Use of radiographs
Use of radiographs
It is essential to perform a clinical examination and full mouth periodontal assessment where clinical signs indicate it is necessary. This is supplemented by radiographic examination to provide information to aid classification and treatment planning where clinically indicated (see figures: Periapical radiographs and Panoramic radiographs). Radiographs allow the practitioner to assess:
- root length and morphology;
- the level of alveolar bone and remaining bone support;
- the periodontal ligament space and periapical region;
- furcation involvement of molar and premolar teeth;
- restorations/caries and sometimes subgingival calculus.
Periapical radiographs are considered the gold standard for periodontal assessment as they provide extensive information about the extent of bone loss, apical status, endodontic-periodontal lesions, root fractures and deposits on root surfaces. However, reviewing existing bitewings or panoramic radiographs, taken as part of the patient’s ongoing general care, may be useful to confirm whether further periapical radiographic investigation is required.
These periapical radiographs, taken using the long cone paralleling technique, show:
A. horizontal bone loss of up to 50% of root length in the upper right quadrant; calculus on root surfaces 17D/18M; inadequate root canal treatment 15;
B. horizontal bone loss 26D/27M of 15% of root length; overhanging restorations 26M, 26D, 27M; fractured restoration/secondary caries 27D.
This panoramic radiograph shows a heavily restored dentition with >50% generalised horizontal bone loss; multiple infrabony defects; furcation involvement of the lower molars.
If radiographs are indicated:
After the clinical examination, consider whether radiographs are required to inform the diagnosis, classification and management of the patient.
- Consider the use of existing radiographs for this purpose.
Where previous radiographs are not available, consider what information is required before taking any new radiographs to ensure appropriate views are recorded.
- Periapical radiographs are considered the gold standard for periodontal assessment, but other radiographic views can also provide useful information.
- Take into consideration the presence of recession and attachment loss when deciding if bitewing radiographs will capture the position of the bone crest.
- Where clinical examination indicates that staging and grading of the disease is not possible without visualisation of the full length of the root, periapical or panoramic views will be needed.
For uniform probing depths ≥4 and <6 mm (maximum BPE Code 3 in any sextant) and little or no recession, consider whether bitewing radiographs will give the information required to make a diagnosis or whether periapical radiographs are required to show the full extent of the root. If the anterior teeth are affected, take intra-oral periapical views using the long cone paralleling technique.
For probing depths ≥6 mm (BPE Code 4), consider which radiographic views will give the necessary information for diagnosis and treatment planning (e.g. vertical bitewings, intraoral periapical views or a panoramic radiograph).
For irregular probing depths, consider if bitewing radiographs will show the extent of bone defects or whether periapical radiographs will give better information for diagnosis and treatment planning.
If an endo-perio lesion is suspected, take an intra-oral periapical radiograph using the long cone paralleling technique.
Where large numbers of intra-oral periapical radiographs are needed, particularly where additional information about other aspects of the dentition is required, consider taking a panoramic radiograph if there is access to a good quality/low dose panoramic machine.
Note that this may need to be supplemented by periapical views of the anterior teeth if these are not clearly seen on the panoramic radiograph.
While cone beam computed tomography (CBCT) is not indicated as a routine method of imaging periodontal bone support, if CBCT images which include the teeth have been obtained for other reasons, the periodontal bone levels should be reported as part of the clinical evaluation.30
A thorough assessment of any radiographs should be recorded in the patient’s clinical record. This includes standard records of the justification for radiographs, doses used and the operator who took the views. In addition specific periodontal information includes:
- the degree of bone loss - if the apex is visible this should be recorded as a percentage of the root surface affected;
- the type of bone loss - horizontal or angular/infrabony defects;
- distribution/extent of bone loss – localised or generalised (where radiographic views of multiple teeth are available);
- the presence of any furcation defects;
- the presence of subgingival calculus;
- other features including endodontic-periodontal lesions, widened periodontal ligament spaces, abnormal root length or morphology, overhanging restorations, root fillings, caries.
The SDCEP Practice Support Manual15 provides further information on the use of radiography in dental practice.