Conventional versus Hall technique for preformed metal crown restorations of carious primary molars-a randomised controlled trial comparing treatment duration and child and parental perceptions

Abstract

Purpose The preformed metal crown (PMC) is an extremely durable restoration for cavitated carious primary molars. Clinically, the PMC is delivered either by the conventional technique (CT) or the more conservative Hall technique (HT). The present study aimed to compare procedural time, child pain perception and behaviour, and parent acceptability, when the CT or HT were used to restore carious primary molars with PMCs.

Methods This was a primary care-based, two-arm parallel-group, randomised controlled trial with 80 participants randomly assigned into the CT and HT groups. To ensure standardisation, potential participants were screened and treated by a single paediatric dentist. Outcome measures evaluated included the procedural time taken; child’s pain perception (Wong–Baker FACES Pain Scale); child behaviour (Frankl scale); and parental perceptions and acceptability (5-point Likert scales).

Results Procedural time required for the CT and HT treatment groups was 17.4 ± 2.9 and 7.1 ± 2.8 min, respectively (P < 0.001). Child self-reported pain intensity perception was statistically significantly higher in the CT group (Χ2 = 12.27; P = 0.03). Dentist-evaluated child behaviour was comparable for both treatment groups with 65% of the CT group children and 85% of HT group children rated as ‘Positive’ or Definitively positive’. Parental perception of child’s comfort during the treatment procedure showed no statistically significant difference between children who received the CT versus the HT (Χ2 = 5.97; P = 0.20). However, parents of children who underwent the HT expressed statistically significantly better responses with regard to procedural ease (Χ2 = 21.74; P < 0.001), treatment duration (Χ2 = 21.58; P < 0.001), satisfaction with the treatment procedure (Χ2 = 22.04; P < 0.001), and desire to choose the same treatment procedure again (Χ2 = 24.47; P < 0.001).

Conclusions Compared to the CT, the HT of delivering PMCs to restore carious primary molars required shorter procedural time, elicited lower child pain perception, and better parent acceptability.