Switching Back to Screw Retention for Implant Fixed Partial Dentures?

After years of doing almost everything cement-retained, I am going back into screw-retained whenever possible. A single tooth, no problem for cement retained. But anything more than that, I like the idea of being able to retrieve consistently the restorations. Plus, there are many ways of getting great esthetics on the access hole today. And if someone mentions occlusion as being a problem ("unstable occlusal contacts due to composite wear"), let me ask: do you not place posterior composites in your practice? Just my two cents.

Now we go back to the passive fit test. I guess we will need to go back to laser welding to get a passsive fit. Must add to cost and will it solve the issues??? Switch to using a temp cement or lubing one of the metal surfaces. Worst comes to worse the crown needs to be cut off. On a side note, I ask my lab to over-engineer the frameworks to minimize the risks of porc fracture. Never more than 2mm of unsupported porc. I have found that most failures of Marginal ridges and cusp tips are due to the under design of the metalwork. This applies double to the new Zr frames the labs and implant companies are pushing.

This may sound like a bit of self promotion, but I have to answer this question as we have finally solved this problem. I started my own lab to address the inherent problem with long span cemented bridges. What we have done, is import the techniques of Dr. Philippe Leclerq and his head technician, Jean-Francois Martinez. We fabricate what I call the LM Bridge (Leclerq-Martinez Bridge). You have probably seen some Europeans and Brazilian presenters at the meetings show cases like this. Basically, it is a cast framework that is screw retained, with individually cemented crowns. The greatest strength of the LM Bridge over similar types of designs, is the ability to be used in situations where pink gingiva is NOT desired. Thus, the teeth look as if they are coming directly out of the gums. We are able to fabricate this is any size, for far less than any lab I am aware of. The main benefits to the patient are repairability of each individual crown, as they are individually cemented onto the frame; cross arch stability, thus long life span for full arch cases; esthetics due to individual cementation. The main benefits to the doctor are splinting of posterior units, easier correction of non-parallel implants, ability to incorporate totally misangled implants, no cement below abutment margins, simple crown remake type repairs.

I never stopped doing screw retained restorations due to the inevitable maintenance issues that arise with anything mechanical. As I've seen recently, "Team Atlanta", the practice with Drs Goldstein, Garber and Salamas, with the worldwide reputation for excellent care and esthetics has changed back to screw retention in many or most cases due to ability for repair and modification. My feeling has always been, "Who wouldn't want any part of their body to be able to be removed, repaired and replaced whenever it is needed". Screw retention has its problems as well as cement retention but as stated, predictable retrievability gives significant peace of mind to the Dr and patient. Its more difficult to do well for the Dr and lab, so it has fallen out of favor. The advantages once completed have never fallen out of favor. Hope this is helpful

I need to disagree I have used cement retained for over 15 years Apart from being simpler to fabricate and far superior aesthetics I do not see a problem with this . I fit around 80 + units per month and porcelain fracture is rarely a problem. When it is an issue , its due to unsuported porcelain or a bruxist or clencher or another occlusal issue Screw retention does not solve any of these issues . a bite guard and properly designed metal frames might however -Screw retained is ugly -Such precision work in gold and ceramics to be stuffed with cotton and a blob of composit resin! Thats like duct tape tape on a Mercedes! -The screw hole by definition is right on the occlusal surface where maximum force comes you have a porcelain edge ...now you get MORE fractures than ever before -Cement retained IS retrievable if your prosthetics is good ..long parallel abutments at least 4mm tall and parallel provide very good retention with softer cements. If occasionally you need to remake ..big deal.. replace it ..Same hassle as screwing it off and fixing it anyway I would not pay big bucks for ugly and more fragile work in my mouth In Prosthodontics on regular teeth were you having the same problems all these years?

Another benefit of screw retention is the avoidance of retained subgingival cement which often results in peri-implantitis issues.

Use what works best in your hand. There is no wrong or right way, as long as the objective of the procedure is obtained.

In response to Dr S: Congratulations on the # of units you place and the scarcity of porcelain fractures. Porcelain fractures in my patients have ocurred infrequently but when you do enough units they add up. This has been the same with conventional C&B. I agree that the screw holes can look ugly(although a well done resin can look reasonably esthetic) and therefore I use lingual screws in the mandible so there are no occlusal access holes to disturb the esthetics and occlusion. Certainly a night guard would help but we have no control regarding nightly wear. Regarding composite for the occlusion, modern composites have excellent wear resistance and they can be bonded to the porcelain if needed. Basically, there are advantages and disadvantages to each and we 'pick our poison'. Once again, anything mechanical can and will have problems and I and my patients appreciate the reassurance of retreivability.

La verdad es que creo que cada profesional debe usar lo que mejor domina, y donde tiene mejores resultados. El tipo de implante también influye ... si tiene un cono Morse tal vez no tenga tantos aflojamientos de su pilar. Yo he usado el sistema cementado desde hace más de 15 años. Ahora vuelvo al atornillado. Me dá más tranquilidad ... y por supuesto en 3 minutos lo desmontas ! Saludos desde Barcelona (Spain)

I use the premier implant cement with the lubricant to cement the prostethic devices. If I have a fracture it is easier to remove and send it back to the lab for repair. I don't use hard cements. If you use these you can drill a whole through your crown and try to unscrew the abutment and send this back to the lab. You then get a screw retained prosthetic which the lab can repair. This won't work if someone put the hard cement on top of the srew of the abutment!! I hope this will help. Srewing is also a good solution, but I think a lot of people went back to this methode because of the risks of cement producing a peri-implantitis when it is not removed under the gum.

It seems the controversy is again being discussed for screw vs cement fixation.It is absolutely necessary to have restoration retreivable.There is no doubt.Screw retained is the best solution.The only drawback is screw breaking and loosening.If enogh followup help is possible then this also can be taken care of.We are doing implants since 22 years.We had no such support in those years.But scenerio is totally different now.Almost everyone says I am doing implants.Still few can be truly experienced to help patient in need.In short,if possible try to give screw retained with full understanding of the patient of possibilities.This will be far better than not able to remove and help in case repaire required. Screw retained requires lot of training in making from doctor to lab.Keep this in mind.

It is the doctors choice. Me, I like to cement with ZnPO4 for implant cases. There are times when screws are in order.

Hello All The posts here all are correct It generally is decided by what is in front of you at the time. A well placed implant you can direct the screw hole according to the bone. A poorly placed implant gives you less than desirable access. As with anything, a well planned case will give you what you want ( a screw retained or a cemented) all to often to have the planned changed and the compromise to begin. Fail to plan is plan to fail. A well executed plan with the best diagnostics and treatment plan is the bullseye in the case. Shoot for a bullseye and see how close you get. Every throw is a crap shoot. Or is It?

One more time Give a dart to the Surgeon, the Restoring doctor or denturist , The laboratory and then see if they hit the same spot. No wonder implants require team work. The restoring doctoer is the general contractor. everything else is a compromisesince that is the reason for doing the implant.

Screw retained prosthesis is not predictable if they are not telescoped over the abutment. Cementable with traditional dental coping is risky beacsue the thin metal at the margin of coping will flex and thereby cause procelain fractures in long term use. We can however combined the best of both world having a coping that is not thin at the margin and telespocially screw retained the prosthesis over the abutments. IF you are interested in how this can be done, please email me.

A well placed implant you can direct the screw hole according to the bone. A poorly placed implant gives you less than desirable access. I don’t use hard cements. If you use these you can drill a whole through your crown and try to unscrew the abutment and send this back to the lab. You then get a screw retained prosthetic which the lab can repair. This won’t work if someone put the hard cement on top of the srew of the abutment!! I hope this will help. ________________________________________ Whiteblack