What Are Endo-Perio Lesions?
Endo-Perio lesions are dental disease entities characterized by the mutual involvement of pulpal and periodontal disease of the tooth. Microorganisms, root resorption, perforations, and dental malformations can lead to the development and progression of such lesions. An endo-perio lesion can have varied disease mechanisms that range from simple to complex. However, iatrogenic endo-perio lesions can also be inflicted accidentally or by a lack of knowledge due to the operator. Hence, the dentist must take care of appropriate diagnosis and treatment planning, as operator experience and tactility can prevent iatrogenic errors.
What Are the Iatrogenic Factors for Endo-Perio Lesions?
The iatrogenic factors inducing periodontal and pulpal disease lesions are listed as follows :
- Root Perforations: Iatrogenic root canal perforation is a complication of dental treatment having a poor outcome. Perforation can be produced by powered rotary instruments during careless tooth manipulation. It can happen during an attempt to gain access into the root canal space or during or after the root canal treatment (RCT). Also, when there is improper manipulation or handling of endodontic instruments, it can lead to perforation of the tooth root. When such an iatrogenic root perforation occurs, communication is established between the root canal system and the periradicular tissues (around the root). As a result, it reduces the prognosis and success of the treatment due to prolonged inflammation at the perforation site. Furthermore, when the periodontal ligament is impacted by such injuries or manipulation, the formation of a periodontal lesion that progresses to an endodontic lesion is frequent.
- Coronal Leakage: Coronal leakage is the leakage of bacterial elements from the oral environment through the margins of the dental restoration to the endodontic filling. Research indicates that it may be the most crucial cause of endodontic treatment failure. Root canals can also become recontaminated post-treatment by microorganisms. According to studies, the exposure of root canals to the oral environment leads to coronal leakage. In some cases, it may occur along the entire length of the root canal. Also, certain defective restorations are associated with a higher incidence of root canal or endodontic failures compared to quality restorations.
- Dental Injuries or Trauma: These are common causes of endo-perio lesions. The treatment of traumatic injuries mainly depends on the type of injury caused to the dental tissues. The extent and depth of injury will determine both the pulpal and periodontal ligament healing prognosis for the tooth. The most common cause of vertical root fracture is excessive force used by the operator during the lateral condensation of the root canal filling or gutta-percha. The patient may experience mild pain, discomfort, and swelling, which are the usual post-operative clinical symptoms.
- Chemicals Used in Dentistry: Some commonly used chemical agents in dentistry may cause root resorption. Clinical reports have shown that intracoronal (in the tooth crown) bleaching with highly concentrated oxidizing agents, such as 30 to 35 percent hydrogen peroxide, can induce root resorption. Also, hydrogen peroxide is one of the most irritating chemicals that can diffuse through the dentinal tubules. Such chemicals, when combined with heat are likely to cause cementum necrosis (death of the cementum tissue of the tooth) and inflammation of the periodontal ligament. Subsequently, it can lead to tooth-root resorption.
- Ankylosis: Ankylosis is a phenomenon in which there is extensive necrosis or cell death of the periodontal ligament of the tooth. It is followed by bone formation onto the denuded area of the root surface. This condition happens as a result of a complication of luxation injuries. Furthermore, it can happen in avulsed teeth that have been out of their sockets in dry conditions for several hours.
- Vertical Root Fractures: These are the artificial pathways created between the periodontal and pulpal/ root canal tissues as a result of the vertical fracture of the tooth root. In vertical root fractures, the primary cause is trauma. It has been reported to occur in both the vital (living) and nonvital (dead) teeth. In vital teeth, vertical fractures are seen as continuations of coronal or tooth crown fractures (as seen in the “cracked tooth syndrome”). However, they can also occur as root surface fractures that are operator induced during dental extraction or endodontic and deep periodontal surgical procedures.
- Misdiagnosis of a Lesion: A dentist must establish the correct diagnosis of endodontic and periodontal diseases. Because the cause of dental pain is sometimes difficult or clinically challenging, it is still important to make a correct diagnosis. Misdiagnosis of these lesions may produce a detrimental impact from a lack of addressing the main reason behind dental pain.
Although the main step is to close an iatrogenic communication, the aim is to produce a proper seal. The outcome of root perforation treatment depends on the size, location, time of diagnosis and treatment, and the degree of periodontal damage. Studies suggest that the treatment success depends on immediate sealing of the perforation and appropriate infection control. The prognosis of endo-perio lesions is poor. But, a successful outcome can be achieved with adequate management.
Conclusion
Endodontic-periodontal lesions are clinically challenging to diagnose for the dentist and need to be adequately resolved. A proper diagnosis can help in accurate treatment planning and improve the prognosis of the involved teeth. A dentist must carefully investigate the etiologic factors and other contributing factors such as trauma, root resorptions, perforations, and dental malformations. Also, endodontic treatment can be completed before periodontal treatment when there is no communication between both.
Operator tactility plays an important role in the success of dental treatment, the dentist must carefully perform instrument handling/instrumentation and material usage. Also, to ideally prevent the development and progression of any endo-perio lesion, an interdisciplinary approach or a good collaboration between endodontists, periodontists, and microbiologists/oral pathologists is imperative.
