Introduction

The treatment of teeth that have sustained a traumatic dental injury (TDI) with vital pulp treatment (VPT) is not new, as it was pioneered by Cvek in 1978 (1). Maintaining pulp vitality to allow further root maturation is the principal goal of VPT, as pulp necrosis or injudicious removal of a healthy pulp has unfortunate consequences, particularly for immature teeth (2). Purported advantages of maintaining pulp vitality for mature and immature teeth include an improved likelihood of survival (3) plus the maintenance of dentine deposition and further repair mechanisms, immunological response and proprioceptive functions, among others (4). Interest in VPT in mature teeth has been reinvigorated recently due to an increased understanding of the reparative processes of the pulp, multiple improvements in the management of dental tissues, the availability of bioactive hydraulic calcium silicate cement (HCSCs), its less‐invasive nature and its reported successful outcomes (4).

It is the purpose of this chapter to outline the developments and outcomes when mature and immature teeth with complicated crown fractures (CCFs) with luxation or root fractures are treated with VPT and showcase the current techniques with contemporary materials.

Traumatic Dental Injuries

TDI have the fifth highest incidence in diseases and conditions are commonly unreported (5). TDIs are mostly associated with children and young adults; therefore, subjects potentially present with mature and immature permanent teeth (6). Of TDIs in the permanent dentition, crown fractures are the most prevalent and are classified as either complicated or uncomplicated, depending on whether the pulp is exposed (7).

CCFs and root fractures involve the enamel, dentine and dental pulp (8, 9). Similarly, the dental pulp is commonly involved in crown‐root fractures when the tooth in question has fully erupted. The cement and surrounding periodontal tissues are involved in root fractures and may be involved in crown‐root fractures (8, 9). Crown‐root fractures often have a limited displacement of the coronal segment and a transverse direction, with a more coronal position in the buccal aspect of the tooth when compared with the palatal/lingual surface. In addition, luxation includes further damage to the periodontium and a subsequent displacement of the coronal segment in question with further injury to the dental pulp (10).

Teeth with CCFs are the most likely to undergo pulp necrosis without appropriate management and the most likely to benefit from VPT, though it has been shown that inflammation is limited in the earlier stages of exposure (11). Clinically, there are various presentations ranging from a slight haemorrhage to the formation of a pulp polyp, depending on the degree of contamination and the ability of the pulp to respond to the injury, with immature teeth expected to have more favourable outcomes compared with mature ones. Other TDIs, such as avulsion and luxation, are less likely to be treatable with VPT as the vasculature is compromised (12). Concomitant crown fractures and luxation injuries in permanent mature teeth are significantly associated with pulp necrosis (13, 14). In general, for most root fractures, the apical part of the pulp will remain vital, with no treatment required other than repositioning and fragment stabilization (15). Significant clinical factors that influence the healing of intra‐alveolar fractures include mobility and dislocation of the coronal fragment, plus the diastasis between fragments which have been associated with rupture and/or stretching of the tissues (15).

Outcome measures considered in the literature have varied with time. In the classic literature, for CCFs in particular the absence of clinical symptoms, absence of radiographic radiolucency suggestive of pathosis, continuous root development and the presence of a hard‐tissue bridge as well as a response to pulp sensibility testing were considered important (1, 16). Whereas loss of the injured tooth is a possible complication of root fractures (17). More recently, a core outcome set for TDIs in children and adults has been developed by the International Association of Dental Traumatology (IADT) (18). These include generic outcomes, such as injury activity (periodontal and pulpal healing), physical consequences of disease (pain and discolouration), functional status (tooth loss), social outcomes and quality of life (quality of life and aesthetics), side effects of therapy (dental anxiety) and health resource utilization (number of clinical visits) (18). In addition, injury‐specific outcomes have been proposed, those relevant to this chapter being quality and loss of restoration for both types of injuries and mobility for crown‐root fractures (18).

Therefore, the focus of this chapter relates to VPT for the management of CCFs associated with luxation and crown‐root fractures and will also aim to discuss, when available, the core outcome measures of relevance.

Diagnosing the Pulp Condition

An accurate diagnosis is essential for any management and therefore is critical for predictable outcomes. The trauma is sudden, emotional, the impact is visually notable and often associated with soft tissue lacerations and swelling. Therefore, achieving an accurate diagnosis is challenging in traumatic injuries, especially in children. In fact, TDIs present most often in children aged between 6 and 12 years (19, 20) and it is understandable that obtaining an accurate diagnosis in this cohort will be difficult.

TDIs most commonly involve the maxillary central and lateral incisors (21), and CCFs may encompass a third of TDIs (19, 20) involving the maxillary central incisor in particular (22).

In the presence of CCFs, sensitivity to thermal changes is a common symptom. Pulp sensibility testing may be unreliable in children for emotional reasons such as anxiety and distress, difficulty in interpretation and inadequate neural development as the plexus of Rashkow does not fully develop for up to five years after a tooth erupts (23), in addition to the issues caused by laceration of the pulp tissues. Furthermore, pulpal oedema from the traumatic injury can lead to a temporary loss of sensibility (24). Thus, a non‐response to pulp sensibility testing is not conclusive for pulp necrosis in TDIs (25–28). The concerns in a reliable assessment of the status of the traumatized pulp are outlined in the European Society of Endodontology (ESE) position statement: Endodontic Management of Traumatized Permanent Teeth (ESE 2021) (29).

A series of radiographic examinations at varying vertical angulations is required to diagnose concomitant TDIs such as luxations and root fractures. Cone beam computed tomography (CBCT) can particularly assist in assessing the extent and position of crown‐root fractures (30). This is important as luxation injuries may synergistically affect the viability of VPT for the treatment of CCFs due to disturbance to the neuro‐vascular bundle at the apical foramina. Diagnostic issues, nonetheless, are common even when three‐dimensional imaging is used during the management of TDIs.

Direct Pulp Capping and Pulpotomies for Managing Traumatised Teeth

The IADT (2020) (31), the ESE position statement on Endodontic Management of Traumatised Permanent Teeth (ESE, 2021) (29) and The American Association of Endodontics “Treatment of Traumatic Injuries” (AAE 2013) (32) all advocate the use of VPT by either pulp capping or pulpotomy for CCFs and crown‐root fractures (29, 31, 32). However, there are some inconsistencies in the recommendations/guidelines regarding the management of the exposed pulp. The IADT (2020) and AAE (2013) guidelines recommend either a pulp cap or a partial pulpotomy (ESE 2021). The IADT (2020) guidelines list partial pulpotomy followed by direct pulp capping, whereas AAE (2013) lists pulp capping first, followed by partial pulpotomy. Neither the IADT (2020) nor the AAE (2013) makes specific indication as to when either pulp capping or pulpotomy would be indicated as the first treatment choice. However, the ESE (2021) is more specific and recommends a partial pulpotomy for large exposures or when there is a treatment delay, and advocates pulp capping for minor exposures that have occurred within a few hours of the trauma, as it is considered that there has been less microbial challenge to the pulp, therefore a reduced risk of demise. The ESE (2021) further clarifies that root canal treatment is only indicated if there is a concomitant luxation injury or the restorative requirements indicate that a post is needed to restore the tooth. Both the IADT (2020) and AAE (2013) have specific guidelines for complicated crown‐root fractures in which pulpotomy is recommended for immature teeth with incomplete root development and a pulpectomy is advised for a mature tooth if the tooth can be retained. Pulpectomy is also indicated if restoration with a post is required and may also involve either orthodontic extrusion with or without periodontal re‐contouring of the gingiva or surgical extrusion. Autotransplantation is another option.

What is the Evidence for the Preferred Treatment Choice?

Several studies have shown a higher incidence of pulp necrosis for teeth treated with pulp capping rather than pulpotomy (16, 17, 33). A study of 76 teeth with CCFs reported a success rate of 92% for teeth treated with calcium hydroxide pulpotomy and 81.5% for teeth treated with direct pulp capping (16). However, there were also differences in the pre‐operative status of the groups, as 38 of the teeth were mature and presented with pinpoint exposures treated by direct pulp capping, whereas the remaining 38 teeth were immature and treated with a pulpotomy. In another study of 76 teeth with CCFs followed for five years, pulp survival was only 32%. Unfortunately, the reason for the poor outcome was that most mature teeth had the pulp extirpated in primary care prior to referral. In teeth treated with VPT, pulp vitality rose to 75.8%. However, the incidence of pulp necrosis was higher for pulp capping (45.5%) when compared to partial pulpotomy (13.6%) over five years of review (17). In a more recent study of 375 teeth, the incidence of pulp necrosis for pulp capping was 57.1%, whereas teeth treated with partial pulpotomy was 10.1% and 9.8% for coronal pulpotomy and just 6.1% required retreatment with either a partial or coronal pulpotomy after the tooth had been initially treated by direct pulp capping (33). In this study, the retreatment of the pulp capping by pulpotomy offered a much better outcome than direct pulp capping and comparable outcomes to an initial treatment with pulpotomy. Twenty‐eight teeth were retreated with pulpotomy and 75% (21/28 teeth) were retreated in less than 24 hours, 14.8% (4/28 teeth) in 24–72 hours and 11.2% (3/28 teeth) in more than 72 hours (33).

A recent systematic review has suggested that partial pulpotomy as opposed to pulp capping, should be the preferred treatment option for both mature and immature teeth that have sustained CCFs (34). However, the severity of the traumatic injury, the size of the pulp exposure, the presence of a concomitant luxation injury and any delay in treatment being initiated may influence pulp healing and the potential for pulp necrosis (1, 16, 35).

A recent study in a major hospital setting reported a success rate of only 61% for 56 teeth that had sustained either CCFs or complicated crown‐root fractures (CCRF) that were treated with the Cvek protocol (36). Pulp survival was reported as 54.1% and 73.7% for teeth treated with partial and full coronal pulpotomies, respectively. Pulp survival for four teeth with CCRF was 50%. A concomitant luxation injury was noted in 30% of treated teeth. The experience and training of the clinician impacted the outcome. Pulp survival was reported in 70.4% and 71.4% of the teeth treated by post‐graduate registrars and paediatric specialists, respectively. In contrast, pulp survival for teeth treated by general dental practitioners was 33%. This suggests that VPT is a clinically sensitive technique, and clinical experience can account for differences in outcome. The important factor of a concomitant luxation injury emphasises the need for a complete diagnosis prior to treatment.

Overall experience of the clinician in treating trauma is another barrier to treating CCFs with VPT. As stated above, Hecova et al. (17) reported poor outcomes for teeth with CCFs in most mature teeth when the pulp was extirpated in the primary care setting. Another study reported that the initial treatment for CCFs was pulp extirpation (44% overall; 61% of mature teeth and 35% of immature teeth), which was generally provided outside the hospital setting (37). These authors advocated the use of a pulp ‘bandage’ using a glass‐ionomer cement restoration in the primary care setting prior to referral for the appropriate treatment. This is indeed suitable, as teeth treated with pulpotomies as either primary care or secondary to the emergency placement of a pulp cap were reported to be successful treatment approaches. Importantly, several studies show similar outcomes for either mature or immature teeth treated with pulpotomies (36, 38, 39), so a mature tooth should be treated with VPT rather than pulp extirpation except when it is considered that a post would be required for successful restoration of the tooth.

Several recent reviews have been published on VPT in CCFs (34, 40, 41). The relevant studies assessing pulp survival are included in Table 8.1. If pulp necrosis develops, it is generally within the first six months (16, 54), although other studies have reported one year (49) and others report two years (13).

Factors that Affect Outcomes of VPT in TDI

Mobility

Tooth mobility is an injury‐specific core outcome for root fractures (18). At the same time, pre‐operative mobility of the coronal fragment has a negative influence on the survival of the coronal pulp and on fracture healing with hard tissue, the latter being considered a positive outcome for this type of injury (15). For crown‐root fractures, there is often mobility of the retained fractured segment, which has some attachment to the PDL apparatus. Different healing patterns in intra‐alveolar root fractures are possible. These include the interposition of soft tissue exclusively or the presence of chronic inflammatory tissue – that should be described as “non‐healing”, which may be associated with increased mobility compared with healing that includes hard tissue, at least partially (15). Regarding CCFs, mobility is likely to be associated with a concomitant luxation injury, and the crown should be promptly restored as described above.

Delay in Treatment

TDIs are among the most urgent dental presentations in clinical practice. Nonetheless, although the importance of early diagnosis needs to be reiterated, the necessity for prompt treatment will differ based on the injury type, and treatment delay may not negatively affect treatment outcomes in specific clinical presentations. For CCFs, according to a recent review (34), four studies assessed the time delay for treatment with a pulpotomy following injury and found no impact on pulp survival and the absence of apical periodontitis (16, 38, 42, 44). However, one of these studies did find a significant difference in successful outcomes for teeth treated within 72 hours following trauma compared to longer delays before treatment (38). Another study of 175 teeth treated with a pulpotomy reported that 12% of teeth treated within 24 hours of the injury lost pulp vitality, compared with 32% for teeth treated after 24 hours (43). In a primate study of mechanically exposed pulps that were pulp capped with either setting calcium hydroxide Dycal (Batch Catalyst 070929, Base 070979, L. D. Caulk, Milford, DE 19963, USA). or Life (Batch Base 9‐1207, Cat. 9‐1226, Sybron/Kerr Dental Products Division. Romulus, MI 48174, USA), favourable outcomes were reduced from 93% to 56% when treatment was delayed from one hour to seven days (59). This would suggest that where there is a significant delay in treatment for CCF, a pulpotomy may be the preferred option for treatment. It would be prudent to treat all CCFs as early as possible after the trauma, especially when the patient is in pain. However, where treatment is delayed, VPT can maintain pulp vitality and should be the preferred treatment option. Regarding root fractures, no significant relationship was found in a seminal study between treatment delay and type of healing, even if the time length was more than three days after the TDI occurred (60).

Size of Pulp Exposure

The dental pulp has a remarkable ability to withstand exposure to the oral cavity. Cvek (1), in a study of 60 teeth where the pulp exposure associated with CCF varied from 0.5 to 4.0 mm, demonstrated that the pulp chamber size was not a critical factor for pulp healing, with most cases being treated 30 or fewer hours after the accident. Few studies have assessed the effect of pulp exposure size on outcomes. However, the determining factor is the vitality of the treated pulp rather than the size of the pulp exposure (44, 56). Therefore, the ability to achieve haemostasis following amputation of the superficial layer of the pulp as per the Cvek protocol is the more important determining variable on outcomes. The ESE (2021) guidelines advise a partial pulpotomy for large exposures as the preferred treatment but do not define what is a large exposure (29). The IADT (2020) and AAE (2013) guidelines make no recommendation on the size of the pulp exposure (31, 32).