Outcomes of preformed metal crowns placed with the conventional and Hall techniques: A systematic review and meta-analysis.

Background: Preformed metal crowns (PMCs) have been used to restore carious primary molars and have a high success and survival rate. There are two methods currently employed for PMC placement - the conventional technique (CT) and Hall technique (HT).

Aim: This systematic review aims to compare the outcomes of PMCs placed using the CT and HT.

Design: This systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. A literature search of five databases was performed up to 23 August 2022. Clinical studies comparing carious primary molars restored with PMCs using either technique with a minimum 12-month follow-up were included. Risk of bias (RoB) assessment was performed using the National Institutes of Health Quality Assessment tool.

Results: Five articles met the inclusion criteria, and four were included for meta-analysis. The 12- and 24-month success and survival rates were above 85% for both groups, with no significant differences shown at 12 and 24 months. The HT requires a shorter treatment duration, is more cost-effective and has a high level of acceptability among parents when compared to the CT. Four articles were rated fair, and one article was rated good in the RoB assessment.

Conclusion: Greater consideration may be given towards using the HT as part of standard treatment procedures in managing carious primary molars. Future studies should standardise reporting of outcomes to facilitate a more homogeneous pool of data for future meta-analysis.