Objectives: The objective was to assess long-term durability of screw-retained, implant-supported restorations fabricated chairside from a bis-acrylic composite resin (Protemp 4, 3M ESPE). Variables investigated were wear, gingival health and maintenance of luster.
Methods: Two adult patients in need of single implant-supported crowns were selected for this clinical trial. After the informed consent of the patients, diagnostic casts were fabricated and diagnostic waxings of the selected teeth were made. After initial diagnosis and treatment planning, the involved teeth (3 per patient) were extracted and an implant (Replace Select Tapered, Nobel Biocare) was immediately placed at each extraction site. Implants were immediately placed in function with screw-retained restorations. Implant-supported crowns were made by using a poly-vinyl siloxane impression material (Express XT, 3M ESPE) matrix prior to tooth extraction that also served as a guide for implant placement. After pick-up of the temporary components, restorations were carved for optimal occlusal and proximal contacts as well as to allow soft-tissue healing. Recalls were made at 1, 3, 6 and 12 months and every 6 months thereafter for up to 3,5 years. Performance of the restorations was evaluated with clinical examination and photographic documentation. Clinical handling and patient satisfaction were documented also at each recall.
Results: There were no recorded failures for up to 42 months. Overall satisfaction was very high. Restorations did not stain or lose their luster, and the periodontal condition was favourable.
Conclusions: Within the limitations of this observation, it was concluded that the direct technique may be a viable treatment option when using bis-acrylic composite resin materials to fabricate implant-supported restorations. Protemp 4 material performed well after 42 months.