Perspective Chapter: Splinting of Traumatized Teeth

Abstract

Repositioning or replantation followed by stabilization with splint is the standard management of traumatized teeth. Numerous types of splints are being used and each type has its own advantages and disadvantages. Knowledge on the different types of splints and its effect on dental tissues so as to aid in the clinical decision on the type of splint to be used for managing a particular type of traumatic dental injury and its fixation period are important. Therefore, this chapter aims in explaining the different methods of splinting along with its advantages and disadvantages of each type along with the standard recommendation for duration of splinting.

1. Introduction

Splinting is recommended in the management of traumatic dental injuries which requires repositioning and stabilization of the luxated teeth. Earlier, the management of luxated teeth was similar to the management of fractures of Jaws, which are arch bars with wires and cap splints. But due to their negative effect on periodontal structures along with the advent of adhesive materials, a wide range of splints are being developed [1, 2]. A splint is “An apparatus used to support, protect or immobilize teeth that have been loosened, replanted, fractured or subjected to certain endodontic surgical procedures” [3]. The aim of this chapter is to enumerate the ideal requirements of splints, types and description of each types of splints and International Association of Dental Traumatology (IADT) recommendations of splinting duration and types.

2. Ideal requirements of splints

1. The splint design must allow direct intraoral application without any laboratory support

2. The materials used for the splint must be easily available

3. The application and removal of the splint must be easy and should not damage the dentition or the surrounding tissues

4. A splinting technique must be applicable for all types of situations like patients with missing tooth, unerupted tooth or clinically short or conical crowns.

5. Throughout the splinting time period, the splint must be able to stabilize the tooth in its correct position and provide proper stabilization.

6. The splint should be passive without exerting untoward forces on the injured teeth.

7. It should be versatile that is it could be applied as rigid, semi-rigid or flexible splint.

8. Once placed, it should neither interfere with occlusion or occlusal movements nor impinge the gingival tissues.

9. Should allow easy maintenance of oral hygiene, thus not predisposing to caries and periodontal problems

10. Should permit diagnostic procedures like pulp testing to be performed and also provide access for performing endodontic procedures.

But, all the splinting techniques do not satisfy all the requirements mentioned above [1, 4, 5].

3. Classification of splints

Splints can be classified as

1. Rigid splints

2. Semi-rigid splints/Flexible splints

3.1 Rigid splints

Rigid splints are those splints which does not allow physiologic movement of the repositioned teeth [2].

Eg: Erich arch bars, Acrylic cap splint, Schuchardt splint, Interdental wiring methods like figure-eight wiring & loop wiring.

In case of arch bar splints (Figure 1) and the interdental wiring methods, the ligature wires used in these splints tend to become loose with time and come to rest on the marginal gingiva. This could cause gingival irritation and inflammation as it becomes the site for plaque deposition. The patient’s inability to maintain good oral hygiene around the wires could worsen the condition [4, 6]. These splints also cause physical damage to gingiva and cementum surface when removed after the splinting period [7]. If these ligature wires, when positioned apical to the cervical prominence while splinting especially in a mobile tooth, they tend to elevate the tooth slowly making the cemento-enamel junction lose its integrity [4, 6].

Figure 1.

Arch bar splint.

Schuchardt splint was initially designed for splinting of luxation injuries. But its extreme rigidity and difficulty in adapting to the arch form accounts for its high thickness of 2 mm diameter bar made of aluminum-brass alloy. Acrylic cap splint is cemented on uninjured teeth when used for luxation injuries provides too much rigidity [6].

In addition to these disadvantages, there is high incidence of pulp necrosis, external root resorption and ankylosis of the repositioned teeth when rigid splints are applied [2, 8].

For the above reasons, the usage of rigid splints is restricted only for stabilizing jaw fractures.

3.2 Semi-rigid/flexible splints

Flexible splints are those splints which allow functional movement of the stabilized teeth [4]. Studies conducted on animals had shown that normal masticatory stimulation can lower the incidence of ankylosis which led to the development of flexible splints so as to allow the functional movement of the traumatized and stabilized teeth [9].

Many varieties of flexible splints are being introduced. Most of these splints make use of the acid etch technique.

3.2.1 Composite and wire splints

Flexible wire composite splint (Figure 2) uses a wire of 0.3–0.4 mm in diameter bonded onto the labial surface of the teeth with composite [4]. Rigidity of the splint increases with increase in the thickness of wire or by adding composite in the interdental space [1]. Rigidity also increases with increase in the length of the wire splint [10].

Figure 2.

Wire composite splint.

The main advantage of this splint is that the materials used for the construction of this splint are routinely available in all dental clinics. Other advantages are it is well accepted by the patients, does not cause any injuries to the supporting structures and easy maintenance of oral hygiene. But a major disadvantage is that it can cause potential damage to enamel while removing [1].

3.2.2 Other alternatives

Many splints are being constructed using other materials as an alternative to wire.

1. Nylon/Fishing Line splint (Figure 3) – In this splint a thin nylon/Fishing line is used instead of wire. The advantages of this splint is that it is atraumatic to supporting structures, relatively esthetic, easy to maintain oral hygiene, inexpensive and comfortable for patient [11]. The main disadvantage is that it is slightly difficult to position the nylon line as it is thin. This problem can be overcome by fixing the nylon line and light curing the composite one tooth at a time and thus it is slightly time consuming [12].

2. Power chain (Figure 4): Power chain is made of rubber and is used in orthodontics for traction purposes. The advantages of power chain is that it’s an easily available, inexpensive material with good esthetics and comfort to the patient. It is very flexible and has holes into which composite can be applied without flowing out and thus reduce the bulk of composite around the splint. Care must be taken not to activate the elastic and it must be used in a passive state. The disadvantage is similar to nylon line as it has to be fixed one tooth at a time to avoid it from slipping [12, 13].

3. Waxed dental floss and flexible orthodontic wires are also successfully used instead of stainless steel wires [6].

Figure 3.

Nylon line splint.

Figure 4.

Power chain splint.

3.2.3 Suture splint

It is the simplest form used as temporary splinting of traumatized deciduous teeth or partially erupted permanent teeth in a situation where the child is difficult to manage. It is a temporary splint because it is retained only for 3 to 4 days until the child becomes more receptive to a definitive treatment. A suture is placed over the incisal edge from palatal gingiva to the labial gingiva. (Figure 5) It prevents the tooth from extruding. But the biggest disadvantage of this splint is that sometimes the incisal edge has to be grooved to hold the suture material in position [1, 5].

Figure 5.

Suture splint.

3.2.4 Orthodontic splint

It requires the orthodontic materials like brackets and wires (Figure 6). The brackets are bonded to the teeth and are connected by 0.014 NiTi flexible wire [4].

Figure 6.

Orthodontic wire splint.

It is indicated in a few clinical conditions like:

1. severely malpositioned teeth which makes the placement of wire-composite splint difficult.

2. In case of intrusive luxation, where repositioning of the tooth is to done [14].

The main advantage of this splint is that it is the least traumatic technique for repositioning tooth with intrusive luxation injury [14]. However, when used in other situations except intrusive luxation, care must be taken to reduce orthodontic forces that disturbs the healing of the luxated tooth [15].

It is known through studies that splints constructed with orthodontic materials always generate some amount of force over the teeth, but these forces could be reduced with certain conditions like the form of arch wire, type of cross section of the wire and the type of ligature used [16]. Hence, it is recommended that only trained clinician in handling orthodontic materials can utilize this splint properly. This becomes a major disadvantage of this splint [17]. Other disadvantages are the requirement of materials which are not commonly available in clinics and irritation to the lips and buccal mucosa and discomfort to the patient especially at the beginning of the treatment, which can be reduced by lubricating the lips [18].

3.2.5 Fiber-reinforced composite splints

These splints use fibers which are attached to the teeth either by unfilled resin or with composite [4].

The commercially available fibers are:

• polyethylene fibers eg. Ribbond (Figure 7)

• Glass fibers eg. Fiber-splint and quartz splint

• Kevlar fibers [17]

Figure 7.

Ribbond splint.

Fiber splints are esthetically acceptable and it is easy to apply and remove. It does not cause any trauma to surrounding structures and maintenance of oral hygiene is easy. Fiber splints are associated with highest frequency of healing outcomes [19].

3.2.6 Titanium trauma splint (TTS)

This splint was developed by von Arx in collaboration with Medartis AG, Basel, Switzerland. The objective behind developing this splint was to optimize the splinting techniques, (i.e) ease of application and removal from the dental surgeon’s aspect and increase in comfort and easy maintenance of oral hygiene from the patient’s aspect.

It is a pre-fabricated splint made of titanium of 0.2 mm thickness and 2.8 mm width. Due to its least thickness, it is operator friendly, it does not require any special pliers or other instruments to manipulate; it can be easily adapted onto the arch by fingers. It is available in two different lengths 52 mm and 100 mm and it could be cut to the desired length.

Its unique design with a rhomboid mesh structure makes the splint more flexible without subjecting the splinted teeth to any orthodontic forces. Yet another advantage is that it could be easily secured to the teeth. The rhomboid openings are in the size of 1.8x2.8 mm and hence only a small area of bonding is needed with the tooth. It does not require a bulk composite around the splint; only a thin layer of flowable composite is required.

While removing the splint, the composite can be ground down to the level of TTS and the splint can be “peeled-off” easily from the tooth with a hemostat. Any remnant composite can be removed with easily with a curett and tooth surface can be polished [20]. The only disadvantage of this splint is its high cost [4].

3.2.7 Resin splint

This splint is applied with resin materials like Protemp and Luxatemp, which are used in temprorary prosthetic restorations and for lining prefabricated crowns. Luxatemp is dual cured; by both chemical and light cured, while Protemp is chemically cured material [1]. The resin materials are available in syringe forms and can be directly applied to the labial aspects of the crowns of the teeth to be splinted. Once the material is set/cured, any sharp edges can be removed to prevent irritation to the surrounding soft tissues [21].

The advantages are these materials do not exert any force on tooth during application and are acceptable esthetically and hygienically. They are not indicated when the adjacent are not fully erupted and difficult in case of any edentulous area. The main disadvantage is that they tend to fracture easily and care must be taken during removal. [1].

4. Splinting type and duration

4.1 For permanent dentition

Experiments and studies demonstrated that rigid immobilization for longer duration of time increased the risk of pulp necrosis, external root resorption and ankylosis. The International Association of Dental Traumatology (IADT) has formulated guidelines for the management of traumatic dental injuries. Based on current evidences, short-term, passive and flexible splints are recommended for splinting luxated, avulsed and root-fractured teeth. For alveolar bone fractures, splinting of teeth may be used for bone segment immobilization. Splinting duration depends on the type of dental injury. The duration of splinting for Permanent Dentition as given by IADT 2020 is given in Table 1 [22].

S. No.	Types of Dental Injuries	Duration of splinting
		2 Weeks	4 Weeks	4 Months
1	Subluxation	✓; (if splinted)
2	Extrusion	✓
3	Lateral Luxation		✓
3	Intrusion		✓
4	Avulsion	✓
5	Root Fracture (apical third, Mid-third)		✓
6	Root fracture (cervical fracture)			✓
7	Alveolar fracture		✓

Table 1.

IADT guidelines for splinting duration of permanent dentition.

4.2 For primary dentition

According to IADT guidelines, splinting of primary dentition is recommended only in case of alveolar bone fractures. Root fractures and lateral luxations may occasionally require splinting. Only flexible splints are used including alveolar fracture where the splint is stabilized on adjacent uninjured teeth for 4 weeks. (IADT guidelines) The duration of splinting for Permanent Dentition as given by IADT 2020 is given in Table 2 [22].

S. No.	Types of Dental Injuries	Duration of splinting
		2 Weeks	4 Weeks	4 Months
1	Lateral Luxation		✓; (If splinting required)
2	Root Fracture		✓; (If splinting required)
3	Alveolar fracture		✓

Table 2.

IADT guidelines for splinting duration of primary dentition.

5. Removal of splint

One of the important requirement of a splint is that it should be applied and removed easily without causing any damage to the enamel surface. The resin-based materials cause iatrogenic enamel damage while removing them is a major concern. Various techniques are employed for removing the remnant composite material used for retaining the splints from the enamel surface. They are hand instruments like scalers and pliers, burs, abrasive discs, rubber wheels and cups. In an experimental study conducted to assess the surface roughness of enamel after employing various methods to remove the material, it was noted that Soflex discs and 16-blade tungsten carbide bur cause least damage to the enamel [17, 23].

6. Emergency splinting

Patients with multiple injuries as in road traffic accidents, often sustain dental injuries. Traumatic dental injuries not being life-threatening, emergency rooms not being equipped to manage traumatic dental injuries, inadequacy of knowledge and skill of medical personal handling the patients are the reasons for either delaying/ignoring the management of traumatic dental injuries [24, 25]. In such emergency situations, an easy to perform splinting technique is “criss-cross” pattern suture splints which can be rapidly placed by any medical personal. This splint can be placed with 2/0 silk suture material with a horizontal locking mattress design to keep the reimplanted tooth in position until the patient could be mobilized to Dental Department for more definitive management. The advantage of this technique is that it is a quick method which could be performed by any medical personal when the patient is treated under General Anesthesia for other injuries and does not delay the general treatment procedures.

The criss-cross pattern splint is given by the following steps:

Step 1 – the first bite (point 1 in Figure 8) is taken at the base of the distal interdental papilla on the labial side of the tooth to be repositioned and crossed over the incisal edge towards the mesial-palatal aspect.

Figure 8.

Criss-cross splint.

Step 2 – suture then penetrates the base of the mesial interdental papilla (point 2 in Figure 8) on the palatal side and emerges out at the base of the distal interdental papilla on the palatal aspect (point 3 in Figure 8).

Step 3 – the suture then crosses over the incisal edge to pierce the base of the mesial interdental papilla on the labial aspect (point 4 in Figure 8).

Step 4 – from point 4, the suture retraces the path underneath the previous suture upto the criss-cross point (point 5 in Figure 9) on the labial aspect and winds around the point 5 to pierce at mid buccal region (point 6 in Figure 9) on the labial aspect.

Figure 9.

Criss-cross splint.

Step 5 – knot is placed between point 1 and 6 (Figure 9) [24].

7. Home-care instructions to parents

Post-treatment maintenance of good oral hygiene is the key to uneventful healing of the injured tissues. Therefore, parents/caregivers must be sensitized about the importance of maintaining good oral hygiene and also taught the methods to maintain it. Most important instructions to be given are:

1. To avoid their children from participating in contact sports

2. To give only soft diet for a minimum of 2 weeks

3. To brush the teeth only with a soft brush after each meal

4. To use 0.12% chlorhexidine mouth rinse twice a day for 2 weeks

5. Strict adherence to follow-up schedule [26].

8. Conclusion

To summarize, splinting is important for stabilizing the luxated teeth; use of semi-rigid/flexible splints is mandatory as it allows functional movements of the tooth and short-term immobilization is recommended as longer period of splinting is associated with complications.