|LETTER TO EDITOR
|Year : 2012 | Volume
| Issue : 2 | Page : 104-105
Vacuum formed splints: A flexible option
Vishal Khandelwal1, Nayak Ullal Anand2, Nayak Prathibha Anand3, Ninawe Nupur4
1 Department of Pedodontics, Modern Dental College and Research Centre, Indore, Madhya Pradesh, India
2 Department of Pedodontics, Mahatma Gandhi Dental College, Jaipur, Rajasthan, India
3 Department of Periodontics, Mahatma Gandhi Dental College, Jaipur, Rajasthan, India
4 Department of Pedodontics, VSPM Dental College and Research Centre, Nagpur, Maharashtra, India
|Date of Web Publication||6-Mar-2013|
Department of Pediatric and Preventive Dentistry, Modern Dental College and Research Centre, Gandhinagar, Airport Road, Indore, Madhya Pradesh - 453 112
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Khandelwal V, Anand NU, Anand NP, Nupur N. Vacuum formed splints: A flexible option. Saudi Endod J 2012;2:104-5
Splinting is the standard care for stabilization of replanted or repositioned permanent teeth following trauma. A splint is a 'rigid or flexible device or compound used to support, protect, or immobilize teeth that have been loosened, replanted, fractured, or subjected to certain endodontic procedures'.  Historically, splinting of teeth utilized the principles of jaw bone fracture with rigid, long-term immobilization for a few months. However, the use of long-term rigid splinting was questioned when experimental evidence demonstrated rigid immobilization increased the risk of pulpal necrosis and external root resorption.  Thus, the semi-rigid splints are traditionally used to stabilize the repositioned tooth where the support is taken from adjacent teeth.
It is generally accepted and recommended that teeth subjected to trauma should be splinted after repositioning of the tooth to prevent displacement and further injury to the pulp or the periodontal ligament during the healing phase. 
Until, the 1970s, splinting of traumatized teeth was primarily accomplished using methods employed in the treatment of jaw fractures with cap splints, arch bars, and wires. This was because of lack of knowledge of healing mechanism of injured teeth and lack of appropriate materials.
The splint may be direct-formed or indirect one. The various types of direct-formed splinting devices include suture splint, arch bar splint, arch bar splint with acrylic, flexible wire composite, rigid wire composite, composite splint Protemp, luxotemp, TTS splint, and orthodontic splint.  Wire - composite splint is direct-formed splint, which is most common and reliable method for fixation of a luxated tooth.
The vacuum formed bio-acrylic splint may be a useful alternative to arch wires in managing traumatic injuries especially where the adjacent tooth gap is wide or only minimal anchorage and support are available from the adjacent teeth. Situations, especially mixed dentition and primary teeth where adaptation of the wire composite splint is difficult due to retention problems, ,, the vacuum formed splint-the indirect one-offers an alternate in such situations. Also, in this method, it is not necessary to position the tooth in its final position before impression making.
The procedure for forming vacuum formed splints includes carefully making of impression, after infiltrating the local anesthesia around the site and plaster models are prepared. The displaced tooth is then cut-off from the model by using an engine driven bur. After establishing the correct position of the tooth on the cast, it is then fixed back on the cast using zinc phosphate cement. A Biocryl® (acrylic sheet approx. 1.5 × 125 mm thick) is then heated and drawn over the cast under vacuum pressure. The formed splint is removed from the cast and is trimmed up to the gingival margin. The splint is ready to insert in the mouth. At this point, the luxated tooth can be positioned to its original place, and a splint is inserted in the mouth in correct position.  Further, to increase the stability of splint in the mouth, the splint can be loaded with a thin layer of luting cement on the occlusal surface of molar region.
Experimental studies in non-human primates have demonstrated that rigid splinting, i.e., immobilization, or a prolonged splinting period may lead to extensive periodontal ligament healing complications, such as dentoalveolar ankylosis or external root resorption (also called replacement resorption).  Thus, maintaining a certain degree of tooth mobility appears to be beneficial to periodontal healing of traumatized teeth. Another prerequisite for periodontal healing is that the splint should not impinge on the marginal tissues thus preventing additional periodontal damage. In addition, mechanical tooth cleaning should not be impaired by the splint, thus, reducing the impact of plaque accumulation with respect to soft tissue and periodontal healing. The vacuum formed splint gives a luxated tooth physiological stimulation that is beneficial for the development of a functional periodontal attachment. , Bio-acrylic splints were flexible in all dimensions, therefore, allows physiologic tooth mobility without transferring orthodontic forces to the splinted teeth. On the other hand, the material and dimensional characteristics of the splint also guarantee a certain mechanical stiffness to withstand shearing forces.
Other advantages of the vacuum formed splint include improved patient comfort, reduced bonding time, protection of injured teeth, elimination of custom wire bending, ease of access for oral hygiene, and lack of dietary restrictions. It can save clinical side time too. Thus, a vacuum formed splint offers an alternate to traditional splinting.
Disadvantages include laboratory time and need for patient compliance with alginate impressions, wearing the splint as well as the necessary adjustment to eating and speaking with the splint in place. 
The acrylic splint may be a useful alternative to arch wires in managing traumatic injuries especially in young children, who may be having missing teeth adjacent to traumatized teeth, uncooperative or handicapped patients, and this may also be useful where the adjacent tooth gap is wide or only minimal anchorage and support are available from the adjacent teeth. 
| References|| |
|1.||American Association of Endodontists. An Annotated Glossary of Terms Used in Endodontics. 7 th ed. Chicago: American Association of Endodontists; 2003. p. 15. |
|2.||Kristerson L, Andreasen JO. The effect of splinting upon periodontal and pulpal healing after auto transplantation of mature and immature permanent incisors in monkeys. Int J Oral Surg 1983;12:239-49. |
|3.||Andreasen JO, Andreasen FM. Textbook and Color Atlas of Traumatic Injuries to the Teeth. 3 rd ed. Mosby: Munksgaard; 1994. p. 14, 17. |
|4.||Andreasen JO, Andreasen FM, Andersson L. Textbook and Color Atlas of Traumatic Injuries to the Teeth. 4 th ed. Oxford, England: Wiley-Blackwell; 2007. p. 842-3. |
|5.||Yeung C, Yen SL. Extrusion of a traumatically injured tooth with a vacuum-formed splint. J Clin Orthod 2003;37:361-3. |
|6.||Horie N, Shimoyama T, Nama Y, Nasu D, Kaneko T. A vacuum-formed splint for luxated tooth with a repositioning on the model. J Clin Pediatr Dent 2005;29:123-5. |
|7.||Skyberg RL. Stabilization of avulsed teeth in children with the flexible mouth guard splint. J Am Dent Assoc 1978;96:797-800. |
|8.||Mandel U, Viidik A. Effect of splinting on the mechanical and histological properties of the healing periodontal ligament in the vervet monkey (Cercopithecus aethiops). Arch Oral Biol 1989;34:209-17. |