There are numerous debated clinical procedures, routinely performed in dentistry. One such procedure is “clinical crown lengthening”. Clinical crown lengthening has been known to be achieved to procure an increment in the clinical crown height so as to enable it to receive suitable restorative treatments thereafter.

It can be achieved by a variety of techniques, most of which are associated with either aesthetic and functional limitations or an elongated duration of time. For example, clinical crown lengthening can be brought about by surgical gingivectomy around the tooth margins, orthodontic extrusion of tooth or in rare cases, surgical extrusion of tooth.

In cases, where surgical gingivectomy is contraindicated due to possibility of violation of the biological width and orthodontic extrusion is not possible due to tie constraint, clinician might need to resort to other methods to bring about clinical crown lengthening in interest of the patient. On of such methods is “surgical extrusion of the tooth”. Surgical extrusion, also called intra-alveolar transplantation was first described by Tegsjo in 1978. [1]The technique is based on the fundamentals of healing process occurring post re-implantation of the tooth after avulsion[2, 3] and auto transplantation.[4, 5]

This technique allows us to extrude the root, in a single visit, short period of time without violating the biological width. However there are some absolute contraindications; for e.g. presence of systemic condition that contraindicates surgery, patient on a long term biphosphonates therapy, presence of ankylosed root and risk of furcation exposure, high risk of root fracture during the tooth luxation, crown root ratio equal or less than 1:1.[6-10]

While few indication of surgical extrusion are as follows:-

Following is a case requiring clinical crown lengthening where novel technique of surgical extrusion is demonstrated along with the treatment outcome.

A 38 year old female patient reported to dental clinic with a chief complaint of decayed upper left tooth accompanied with no pain. Upon examination, grossly decayed premolar (24) was present. No pockets were seen in with respect to 24. There was no history of pain or relevant medical history or any known allergies. Patient gave a history of minor fillings and few extractions of posterior teeth in past due to extensive dental caries. The pre-operative clinical and radiographic appearance of decayed tooth (24) is shown in figure 1 and 2.

Figure 1 : Pre-operative clinical image Figure 2 : Pre-operative radiographic image

Vitality tests were performed using heat, cold and electric pulp tester. With, all the tests, tooth in question gave no response suggestive of non vital pulp. Thus, the final diagnosis was grossly decayed tooth with non vital pulp associated with no periapical pathosis. The patient was given radical and conservative treatment options for which patient went ahead with conservative treatment option.

Figure 3 : a,b : Wedging of tooth with periosteal elevator

c : Use of forceps

d : Extruded tooth to the required height.

Figure 4 : a ,b : Simple interrupted sutures: buccal view

c : Sutures, Occlusal view

d : Fibre reinforced splinting

The line of treatment followed in the conservative option was to save the natural tooth by extruding the tooth following which root canal treatment with a suitable post endodontic restoration would be performed. Due to expressed time constraint of the patient, decision to surgically extrude the tooth was taken. To assess the amount of decayed tooth structure, an emergency access opening was done and tooth was temporised, following which tooth was surgically extruded. (Figure 3). The surgical process was started under local anaesthesia, followed by reflection of gingival locally and wedging the tooth using periosteal elevator.(figure 3,b). Finally positioning of maxillary forceps (figure 3, c) at the level of CEJ was done with gentle force to extrude the tooth vertically to gain sufficient clinical crown height compensating for the removal of caries over the occlusal surface of tooth which would be done prior to performing root canal therapy. Figure 3,d shows the final level of surgical extrusion after which the tooth was stabilised using simple interrupted sutures around the tooth and fibre reinforced splint cemented with flowable composite (Filtek^TMZ350 XT, Flowable restorative, 3M ESPE) for ten days. Figure 5 shows the radiograph of the extruded tooth after the surgical extrusion process.

Figure 5: Post extrusion radiograph

Figure 6 : a: Working length radiograph

b: Mastercone radiograph

c: Obturation radiograph

d: Glass fibre post cementation

e: Glass fibre post radiograph

f: Composite core build up

Endodontic treatment was done as shown in figure 6a, 6b and 6c followed by glass fibre post cementation using resin cement (SpeedCEM Plus, ivoclar vivadent) and final core was build up using composite (Filtek^TM Z350 XT, universal restorative, 3M ESPE). (Figure 6d, 6e, ). Finally, tooth was prepared to receive full coverage restoration and impression was made. (Figure 7) Porcelain fused to metal (PFM) crown was cemented with Type 1 Glass Ionomer Cement and flash was removed. (Figure8a, 8b) Follow up radiographs were taken at one month and 8 months interval. (figure 8c, 8d)

Figure 7 : a: Post endodontically restored tooth with core material

b: Tooth preparation for PFM crown ; occlusal view

c: Tooth preparation ; buccal view with retraction cord

d: Impression of the prepared tooth

Figure 8: a: Crown cementation; buccal view

b : Crown cementation ; occlusal view

c : Follow up radiograph ; one month

d : Follow up radiograph ; eight months

Figure 9: a: Pre operative clinical image

b : Post operative clinical image

c : Pre operative radiographic image

d : Post operativeradiographic image - eight months