Cost Effectiveness of the Hall Technique Preformed Metal Crowns (HTPMC) in the Management of Caries in Primary Teeth: A Systematic Review and Service Evaluation study

Abstract

Background: Children referred to a specialist paediatric dentistry department clinic at a United Kingdom dental hospital for caries management are usually seen for dental extractions under General Anaesthesia (GA). However, following a comprehensive clinical and radiographic examination, some of these children may be offered an alternative treatment plan. This plan could include the use of Hall Technique Preformed Metal Crowns (HTPMC), with or without the need for extraction. The HTPMC presents a treatment option that is often less costly to perform and has been shown to offer greater clinical effectiveness, cost effectiveness, and success. Aim of study: To evaluate the cost-effectiveness as well as the clinical effectiveness of using Hall Technique Preformed Metal Crown for primary teeth caries management, through a systematic review data appraisal and retrospective service evaluation clinical case notes assessment.

Objectives: This study composes of two different study designs: A Systematic review: to summarise available economic evidence of the HTPMC through presenting a clinical healthcare and cost evaluation results of placing HTPMC compared with other conventional treatment of caries in primary teeth. Service evaluation: to evaluate success of using the HTPMC on children’s teeth in preventing or minimising the time in general anaesthesia session on the undergraduate clinics. Study design: Systematic review design: MEDLINE, Embase, NHS EED via Centre for Reviews and Dissemination databases, EconLit and CEA registry and International Health Technology Assessment Database were searched for clinical and economic studies conducted until 2021 evaluating cost effectiveness of HTPMC in primary teeth. The search followed the general principles for undertaking a systematic review reported in Higgins and Green, (2019) and the PRISMA reporting guidelines. Two reviewers independently screened, data extract and quality assessed studies. Eligible studies have reported findings supporting the aim of study. The method quality of the included studies was assessed by using a previously established checklist. A narrative synthesis was conducted. Service evaluation design: a retrospective service evaluation study of the clinical effectiveness of treating carious lesions using HTPMC, a randomly selected 100

case notes for patients attended Liverpool University Dental Hospital (LUDH) between 1st Jan 2018 and 1st Jan 2022, notes and radiographs were examined. Data were collected using a previously established data collection form with the inclusion criteria of children who suffer from dental caries and had at least one crown placed in their teeth, and children who had crown placement for other reasons including dental anomalies were excluded. Data collection form was piloted on ten cases, calibrated for intra and inter-examiner reliability and analysed using descriptive statistical analysis. Results: Systematic review: 173 papers were identified, 23 were retrieved for eligibility assessment and five matched the inclusion criteria. Included studies were conducted in three different settings. Children aged between three and ten years were included. All studies evaluated HTPMC vs pulpotomy, conventional filling or conventional PMC. The primary outcome was years of tooth retention, the secondary outcomes included teeth remaining asymptomatic and not requiring any future interventions. Two different studies reported pulpotomy and conventional PMC having similar clinical outcomes to HTPMC but at greater cost. A limitation of included studies was that most studies evaluated direct expenditure only. Service evaluation: 100 patient (260 teeth treated with HTPMC) were evaluated retrospectively. Maximum number of visits per patient to have HTPMC treatment was 11 visits. A total of 30 patients received treatment under general anaesthesia after having treatment at the dental clinic using HTPMC and only 171 teeth (73.4%, average= 5 teeth per patient) were extracted.

34 patients were referred specifically to have treatment under general anaesthesia (GA) or for behavioural management (total = 246 teeth), only 13 patients (73 teeth, 27.6%) received treatment under GA. Failure of HTPMC was reported on seven patients, one patient (2 teeth 0.8%) has reported failure of HTPMC treatment with teeth developing abscess post operatively and the need for extraction under general anaesthesia, and six patients (8 teeth, 3%) were diagnostically decided by dentist that teeth have been restored using HTPMC but, at theatre session were extracted. Conclusion: The evaluated studies in the systematic review reported outcomes that support the cost effectiveness of HTPMC, and the service evaluation study proved the effectiveness of HTPMC when used in the undergraduates clinic with only 0.8% failure within the limited review period. The technique has also determined the effectiveness in reducing the need for a general anaesthesia session and reducing the number of teeth requiring extraction per patient. Due to the limited evidence available, further well designed studies that include direct and indirect treatment expenditures and report patient quality of life outcomes are recommended.