Poor design remains the greatest underlying cause contributing to complications with implants and prostheses. In order to prevent potential complications, treatment planning should encompass and consider contingency, priority and risk perspectives (CPR).
Effective CPR evaluation examines the patient's condition in different ways to establish an ideal and thorough treatment plan. Since CPR is also a universally-utilized acronym to describe the emergency protocol for assisting a patient who has experienced cardiac arrest (Cardio Pulmonary Resuscitation), it would be metaphorically appropriate to use it when treatment planning a seriously damaged dentition.
Contingency planning for prosthetic treatment
Contingency addresses a future event or circumstance that is possible, but cannot be predicted with certainty. In some instances, radiographic evaluation of a reconstruction demonstrates that no contingency plan was developed at the time the prosthesis was delivered.
This can necessitate removal of the entire implant and restoration complex, and development and placement of a newly designed implant-supported restoration.
For patients with periodontal disease, extensive deficiencies of supporting hard and soft tissues, as well as atrophy of the alveolar ridges, are frequent. While prosthetic reconstruction of major tissue defects is possible, creating predictable, functional, and esthetic implant-supported prosthetic restorations is challenging. Establishing proper implant position and angulation ensures functional and optimal esthetic implant rehabilitation, helping clinicians predict the successful future of the implants/restorations when a contingency plan is needed.
An example of incorporating contingency into treatment planning includes evaluating a partially edentulous patient with an implant-supported restoration and several crowns and/or bridges on the remaining teeth that are experiencing mechanical complications.
Extensive decay may occur and require conversion into a full-arch reconstruction. If there was a previous cement-retained restoration in one section, evaluating possible contingency measures such as splinting scheme or type of retention may suggest a different solution for the patient.
Although a patient may be transitioning into full-arch reconstruction, converting the reconstruction into a screw-retained option in a segmented arch design can provide much easier access and/or lower cost to the patient if (or when) repair of the prostheses are needed. The clinician could move from one design to the other, providing a contingency plan.
Considering contingency during treatment planning forces clinicians to create a solution for a problem they know will or may occur. It focuses on providing solutions to problems after the treatment develops the anticipated complications. For example, a spare set of the implant-supported reconstruction was fabricated utilizing temporary abutments and cold-cure acrylic resin for use if and when a repair of the definitive prosthesis was needed.
Risk assessment, which is discussed later, has an impact on contingency considerations and, therefore, a patient's risk must be addressed when determining contingencies in treatment plans. Patients presenting with high functional risk (e.g. parafunctional activity, tooth fractures, excessive wear, etc.) will still have parafunctional risk after implant placement, and clinicians must be prepared to properly treat these patients in order to prevent implant damage; they should also be aware that extensive wear and/or fractures may occur to the material used to fabricate the implant-supported restoration.
One of the most important aspects in evaluating contingency is to share the contingency plan with the patient, with a realistic understanding. This way, patients are better prepared to deal with complications associated with their implants.
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