After reading this chapter, the student should be able to:
Discuss the role of adjunctive endodontic surgery in patient treatment planning.
Recognize situations in which adjunctive surgical procedures are the treatments of choice.
Define the terms incision and drainage, root resection, hemisection, crown lengthening, tooth replantation, tooth transplantation, and socket preservation.
Discuss the indications for each procedure listed in objective 3.
Describe in brief the step-by-step procedures involved in objective 3.
Discuss the prognosis for each procedure listed in objective 3.
Adjunctive surgical procedures are those that are used to treat either pathologic conditions or mishaps that occur during root canal treatment. One of the pathologic conditions that requires an adjunctive procedure is an incision for drainage for acute apical abscesses. As discussed in Chapter 18 , most procedural accidents can be corrected nonsurgically. When nonsurgical correction is not feasible or impractical, these conditions are treated surgically, as discussed in Chapter 20 . Adjunctive surgical procedures are additional. So it is additional treatment modalities to treatment modalities prevent tooth loss and preserve natural dentition. The purpose of this chapter is to discuss the indications, contraindications, procedures involved, and prognosis for some of these procedures such as incision for drainage, root resection, hemisection, crown lengthening, tooth replantation, and transplantation. In addition, principles and materials for socket preservation after extraction using regenerative techniques and guided bone regeneration (GBR) will be discussed.
Incision for Drainage
The objective of incision for drainage is to remove inflammatory exudates and purulence from a soft tissue swelling. Incision for drainage reduces discomfort resulting from the buildup of pressure and speeds healing.
The best treatment for swelling originating from an acute apical abscess of pulpal origin is to establish drainage through the offending tooth ( Fig. 21.1, A ; Video). When adequate drainage cannot be accomplished through the tooth itself, drainage is obtained through soft tissue incision. Drainage through the soft tissue is accomplished most effectively when the swelling is fluctuant. A fluctuant swelling is a fluid-containing mass in which a wavelike sensation is felt when pressure is applied ( Fig. 21.1 , B ). Incising a fluctuant swelling releases purulence immediately and provides rapid relief. If the swelling is nonfluctuant or firm, incision for drainage often results in drainage of only blood and serous fluids. Incision and drainage of a nonfluctuant abscess reduces pressure and facilitates healing by reducing irritants and increasing circulation in the area.
There are relatively few contraindications to the use of incision for drainage. Patients with prolonged bleeding or clotting times or those who are on bisphosphonates must be approached with caution, and hematologic screening is often indicated. An abscess in or near an anatomic space should be handled very carefully.
Profound anesthesia is sometimes difficult to obtain in the presence of inflammation, swelling, or exudates. Because direct subperiosteal infiltration is ineffective and may be quite painful, regional block anesthetic techniques are preferred. Mandibular blocks for posterior areas, bilateral mental blocks for the anterior mandible, posterior superior alveolar blocks for the posterior maxilla, and infraorbital blocks for the premaxilla area are the preferred choices. These injections may be supplemented by regional infiltration.
In addition to block anesthesia, one of the following methods may also be used. The first technique is infiltration that starts peripheral to the swelling. After the application of topical anesthetic, the solution is injected slowly with limited pressure and depth, and this is followed by additional injections in previously anesthetized tissue, moving progressively closer to the center of the swelling. This procedure results in improved anesthesia without extreme discomfort.
The second technique is the use of topical ethyl chloride. A stream of this solution is directed onto the swelling from a distance, permitting the liquid to volatilize on the tissue surface. Within seconds, the tissue at the site of volatilization turns white. The incision is quickly accomplished with continued ethyl chloride spray. This topical anesthesia is a supplement to block anesthesia when a quick incision is required. If none of these procedures work, nitrous oxide/oxygen sedation or intravenous (IV) sedation can be used for incision and drainage.
After anesthesia, the incision is made vertically with a No. 11 scalpel (Fig. 9-6C). Vertical incisions are parallel with the major blood vessels and nerves and leave very little scarring. The incision should be made firmly through periosteum to bone. If the swelling is fluctuant, pus usually flows immediately, followed by blood (Video). If the swelling is nonfluctuant, the predominant drainage is blood.
After the initial incision, a small closed hemostat may be placed in the incision and then opened to enlarge the draining tract (Fig. 9-6D). This procedure is indicated with more extensive swellings. To maintain a path for drainage, an I-shaped or “Christmas tree” drain cut from a rubber dam or a piece of iodoform gauze can be placed (suturing is optional) in the incision ( Fig. 21.1, C ; Video). The drain should be removed after 2 to 3 days; if it is not sutured, the patient may remove the drain at home.
Root resection is removal of the whole or part of a root from any multirooted tooth. This operation is usually performed in maxillary molars, but it can also be done in mandibular molars.
The main indication for root resection is presence of severe bone loss in a periodontally involved root that cannot be treated by periodontal treatment. In addition, root resection is indicated for root(s) of multirooted teeth with severe caries, resorption, vertical root fracture, or untreatable procedural accidents in the furcation of multirooted teeth.
Root resection is contraindicated when there is insufficient bony support for the remaining root(s), patients on bisphosphonates, and in the presence of fused roots.
Root resection can be performed with and without a surgical flap. Raising a surgical flap provides better visibility for the operator. After raising a flap, root resection is performed using a fissure bur to cut the involved root and separating it from the crown. The remaining stump should be contoured to the surface of the crown, providing the patient a good hygiene ( Fig. 21.2 ). The prognosis for root resection has been reported as fair to good depending on case selection, patient hygiene, and motivation ( ).
Hemisection is the surgical division of a multirooted tooth into two segments. It is usually performed in mandibular molars and in rare occasions in maxillary molars. The indications and contraindications for hemisection are similar to those for root resection.
Like in root resection, hemisection can be performed with and without a surgical flap. After raising a flap, a vertical cut is made through the crown into the furcation using a fissure bur. The initial cut should be made close and at the expense of the unsalvageable root. The tooth is sectioned through the bifurcation. The unsalvageable root is then removed. The anatomic crown of the remaining root(s) should then be contoured to the surface of the root without any ledges. This action provides good, smooth margins for the prosthetic crown and adequate access for good hygiene by the patient ( Fig. 21.3 ). The success rates of teeth that have had root amputation or hemisection has been reported to be 70% to 85%. , Like root resection, the main factors affecting the long-term success of this procedure are case selection and the patient’s oral hygiene ( ). , ,
Although clinicians often prefer supragingival margin placement, some situations like presence of subgingival decay, crown fracture, root perforation, short clinical crown, tooth hypersensitivity, or esthetic demands may dictate subgingival margin for placement of restoration. Placing restoration margins below gingiva can cause persistent gingival inflammation and eventually tooth loss. To prevent these complications and establish biological width, crown lengthening can be performed either surgically or nonsurgically. Surgical crown lengthening (SCL) usually consists of removal of soft and/or hard tissues to achieve a longer clinical crown and reestablish the proper biologic width dimensions around a tooth.
SCL is indicated for teeth with a short natural clinical crown and shortened clinical crown resulting from the presence of pathologic conditions such as extensive decay, resorption, iatrogenic perforation, or crown fracture extending subgingivally. SCL is indicated when the operator expects that the final restorative margin will be located less than 3 mm from the alveolar bone crest.
SCL is contraindicated for medical reasons, patients on bisphosphonates, when the procedure could result in exposure of a tooth furcation, or it is near vital anatomic structures such maxillary sinus or mental foramen and for teeth in the esthetic zone, when the procedure results in the presence of a long clinical crown for only one tooth.
SCL is typically accomplished by either gingivectomy or placing gingival tissue flap apically with or without bone removal. After raising a full-thickness flap, a submarginal incision is performed. Then, soft and hard tissues are removed, and the flap is sutured in the appropriate level to allow reestablishment of the epithelial and connective tissue attachment and for allowance of enough tooth structure for adequate support of the planned restoration ( Fig. 21.4 ). The mean survival rates of SCL procedure have been reported at 83% after 10 years. However, a recent systematic review with limited data concludes that SCL can result in increased crown length and possible gingival margin rebound.
An alternative to SCL is orthodontic extrusion or forced eruption. ,
Indications and Contraindications
Root extrusion is indicated for any tooth with horizontal crown or root fractures, decay, resorption, or accidental perforations that extend below the crestal bone 0 to 4 mm. The contraindications for root extrusion are short roots, insufficient space to extrude the root, and periodontal disease.
If there is enough tooth structure available after root canal treatment, brackets are placed on the incisal third of the crown of the involved tooth and the adjacent teeth. Vertical force is applied to the involved tooth by placing elastic bands on the adjacent teeth and connecting them to the endodontically treated tooth with inadequate coronal structure ( Fig. 21.5 ). When there is not enough coronal tooth structure available, a paper clip is cemented with intermediate restorative material (IRM) in the coronal portion of the root canal treated tooth. After cementing a horizontal wire on the adjacent teeth, vertical force is applied to the involved tooth by placing elastic bands from the paper clip in the root canal-treated tooth and the horizontal wire. Because of light extrusion forces, the tooth and the entire periodontal attachment apparatus will move coronally. This procedure may take 2 to 4 weeks. After accomplishing adequate extrusion, the tooth must be stabilized for at least 2 months before placing a final restoration ( Fig. 21.6 ). This treatment can also be expedited with fiberotomy. When performed, the marginal bone level will mostly stay in the original position.