Reinsertion of a fractured clinical crown as a biological restoration after dental trauma.

This clinical report describes the rehabilitation procedure of an upper central tooth with a coronal fracture without compromising the root. The treatment plan consisted of the reinsertion of the fractured fragment as a definitive cemented biological restoration. Due to the deficient remnant, a fiber-reinforced composite post was used. The objective of this clinical case was to report the biological behavior of the enamel and dentin of a biological restoration after dental trauma. Patient satisfaction with the treatment was achieved by continuing with the same tooth and biomimetizing the fracture line with conventional composites. Controls were conducted, and 1 year after dental trauma, no color changes in dental tissues and no inflammation in periodontal and soft tissues were observed. Copyright:

INTRODUCTION

Any trauma in the oral cavity affects esthetic, mastication, and phonetic function and gives rise to emotional and psychological damage due to the traumatic aspect in the facial area, altering the patient's lifestyle by the physical appearance caused by the trauma.[1] The surgical-restorative treatment and prognosis of fractured teeth depend on many factors such as the degree of affected dental structure, the level and type of fracture, the involvement of soft and periodontal tissues, and the need for endodontic treatment.[2] Dental trauma with a horizontal fracture line is the most common, and this type of trauma suffers undergoes a frontal impact as it follows the course and orientation of the glaze prisms.[34] The term “biological restoration” was provided by Santos and Bianchi in 1991 and allows adherence by relocating the fragment or partial clinical crown, even when completely fractured in the affected natural tooth, offering psychological benefits for the patient of the use of their own tooth and decreasing the cost of treatment.[56]

The fracture line is a key factor for the reimplantation of the fragment; if it is continuous and regular, it will be easier to adapt if it has a broken and irregular fracture line with multiple fragments.[5] Another key point for the success of a biological restoration is the time that the fractured fragment has been out of the mouth and in a storage solution to avoid dehydration, which can cause changes in the color of the enamel and dentin.

Various techniques have been described for the reconstruction of a fractured tooth; however, there is insufficient evidence of the biological and mechanical behavior of a complete clinical crown fractured by dental trauma in a tooth with endodontic treatment that is repositioned as a definitive biological restoration.

The objective of this clinical case was to report the considerations for dental fragment reattachment and the protocol of repositioning a fractured clinical crown that functioned as definitive biological restoration, describing multidisciplinary clinical management. In this case report, a horizontal dental fracture was diagnosed in an upper central tooth caused by dental trauma in a motorcycle accident. The treatment plan consisted of using the fractured clinical crown itself as a permanent biological restoration with a fiber-reinforced composite post. This case report shows a step-by-step protocol for employing a fractured clinical crown as a biological restoration.

CASE REPORT

Case description

A 41-year-old female patient underwent a severe horizontal fracture in the cervical third vestibule-palatine in the upper right central region that was not splinted to the palatal remnant. The etiology of the fracture was direct frontal trauma to the oral cavity due to a fall on a motorcycle, and there was no other relevant medical history. There were no bruises or abrasions on the face or lips. The evolution time was 24 h. Radiological observation showed no signs of radicular fracture.

Clinical examination

The horizontal fracture was localized at the cervical neck of the right upper central tooth, and the patient experienced pain and inflammation in the localized area. The diagnosis was a horizontal vestibule-palatine fracture covering two-thirds of the clinical crown, and the fragment was not completely detached [Figure 1a]. The dental remnant exhibited no movement. A preoperative periapical radiograph was taken to evaluate the level of the dental fracture, to assess the need for endodontic treatment, and to reveal the absence of periapical pathology [Figure 1b].

Figure 1

Intraoral clinical examination, vestibulo-palatine horizontal fracture of the upper right central incisor (a), initial radiography (b), removal of the fractured clinical crown sustained by the palatine face (c), fractured coronal fragment once removed (d), radiography of the root canal desobturated after endodontic treatment (e), and cementation of the provisional crown of autocurable acrylic with a provisional post (f)

Treatment plan

All possible treatment options were explained to the patient, who chose to use the fractured clinical crown as a biological restoration due to the lack of dental remnant once the crown fractured fragment was removed a fiber-reinforced composite post was indicated.

Root canal treatment

The conduct was formed with K-Flexofile (Dentsply, Maillefer, Tulsa, OK, USA) manual instruments, and a protocol was produced for irrigation with sodium hypochlorite at 5.25% and vertical sealing using Sealapex endodontic cement (Kerr, CA, USA).

Separation of the fractured fragment

The fragment of the fractured clinical crown was removed with fine-grained diamond pencil burrs (SS White Dental, NJ, USA) [Figure 1c and d], washed with 2.0% chlorhexidine (Consepsis, Ultradent, UT, USA), and kept in a saline solution at a temperature of 4°C. The gutta-percha was removed with widening burs (Pesso, Dentsply Maillefer) according to conductometry referred by the endodontist, leaving 4 mm of gutta-percha at the apical level, and a control radiography was taken of the root [Figure 1e]. Due to the inflammation, it was decided to set a provisional restoration in place. A provisional autocurable acrylic with a prefabricated plastic additive was manufactured to retain the provisional restoration and was cemented with provisional cement (Temp Bond, Kerr). Excess cement was removed and left out of occlusion [Figure 1f].

Fiber-reinforced composite post

The root canal was configured and prepared with a yellow drill conformer corresponding to a 1.3 mm Relyx Fiber Post (3M ESPE, St. Paul, MN, USA). The post surface was cleaned with 70% alcohol for 1 min and then dried using sterile gauze. A layer of silane (Dentsply Maillefer, USA) was applied to the surface of the post for 1 min, and the root canal was washed with distilled water containing 1% NaOCl, followed by a second washing with distilled water for 15 s before being dried with absorbent paper cones (3M ESPE), and postsettlement was tested. The root canal was lubricated with glycerin, eliminating the excess, and individualization was carried out with composite (ENA, HRi; SYNCA, NY, USA), which were placed on the surface of the post, while the post-resin assembly was inserted into the root canal, followed by light curing for 5 s.

The post was removed, completely photopolymerized outside of the root canal for 40 s, cleaned, and silanized once again [Figure 2a]. The fiber-reinforced composite post was cemented with self-etching resin cement (Relyx U200, 3M ESPE) following the manufacturer's instructions. The resin cement was applied directly into the root canal using an elongation tip; the cement was light-cured for 40 s by placing the tip of the lamp into the coronal part of the post. The remaining tooth structure was reconstructed with composite (ENA, HRi SYNCA), using 2 mm incremental layers of and photocuring each layer for 15 s at 1200 mW/cm2; the reconstruction was prepared to cement the biological restoration [Figure 2b].

Figure 2

Fiber-reinforced composite post before cementing (a), reconstruction with conventional composite after the postcementation (b), definitive cementation of biological restoration (c), and postoperative control at 1 month (d), 3 months (e), and 12 months (f), no enamel color change was observed in the biological restoration, periodontal tissues were stable, without the presence of inflamed tissues, achieving biomimetization of dental tissue

Cementation of biological restoration

The fractured clinical crown was outside the mouth for 72 h in a saline solution, was washed with 2.0% chlorhexidine (Consepsis, Ultradent) and saline solution, and was indirectly dried. Absolute tooth isolation was performed, and the biological restorations were cemented with self-adhesive resin cement (Relyx U200, 3M ESPE). The fracture line was mimicked with composite (ENA, HRi SYNCA) and polished with discs (Sof-Lex Discs, 3M ESPE) and diamond paste (Ultradent). The occlusion was evaluated for it not to present occlusal overload and dental interference. The patient was shown the indications and the brushing technique and instructed to attend periodic control appointments to monitor the hygiene and quality of the restoration [Figure 2c].

Postoperative control

The patient had no pain after cementation of the biological restoration, and biomimetization of the fracture line with the fractured fragment was obtained, restoring the esthetic and masticatory function. The control appointment was made 1 month after the reinsertion of the biological restoration, and at that time, it was clinically observed that there were no changes in the configuration of soft tissues and no presence of inflammation [Figure 2d]. In the biological restoration, no changes in color or appearance were observed after a period of 6 months [Figure 2e]. After 12 months [Figure 2f], the biological restoration was deemed satisfactory and was without any discoloration, marginal breakdown, or loss of restoration.

DISCUSSION

The main focus of this clinical case was to report the biological and mechanical behavior of a biological restoration and the protocol of repositioning of a fractured clinical crown that functioned as a definitive biological restoration demonstrating the procedure of repositioning. Each case must be individually reviewed, as there are several parameters that can affect the success of biological restoration.[7]

The restoration of a fractured tooth with composite entails some complexity, but it is not impossible. Dentists must know the materials and their manipulation to imitate tonality, translucency, and form. However, when the fragment has been recovered, the first treatment option would be to adhere it provisionally or even permanently.[8910] When the fractured fragment covers two-thirds of the tooth, the treatment is usually minimally invasive because it only involves adhesion. On the other hand, in this case, the fractured fragment covered the entire clinical crown, which resulted in a treatment that was actually more invasive. This was due to the need to place a fiber-reinforced composite post because of the lack of remaining substrate to attach the crown and provide stability to the biological restoration.

The fiber-reinforced composite post decreases the stress caused in the dentin; in addition, it offers excellent adhesion, functioning as a monoblock; this is due to that composites adhering to the prefabricated post decreases the space for cement between dentin and the post[111213] and improves the biomechanical behavior.[1415]

It has been considered that biological restorations provide both esthetics and biofunctionality[16] and that the most natural morphology is supplied by the biological restoration itself.[17] In vitro studies have shown that there is no material that provides the same resistance to fracture as a healthy tooth,[18] and the same is true with biological restorations. The fractured fragment will not recover the normal resistance of a healthy tooth; therefore, the mechanical behavior of the teeth will be compromised by the existence of the cemented fractured fragment.[19] On the other hand, successful repositioning depends on the degree of dehydration of the fractured fragment, that is, the time that it has been outside of the mouth without being incubated in a storage solution. This is due to its having been reported that the tissue becomes more fragile with the loss of wetness, in that this natural wetness is essential to achieve resistance between the fractured fragment and the restored material. The hydration maintains the appearance of enamel's color, and some solutions have been employed such as water, saline, and artificial saliva.[20]

It has been suggested that the techniques utilized to reposition the fractured fragment depend on the type of fracture when the dental remnant adapts without a preparation technique, that is, without a bevel or a finish line. It has been reported that when a bevel preparation is made on the fracture line, the area of contact increases the union between the two pieces by 60%.[21] The biological behavior of the enamel and dentin of the fractured fragment will behave similarly to that of an endodontic tooth; however, this dental fragment was possibly subjected to a period of dehydration, which can compromise the properties of dental tissues. Conservative restorative treatment combined with biological restoration and a fiber-reinforced composite post when the dental fracture compromised the tooth remnant for reconstruction offers a prosthetic alternative with excellent esthetic and functional results. However, it is necessary to perform other types of studies to understand the long-term benefits of this type of treatment.

CONCLUSIONS

Contemporary management of biological restorations is a reliable treatment option when the fractured fragment is in good condition and can be repositioned. On the other hand, modern restorative dentistry provides adhesive systems and materials that permit biomimetic fracture lines. Biological restorations offer esthetic and functional advantages, and the patient gains a psychological benefit from knowing that they have retained their own natural tooth fragment.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient gave their consent for their images and other clinical information to be reported in the journal. The patient understands that her names and initials will not be published and that due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

Conflicts of interest

There are no conflicts of interest.