Hall technique versus conventional restorations for carious primary molars: a systematic review

Introduction: Untreated caries in primary molars remains a leading cause of pain, infection and treatment need in childhood, and conventional restorations fail frequently in multi-surface lesions. Methods: This systematic review followed the PRISMA 2020 statement. OpenAlex, PubMed and Crossref were searched for studies published between 2018 and 2025 that compared the Hall technique with conventional treatments for carious primary molars. Risk of bias was assessed with the RoB 2 and ROBINS-I tools and the evidence was synthesized narratively. Results: Ten studies (nine randomized trials and one retrospective cohort) were included. Success and survival of the Hall technique ranged from 84.6 percent at 60 months to 100 percent at shorter follow-up. The Hall technique showed higher survival than resin composite and atraumatic restorative treatment, higher success than compomer and modified atraumatic restorative treatment, similar survival to conventionally placed preformed metal crowns, and similar postoperative pain to pulpotomy. Major complications were infrequent and comparable between groups, minor failures were less common with the Hall technique, and early occlusal changes resolved within weeks to months. Conclusions: In carious primary molars without pulpal involvement, the Hall technique achieves success and survival at least equivalent to, and often higher than, conventional treatments, with a low frequency of major complications, although the evidence is limited by small samples and risk of bias.