Root Fracture: Healing and Management of Fracture Segments

Healing of a root fracture depends greatly on the interaction between the pulp and periodontal ligament at the fracture site. This healing process is strongly influenced by the presence or absence of bacteria and several clinical factors, including the mobility and position of the coronal segment, pulp vitality, the distance between the fractured segments, the maturity of the tooth, and whether the fracture communicates with the oral environment (Andreasen et al., 2007; Herweijer et al., 1992).

Andreasen et al. (1967) described four possible patterns of healing following root fractures. Understanding these healing patterns is important because they can help clinicians assess the prognosis of the injured tooth and determine whether further treatment is required.

Healing by Calcific Union

Calcific union is considered the most desirable form of root fracture healing. In this type of healing, the fractured root segments become connected through the formation of hard tissue. Radiographically, the fracture line may remain visible, but there is no associated radiolucency around the fracture site. This type of healing occurs in approximately 30% of cases (Versiani et al., 2008).

Healing by Connective Tissue

Connective tissue healing is the most commonly observed type of root fracture healing, occurring in approximately 43% of cases (Andreasen et al., 2004; Berman, 2007).

In this type of healing, a thin radiolucent line remains between the fractured segments, with the edges of the fragments appearing rounded. Although the fragments do not become directly united by hard tissue, the tooth can remain functional and clinically healthy.

Healing by Bone and Connective Tissue

Healing by bone and connective tissue is a less common pattern, occurring in approximately 5% of cases (Versiani et al., 2008; Berman, 2007).

Radiographically, the fractured segments appear separated, with each fragment surrounded by its own lamina dura. This indicates that bone and connective tissue have developed between the two root fragments.

Healing by Granulation Tissue or Non-Union

The final pattern is healing by granulation tissue, also referred to as non-union. This occurs when persistent inflammation results in the formation of granulation tissue between the fractured segments. The granulation tissue may originate from the gingival sulcus or from necrotic pulpal tissue (Andreasen et al., 2004; Berman, 2007).

This type of healing is observed in approximately 22% of cases and is generally associated with an unfavourable healing response.

Vertical root fractures

Vertical root fractures are relatively uncommon, accounting for approximately 2–5% of root fractures. They are considered particularly challenging because both diagnosis and treatment can be difficult. They are most frequently reported in older patients, particularly in posterior teeth that have undergone endodontic treatment and have a non-vital pulp.

Vertical root fractures can be classified as either complete or incomplete. Their development is commonly associated with iatrogenic factors, particularly excessive preparation of the root canal. Many affected teeth also have extensive restorations and post-and-core restorations, which can increase the risk of fracture (Kawai & Masaka, 2002).

Premolars are considered the teeth most susceptible to vertical root fractures, followed by molars. Vertical root fractures are rarely observed in anterior teeth. In posterior teeth, the fracture line commonly extends in a buccolingual direction and may involve an individual root.

Treatment of Vertical Root Fractures

Treatment depends on the location of the fracture and the tooth involved. For anterior teeth, extraction is generally considered the ideal treatment option.

In posterior teeth, however, tooth-preserving treatment may sometimes be possible. Depending on the location and extent of the fracture, treatment options can include root hemisection or complete root amputation (Mokbel et al., 2019).

References

• Kawai K, Masaka N. Vertical root fracture treated by bonding fragments and rotational replantation. Dent Traumatol 2002;18:42-5.

• Mokbel, N., Kassir, A.R., Naaman, N. and Megarbane, J.M., 2019. Root Resection and Hemisection Revisited. Part I: A Systematic Review. International Journal of Periodontics & Restorative Dentistry, 39(1).

• Andreasen, J.O., Andreasen, F.M., Mejàre, I. and Cvek, M., 2004. Healing of 400 intra‐alveolar root fractures. 1. Effect of pre‐injury and injury factors such as sex, age, stage of root development, fracture type, location of fracture and severity of dislocation. Dental Traumatology, 20(4), pp.192-202.

• Berman, L.H. (2007). Intra-alveolar root fractures. In: A Clinical Guideline to dental Traumatology. Berman, L.H., Bianco, L., Cohen, S. eds. Mosby Elsevier: pp51-71.

• Fuss, Z., Lin, S., Tsesis, I. (2007). Intra-alveolar root fractures. In: A Clinical Guideline to dental Traumatology. Berman, L.H., Bianco, L., Cohen, S. eds. Mosby Elsevier: pp12-26.

• Herweijer, J.A., Torabinejad, M. and Bakland, L.K., 1992. Healing of horizontal root fractures. Journal of Endodontics, 18(3), pp.118-122.

• Versiani, M.A., Sousa, C.J.A.D., Cruz‐Filho, A.M., Perez, D.E.D.C. and Sousa‐Neto, M.D., 2008. Clinical management and subsequent healing of teeth with horizontal root fractures. Dental Traumatology, 24(1), pp.136-139.