Evaluation of the Cost-Effectiveness of Root Canal Treatment Using Conventional Approaches Versus Replacement With an Implant

Dental services consumed £1.6 billion of NHS expenditure in 2002, of which around 5% was spent directly on root canal treatment. Despite the level of expenditure, investigation of the cost-effectiveness of root canal treatment has not been extensively pursued. Recently, implant technology has provided an alternative to traditional orthograde (access through the crown) and retrograde (access through the gum) root treatment. While the initial cost of implant placement is high, implant supported restorations may be more durable than a root-filled tooth with significant decay, reducing maintenance costs. Previous evaluations of single implant supported restorations have considered only costs over a short period of time. This study examines costs and outcomes over the lifetime of the patient. Ten principal treatment strategies for an upper front tooth with a root canal infection are evaluated. The strategies include interventions to preserve the endodontically infected tooth and to place a single implant supported restoration. Failure of all proposed interventions necessitates a bridge or denture to replace the tooth. A Markov model is used to predict the intervention costs of each treatment strategy over the lifetime of the patient. The primary outcome assessed is the duration of the tooth or implant supported crown prior to placement of a bridge or denture. All of the significant mechanical and biological complications arising after root treatment, implant installation or placement of a bridge or denture are modelled, to provide a comprehensive picture of the lifetime costs and outcomes of each treatment strategy. Whilst no treatment (tooth replaced with bridge or denture) is the cheapest strategy, orthograde root treatment with no further treatment is cost-effective at very modest Willingness-to-pay values for the primary outcome (£5-10 per year of bridge/denture use avoided). Orthograde treatment and re-treatment is cost-effective at £15 per bridge/denture year avoided. Retrograde root treatment is never cost-effective. Immediate implant placement is very unlikely to be cost-effective, but provision of a single implant restoration after failure of orthograde treatment and re-treatment is cost-effective at £57-158 (male age 35 to 75) per bridge/denture year avoided.