This chapter discusses the dental surgery or theatre, the instruments for oral surgical operations and the preparation of the surgical team.

The Operating Room

The operating room in both hospital and general dental practice should be of simple design, the walls and furniture should be made of easy-to-clean materials, and the equipment normally required should be accommodated without overcrowding.

It should be well ventilated and kept at an even temperature of 18–21°C, without undue humidity. In hospital theatres this is best done by positive pressure air-conditioning, which also prevents contamination from the outside atmosphere. There should be a recovery room with experienced nursing staff where the patient may recover on a bed or trolley within easy reach of surgeon and anaesthetist until the patient is fit to return to the ward or go home.

Equipment

Light

The light source should provide adequate illumination without undue production of heat, and be easily adjusted to shine into the mouth. A headlamp or fibre-optic light attached to a handpiece is recommended for operations involving the palate or deep cavities such as cysts or the antrum.

Suction Apparatus

No procedure, however minor, particularly under general anaesthesia, should be attempted without suction apparatus. This must be tested before the operation starts and whenever possible an alternative form of suction should be available in case of breakdown. Electrical apparatus is very powerful but does occasionally fail. Compressed air can also provide powerful suction in a similar way. Whichever method is used, a catchment bottle must be included in the circuit so that if roots or any foreign objects are lost the bottle may be searched.

Radiographic Viewing Box

This should be placed such that the surgeon can see it without moving from the dental chair or operating table. It should incorporate a spotlight. Digital radiographs will require a suitable computer terminal.

The Dental Motor (Drill)

Though the conventional dental handpiece can be sterilised, its attachment to the dental electric engine or air motor presents a problem. The surgeon may be contaminated from the cable drive unless this is covered with a sterile sleeve. Alternatively, sterilisable surgical motors and handpieces are available, but due to their high cost these are usually only found in hospital practice. For the clean and rapid cutting of the bone without overheating it is necessary that the bur be washed by a continuous stream of sterile water. Handpieces with an integral irrigation system are available and provide automatic irrigation of the bur. The air-rota is not advocated for oral surgery due to the risk of contamination of the wound with oil and the introduction of air into the tissues, causing surgical emphysema. The modern electrical motor gives very adequate speed and torque.

The Dental Chair

This should be of a design in which the patient can lie flat and the operator may work seated, as this is the position of choice. The light, drill and suction should be sufficiently adjustable that they can be used with a supine patient from either right or left side.

Electrical Equipment

Where this is to be used in the presence of anaesthetic vapours which may form explosive mixtures of gases, the equipment, particularly the drill, must be adequately sealed and earthed to prevent sparking or a build-up of static electricity which might cause an explosion.

Diathermy

Diathermy or electric cautery can be very useful in the control of haemorrhage encountered during surgery of the soft tissues. Monopolar diathermy uses a negative electrode on the body of the patient and is usually employed under general anaesthesia in situations requiring the greater current available. This is less localised than bipolar diathermy which uses current between the beaks of the diathermy forceps to achieve ablation in areas where it is important to reduce the local damage, e.g. around nerves.

Lasers

Modern lasers give excellent control for dissection of soft tissues. Cells in the path of the cut are vapourised with little damage on either side. Their principal advantage in excisions in the mouth is the relatively small amount of postoperative pain, and a reduction in tissue swelling. Stringent safety measures must be taken during the use of the equipment to avoid damage to the patient and the operators. Laserproof glasses should be worn by all personnel in theatre at all times when the laser is in use to protect the eyes. Under general anaesthe­sia the endotracheal tube should also be protected to avoid inadvertent puncture, and metal instruments should be avoided to decrease possible reflection of the beam.

Cryotherapy

Cryosurgery using liquid nitrous oxide, carbon dioxide or nitrogen destroys cells by intracellular ice crystal formation which ruptures the cell membrane. Healing of the tissue damage is by regeneration of normal tissue. It is of particular benefit in the treatment of benign soft tissue lesions and fluid-filled lesions such as haemangiomas.

Operating Microscope

This is essential equipment for microvascular surgery and nerve repair and is increasingly used for apical surgery. Up to 40x magnification is possible.

Instruments

The selection of hand instruments depends on the surgeon’s preference. In the succeeding chapters instruments suitable for the various procedures are suggested. It is the surgeon’s responsibility to check that all those needed are readily available. They should be laid up on sterile towels on a trolley.

Care and Maintenance of Surgical Instruments

The principles of care and maintenance are:

• to clean the instruments thoroughly
• to examine them for defects
• to repair or discard those that are defective.

Mechanical Cleaning

Mucus and clotted blood may harbour and protect bacteria and make it impossible for steam to reach them. The first step in the process of sterilisation is to scrub all instruments until clean with a brush under a running cold water tap. A bath agitated by ultrasonic vibrations produces a very high standard of cleanliness, especially for hinged instruments and for suction tubes and heads. The latter should have cold water sucked through them immediately the operation is finished.

Cleaning also includes stripping down, cleaning and oiling all working machinery such as handpieces.

Examination for Defects

Broken or bent instruments should never be used as their breakage during surgery can result in serious damage to the patient, either directly from the fractured ends or during the retrieval of the fragment (see Chapter 10). Disposable items, burs, injection needles and scalpel blades are discarded after use.

Sterilisation

• Kills all microorganisms
• Chemical or physical methods are used
• Steam at high pressure (autoclave)
• Boiling water only disinfects.

Physical and chemical methods are both in use today. Physical methods include wet and dry heat, and gamma radiation (used commercially for sterilising packed instruments such as scalpel blades). Boiling water is no longer regarded as a safe method of sterilisation as it only disinfects and does not kill sporing organisms.

Autoclaves use steam under pressure. Some are high vacuum but all depend on downward displacement of air by steam. Steam at 2 kg/cm² pressure gives a temperature of 134°C, which will destroy all organisms and spores within 3 minutes. It is the method of choice for dressing and towels, but they must be packed loosely to allow the steam to circulate. Blunting of instruments is due to oxidation, which should not occur in a properly functioning autoclave, so it can be safely used for sharp instruments. Vapour phase inhibitor (VPI) paper can be used to wrap instruments such as burs, which tend to rust if autoclaved. Handpieces must be cleaned and oiled before being placed in the autoclave. The oil must not become oxidised or lose its oily properties at high temperatures.

Dry heat is effective in ovens that have fans to ensure even heat distribution and a door-lock that prevents opening dur/>