Dental Tribune United Kindom Edition

July 18-24, 2011United Kingdom Edition3384-1106©DirectaAB NEW! Work faster and safer ” NEW! Distributed in the UK by Trycare Tel. 01274-88 10 44 Protects the adjacent tooth and surrounding gingiva by major preparations such as crowns, veneers and inlays. FenderMate sectional matrix for preparation and restora- tion of primary teeth. page 19DTß References 1 Estrela C, Bueno MR, Leles CR, Azevedo B, Azevedo JR (2008) Accuracy of cone beam computed tomography and pano- ramic and periapical radiography for detection of apical periodontitis. Journal of Endodontics 34, 273–9 About the author Dr Daniel Flynn is a Specialist in Endodontics and Clinical Director of EndoCare. After qualifying from Trin- ity College Dublin in 2002. Daniel spent a year as a House Officer in the Dublin Dental Hospital, concentrating on both restorative dentistry and oral surgery. Following this, he worked in private practice for over two and a half years and completed the MFDS exams before beginning a three-year pro- gramme in Endodontics at the East- man Dental Institute. He lectures and gives hands-on courses for general dentists. Daniel also teaches Endodon- tics at the Eastman Dental Institute for Oral Healthcare Sciences. On examination of the periapical radiograph it appeared that the radiolucency associated with the mesial root had healed and the radiolucency associated with the distal root had reduced in size and another review appointment was scheduled for a year’s time (Figure 3). The treatment was deemed to be a success. Embarrassingly, a couple of weeks later the patient presented with a swelling associated with the ll6. The tooth was tender to per- cussion and the associated buccal mucosa was tender to palpation. The ll7 was still positive to sensitiv- ity tests. This time we took a CBCT scan. There was a large periapical radiolucency associated with the distal and mesial roots (Fig 4a, 4b). The point of this article is that we as clinicians underdiagnose pathology from periapical radio- graphs. At the review appointment the endodontic lesions on the periapical radiograph appeared to have reduced in size and the case was deemed to be successful. The mesial root was judged to be com- pleted healed while the distal root was deemed to be healing. The fact the patient had symptoms shortly after the review confirmed that there was pathology still present. The bone loss evident on the CBCT scan (Fig 4a and b) showed that there was significant bone loss as- sociated with the mesial and distal roots which was not demonstrated on the periapical radiograph. Com- pare figure 3 and figure 4a! Reasons for endodontic failure include; 1Persistent intra-radicular in- fection ie missed canals, lateral ca- nals or apical deltas 2Extra-radicular infection in- cluding the presence of cracks 3 Cyst formation 4Foreign body reaction In order to truly assess healing in 3 dimensions, one would need a CBCT scan pre-operatively and again at review. At this juncture root canal treatment is so suc- cessful I feel it is not necessary to do this routinely. However we do need to keep in mind the limita- tions of the imaging tools we use to make decisions. Traditionally we have used evidence of a J-shaped lesion on a periapical radiograph as evi- dence that a root may have a ver- tical crack. Vertical cracks can be extremely difficult to diagnose if it is not possible to visualise it micro- scopically when the tooth is stained with methyl blue. I have many ex- amples of j-shaped lesion visual- ized on CBCT images where the roots are not fractured. It should be remembered that lateral canals can produce a similar effect. This case is an exception to the day to day cases we treat. When root canal treatment is completed to a technically excellent level suc- cess rates up to 96per cent can be expected. However, even when the most stringent protocols are used and executed to specialist standard occasional failures occur. However, I think it is important to examine our failures closely to see what we can learn. CBCT is proving to be a very useful tool for modern day endo- dontics. I am not advocating and do not use CBCT for every case. I find it is an excellent adjunct to our traditional methods of diagnosing and treating endodontics condi- tions when I have a ptient in the chair and I’m unsure what is the best course of action. Following on from this case the CBCT scan can be used to help plan the fu- ture treatment needs if the patient wishes to proceed with endodontic microsurgery or implant place- ment. In the future as radiation doses reduce small volume CBCT will become the gold standard in endodontic imaging. DT Fig 4a Radiolucency associated with the distal root clearly defined. Fig 4b Lesion not in contact with the cortical plate therefore not showing up radiographi- cally