Survival of hollow metal post-retained restorations:A long term clinical follow-up

Aim Aim of the research was to evaluate the long term results of an innovative system for the restoration of endodontically treated teeth. Material and methods A prospective evaluation was performed on 246 post and core build-ups. A total of 189 patients (57 lost) underwent clinical and radiological follow up from 1 up to 11 years. Tooth shape, post length and the presence of prosthetic crowns were recorded. Causes of failure considered were: root fracture, build-up detachment, restoration fracture, marginal infiltration and post fracture. The proposed restorative technique exploits the resin cement injection through a metal cylinder placed into the post space. The carrier was incorporated into the composite after polymerization. Results The statistical analysis showed how the global success rate of the technique is 96.8%. The failures were caused by marginal infiltration (2,65%) or core fracture (0.53%). The Cox regression shows that success is not related to post length (p=0.786) nor to the prosthetic crown (p=0.120). In the upper jaw the success was statistically related to the presence of the crown (p=0.47). Hazard ratio curves, related to the shape of treated teeth, underlined how premolars and molars are characterized by a higher risk of fracture when compared to incisors and canines. Log rank test does not gishowves any significant difference between the treated teeth. Conclusion The follow-up results highlighted a low incidence of failures of the procedure. The presence of prosthodontic crowns increases the success rate.