- Cross-sectional imaging are only justified in the presence of certain symptoms, except as part of ethically approved clinical research and informed consent based on the Helsinki Declaration. Anamnesis and/or clinical examination which indicate demand for further examination.
- In cases of post-operative complications, conventional radiographs might provide additional information. In case of postoperative infections in relation to sinus cavities close to implants, or suspected nerve damage, cross-sectional imaging may be justified.
- Digital radiographs are superior, since allowing a low radiation dose for the patient.
Type of radiographs chosen
Clinicians who provide diagnostic imaging services should always consider the optimum imaging technique for the patient/procedure, even if this means referral to another center.
Digital intraoral radiography taken with the paralleling technique are the best way to monitor on-going health around a dental implant, to measure the marginal bone level, to check the proper abutment-to-implant adaptation and the potential presence of subgingival cement*. A baseline image should always be taken once an implant is restored so that there is a way to determine if there is bone loss over time, after the initial, physiological, bone resorption. Nevertheless, a relationship between probing and radiographic evaluation may be used to assess examination needs, suggesting that when changes in probing levels occur, radiographic assessment may be advised.
Radiographs once a year around an implant is the best time to follow-up the peri-implant bone health. Implant threads allow precise distance calculations with the shoulder or the top of the implant as reference point. Generally, bone loss of >1 mm within the first year of implant placement and >0.1 mm annually, may indicate a problem.
Intraoral radiographs are superior to panoramic radiography. The clinicians should be aware of distortions and magnification inherent to panoramic imaging because of projection geometry. Furthermore, parallelism of implants cannot be checked on panoramic radiography.
Cone beam computer tomography (CBCT) scan may be the method of choice if case of doubts of in case of post-operative major complications. CBCT scan also allows for evaluating bone augmentation procedures in the oral cavity (guided bone regeneration) or in the maxillary sinus.
Figure 1: Pre-clinical situation Figure 2: CT scan after tooth extraction Figure 3: Surgical view
Figure 4: CT scan at the II stage Figure 5: 1-year intraoral view Figure 6: 1-year radiograph
* Not all cements are visible in radiographs