Stripped head while tightening screw – recently placed – another implant rescue 2/2

A dental implant is an element that interfaces with the bone to back up dental prosthesis or to play role as an orthodontic anchor. The most important for dental implants is a biologic process called osseointegration where materials, such as titanium, form an intimate bond to bone. The implant fixture is first placed, so that it is likely to osseointegrate, then a dental prosthetic is added. A variable amount of healing time is required for osseointegration before either the dental prosthetic (a tooth, bridge or denture) is attached to the implant or an abutment is placed which will hold a dental prosthetic.Success or failure of implants depends on the health of the person receiving it, drugs which impact the chances of osseointegration and the health of the tissues in the mouth. The amount of stress that will be put on the implant and fixture during normal function is also evaluated. Planning the position and number of implants is key to the long-term health of the prosthetic since biomechanical forces created during chewing can be significant. The position of implants is determined by the position and angle of adjacent teeth, lab simulations or by using computed tomography with CAD/CAM simulations and surgical guides called stents. The prerequisites to long-term success of osseointegrated dental implants are healthy bone and gingiva. Since both can atrophy after tooth extraction pre-prosthetic procedures, such as sinus lifts or gingival grafts, are sometimes required to recreate ideal bone and gingiva.The final prosthetic can be fixed, where a person cannot remove the denture or teeth from their mouth or removable, where they can remove the prosthetic. In each case an abutment is attached to the implant fixture. Where the prosthetic is fixed, the crown, bridge or denture is fixed to the abutment with lag screws or dental cement. if the prosthetic is removable, a corresponding adapter is placed in the prosthetic in order the two pieces can be secured together.

There are times that I will see a case that is simple, but yet difficult. Advanced magnification of using a microscope assists the dentist to see the reason why the problem exists. This is clearly a case where the proximal contacts of the screw – retained – crown prevented the proper engagement of abutment interface with that of the implant fixture. The screw was removed by pre-soaking with tarter and stain remover and the use of an endodontic explorer. The crown was removed, proximal contacts adjusted, and crown reseated with a new screw tightened to 35 Nt/cm. The patient’s feedback was very useful throughout the rescue. He could sense the amount of tightness coming from the proximal contacts during insertion. Needless to say, he was very comfortable with the final outcome.