Screw- Vs Cement-Retained Prostheses in Implant Therapy

Both screw- and cement-retained prostheses are acceptable treatment options for single and multiple fixed implant restorations. However, there is debate over which is the better option in the long term.

A cement-retained prosthesis has several advantages over a screw-retained prosthesis in terms of cost, ease of fabrication, lack of an access hole (advantageous for a narrow-diameter implant with limited restorative space), and ability to change the angulation of the implant axis by utilizing angled abutments.^1,2 A systematic review by Wittneben et al³ compared cement- and screw-retained implant-supported restorations. The 5-year cumulative survival rate of cement-retained reconstruction was 96.03%, while it was 95.55% for screw-retained prostheses. There was no statistically significant difference between the two groups. However, this study revealed that screw-retained fixed prostheses exhibited a slightly lower biological complication rate, such as the presence of fistula/suppuration rates. In addition, the major negative aspect of cement retention is the presence of residual cement following delivery of the prosthesis that can lead to peri-implant mucositis and peri-implantitis. A clinical trial has shown that approximately 80% of the cement-retained implant prostheses with radiological and clinical signs of peri-implant disease had subgingival residual cement.⁴ Thus, it was concluded that residual cement might play an important role as a bacterial reservoir, leading to soft tissue irritation that contributes to peri-implant tissue breakdown.

In this case (Figure 1), the patient presented to a graduate clinic with 5-mm to 7-mm probing depths and bleeding on probing around implant #8. Clinically, tissue inflammation was noted on the gingival margin of #8. Upon examination, residual cement was noted in the subgingival area. This represents the obvious etiologic factor for iatrogenic peri-implant disease (Figure 2). To reduce complications associated with the presence of residual cement, clinicians should consider using screw retention as the connection of choice.² Linkevicius⁵ investigated the relationship between crown margin position and undetected residual cement. This study revealed that more remnant cement was found on sites with a deeper subgingival margin area. In addition, the majority of excess cement was not found with radiographic examination. If implant position is compromised and a screw-retained connection cannot be used, utilizing a custom abutment to place the crown margin < 2 mm submarginally is recommended.

References

1. Shadid R, Sadaqa N. A comparison between screw- and cement-retained implant prostheses. A literature review. J Oral Implanto 2012;38:298–307.
2. Wittneben JG, Joda T, Weber HP, Brägger U. Screw retained vs. cement retained implant-supported fixed dental prosthesis. Periodontol 2000. 2017;73:141–151.
3. Wittneben JG, Millen C, Brägger U. Clinical performance of screw- versus cement-retained fixed implant-supported reconstructions — a systematic review. Int J Oral Maxillofac Implants. 2014;29 (Suppl):84–98.
4. Wilson TG Jr. The positive relationship between excess cement and peri-implant disease: a prospective clinical endoscopic study. J Periodontol. 2009;80:1388–1392.
5. Linkevicius T, Vindasiute E, Puisys A, Linkeviciene L, Maslova N, Puriene A. The influence of the cementation margin position on the amount of undetected cement. A prospective clinical study. Clin Oral Implants Res. 2013;24:71–76.

This information originally appeared in Hamada Y, Hill K, Chang J, John V. Addressing risks of implant complications. Decisions in Dentistry. 2017;3(10):14–21.