Position Paper in Implant Dentistry

Position Paper: Implant Dentistry, Vol. 10, No. 4, 2002, P 231-233.

Immediate Functional Loading of Dental Implants

Glenn J. Wolfinger, DMD, FACP
Thomas J. Balshi, DDS, PhD, FACP

Background and Rationale
We have been invited to write a position paper on a treatment protocol we have been using for the past seven years termed TEETH IN A DAY. Essentially, TEETH IN A DAY is the immediate functional loading of titanium screw shaped dental implants. This protocol is gaining great popularity throughout the world for both professionals and patients interested in reducing or even eliminating the waiting period for implant supported fixed teeth. With these proven scientific breakthroughs, there may be questions regarding a violation of the bone healing mechanism and the long-term prognosis for the fixed prosthesis. This position paper describes the protocol for TEETH IN A DAY, along with the indications for treatment, and the advantages, or disadvantages that may exist. The implications of such treatment will be discussed, how it is perceived today, and how future advances may further improve this protocol.

The concept of immediate functional loading of dental implants is not new. Prior to the days of osseointegration, many implantologists immediately loaded dental implants. There was very little good scientific data to support the early techniques of dental implants placed in function and immediate loading probably played a large role in producing mobility leading to early failures. The imprecise drilling methods used to prepare the osteotomy site for placement of implants resulted in implants lacking initial stability having substantial voids adjacent to the implant. These implants were then immediately loaded. The premature loading of unstable implants caused the implants to loosen and become fibrous encapsulated.

The research by Professor Brånemark leading to the discovery of osseointegration has been a dramatic breakthrough in the field of implant dentistry. The incredibly detailed scientific research and clinical studies that were done in support of the Brånemark System was something that we were unaccustomed to seeing in the field of implant dentistry. Brånemark’s ‘recipe’ for osseointegration contained a number of specific details, which he felt needed to be followed in order to make this procedure work .

Since this time, many of these ‘critical factors’ for osseointegration have been challenged, the most notable being the need for an undisturbed healing period. Paul Schnitman and his colleagues at Harvard University School of Dental Medicine, were the first to challenge the undisturbed healing period by immediate functional loading of Brånemark implants in edentulous mandibles. This research began over ten years ago.

In 1993 we, at Pi Dental Center, initiated a similar study by immediately loading Brånemark implants in edentulous mandibles to also challenge the premise that Brånemark implants needed an undisturbed healing period . One reason immediate functional loading is successful with root form implant systems is attributed to the precise preparation of the osteotomy site. The use of a series of standardized drills with copious irrigation creates an intimate receptor site. The implant then has excellent initial stability at the time of implant placement. Additional steps can be taken during the site preparation or implant selection to further improve the initial stability for immediate functional loading. Some may wonder why immediate functional loading does not violate the bone healing mechanism. The initial stability that is achieved with implant placement, combined with the splinting effect that is achieved by joining multiple implants together with an all acrylic prosthesis, acts to stabilize the implants and control the load during the osseointegration healing period.

There is a certain amount of micromotion that can be tolerated during the healing period. Brunski theorized that 100 microns of micromotion might be the limit at which point fibrous encapsulation may take place . By having an implant with excellent primary stability splinted and stabilized with the adjacent implants, the amount of micromotion is limited and controlled to achieve osseointegration in a predictable fashion.

Technique Outline
The technique for immediate loading can be best accomplished by a prosthodontist who surgically places dental implants or a surgical and prosthodontic team working in the same facility. The prosthodontist can fabricate a provisional restoration prior to surgery and place the implants in the ideal position for the prosthetic restoration. The abutments and prosthetic cylinders are connected to the implants. The prosthetic cylinders are then in turn connected to the provisional restoration intraorally using auto polymerizing acrylic resin following the conversion prosthesis technique . Immediate functional loading can be employed for: single tooth, partial edentulism and fully edentulous arches. This technique allows for the placement of the implants in the proper position for each individual patient, followed by customization of the provisional restoration before surgical flap closure. By wearing the provisional restoration during the healing period, the prosthodontist has the opportunity to evaluate the esthetics, phonetics, and functional loading during the normal osseointegration healing period, 3 months in the mandible and 5-6 months in the maxilla. Impressions can then be taken for the final restoration either at stage one surgery or at a later date.

There has always been concern about the ability to make an accurate impression for osseointegrated dental implants. There is always distortion that takes place in all stages of the process, from impression making to pouring the cast, to casting the framework, to applying the prosthetic veneering materials, etc. By using the all-acrylic splint, which has been connected to the implants since the day of stage 1 surgery as an impression splint, it is our opinion that one of the inaccuracies in the process has been eliminated. The master cast should be exceptionally accurate. The premise relies on the fact that the bone is healing around the implants to conform the positional relation of this all-acrylic splint. This theory is accepted by many biomechanical engineers and will soon be tested through clinical studies.

Indications for TEETH IN A DAY
Not every patient and not every site is indicated for TEETH IN A DAY. Patients need to understand the limitations of such treatment and be willing to accept the precautionary measures that are scientifically set forth. It is strongly recommended that patients be on a soft diet during the three-month healing period to limit the functional forces during osseointegration. While this cannot be easily enforced, patient compliance is an important factor in achieving success.

It is recognized that occlusal forces are greater in the posterior region than in the anterior area of the mouth. In an area for single tooth replacement, a single posterior tooth may be subjected to 3-4 times the occlusal forces than an anterior tooth. When it comes to immediately loading a single posterior tooth, especially a molar, the disadvantages may far outweigh the advantages of such treatment. Immediate functional loading is an excellent option for someone who does not want to deal with an esthetic deficit. Immediately loading a single anterior tooth, which is subjected to small occlusal forces and has a great esthetic advantage, may be an indication for single tooth treatment. In a situation where a patient can tolerate wearing a removable denture, and has worn one for many years, immediate loading may not be as critical as for a patient who is being transitioned from natural teeth to dental implants.

If a few key natural tooth abutments can be saved, the implants can be submerged and the natural teeth can help support the provisional restoration . When that is not possible, and the patient is averse to wearing a removable denture, then immediate loading becomes a great option for transitioning the patient.

Since our initial study in 1993, there have been several other centers that have also tested this concept of immediate functional loading. The results worldwide have been outstanding and the predictability for osseointegration is very close to, if not the same as, that of placing the implants using the prior two stage protocol .

The advantages are easy to recognize: The ability to have fixed teeth immediately (TEETH IN A DAY); no need to use an uncomfortable removable prosthesis; provides functional advantages; improved esthetics; and improved patient self-image.

Future advances on bone healing, implant surface modifications, and prosthetic advances as well, will all make this an increasing popular and predictable procedure for dental implant treatment.

Thomas J. Balshi, DDS, PhD, FACP
Glenn J. Wolfinger, DMD, FACP
Institute for Facial Esthetics
467 W. Pennsylvania Avenue
Fort Washington, PA 19034

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Pi Dental Center, Fort Washington, PA