Both screw- and cement-retained fixed dental restorations have their advantages and limitations. The clinical decision as to which type best suits the patient depends on several factors, such as the indication, retention provided, retrievability, esthetics and clinical performance . We’ve put together the following guide to help you in the decision making process.
There are many factors to take into consideration when deciding between cement- or screw-retained implants, including retrievability, esthetics, location, and even personal preference. While each implant option comes with its own set of pros and cons
Weighing the pros and cons
Cementation is the most commonly used restoration in dental implantology. Advantages include the compensation of improperly inclined implants, easier achievement of passive fit due to the cement layer between the abutment and reconstruction, lack of a screw access hole, and thus the presence of an intact occlusal table and easier control of occlusion.
Nonetheless, one major disadvantage is the difficulty of removing excess cement, which has been associated with the development of peri-implant mucositis and peri-implantitis.
Screw-retained restorations on the other hand have the advantage of more predictable retrievability. They require a minimal amount of interocclusal space and are easier to remove when hygiene maintenance, repairs or surgical interventions are required. Additionally, angulated screw channel solutions have made screw-retained restorations available for a wide range of indications.
Esthetics can affect the design of screw-retained implant restorations and they are not recommended for anterior teeth. If an anterior screw-retained crown were to be placed, the the screw emergence would be situated in the cingulum area, compromising esthetics and creating a design that could be tricky for the patient to keep clean. When restoring a posterior tooth, the access hole in a screw-retained restoration is through the central fossa, affecting the cosmetic appearance of the crown.
Cement-retained implant restorations are highly esthetic, eliminating screw access holes which can be difficult to hide entirely. When choosing a cement-retained restoration, it’s possible to use an angulated abutment, creating a more natural emergence profile. A cement-retained crown allows occlusal forces to be evenly distributed along the axial inclination.
Factors affecting cement-retained implant restorations include the height of the abutment. Cement-retained restorations are not recommended at minimal occlusal height as retention may be inadequate, and a screw-retained prosthesis may be more appropriate.
Screw-retained restorations offer good retention at minimal occlusal height. A screw-retained restoration has a low-profile abutment, which may be advantageous in certain situations, as when using a bar retained overdenture. This allows for thicker acrylic and creates more room for denture teeth.
Both types of restorations have similar success rates that are largely dependent on the forces and stresses applied to the implant and bone. Improved implant components provide greater predictability and stability for cement-retained and screw-retained restorations. For clinicians who feel comfortable in their technique for successfully removing all excess cement, the main considerations are more likely to be esthetic.
The bottom line is clinicians need to evaluate each case and its indications individually and make determinations accordingly. For cases where esthetics are prioritized, cement-retained implants are the superior choice. When esthetics are of lower priority, screw-retained restorations provide clinicians with increased flexibility and eliminate the risk of infection or implant failure due to excess cement.
Regardless of the chosen method of retention, with careful planning and execution, practitioners can create a long-lasting restoration that meets the patient’s needs.