Comparing Hall vs Conventional Technique in Placing Preformed Metal Crowns From Sudan

A Randomized Clinical Trial Comparing Hall vs Conventional Technique in Placing Preformed Metal Crowns From Sudan

Preformed metal crowns (PMCs) have high success rates in restoring primary molars in children but they were not generally used by dentists, especially in developing countries due to its demand of high clinical skills with the conventional technique (CT). The biological approach, Hall technique (HT), requires less training and can be placed by less experienced dental operators including therapists. Previous studies were mainly carried out in developed countries. The aims were to investigate and compare the efficacies and cost-effectiveness of PMCs placed by these two techniques.

A prospective randomised control trial design was used. The study was carried out in a dental practice in Sudan, an under-developed country with lower social economic group. Children between 5-8 years were invited and selected if they met the inclusion criteria. Only those who had 1-2 carious primary molars needing PMCs were randomised. The PMCs were placed by a dentist in the CT arm and by a therapist in the HT arm. The children were follow up every 6 months up to 2 years. The demographic details, periodontal health, occlusion, children anxieties, and procedure time were recorded. The Kaplan-Meier survival rates for each arm were calculated. The incremental cost effectiveness ratio (ICER) was calculated using the results and the local salaries

The intervention involves removal from the primary molar and a preformed metal crown is placed using glass ionomer. The subject is then asked to bite until crown is seated. No occlusal adjustment is carried out.

The procedure involves administering local anesthetic and the intervention involves remoal of caries from the affected primary molar. The tooth is then reshaped and contoured to to enable a preformed metal crown placement. Occlusal and marginal fit is improved by crimping the metal crown to improve fit. The preformed metal crown is cemented with glass ionomer restorative material and occlusion finally checked. The subject is then asked to bite on a cotton roll for two minutes until the cement has set.

Modified gingival index after Löe et al. (1967); Scale; 0=No disease; 1=hyperplasia with no bleeding; 2= hyperplasia with bleeding

Plaque accumulation around preformed metal crown after Loe et al (1967); Scale: 0= no plaque, 1= subgingival plaque; 2= supragingival plaque

Self perceived anxiety using facial image scale after Buchanan and Niven (2002) using 5 facial diagrams ranging from sad to smiley faces: Scale; 1-5; 1=extremely happy to 5=extremely unhappy

Inclusion Criteria: Healthy children with Class I or class II carious primary molars Exclusion Criteria: Had a compromised medical history Were pre- or un-cooperative to have clinical examinations Lived in remote villages and were unlikely to return for follow-up Had teeth with pain or sepsis Had teeth with caries extended in pulp either from clinical or radiographic examinations

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Loe H. The Gingival Index, the Plaque Index and the Retention Index Systems. J Periodontol. 1967 Nov-Dec;38(6):Suppl:610-6. doi: 10.1902/jop.1967.38.6.610. No abstract available.

Buchanan H, Niven N. Validation of a Facial Image Scale to assess child dental anxiety. Int J Paediatr Dent. 2002 Jan;12(1):47-52.

Elamin F, Abdelazeem N, Salah I, Mirghani Y, Wong F. A randomized clinical trial comparing Hall vs conventional technique in placing preformed metal crowns from Sudan. PLoS One. 2019 Jun 3;14(6):e0217740. doi: 10.1371/journal.pone.0217740. eCollection 2019.