Top Tip: A tooth-by-tooth prognosis can’t always be obtained without taking drill to tooth and carrying our an invasive exploratory procedure. Communicating this with the patient is vital, because after this procedure, the tooth could be deemed unrestorable and, therefore terminal.

A tooth will have 3 main areas needing to be assessed as to whether we can save it or not.

Having a structured strategy (the famous checklist) is important for many reasons: so we don't miss vital information and also helps prevent us from becoming overwhelmed. This system allows a more predictable plan for success and will direct the treatment needs regarding materials to use, how to cement, and structure the sequence of procedures needed.   

Below are some general principles to help you piece together what it is you are seeing during your examinations, alongside the patients histories and presenting complaint, to create the full picture.

Individual patient factors do need to be considered when assessing a tooth for treatment planning, for example age. How long has it taken for the oral condition to be in its current state?

The Single Tooth Assessment: 

Periodontal Status

"You wouldn’t by new curtains for a house that is about to fall down”

• This is about the control of the biofilm and bacterial extracellular matrix alongside the host response. 
• The control of inflammation, through risk factors both local and systemic. (1)

Once the BPE screening has been carried out it can lead you to needing more detailed investigations. The specifics for radiographic needs, alongside how to carry out a full periodontal assessment (yes, including the 6PPC) will be covered in our periodontal topic area. 

Carrying out these investigations shows us, and the patient, the foundations that support the tooth. With the new perio classifications, we can now, more accurately stage and grade the severity of the disease, and how fast it is progressing. The system also helps us understand if the disease is stable, in remission or unstable. (See third party reading for BSP link)

Aetiological Factors:

This links to our history taking and examinations. The ability to piece together the puzzle and whether the individual bits of information add up. This skill will always be continuously developing, but we should always be asking why? (2-3)

Example - Generalised Chronic Periodontitis Stage 3 Grade B which is unstable in a patient who smokes and has diabetes. Here we have a moderate disease with a moderate rate of progression which could in the not so far away future become severe. If we don’t get on top of the patients behaviours - offer smoking cessation, preventative advice, further investigate their systemic health, our restorations may last a while but the tooth in the mouth won’t. Whether you guard the prognosis of the teeth or diagnose a poor prognosis, these are important discussions to have and the patient must understand that the success of any restorative work is an unlikely outcome if things don’t change. 

Gingival biotype assessment:

This is easy to forget.

Example: We could have a patient who’s gum health is stable but they require a full crown after receiving endodontic treatment because of trauma to the tooth who’s pulp has since aseptically necrosed. The tooth in question is the upper right 1 which became discoloured and responded poorly to bleaching; therefore, placing a veneer in ceramic or composite isn't able to mask the dark shade of the underlying tooth. We now need to decide where we put the margins of our crown. It is the general consensus that subgingival margins shouldn’t go beyond 0.5mm of depth and the risk of adverse perio effects are seen to increase if placed over 1mm. The gingival width is the vertical dimension of the sulcus, and impinging the periodontal fibres in this area with our restoration can exacerbate inflammatory responses and lead to a poor aesthetic result: acutely as local swollen erythema and if prolonged attachment loss can occur leaving recession and a poorly contoured gum. 

If the patient has a thin biotype they are more prone to recession and the show through of the margin, defeating the point of aesthetic placements. Biotype is also important for contour and “black triangles” Patients need to be aware of the loss of papillae during these types of cases.

Systemic Awareness: 

Some common diseases and conditions that are renowned to show effects on the gingival health either via the direct effects of the disease or due to secondary side effects of the treatment are: diabetes, CVD, Neutropenia and Leukaemia. It is also important to have an awareness of the transient periodontal disease which can be seen in the pregnant patient. Cancer treatments can also impact the mucosal health and is known as mucositis. (4)  

Restorability Status

This is where we can apply the concept of the famous Ferrule, which I've found as students, we can’t stop saying this once we’ve been taught about crowns/posts and cores. The minimal needed is a height of 2-3mm with 1mm thickness (if endodontically treated) that is ideally a 360^o.  

This assessment of the tooth is about the Quantity and the Quality of the structure

A short list that helps me is: 

• What is the tooth condition before I start investigating?
• How much of the tooth is left after clearing all caries and restorations? 
• Has it had endodontic treatment?
• What is the quality of what is left? - (fracture lines, sclerosed, stained)
• Is what tooth material is left? dentine or enamel? (Bonding/cement)
• Is the tooth symptomatic?
• Why is the tooth in this condition to begin with?

Again mastering the aetiology of what has caused the current condition of the patients mouth is key for us to provide successful interventions. As students we are keen to want to carry out procedures (which we may have targets for as well), but showing a full understanding and taking that little bit more time before rushing in to try and treat, allows for more predictable result after planning.

References (5-7)

Endodontics Status

Endodontics isn’t just root canal and looking at the periapical area on a radiograph. It’s about the preservation of the pulp and vitality of the tooth. Every intervention we carry out with a handpiece we causes trauma to the tooth. If the cavity is deep we will be exposing many dentinal tubules. Life sciences has taught us that odontoblasts have their processes in these tubules which sense hydrodynamic pressure changes (affected my osmolarity, temperature, exposure). If the procedure causes excessive tooth removal, which can be experienced as postoperative sensitivity and pain, these cells will react by laying down tertiary dentine leading to tubule sclerosis; the pulp ‘retreats’ and eventually may die and necroses, if the insult(s) out-weight the ability to heal and regenerate. 

With this in mind we should always be thinking what is the most conservative procedure and how great a risk is there to the pulp?

When we crown teeth, papers have found that 20% of teeth will lose vitality within 15-20years after treatment. (Ref: 8-9)

Key questions:

• Is the tooth vital? We test this via sensibility tests. It is important to use more than one method as false positives and negatives can occur. Also, use a reference tooth to make comparisons to the response. Methods would be Temperature: hot GP or more commonly cold via Ethyl Chloride (endofrost -50^oC), alongside electric pulp testing (EPT), percussion tests (note: vertical movement) and the use of a Tooth Slooth to detect cusp fractures. The most accurate test is to perform a test cavity in the absence of LA. Piecing together the findings of these tests in addition to the radiograph and patient history can help provide a diagnosis as to whether the pulp is reversibly or irreversibly effected. 

Radiographic signs may appear as widening of the PDL, loss of the lamina dura or an obvious apical area (be aware in the lower premolar area of the mental foramen and in the upper central area, the nasopalatine canal). Taking two radiographs may help using the SLOB rule to help further investigate if things aren’t clear on the first rad, or if canals disappear (remember its only a 2D image).

• Important: If things don’t add up, then monitor, patients don’t mind us not knowing the diagnosis if it isn’t absolutely clear. Providing them with emergency details as they leave, book them in for a review to see if things have progressed. Appropriate analgesics should also be recommended for the interim. On review if symptoms are now more prominent, we can be more confident which tooth to treat. We don't want to treat a tooth that didn't need it.

• Atypical pain will be covered separately, but it is important to mention here. Odd signs and symptoms such as referred pain that aren’t consistent to the nerve pathways, or pain that crosses the centre line are important to recognise, because it could prevent unnecessary invasive procedures and should warrant referral to a specialist department. 

• Has the tooth already been root treated? If so: Is the GP to working length (within 2mm of the apex), well condensed with no voids, and are all the canals filled. Once a thorough investigation has occurred of the root, we need to deduce how good is the coronal seal?

• How complex is the canal system (curvatures over 40^o)?
  (7)

• Palpate: Is there any tenderness of the alveolar bone, or any obvious sinus, swelling +/- suppuration discharge present? 

Endodontic References (10-11)