Treatment versus Implant

Implantology has modified treatment planning dramatically in odontology. However, the operating microscope and its new armamentarium in endodontics have so broadened what can be treated, both surgically and non-surgically, with success and predictability that a comparison with studies done before the microscope's introduction is difficult. Rotary NiTi files have standarized the cleaning and shaping of canals, reduced the ledges, blocks, zips, tear-drops and perforations, and increased the success rate of endodontic treatments and retreatments.

The design of modem implants has improved their initial stability so much that they can be loaded when placed into fresh sockets. However, implant treatment is monophase: extraction then implant, no other alternatives. Endodontic treatment is multiphase: endo treatment, retreatment, apicoectomy, root amputation, hemisection-ing, replantation.

Before the introduction of the operating microscope, implantolo-gists could be excused for accusing endodontists of overtreatment on teeth with a bad prognosis, like an isolated monoradicular tooth or distal abutments of fixed or mobile prostheses. Comparison of the success of endo treatments and implant treatments must be focused on the single implant among natural teeth where there is no modification of the general occlusal outline.

Placement of an immediate implant in the socket of a tooth with previous endodontic failure is not the same - in terms of time, number of sessions required, budget, esthetics, etc. - as a case with a pristine alveolus. Most often there are residual bone defects that require the use of GBR; and to regenerate bone defects of endodontic origin, the best, predictable, cheap and scientifically proven method is the endodontic treatment. Even in the case of a non-restorable tooth, the endodontic treatment could be indicated for bone defect regeneration and then extraction, with immediate implantation afterwards.

There are many difficulties in trying to compare endo treatments with implant treatments, beginning with just how to define "success". While most implant studies define success as “survival" (being in the mouth, even with exposed threads and gingival inflammation), endodontic studies apply strict clinical and radiological criteria, so clinical signs and/or radiological findings mean "failure". The recognition that pulpal and periradicular disease may be managed but not eliminated is an important departure from the traditional method of evaluating outcomes based on clinical symptoms and radiographic findings65. Also, the introduction of factors like esthetics, peri-implant tissue stability and function of the prosthetic reconstruction to define implant treatment success (instead of just implant stability alone), could help to make a more fair comparison.

As said earlier, endodontic treatment is multiphase. In the case of a tooth with irreversible pulpal disease, endodontic therapy is a highly predictable method to treat and retain the tooth in the mouth (94% success). If the case is a previous endodontic treatment failure, non-surgical retreatment can safely remove the previous treatment, do a correct new one, and preserve the tooth (69% success), as well as avoiding the need for surgery. In the case of a tooth where access to the foramen cannot be accomplished, surgical retreatment can solve the problem of pure endo origin, with more than 95% success68.

Good marginal sealing of the restoration of the endodontically treated tooth to prevent coronal leakage, and sufficient remaining dentin structure for a ferrule to prevent VRF occurrence, ensure the long-term success of the endodontic treatment in a tooth with proper periodontal support.

In a case where access to the apex or perforation site cannot be accomplished, either non-surgically or surgically, then intentional replantation (95% success at 3 years), hemisectioning, or root amputation can solve the problem and retain the tooth.

The success rates of endodontic treatment and a single implant are similar. Two large studies from insurance company databases (1.5 million and 44,000 teeth) reported that retention rates after general dentists' and endodontists’ treatment for 8- and 3.5-year follow-up time were 97% and 94%. These results are comparable to those for single tooth implant survival rates.

However, failure rates are totally different. Implant failure is associated with significant implant movement, and extraction is the only alternative. The extraction may require surgery. Restorations must be removed, leading to altered function and possibly appearance. The bony defect must heal before further treatment can be undertaken65. However, exposed threads, implant surface contamination, gingival inflammation, and bone resorption are not considered to be implant failure, although affecting the esthetics, and are extremely difficult to treat in a case of the single crown between teeth.

Fortunately, a negative outcome following endodontic treatment can be managed with more flexibility, and in stages: retreatment, periapical surgery, periradicular surgery (hemisectioning and tooth sectioning), intentional replantation, or transplantation can prolong the life of the tooth for many years. This can have psychological and economic benefits for the patient. Trope has outlined such a scenario for 100 teeth requiring initial endodontic treatment. When the lowest reported positive outcome rates are applied to the initial treatment, retreatment, and then surgery, only three teeth will require extraction. Restorations are retained, and function is unaltered.

However, if after that multiphase selection process there is still an indication for extraction of the tooth (content), a new scenario is created. A detailed study must be made of the remaining bone topography (container) after the extraction, the status of the gingival framework, and the relationship of these important factors to the neighboring and antagonist teeth and the impact in the general esthetics of the mouth. The patient must then be informed of the alternative treatments, treatment timing and costs.