Image 1: Intraoral welding abutments placed.
Image 2 and 3: Bar bent and welded to abutments
Implant retained full arch prostheses have come a long way. Studies have shown that just two implants are capable of retaining a removable denture on the mandible. Some patients would like something more stable that is not removable. A fixed hybrid denture is usually fabricated with some kind of metal bar by a lab. This type of prostheses requires multiple appointments with the dentist to try it in several times to make sure that the fit of the bar and prosthesis matches the mouth. This is an expensive and time consuming process.
In Italy, progress is being made on a procedure that would simplify the metal bar-making process for a fixed denture. They are calling the process intramural welding and seems to be a very promising idea.
This technique was originally published in 2006 by this same author. Intraoral welding is performed once the implants are placed. In this study, four implants are placed intra-foraminally. A special intraoral welding abutment is placed and a metal bar bent to closely approximate all abutments. The bar is then welded to the abutments with a special instrument, that heats, then cools the metal, in a fraction of a second. Once the bar is welded then the abutments and bar are taken out of the mouth, opaqued, and fitted with an acrylic denture. The whole prosthesis can be fabricated and delivered the same day. Because the bar is welded in the mouth with the abutments in place, passive fit is ensured with minimal time and money spent in the process.
In this report, 80 implants were placed and they found a 100% survival rate after 2 years. Only one patient reported and prosthesis problem, which was an incisal fracture that was easily repaired. Survival of implants does not necessarily mean that the implants were successful. The authors looked at bone levels which can give a good indication of success rate, as stable bone levels usually indicate healthy esthetic implants. Average bone levels remained stable through the length of the observation period.
The final prostheses.
Take home: Intraoral welding can significantly reduce the time, money, and inconvenience of making a bar-implant retained fixed prostheses. This study only looked at mandibular full arch cases, but there is no reason why it could not be applied to upper prostheses as well. It would also be interesting to use these bars with an acrylic restoration for 3-5 unit, acrylic, fixed prostheses that would not include the entire arch. This would be a low cost way to replace many teeth.
Fetner and Hartigan periodontics and implants has been serving the Jacksonville community for over 25 years. The practice is family owned and operated, and is always on the cutting edge of dental technology.