Message Boards
Today's Active Topics Today's Active Cases Browse Forum Categories My Recent Activity My Messages Private Groups My Marked Threads My Subscriptions
Today's Active Images Today's Active Polls Most Active Topics Global Townie Map Advanced Message Board Search Message Board Terms of Use

External Resorption: Causes and Possible Conservative Treatments with Tricalcium Silicate and Compos Richard Trushkowsky, DDS and Natalia Rabago, DDS

View Comments (1)

Root resorption is the loss of hard dental material consisting of cementum and dentin. It entails two stages: injury and stimulation. Injury is associated with non-mineralized tissues covering the outside surface of the root (precementum) or it can involve the interior of the canal. The injury may be a result of mechanical injury as a result of dental trauma, surgical procedures or pressure from an impacted tooth. It also may be initiated by chemical irritation such as bleaching with 30% hydrogen peroxide.

The root resorption is a sequel to odontoclastic activity. The denuded mineralized tissue is invaded by multinucleated cells that start the resorption progression. The resorptive cells require additional stimulation or the process terminates spontaneously. Cementum-like material may mend the injured surface if the area isn't too large. Extensive areas may result in invasion of bone cells that may attach to the root, resulting in ankylosis. Additional stimulation by factors of infection or pressure will allow active resorptive process to continue.1 Cementum usually will protect the underlying root dentin. However, damage or lack of this shielding layer below the epithelial attachment allows osteoclasts to resorb the dentin. The anatomic profile of the cementoenamel junction (with frequent gaps of cementum) predispose this area to potential problems.2

Root resorption is often classified by its position relative to the root surface. The resorption can be external or internal. External resorption can be further divided into surface resorption, external inflammatory resorption, external replacement resorption, external cervical resorption and transient apical breakdown.

External cervical resorption (ECR) has been extensively characterized by Dr. G.S. Heithersay, who actually prefers the term invasive cervical resorption (ICR). ECR most often occurs immediately below the epithelial attachment and at the cervical area of the tooth.3 Heithersay divides ICR into four classes according to the degree of damage to tooth structure. Class 1 is a small invasive resorptive lesion near the cervical area with shallow penetration into dentin. Class 2 is a well-defined resorptive lesion close to the coronal pulp chamber with little or no extension into the radicular dentin. Class 3 presents a resorptive defect involving the coronal third of the root. And Class 4 is a resorptive lesion extending beyond the root's cervical third.4

Dental trauma is a problem that most often affects children and adolescents with sometimes devastating consequences. Boys are usually most often affected and the central incisors are commonly involved.5 Overjet more than 5mm increases the risk factor and falls, crashes, sports, violence and automobile accidents provide causes. Studies have demonstrated posttraumatic injuries to permanent teeth between 3.9 and 58.6 percent.6 These injuries can result in pulp necrosis, internal or external resorption, calcific metamorphosis and ankylosis.

Clinical case
A 32-year-old male with no significant medical history presented to the Department of Aesthetic Dentistry at NYU College of Dentistry complaining of a discoloration at the gingival margin of his right central incisor. He had a history of trauma to the area when he was a teenager playing soccer. The tooth was asymptomatic. Clinical examination revealed a rosacea-like discoloration under the overlying enamel (Figs. 1 & 2) and a radiograph revealed a radiolucent area in the same location. No similar lesions were present elsewhere.

Fig. 1: External cervical resorption
Fig. 2: Pink hue
Fig. 3: Removing granulomatous tissue
Fig. 4: Dispensing Biodentine liquid



Periodontal probing the area demonstrated the lesion only extended slightly subgingivally and didn't invade the epithelial attachment. Initially, due to the size of the lesion, endodontic treatment was going to be initiated. The tooth was not sensitive to hot or cold and negative to percussion. However, the recent introduction of bioactive material such as a medical-grade, calcium-silicate–based material like Biodentine from Septodont and Activa Base/Liner from Pulpdent allowed the consideration of a more conservative procedure. It was decided to excavate the lesion and place Biodentine and then a composite resin as the final restoration.

Restorative procedure
After patient consent, the patient was anesthetized and then the thin shell of overlying enamel was removed with a high-speed handpiece and water. The dentin (or body) shade was selected from the cervical area or exposed dentin. The Vident's Vitapan classical tooth guide was utilized while the tooth was hydrated. The lesion was carefully hand excavated with a spoon excavator until a hard surface was obtained (Fig. 3).

Cavity disinfection and control of gingival bleeding was performed with sodium hypochlorite. A capsule of Biodentine was tapped lightly on a hard surface to loosen the powder and then opened and placed on the white capsule holder. A single-dose container of liquid was detached and gently tapped to allow all of the liquid to enter the container. The cap was then twisted open and five drops from the single-dose container were placed into the capsule (Fig.4).

Fig. 5: Packing Biodentine
Fig. 6: Geristore syringeable
Fig. 7: Geristore syringeable placed at gingival margin
Fig. 8: Tooth etched with 37% phosphoric acid
Fig. 9: Selection of composite



Fig. 10: Application of bonding agent
Fig. 11: Composite is sculpted with a brush
Fig. 12: Trim with scalpel
Fig 13: Final aesthetic result
Fig. 14: Radiograph six months later
The capsule was placed in a mixing device for 30 seconds at a speed range of 4,000-4,200rpms. The capsule was opened and the consistency verified. A thicker consistency was desired so the material was allowed to sit for 30 seconds. The capsule was opened and the Biodentine removed with the instrument supplied in the box. A plastic instrument was used to carefully place a layer of Biodentine covering the floor of the preparation avoiding entrapping air bubbles.

The material was flattened without excessive pressure and judiciously adapted to the cavity walls (Fig. 5). Excess was removed with a spoon excavator. The material was allowed to set for 12 minutes. Geristore syringeable by DenMat (Fig. 6) was placed at the cemento-enamel junction (Fig. 7), and after initial set (material will reach final cure in 3-4 minutes from the time dispensed) was light cured. The preparation (10 seconds) and surrounding enamel (15 seconds) were etched with 37% phosphoric acid (Fig. 8). Rinsed with a copious stream of water, a high volume vacuum was then used to remove excess water and the area blot dried with a moist cotton pellet. Prime & Bond NT by Dentsply Caulk was then used (Fig. 9) and allowed to remain wet for 20 seconds and then lightly air dried for five seconds.

The surface had a glossy appearance. The bonding agent was light cured with an Ultradent Valo light for 10 seconds. 3M ESPE's Filtek Supreme Ultra Universal Restorative (Fig.10) A2 dentin, A2 enamel and clear translucent were built up in layers. Septodont's N'Durance, a nano-dimer composite with a low volumetric shrinkage, also available in Vita shades, universal opaque and translucent shades, was an alternative choice. The varying opacities allowed an excellent match to the surrounding tooth structure. Cosmedent Dental Composite Brushes (Fig. 11) allowed contouring and blending to the surrounding tooth structure. 3M ESPE's Sof-Lex Contouring & Polishing Discs were used initially followed by a Diamond Twist SCO — Intra-Oral Polishing Kit, from Premier Dental, to achieve a final polish. Any remaining excess was trimmed with a 12C scalpel blade (Fig. 12). The final aesthetic result restored normal anatomy and emergence profile (Fig. 13). Radiograph taken six months later demonstrated no perapical pathology and no further progression of the lesion. The tooth needs to be closely monitored so that there is no reoccurrence (Fig. 14).

Discussion
External cervical resorption as a consequence of dentoalveolar trauma may result in functional and aesthetic modifications of the patient's dentition. Sometimes a multidisciplinary treatment may be required. Endodontic treatment and reconstructive periodontal surgery are often required.7 Dental trauma is often the chief element that predisposes the development of ECR. In this case report, the development of ECR was possibly related to the trauma the patient was subjected to during a soccer game. Invasive cervical resorption is often challenging to both diagnose and determine the extent of the lesion.8

Different approaches have been advocated for treatment of ECR. Initially the application of trichloractic acid to the resorptive tissue and curettage are recommended.9Calcium-silicate- based cements were first introduced by Dr. Mahmoud Torabinejad in 1993 as a root-end filling for endodontic surgery, mineral trioxide aggregate (MTA). Since that time, MTA has also been used as a pulp capping material with great success.

In 2011, Biodentine, a highly purified tricalcium silicate prepared in the lab, was introduced by Septodont. Additionally, Biodentine contains di-calcium silicate, calcium carbonate and zirconium oxide as a radiopacifier. Calcium-silicate- based cements set through a hydration reaction. The hydration reaction starts with the fast dissolution of the tri-calcium silicate particles and this allows the relatively quick setting reaction. Calcium chloride in the liquid speeds up the hydration and the absence of calcium sulphate that acts as a retarder. The alkaline caustic effect of the calcium of the calcium silicate hydration products results in a degradation of the collagenous section of interfacial dentin. This creates a porous structure and allows increased concentration of Ca2, OH- and CO 3 2- ions, resulting in increased mineralization in the mineral infiltration zone.10

The use of hydraulic calcium silicate cement stimulates pulpal recruitment and differentiation up-regulates gene transformation factors and promotes dentinogenesis.11 Recent introduction of Biodentine with dentin-like properties and the ability to stimulate tertiary dentin formation, may allow a more conservative biomimetic treatment of ECR. The restoration of choice in resorption lesions should strengthen remaining tooth structure, have a thermal expansion close to that of tooth structure and be biocompatible. Biodentine as a dentin substitute in areas under the CEJ performed well without conditioning treatment12 and when covered by composite, was well tolerated as a dentin substitute.13 Biodentine can also be used for pulp capping as it enhances the spread, movement and adhesion of human dental pulp stem cells.14

The resin ionomer Geristore has been used extensively for root perforation repairs. Geristore is a dual cure (both self and light-curing), hydrophilic, nonaqueous polyacid modified composite resin composed of fluoride-releasing glass, mainly barium fluorosilicate, and a polymerizable organic matrix (modified Bis-GMA, including 2-HEMA) combined with a photoinitiator. Advantages of these materials include insolubility in oral fluids, increased adhesion to tooth structure, dual-cure capabilities, low-cure shrinkage, low coefficient of thermal expansion, radiopacity, fluoride release and biocompatibility. Several clinical studies have demonstrated Geristore could repair subgingival and subosseous defects and could be used as a barrier for guided tissue regeneration.15,16 Gingival fibroblasts attached to Geristore in an integrin-independent manner indicating that integrins (transmembrane receptors that mediate the attachment between a cell and its surroundings) do not directly mediate attachment to this material.17

Conclusion
Traumatic injury to teeth may present a considerable challenge to the practitioner. Proper diagnosis and appropriate treatment sequence are critical to success. At times, surgical, restorative, endodontic and orthodontic approaches are required. Treatment should be evidenced-based and biomimetic. The recent introduction of bioactive materials may open a whole new avenue of treatment.

References
  1. Fuss Z, Tsesis I, Lin S. Root resorption--diagnosis, classifi cation and treatment choices based on stimulation factors. Dent Traumatol. 2003;19(4):175-182.
  2. Patel S, Kanagasingam S, Pitt Ford T. External cervical resorption: a review. J Endod. 2009;35(5):616-625.
  3. Tronstad L. Root resorption--etiology, terminology and clinical manifestations. Endod Dent Traumatol. 1988;4(6):241-252.
  4. Vinothkumar TS1, Tamilselvi R, Kandaswamy D. Reverse sandwich restoration for the management of invasive cervical resorption: a case report. J Endod. 2011;37(5):706-710
  5. Artun J, Behbehani F, Al-Jame B, Kerosuo H. Incisor trauma in an adolescent Arab population: prevalence, severity, and occlusal risk factors. Am J Orthod Dentofacial Orthop.;128(3):347-352
  6. Glendor U. Aetiology and risk factors related to traumatic dental injuries--a review of the literature. Dent Traumatol. 2009;25(1):19-31.
  7. Proffit William R, Contemporary Orthodontics 4th Edition, Mosby 2007
  8. Alves TP1, Soares TR, Barreto SC, Fried H, Pereira GD, Maia LC, Santos AE. Multidisciplinary approach for the treatment of extensive external cervical resorption after dental trauma. Oper Dent. 2013;38(4):349-357.
  9. Heithersay GS. Treatment of invasive cervical resorption: an analysis of results using topical application of trichloracetic acid, curettage, and restoration. Quintessence Int. 1999;30(2):96-110.
  10. Watson TF, Atmeh AR, Sajini S, Cook RJ, Festy F. Present and future of glass-ionomers and calcium-silicate cements as bioactive materials in dentistry: biophotonics-based interfacial analyses in health and disease. Dent Mater. 2014;30(1):50-61.
  11. Bogen G, Chandletr N. pulp preservation in immature permanent teeth. Endod Topics 2012;(23):131-152.
  12. Raskin A1, Eschrich G, Dejou J, About I. In vitro microleakage of Biodentine as a dentin substitute compared to Fuji II LC in cervical lining restorations. J Adhes Dent. 2012;14(6):535-542.
  13. Koubi G1, Colon P, Franquin JC, Hartmann A, Richard G, Faure MO, Lambert G. Clinical evaluation of the performance and safety of a new dentine substitute, Biodentine, in the restoration of posterior teeth - a prospective study. Clin Oral Investig. 2013;17(1):243-249.
  14. Luo Z, Li D, Kohli MR, Yu Q, Kim S, He WX. Effect of Biodentine™ on the proliferation, migration and adhesion of human dental pulp stem cells. J Dent. 2014;42(4):490-497.
  15. Scherer W, Dragoo MR. New subgingival restorative procedures with Geristore resin ionomer. Pract Periodontics Aesthet Dent 1995;7(Suppl):1– 4.
  16. Dragoo MR. Resin-ionomer and hybrid-ionomer cements: part I. Comparison of three materials for the treatment of subgingival root lesions. Int J Periodontics Restorative Dent 1996;16:594-601.
  17. Camp MA, Jeansonne BG, Lallier T. Adhesion of human fibroblasts to root-end-filling materials. J Endod 2003;29:602–607.

Dr. Richard Trushkowsky is Clinical Associate Professor and Associate Director for the Advanced Program for International Dentists in Aesthetic Dentistry at NYU College of Dentistry.

Dr. Natalia Rabago is a resident at the New York University College of Dentistry Advanced Program for International Dentists in Aesthetic Dentistry.
Dentaltown Magazine
September 2025
Dentaltown Magazine September 2025 Read Current Issue Read Archived Issues
Sponsors
Townie Perks
Townie® Poll
Who or what do you turn to for most financial advice regarding your practice?
  
Site Menu
Message Boards Magazine Continuing Education Podcasts Blogs Classifieds Dental News Events Townie® Poll Ebooks Townie Choice Awards
Company Info
Contact Us Advertise With Us Howard Farran DDS, MBA Policies and Agreements
Site Help
Sally Gross, Member Services Specialist
Phone: +1-480-445-9710
Email: sally@farranmedia.com
©2025 Dentaltown, a division of Farran Media • All Rights Reserved
9633 S. 48th Street Suite 200 • Phoenix, AZ 85044 • Phone:+1-480-598-0001 • Fax:+1-480-598-3450