Apicoectomy

Apicoectomy is the surgical resection of the root tip of a tooth and its removal together with the pathological periapical tissues. Accessory root canals and addition- al apical foramina are also removed in this way, which may occur in the periapical area and which may be considered responsible for failure of an endodontic therapy.

Indications
The indications for apicoectomy include the following cases:
1. Teeth with active periapical inflammation, despite the presence ofa satisfactory endodontic therapy.
2. Teeth with periapical inflammation and unsatis- factory endodontic therapy, which cannot be re- peated because of:
– Completely calcified root canal.
– Severely curved root canals.
– Presence of posts or cores in root canal.
– Breakage of small instrument in root canal or the presence of irretrievable filling material.
3. Teeth with periapical inflammation, where comple- tion of endodontic therapy is impossible due to:
– Foreign bodies driven into periapical tissues.
– Perforation of inferior wall of pulp chamber.
– Perforation of root.
– Fracture at apical third of tooth.
– Dental anomalies (dens in dente).
In the above cases, if after the apicoectomy the apex has not been completely sealed, then retrograde filling is required, which is described further down. The pur- pose of retrograde filling is to obstruct the exit of bacteria and the by-products of nonvital pulp, which remained in the root canal.

Contraindications
The contraindications for apicoectomy are as follows:
● All conditions that could be considered contrain- dications for oral surgery concerning the age of the patient and general health problems, such as severe cardiovascular diseases, leukemia, tubercu- losis, etc.
● Teeth with severe resorption of periodontal tissues (deep periodontal pockets, great bone destruction).
● Teeth with short root length.
● Teeth whose apices have a close relationship with anatomic structures (such as maxillary sinus, man- dibular canal, mental foramen, incisive and greater palatine foramen) and if causing injury to these during the surgical procedure is considered probable.

Armamentarium
The following instruments are necessary for perform- ing an apicoectomy:

● Microhead handpiece (straight and contra-angle) and microbur (Fig. 13.1).
● Special narrow periapical curette tips for prepara- tion of the periapical cavity (Fig. 13.2).
● Apical retrograde micro-mirror and micro-explor- ers (Fig. 13.3).
● Local anesthetic syringe and cartridges.
● Scalpel handle.

● Scalpel blade (no. 15).
● Mirror.
● Periosteal elevator.
● Cotton pliers.
● Small hemostat.

● Suction tips (small, large).

● Irrigation receptacle.

● Needle holder. 

● Retractors

● Periodontal curette.
● Periapical curette.
● Appropriate burs (round, fissure, inverted cone).
● Miniaturized amalgam applicator for retrograde fillings (Figs. 13.4, 13.5).
● Narrow amalgam condensers (Fig. 13.6).

● Scissors, needles and no. 3–0 and 4–0 sutures.
● Metal endodontic ruler.
● Gauze and cotton rolls/pellets.
● Syringe for irrigating surgical field.
● Saline solution.

Surgical Technique
The procedure for apicoectomy includes the following steps:
1. Designing of flap.
2. Localization of apex, exposure of the periapical area and removal of pathological tissue.
3. Resection of apex of tooth.
4. Retrograde filling, if deemed necessary.
5. Wound cleansing and suturing.

 

Designing of Flap. 

Flap design depends on various factors, which mainly include position of the tooth, presence of a periodontal pocket, presence of a pros- thetic restoration, and the extent of the periapical lesion.

There are three types of flaps principally used for apicoectomy: the semilunar, triangular, and trapezoi- dal. The semilunar flap is indicated for surgical proce- dures of limited extent and is usually created at the anterior region of the maxilla, which is where most apicoectomies are performed. In order to ensure opti- mal wound healing, the incision must be made at a distance from the presumed borders of the bony de- fect, so that the flap is repositioned over healthy bone. If there is an extensive bony defect, especially towards the alveolar crest, then the triangular or trapezoidal flap is preferred. It must be noted that the pathological lesion, which has perforated the bone and has become attached to the periosteum, must be separated from the flap witha scalpel. In case ofa fistula, the fistulous tract must also be excised near the bone, because, if it is excised at the mucosa, then there is risk of even greater perforation, resulting in disturbances of the healing process.

When the apicoectomy is performed at the anterior region (e.g., maxillary lateral incisor) and there is an extensive bony defect near the alveolar crest (Figs. 13.7, 13.8), the surgical procedure is performed using a trapezoidal flap. The incision for creating the flap be- gins at the mesial aspect of the central incisor and, af- ter continuing around the cervical lines of the teeth, ends at the distal aspect of the canine. With a perios- teal elevator, the mucoperiosteum is then carefully re- flected upwards (Figs. 13.9, 13.10). 

 

Localization and Exposure of Apex. 

The next step after creating a flap is localization and exposure of the apex. When the periapical lesion has perforated the buccal bone, localization and exposure of the root tip is easy, after removing the pathological tissues with a curette. If the buccal bone covering the lesion has not been completely destroyed, but is very thin, then its surface is detected with an explorer or dental curette, whereupon, due to decreased bone density, the under- lying bone is easily removed and the apex localized. When the buccal bone remains completely intact, then the root tip may be located with a radiograph. More specifically, after taking a radiograph, the length of the root is determined witha sterilized endodontic file or metal endodontic ruler. The length measured is then transferred to the surgical field, determining the exact position of the root tip. Afterwards, witha round bur and a steady stream of saline solution, the bone covering the root tip is removed peripherally, creating an osseous window until the apex of the tooth is ex- posed (Fig. 13.11). If the overlying bone is thin and the pathological lesion is large, the osseous window is en- larged with a blunt bur or a rongeur. Enough bone is removed until easy access to the entire lesion is per- mitted. A curette is then used to remove pathological tissue and every foreign body or filling material, while resection of the root tip follows (Fig. 13.12).

 

Resection of Apex of Tooth. 

The apex is resected (2–3 mm of the total root length) witha narrow fissure bur and beveled at a 45° angle to the long axis of the tooth (Fig. 13.13). For the best possible visualization of the root tip (Fig. 13.14), the beveled surface must be facing the dental surgeon. After this procedure, the cavity is inspected and all pathological tissue is me- ticulously removed by curettage, especially in the area behind the apex of the tooth. If the entire root canal is not completely filled with filling material or if the seal is inadequate, then retrograde filling is deemed necessary.

 

Retrograde Filling. 

After beveling of the apex and curettage of periapical tissues, gauze impregnated with adrenaline to minimize bleeding is placed in the bony defect. A microhead handpiece with a narrow round microbur is then used to prepare a cavity ap- proximately 2 mm long, with a diameter slightly larger than that of the root canal (Fig. 13.15). The cavity may be enlarged at its base using an inverted cone-shaped bur to undercut the preparation for better retention of the filling material (Fig. 13.16). During preparation of the cavity, the dentist must pay careful attention to the width of the cavity, which must be as narrow as possi- ble, because there is a risk of weakening the root tip and causing a fracture (which may not even be per- ceived) during condensing. After drying the bone cav- ity with gauze or a cotton pellet, sterile gauze is packed inside the bone deficit and around the apex of the tooth, in such a way that only the prepared cavity of the root end is exposed. Splattering of amalgam1) is thus avoided at the periapical region. The amalgam is placed inside the cavity with the miniaturized amal- gam applicator and is condensed with the narrow amalgam condenser (Figs. 13.17, 13.18). The excess amalgam is carefully removed and the filling is smoothed with the usual instruments (Fig. 13.19).

 

Wound Cleansing and Suturing of Flap. 

After placement of the amalgam, the gauze is carefully removed from the bony defect and, after copious irrigation with saline solution, a radiographic examination is per- formed to determine if there is amalgam splattering in the surrounding tissues. The flap is repositioned and interrupted sutures are placed (Figs. 13.20, 13.21). Healing of the periapical area is checked every 6–12 months radiographically, until ossification of the cavity is ascertained. In order to evaluate the result, a preoperative radiograph is necessary, which will be compared to the postoperative radiographs later. When apicoectomy is performed in the anterior re- gion (e.g., maxillary central incisor) and the size of the lesion is small, and when there are esthetic crowns on the anterior teeth, the semilunar flap is preferred. The procedure in sucha case is similar to that of the previously mentioned surgical procedure employing the trapezoidal flap (Figs. 13.22–13.35).

 

Complications

The most common perioperative and postoperative complications that may occur during and after the surgical procedure, respectively, are:
● Damage to the anatomic structures in case of pen- etration of the nasal cavity, maxillary sinus and mandibular canal with the bur.
● Bleeding from the greater palatine artery during apicoectomy of palatal root.
● Splattering of amalgam at the operation site, due to inadequate apical isolation and improper manipu- lations for removal of excess filling material (Fig. 13.36). 

● Staining of mucosa due to amalgam that remained at the surgical field (amalgam tattoo) (Figs. 13.37, 13.38).
● Healing disturbances, if the semilunar incision is made over the bony deficit (Fig. 13.39) or if the flap, after reapproximation, is not positioned on healthy bone.
● Dislodged filling material due to superficial place- ment, as a result of insufficient preparation of api- cal cavity (Fig. 13.40). Incomplete root resection, due to insufficient ac- cess or visualization and misjudged length of root (Fig. 13.41). As a result, the apical portion of the root remains in position and the retrograde filling is placed improperly, with all the resulting consequences.