04 December 2019

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Surgical Extrusion: a Challenge for Restorative Dentistry

Alessandra Abbà

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Restoration of teeth with insufficient coronal tooth structure due to deep caries, resorption or traumatic injury with fracture line extended under gingival margin, is a very common and uncertain challenge. Several times extraction with replacement of the teeth seems to be the easier way. In alternative, surgical crown lengthening and orthodontic or surgical extrusion can be managed. While surgical crown lengthening is a recognized treatment option to ensure adequate biologic width, the procedure may result in unpleasant aesthetics. Orthodontic extrusion avoids this kind of problem, but has disadvantages in terms of time and costs.   In this paper, published on British Dental Journal in May 2019, a new solution which consist in surgical extrusion using a vertical extraction system (Benex) is discussed in comparison with the other techniques above mentioned.    

Matherials and Methods 
The Benex system provides for a self-tapping screw inserted using the screwdriver to the appropriate length and anchored into the root canal. Preparation of the screw space should preserve as much hard tissue as possible. A vertical extraction force-varying from 100N to no more than 500 N- is applied using the extractor, resulting in minimal trauma and no-expanded alveolar bone. Root should slowly reach the desired position, then the extractor can be dismounted and the root can be stabilesd with the help of wooden wedge. The screw is removed and the root splinted to adjacent teeth. If root canal treatment has not been completed, the access may be filled with a temporary material. If the root canal has already been obturated, core build-up can be performed. A post may be necessary for the restoration due to the limited amount of supragingival tissue providing unadequate retention. If restored with a crown, at least 2 mm of supragingival tissue are needed for an appropriate ferrule. Mouthwashes with chlorhexidine should supplement oral hygiene for one week. Complation of endodontic treatment can be performed during the healing period, if isolation with rubber dam is possible. After three to six weeks, the patients is recalled for the removal of the splint.    

Discussion 
In case of tooth presenting little supragingival tissue, with deep caries or root fracture, many options are available for the clinician. The choise should be made based on time, costs, aesthetic parameters and tooth position and anathomy. Orthodontic extrusion is highly predictable and adequate for all tooth types; however, due to its cost, timing and unfavourable aesthetics it is not frequently used. This technique could lead even to a coronal advancement of gingiva, which may not be a desired effect.   For molars aesthetic consideration are less important, but the anatomy of the tooth doesn’t allow surgical extrusion procedure. Thus, surgical crown lengthening is generally the preferred option. Nevertheless Benex system represented a good option for teeth in aesthetic zone. However, its risks have to be carefully considered. Technical mistakes or unfavourable root anatomy may invalidate the procedure.  

Conclusion 
Surgical extrusion may exhibit some difficulties in the practice, but represented an efficient technique in alternative to surgical crown lengthening and orthodontic extrusion, in particular with non-molars teeth.

For additional informations: Restoring the unrestorable! Developing coronal tooth tissue with a minimally invasive surgical extrusion technique.