Single Dental Implant vs 3-Unit Bridge…Pros and Cons
Written by: Dr. Clifford Melnick, DMD
Before the advent and the long-term success rate of implantology, standard dental treatment planning for a missing tooth would be a 3-unit bridge. A unit describes a tooth, so a 3-unit bridge denotes a 3 tooth bridge. The process involves the drilling of the external circumference of the teeth on either side of the missing tooth space and then the cementation of a porcelain fused to metal or PFM bridge. The underside of this bridge is hollow where the teeth insert and the middle missing tooth site is solid . This is called a pontic and the hollowed sites where the teeth insert are called abutments.The bridge is then cemented into place. For the success of a 3 unit bridge, the abutment or supporting teeth need to be healthy with good bone surrounding them. Remember, only 2 teeth are supporting a 3 tooth restoration. If the supporting teeth are periodontally involved (loss of bone due to gum disease), they will not readily support the bridge. Many times, the decisions we make in terms of implants vs bridge are due to the quality of the surrounding bone at the site. An implant is a stand-alone restoration that does not require outside support. It is self supporting.
Many patients do not want a good tooth cut down and feel that a more conservative approach is to place an implant in the missing site. There are many benefits to this line of thinking: When a tooth is cut down with dental drills,it can create trauma to the nerve of the tooth. This may result in the need for root canal treatment either immediately or many years later. This is not always the case, but even in the best of hands and with every effort to reduce trauma to the tooth utilizing cool water sprays to reduce heat transmission to the nerve of the tooth, tooth preparation may lead to tooth sensitivity or root canal therapy. In addition, there may be recurrent caries (tooth decay under or around the abutment teeth) following crown fabrication. In other words, bacteria may seep in around the margins of the crown and undermine or weaken the tooth structure.
A dental implant is composed of pure surgical grade Titanium. It is a similar material utilized in hip and knee replacements. The titanium forms both a physical and biologic bond to the surrounding bone. This bond is extremely powerful and much stronger than the connection between natural teeth and bone; because the implant is made of metal, it will never decay and it will never need a root canal!
The time constraints may influence a patient in making the decision of implant vs bridge. A bridge is done in a relatively short period of time. First the teeth are prepared and then a temporary acrylic (plastic) restoration is placed. An impression is taken and the bridge is returned from the laboratory approximately 2-3 weeks later. It is then cemented in place. An implant takes much longer: After surgical placement in the bone, it takes 3-6 months for osseointegration (bone to implant fusion), then an abutment is screwed into the implant and the general dentist takes impressions for the crown or cap cementation to the implant. In certain instances, immediate implants can be placed which shortens the treatment time, but in general, implant dentistry requires a longer treatment time.
I hope this helps clarify some decision making points in the implant vs 3 unit bridge treatment plan.
If you have any questions about the above, please contact Dr. Melnick at 212 355-1266. We are conveniently located in midtown NYC at 800A Fifth Avenue (at 61st Street)