When it comes to the restoration of implants, we typically have two treatment options: screw-retained or cement-retained.

screw retained implants

Although both treatment options can be used predictably, they each have their own advantages and disadvantages:

Screw-retained

Advantages:

  • Known retention
  • Easy to remove/re-tighten if it were to become loose
  • No risk of leaving residual cement

Disadvantages:

  • Dependent on implant orientation/angulation
  • May be unesthetic
​screw retained implant restoration

Cement-retained

Advantages:

  • Independent of implant orientation/angulation
  • Enhanced esthetics 

Disadvantages:

  • Unknown retention
  • Can be difficult to remove

Although a majority of the implants I restore are done as cement-retained restorations, in the past few years I have transitioned into restoring an increasing number of implants as screw-retained. Why this transition? Mainly because there is a lot of good research showing the problems associated with leaving residual cement.

(Click this link to read more dentistry articles by Greggory Kinzer)

References

The positive relationship between excess cement and perio-implant disease: A prospective clinical endoscopic study. Wilson TG Jr. J Periodontol 2009 80(9): 1388 – 92


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Comments

Commenter's Profile Image Andrew Soulimiotis
January 22nd, 2014
I have tried going the route of screw retained as well. The biggest obstacle from patients is esthetics. They feel like if they are going to pay so much to replace missing teeth, they better darn well look like a real tooth and not a tooth that just had a root canal through a crown. I have tried some zirconia and emax type abutments in the anterior region but have not tried them in posterior areas. Do you think they can withstand the forces in the posterior or do you have any tricks to placing composite in the access hole of a metal abutment and not having a gray shadow show through?
Commenter's Profile Image Gregg Kinzer
January 22nd, 2014
Thanks for your comment Andrew. I think the choice of abutment material depends on many factors (location in the mouth, implant type, implant size, is there a metal "fitting" on the abutment or is it all zirconia). In certain patients with minimal signs of parafunction and a large enough implant / abutment, I would be fine with Zirconia. However, if there are signs of parafunction, a smaller implant / abutment, I think it is always safer to have metal, or at least a metal base or fitting to the abutment. I agree the difficulty with metal ceramics and screw access holes is masking the access to make it look like it isn't there. I wrote another post that will be up soon with regard to sealing the screw access hole….so be sure to keep an eye out for that. One thing I will have the technician do for these restorations is end the metal in the access hole further apical (2mm apical to the occlusal surface). This will give me enough room to place an opaque composite into the access to mask the metal…and still have enough room coronally to place other composite materials to enhance the esthetics.
Commenter's Profile Image Yo On Jeong Hon
January 25th, 2014
Do you think implant/abutment ratio is important to maintain implant prosthetics? There are many papers which say it isn't.
Commenter's Profile Image Sandy Daniels
January 7th, 2015
Can I ask who did your lab work I think those look really nice
Commenter's Profile Image Joshua M.
May 23rd, 2017
For multiple posterior implants that are adjacent do you prefer to do them as single units or to splint them together?
Commenter's Profile Image Greggory K.
May 25th, 2017
Great question Joshua. In general, my answer would depend on what type of implants are present. If they implants are the older, external hex, Branemark style implants….I would want to splint them together to add stability to the restoration and try to prevent structural issues (i.e.. screw loosening). However, if the implants are the newer style internal hex implants (horizontal offset / platform switch), then I would want to keep them as single units. Given the design and fit of the the newer implants, we are just not seeing the same structural problems, so the need to splint the implants together in my opinion, is not as applicable. (It must be remembered that any time you splint restorations together, the problems that you encounter with one…now affects them all). As with anything, there are other factors that will come into play with this decision. Some of these other factors include: length of the implants, ratio of implant : restoration length, the quality of bone in which the implants are placed.