Invasive Cervical Resorption
Invasive cervical resorption (ICR) is uncommon and often aggressive form of external tooth resorption, which may involve any tooth of the permanent dentition. It is defined as a localized resorptive process that involves the surface of root below epithelial attachment and coronal aspect of the supporting alveolar process, namely the zone of connective tissue attachment. Because of its cervical involvement and invasive property, this destructive resorptive defect may lead to the loss of tooth structure. Often, affected tooth may show pinkish discoloration of tooth crown due to resorption of coronal dentin and enamel as highly vascular resorptive tissue becomes visible through this residual structure.
Among the different causes identified, injury and stimulation by sulcular microorganisms in the adjacent marginal tissues is one of the cause and traumatic injuries, orthodontic tooth movement, orthognathic and dento-alveolar surgery, periodontal treatment, and internal bleaching have been reported as predisposing factors for such lesion.
On examination of intraoral periapical (IOPA) radiograph, ICR may represent as a barely discernible radiolucency or may be evident dramatically. The lesions may have well-delineated radiolucencies with irregular borders and sometimes may simulate as caries radiographically.
As initiation of ICR is apical to the epithelial attachment, it is most commonly seen in the cervical area, but it may occur anywhere in the root. Initially at the early stages, it may be somewhat symmetrical but later, asymmetrical nature of larger lesions are more evident.
A successful outcome for such cases generally involve early diagnosis, elimination of the resorption, and restorative management. When ICR is diagnosed, generally, three choices are considerable for treatment:
No treatment with eventual extraction when the tooth becomes symptomatic;
Immediate extraction; or
Access, debridement, and restoration of the resorptive lesion.
Till date, various materials have been promoted to seal the resorptive defect such as mineral trioxide aggregate (MTA), glass-ionomer cement (GIC), calcium enriched mixture (CEM) etc. MTA is a bioactive material that has been used for various endodontic applications since the early 1990s. MTA is indicated for restoring internal and external resorptive defects, horizontal root fractures, sealing communications between the root canal space and external root surfaces, filling root canals of teeth with mature and open apices. MTA has been proved to be biocompatible, stimulate mineralization, and encourage apatite-like crystalline deposits. More recently, other bioactive materials, such as CEM cement, bioaggregate, Biodentine, EndoSequence Root Repair Material (ERRM), and EndoSequence BC Sealer, have also been marketed.
The past decade has revealed the use of the operating microscope and CBCT imaging for surgical endodontics are some of the most significant developments. The microscope enables the surgeon to assess pathological changes more precisely and to remove pathological lesions with far greater precision, thus minimizing tissue damage.