The comparison of cement- and screw-retained crowns from technical and biological points of view.

Objective: The aim of this review was to evaluate the most common complications in implant prosthodontics with porcelain-fused-to-metal crowns, to evaluate the influence of biomechanical properties on fractures and cracks of veneered porcelain, and to compare the effects of crowns with different connections on soft tissues.

Material And Methods: A search of literature in the English language between 2009 and 2015 was conducted using the following databases: Medline via PubMed, Science Direct, Wiley online library, Taylor& Francis, and Cochrane library. In total, 10 studies that met the inclusion criteria were found.

Results: Four investigations showed that technical complications more often occurred in screw-retained prostheses, although two studies concluded that cement-retained crowns were also susceptible to technical complications. Two investigations showed that the deeper the abutment margin was subgingivally, the more excess cement was left in the peri-implant sulcus. Four studies concluded that cement-retained prostheses were more susceptible to biological complications, but two investigations also showed that biological complications were observed in tissues adjacent to screw-retained crowns.

Conclusions: The research of literature data for the last five years showed that screw-retained crowns demonstrated more failures such as porcelain cracks and fractures or screw loosening, while cement-retained crowns caused more severe biological complications such as peri-implant soft tissue inflammation or pathological bone resorption.