Surgical endodontics - Endodontics
The apex resection, also called surgical endodontics, is a treatment in which a piece is usually removed from the root tip. From the apex, the root canal is closed with a filling.
The purpose of an apex resection is that a tooth can be retained. This is done by removing all the inflammatory or granulation tissue that is around the root tip.
Nerve channel treatment must first be done to treat periapical inflammation. If the inflammation does not disappear as a result, an apex resection is done.
The apex resection is performed as:
- A periapical inflammation does not disappear after nerve channel treatment;
- A root-point infection is so extensive that the chance that it heals is small, even after proper nerve channel treatment;
- The dentist cannot file a root canal clean because it is obliterated, or clogged, or is very crooked;
- The dentist cannot file a root canal clean because it contains a silver pin section or a superstructure with a root pin;
- A file is broken in the root canal.
An apex resection has advantages over an endodontic treatment, but the procedure is more complex and is usually performed by an MKA surgeon or endodontist. An apex resection is a combination of an endodontic treatment and the removal of the inflammation process at the root point. The benefits over a normal nerve canal treatment are:
- The dental surgeon can assess the root canal as a whole;
- All inflammatory tissue can be removed during treatment (excochleation);
- The closure of the apex can be checked because the root point is immediately visible;
- To improve the filling of the root tip, a piece of the root tip may be ground off.
There are two types of apex resection:
- The orthographer resection: the root canal is completely accessible;
- The retrograde apex resection: the root canal is not open from the oral cavity, so that the closure can only take place from the apex.
Procedure of orthograde apex resection
After giving anesthesia, the dentist or MKA surgeon makes an incision. He shoves the oral mucosa and the bone membrane, the mucoperiost, loose from the bone. The place where the root point is in the bone is now visible. An opening can then be made to that root point. We call this fenestrating. Sometimes an opening is already present because the periapical process has gone through the bone. Making the hole to the root point (larger) is done with a round drill or an excochleator, a kind of large excavator. With this, the inflammatory tissue around the root tip can be 'spooned out' (see images below).
Orthograde apex resection: a incision; b shearing mucoperiost; c making a window (frontal view); d window; e clearing the root canal; f gutta perchastift is placed.
Inflammatory tissue has been removed and the apex is closed with MTA.
Sometimes a piece is ground off from the root point. The root canal is now filed from the mouth and cleaned. A gutta percha pin is fitted. The channel is dried and the gutta percha pin is fixed with cement. After applying the stylus, the dental surgeon checks whether he is sealing the apex properly. The mucoperiost is put in place and attached. An (emergency) filling must then be made in the mouth.
Procedure for a retrograde apex resection
Sometimes a root canal is inaccessible: there is a strong root curvature, or the canal is closed for example due to a root canal filling or pin structure. It is then possible to make an apical seal with the help of a filling at the root point. We call this a retrograde filling.
The procedure of a retrograde apex resection starts at the same time as that of the orthograde apex resection. The inflammatory tissue around the root tip is surgically exposed and removed. The root canal is partially drilled and cleaned from apical. This is done with a corner piece with a very small cup or an ultrasonic device. The channel opening is filled with a biocompatible, or body-friendly, filling material such as MTA.
An apex resection must be performed sterile to prevent infection of the wound. After suturing, the cavity around the root point will be filled with blood. The healing process starts in the blood clot. If the procedure is successful, the cavity will be completely filled with bone again after a few months (see image below).
Retrograde apex resection: a the root point has been removed; b preparation of the apical part of the root canal; c the retrograde MTA filling has been applied.
Medications in endodontics
Disinfectants are used in endodontics. The most commonly used are isopropyl alcohol to disinfect the work site and NaOCl for cleaning the pulp cavity.
Dentin attenuators (EDTA) are used to dissolve dentin if a narrowing of the root canal makes filing it difficult.
Eucalyptus oil is used to dissolve old gutta percha fillings.