(Top to bottom) Images showing before, during and after an access perforation repair using Mineral Trioxide Aggregate (MTA). Case Study 1 molar roots are affected when the instrumentation is too heavy on the inner curve. Perforations of the middle third can also occur when searching for sclerotic canals. In this case, the use of rotary or ultrasonic instruments to penetrate deep into the root of the tooth may be necessary and risk lateral perforation. Apical perforation can occur when the clinician does not respect the apical anatomy and passes overly aggressive endodontics files through the apical constriction. Improper cleaning and shaping of the canal can result in blockages and ledges. Once formed, these can deflect instruments away from the root centre until a perforation occurs. Rigid instruments placed in curved canals can also straighten the canal, causing zebra perforations. Following obturation, careless preparation of the space can result in perforation. Traditional approaches to retention placement focus on getting the length and width of the post right, creating a risk of apical perforation. Sometimes the post is not placed in the root canal but in the adjacent dentine, with catastrophic consequences. Accidental perforations are identified by the heavy bleeding resulting from the injury. When a perforation occurs in the coronal portion of the tooth, it is even more obvious. If the apical perforation occurs further into the canal, a paper tip inserted into the canal can reveal the bleeding. And in cases where no local anesthetic is administered, sudden and unexpected pain during treatment can also be a sign of a perforation. Apex locators are very helpful in detecting perforations. Placing the file over the perforation gives a zero reading, indicating communication with the periodontal ligament. Surgical microscopes are also becoming increasingly popular for identifying perforations. The operative illumination and magnification make it an excellent tool for visualizing the position and extent of the perforation. Radiographs can be used at the time of perforation, but they have their limitations. Their two-dimensional representation can make it difficult to assess the site and extent of the perforation. Taking a second radiograph and shifting the angulation of the radiographic beam may partially solve this problem (see Case Study 1). “A vertical bite wing is an important tool to determine the angulation of your root relative to your crown and try to pick up on certain complications ahead of time,” says Dr. Dabuleanu. The delayed diagnosis of pathological perforations is largely due to a combination of clinical assessment, radiographs and the nature of the problem. That is why response time is critical. Without detection and repair, periodontal breakdown can lead to tooth loss. Although irreversible inflammation does not always result, if microbial infection Accidental perforations are identified by the heavy bleeding resulting from the injury. When a perforation occurs in the coronal portion of the tooth, it is even more obvious. 30 | 2023 | Issue 1 SupportingYour Practice
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