Cleansability… How Did We Forget?
Alternate solutions to screw-retained implants fabricated with acrylic
By Arian Deutsch, CDT
Cleansability: Interestingly, any dictionary search or spell-check software will not recognize the term as a word. In fact, as the author wrote this article, the Pages application continued to strongly suggest that the words cleanse and ability or the single word cleansable should be used.
However, in the dental field, numerous journals utilize the term cleansability to refer to the ability to cleanse a restoration or prosthesis, specifically the patient’s ability to do so depending on their individual dexterity. A patient’s ability to maintain good hygiene regardless of the particulars of the specific restoration is important.
Particularly when it comes to implant-supported restorations, a shift has occurred in recent years to creating definitive prostheses that are screw retained — therefore not removable by the patient — and fabricated with acrylic as the chosen material.
The Perfect Storm
The 1991 Perfect Storm, also known as the The No-Name Storm, was a nor’easter that absorbed Hurricane Grace and ultimately reverted back into a small unnamed hurricane late in its life cycle.1 A wave height of 100.7 feet was recorded off the coast of Nova Scotia, the highest ever recorded in that province’s waters. In the middle of the storm, the now well known Andrea Gail sank, killing its entire crew of six and becoming the inspiration for the book, and later movie, The Perfect Storm.
Is this concept of the perfect recipe for disaster relatable to the dental field? Is dentistry starting to see the disastrous results of a unique combination of anatomy, circumstances, and treatment protocols when it comes to screw-retained acrylic hybrid prostheses? Have a big-business approach and corporate greed pulled laboratories and the dental team into the dental equivalent of the Perfect Storm? The author will ask the reader to decide.
Listen to History
Most dental professionals who have knowledge of the history of dental implants will admit that most early implant restorations were not very hygienic.2,3,4 Much of the early work pertained to solutions that were not patient removable. However, in many cases there exists a need to restore not only the dentition but also associated gingival architecture and supporting structures where osteoclastic bone resorption has left an obvious impact. Since such cases may require ridge-lapping and soft tissue replacement, are screw-retained acrylic hybrids in concert with CAD/CAM titanium milled bars the answer?
In many cases, the answer is no, in the author’s opinion. Acrylic, at its best, is still a porous material when compared to other dental materials such as porcelain, zirconia, etc., and ideally, acrylic restorations should be fabricated as patient removable if they are to be hygienic.
How Cleansability Was Forgotten
It has been said that many things old undergo a rejuvenation at some point, and this can apply to fads in the dental world. Sometimes concepts are repackaged in a very attractive way, but at their core they remain the same. One such concept is the immediate loading and screw retaining of an acrylic hybrid prosthesis that is strengthened by a CAD/CAM titanium milled bar.
This concept has been very cleverly repackaged and made attractive to surgeons, restorative dentists, and laboratories in the last 10 years, but is it really the best approach?
Additionally, is it a solution that should be marketed to the masses, or is it a smaller percentage of patients who can actually realize any benefit from this solution?
Author and filmmaker Wayne Gerard Trotman recently wrote, “Instead of loving people and using money, people often love money and use people,”5 and that seems appropriate in this situation.
Dental companies and corporations are monetarily driven entities, like most corporations. So it is appropriate to ask as an integral part of the dental team, when called on for direction, guidance, or advice on a particular implant case: Are decisions being influenced by popular solutions that seem to be very profitable, or are they influenced by experience, and what will benefit the individual patient the most?
Back to Basics
The author has observed a renewed interest in an even older, established concept: removable telescopic implant solutions, which by their very nature are extremely hygienic but also very acceptable to patients because they are highly retentive and offer the patient security and cleansability. In fact, the author has seen many clinicians, after being educated regarding this telescoping implant solution, finding patients who were previously not satisfied with screw-retained acrylic hybrid solutions, and converting these cases to implant telescopic cases.
Telescopic prostheses date back to Professor Arnold Gaerny’s early work. In the early 1970s, Gaerny published a book documenting clinical and technical work he performed in the 1950s. At that time his concept involved paralleling fixed and removable milled work to avoid open interdental spaces (Figure 1).6 Figure 2 shows a case Gaerny had parallel milled that remained obviously cleanable 13 years later.