Invasive Cervical Resorption: Causes, Symptoms, and Treatments

Invasive cervical resorption (ICR) is a rare but aggressive dental condition that leads to the progressive loss of tooth structure. It often goes unnoticed in its early stages, making timely diagnosis and intervention crucial. Though the exact cause remains unclear, factors like orthodontic treatment, trauma, or internal inflammation are believed to contribute to its development.

Understanding the signs and available treatments can help prevent unnecessary tooth loss.

Common Signs And Symptoms

ICR often progresses silently in its initial stages, making early detection challenging. Many individuals remain asymptomatic until the resorptive process extends deeper into the dentin, at which point structural compromise becomes evident. Unlike dental caries, which typically present with pain due to bacterial involvement, ICR is often painless early on because the resorption does not initially affect the pulp. This absence of discomfort can delay diagnosis, allowing the condition to advance undetected.

As the resorption progresses, subtle visual changes may become apparent. Affected teeth may develop a pinkish discoloration near the cervical region, caused by granulation tissue infiltrating the resorptive defect. This pink spot is a hallmark of ICR and distinguishes it from other dental pathologies. Over time, the lesion may enlarge, leading to irregularities in the tooth’s contour. Increased translucency in the affected area may also be noticeable, particularly under direct light. These visual cues are often first identified during routine dental examinations, highlighting the importance of regular check-ups.

Functional symptoms tend to emerge as the tooth weakens. Some individuals report sensitivity to temperature changes, particularly with hot or cold foods, though this is not universal. If the resorption extends toward the pulp chamber, discomfort may develop, resembling pulpitis. In more advanced cases, mechanical weakening can lead to chipping or fracturing, especially when biting harder foods, increasing the risk of secondary bacterial invasion.

Diagnostic Imaging Methods

Accurate diagnosis of ICR relies on imaging techniques that assess lesion extent and differentiate it from other conditions. Traditional two-dimensional radiographs, such as periapical and bitewing X-rays, are often the first line of investigation. These images can reveal irregular radiolucent areas near the cervical region, but superimposition of surrounding structures can obscure early-stage lesions, leading to underdiagnosis.

Cone-beam computed tomography (CBCT) has emerged as the gold standard for evaluating ICR due to its superior three-dimensional visualization. Unlike conventional radiographs, CBCT eliminates overlapping structures, providing a precise assessment of lesion depth, location, and proximity to the pulp chamber. A systematic review published in the Journal of Endodontics found that CBCT detected ICR lesions in cases where periapical radiographs failed, improving diagnostic accuracy.

Advanced imaging modalities such as optical coherence tomography (OCT) and micro-computed tomography (micro-CT) have been explored in research settings for detailed insight into the resorptive process. OCT captures high-resolution cross-sectional images of dental tissues, aiding early detection of subtle structural changes. Although not widely used clinically, OCT has shown promise in distinguishing active from inactive resorptive lesions. Micro-CT, primarily used in laboratory studies, offers unparalleled resolution for analyzing the microscopic architecture of ICR-affected teeth, contributing to a deeper understanding of disease progression.

Stages And Classifications

ICR follows a distinct progression, advancing from superficial defects to extensive structural damage. Classification systems help categorize severity, aiding diagnosis and treatment planning. One widely accepted framework, introduced by Heithersay, divides ICR into four stages.

In Class 1, the lesion remains localized to a small area on the cervical region, with minimal invasion into the dentin. The external surface may appear slightly irregular, but the overall structure remains intact. As resorption progresses to Class 2, the defect enlarges, penetrating deeper into the dentin while maintaining a confined shape. These early stages often go unnoticed due to the absence of symptoms, reinforcing the importance of routine imaging.

By Class 3, the resorptive process becomes more aggressive, extending into a significant portion of the dentin and approaching the pulp chamber. Structural weakening becomes evident, and patients may begin to experience sensitivity or minor fractures. In Class 4, the lesion has spread extensively, often involving the root structure and compromising the tooth’s viability. At this stage, restoration efforts become more complex, and prognosis is less favorable.

Possible Treatment Strategies

Managing ICR requires a tailored approach based on lesion severity, location, and structural damage. Treatment ranges from minimally invasive techniques to surgical and restorative interventions. The goal is to preserve the affected tooth while preventing further deterioration.

Minimally Invasive Procedures

For early-stage ICR, conservative treatments can limit progression while maintaining tooth integrity. One approach involves applying trichloroacetic acid (TCA) to coagulate resorptive tissue and facilitate removal. A study in the Journal of Endodontics found that 90% TCA application followed by curettage successfully halted resorption in early lesions. After debridement, the defect is restored with biocompatible materials such as glass ionomer cement or composite resin to seal the area and prevent bacterial infiltration.

Fluoride-based treatments may also help strengthen remaining dentin and reduce susceptibility to further resorption. Fluoride enhances remineralization and inhibits osteoclastic activity. In cases where the lesion is small and asymptomatic, periodic imaging may be recommended to monitor progression before considering more invasive measures.

Surgical Interventions

When ICR extends beyond the superficial dentin, surgical intervention may be necessary. Flap surgery is a common approach, providing direct access to the resorptive defect for thorough debridement and restoration. A retrospective study in Clinical Oral Investigations reported that surgical debridement combined with restorative sealing achieved long-term success when the lesion had not yet reached the pulp.

For advanced cases, intentional replantation may be considered. This involves extracting the affected tooth, removing resorptive tissue extraorally, and reimplanting the tooth. While this technique carries risks such as ankylosis or root resorption, it has been successful in select cases where conventional surgical access is challenging. Endodontic therapy may also be required if the resorption has compromised the pulp.

Restorative Techniques

Once the resorptive process is controlled, restoring tooth integrity is essential. The choice of material depends on the defect’s extent and location. For smaller defects, composite resin or glass ionomer cement provides an effective seal while preserving aesthetics. These materials bond well to dentin and offer sufficient durability.

For significant structural loss, full-coverage restorations such as crowns may be necessary. Porcelain-fused-to-metal or all-ceramic crowns provide strength and longevity, particularly for posterior teeth. If the tooth has undergone endodontic treatment, a post-and-core buildup may be required before crown placement. Long-term follow-up is essential to monitor for recurrent resorption or secondary complications.

Prognosis

The long-term outlook for ICR depends on early detection and treatment effectiveness. Prompt intervention improves the likelihood of preserving the affected tooth, as minimally invasive procedures can halt progression before extensive damage occurs. Studies show that teeth treated early, particularly with debridement and restorative sealing, have high survival rates over several years with proper follow-up care.

For advanced cases, prognosis varies due to the extent of tissue destruction and potential pulp or root involvement. Surgical interventions have demonstrated favorable outcomes, but recurrence remains a concern. Teeth with extensive resorption may exhibit long-term weakening, increasing susceptibility to fractures or secondary complications. Regular follow-up with imaging is essential to detect recurrent lesions early and prevent further deterioration.