For more on this topic, go to www.dentaleconomics.com and search using the following key words: prosthodontics, prosthesis, abutment, implant overdenture, Dr. Joe Massad.
Welcome back! This month's tip involves a simple solution to a problem dentists seem to encounter in about one out of every three implant overdenture cases they handle. This causes frustration and loss of valuable time, which can't be replaced. The more time we waste redoing and/or altering cases, the less time we have for quality patient care and profit. Many dentists have shared instances with me in which their patients, at times, complain that their prosthesis pops up in various places, even though it is secured by an implant with a retentive element. I have been in similar situations myself.
The problem dentists are referring to relates directly to our lack of thinking “in” instead of “out” of the box when dealing with the whole concept of prosthetic fit, occlusion, and vertical dimension, and how these three concepts must be reverified at all prosthetic deliveries. Whether the direct or indirect method is performed, it is necessary to understand how imperative it is that these three principles are applied for optimal results with every prosthetic restoration, especially the implant overdenture.
Remember to be sure to maintain adequate space in the prosthetic receptacle, be sure to maintain intended OVD, and be sure that there is simultaneous tooth contact.
The frequency of misalignment is directly correlated to the absence of any of these three requirements. From a personal and practical choice, I utilize the direct method in the mouth to attach the retention to the abutments, which allows me to evaluate the prosthetic adaptability (fit and space), occlusal contact, and intended vertical at the delivery appointment.
The following is the protocol I developed:
1) Verify occlusion at the appropriate vertical dimension. The prosthesis must be inserted and have no contact with the implant abutments. This will assure that the denture is completely seated and not binding on any of the abutments.
2) Verify the vertical at desired occlusion, and fixate bite registration material (Regisil by Dentsply Caulk) on the prosthetic teeth to guide the patient to closure during the procedure.
3) Next, place the retentive elements onto the abutments, followed by the rubber dams. Recheck the vertical spacing by aligning the dividers to the dot on the nose and chin to be assured they are exactly the same as before the retentive elements were placed. If they are not, this may indicate that one, two, three, or all of the retentive elements are prematurely striking the internal portion of the prosthesis, not allowing it to seat completely. It will then be necessary for the dentist to mark these areas and ream out additional space to assure that the patient will close completely at the proper vertical. Once the dots match, with the patient closed into the index, the retentive elements can be locked into position.
4) After the bonding agent is applied into the receptacle, inject a composite material all the way to the top of the receptacle. Have the patient close to the desired vertical position. Once cured, analyze and remove any excess. With the advent of ERA composite pick–up material (Sterngold), this process becomes predictable.
I hope this tip will help you as much as it has me. For the full video step–by–step version, go to www.dentistryiq.com. See you next month. I hope my pleasure in dentistry will also be yours ... Joe Massad
