Cast metal posts versus glass fibre posts: which treatment of choice based on cost-minimisation analysis?

Aim The aim of this randomised clinical trial based on cost-minimisation analysis was to assess and compare four post-retained restorative strategies for endodontically treated teeth.Methods A total of 225 endodontically treated teeth in 141 patients were evaluated annually between 2009 and 2018. In this sense, the teeth were divided into four groups according to the treatment strategy, where three groups were treated with glass fibre posts in combination with composite resin restorations or single metal-ceramic crown with or without ferrules, and one group was treated with cast metal posts with metal-ceramic crowns. According to the outcome of the treatment during follow-up, the teeth received additional treatments, which ranged from restoration repair, re-cementation, endodontic retreatment, apical surgery, post/crown replacement to tooth extraction and replacement through metal-ceramic implant-supported crown. Thus, cost-minimisation analysis was based on November 2018 values from the Brazilian Public Health System, considering the primary costs related to the post, restoration or crown, and incremental costs related to the outcomes during follow-up.Results Primary treatment costs were lower for the group using glass fibre posts in combination with composite resin restorations (US$27.11), while the highest costs were for the group using cast metal post with metal-ceramic crown (US$153,14). In turn, the incremental costs due to tooth removal, implant placement and metal-ceramic crown (US$363.92) were the highest, while the lowest costs were related to procedures for crown re-cementation (US$6.11) followed by repair of the resin restoration (US$16.47). In this regard, the highest percentage of failures was related to restoration fractures in the glass fibre posts in combination with the composite resin restorations group. However, the average annual cost was significantly lower in the group that used glass fibre posts in combination with composite resin restorations (p <0.001) when compared to the other groups, with or without ferrules.Conclusions The treatment of endodontically treated teeth using glass fibre posts in combination with composite resin restorations presented a significantly lower average annual cost when compared to treatments that consider the use of cast metal posts, metal-ceramic crowns, with or without ferrules.