and in concurrence with previously published studies. Four PMCs failed; one HT-PMC (a result of PMC perforation) and three conventional PMCs (because of loss of crown/retention and abscess formation). Both methods showed comparability in term of proportions of success and average time of failure (p = 0.362). PMCs placed conventionally or by the HT in a postgraduate pediatric dentistry setting have similar clinical and radiographic success rates at 18 months’ follow-up.