Completely Edentulous Patients Screw-retained Maxillary Complete Denture With Electric Welded Metal Framework Versus Cast One, Patient Satisfaction Assessment (Randomized Control, Split Mouth Trial)

In this study twelve completely edentulous patients will be enrolled and In each patient six implants will be inserted in the maxillary arch at crestal bone level in predefined positions (positions 15, 13, 11, 21, 23, 25) with the help of a surgical template following a submerged healing protocol and checked for primary stability clinically. After a 4-month osseointegration period, second-stage surgery will be performed and healing abutments will be placed. After the second-stage surgery, prosthetic procedures will be initiated.

then for one side (the intervention side) the metal framework will be constructed as follow: A preexisting or prepared flat surface area of the welding abutment of implant at central incisor position at one side (right or left) will serve as the welding point. A titanium bar will be shaped following the curvature of the implants positioned. At this point, temporary titanium implant abutments will be welded with the titanium bar in the oral cavity, using the Syncrystallization Unit .The welding process is electrical and protected by an argon gas supply (Syncrystallization). The equipment allows the welding of metallic elements directly in the mouth. Current flowing through the contact points, being in contact with the parts to weld, warms up to the point of fusion, achieving a solid, welded junction. Then will be placed between the two electrodes of a welding clamp. The energy contained in a previously unloaded battery of capacitors is transferred to the electrodes of the welding cycle is subdivided in three stages: Pre-gas, welding, and post-gas phase. While the pre-gas phase allows an oxygen-free welding point prior to the actual fusion, the post-gas phase ensures the absence of oxygen and subsequent oxidation during cooling. Finally, the prosthetic framework, created by welding the titanium bar to the implant abutments, will be removed and opaque will be applied in order to avoid metal shining through the acrylic resin.

for the other side :

At the day of second stage surgery restoration will be fabricated as follow:

For the cast metal framework group, CCM abutments (Titanium base abutments with a plastic cast able sleeve) will be fastened over the analogues of the placed implants, on a verified analogue model.