Surgical adjunctive instruments and devices are now available for the up-to-date dental/oral surgical office to help mitigate possible surgical complications. Both the laser and Piezo instruments are unique devices that can offer the clinician certain advantages that may prove beneficial in the treatment of his or her patients.
Piezo surgery is a useful adjunct in oral surgical procedures because it helps limit any soft tissue damage secondary to bony surgery.
Piezo surgery may limit the amount of sinus membrane perforations during the performance of lateral sinus bone augmentation procedures.
Laser surgery has a place in soft tissue and hard tissue cutting procedures, and may also have value in the treatment of nerve injuries and periodontal regenerative procedures.
The term piezo is derived from the Greek work piezein , which means pressure. It was developed by Italian oral surgeon Tomaso Vercelloti in 1988 to overcome the limits of traditional instrumentation in oral bone surgery by modifying and improving conventional ultrasound technology. The process consists of crystals and ceramics that become deformed when exposed to electric flows resulting in oscillating movements with ultrasound frequency that has the power to precisely cut bone structures without causing injuries to soft tissue. The frequency is usually set between 25 and 30 kHz causing microvibrations of 60 to 210 μm amplitude that provides the handpiece with power exceeding 5 W. The product is targeted mainly at bone removal and soft tissue protection, but some models have a modified setting that can be used for excision of soft tissue lesions. The selective and thermally harmless nature of this instrument results in low bleeding tendency.
During surgical use, the inserts should be moved forward and backward continuously at a high speed with minimum pressure, and the only absolute contraindication in its use is with patients who have a pacemaker. A contact load of 150 g provides the greatest depth of cut because the excessive pressure on the insert leads to a reduction in oscillations and hence the cutting ability. Pressure with the piezo acts counterproductively by limiting movement of the instrument tip and generating more heat. Therefore, patience here is a virtue, and applying excess pressure to hasten the cut may prove counterproductive.
A number of piezoelectric devices with similar mechanical parts are available on the market. Typically, devices will come with settings preset for the intended procedures. There are also a range of inserts and tips available on the market that vary in size, shape and material ( Fig. 1 ). They can be coated with titanium and diamond of different grades. Some examples include the scalpel, cone compressor, bone harvester, and sharp-tipped saw. This is in contrast with conventional microsaws or drills in which the surgeon must apply a greater degree of pressure.
Advantages of the piezo technique relative to drills and saws
Greater precision and safety in bone surgery.
Less adverse damages to soft tissues.
Less potential for associated bone necrosis.
A link flood system that ensures work and comfort of the surgeon by increasing visibility through the cavitation effect—physical effect—resulting from ultrasound vibration with water that removes debris from the cutting area.
Better healing and reduced postoperative swelling of patients.
Different angles permit it to be used in areas where it is difficult to see and reach.
The absence of macrovibrations make patients feel comfortable during oral surgery procedures under local anesthesia and intravenous sedation.
Disadvantages of piezo surgery
This procedure should not be used in patients with pacemakers.
The financial cost is a consideration.
The duration for procedures tends to be longer.
There is a learning curve with its use.
Piezo Use in Oral Surgery
Dentolalveolar surgery : The Piezo device can be used to assist in all types of dentoalveolar surgery, including endodontic and periodontal surgeries. , It has the theoretic ability to decrease the potential damage to both the lingual nerve and the inferior alveolar nerve during the removal of wisdom teeth, though there are no studies to prove this point. Liu and colleagues performed a systematic review and meta-analysis of randomized controlled trials comparing the piezo versus conventional rotary instruments for third molar surgery. The study enrolled a total of 402 patients in which the piezo surgery group showed a lower postoperative pain score, less swelling, and greater mouth opening relative to the conventional group. However, more operation time was needed with the piezo and there was no statistically significant difference in postoperative analgesic use by either group. Although studies are limited, it has not been associated with impaired third molar wound healing or increase in dry sockets. Tsai and colleagues evaluated the periodontal condition after third molar removal that showed no statistical difference of average pocket depth or attachment level on the distal side of the second molar when using the piezo versus conventional drills.
Dental implantology: Implant site preparation could allow for the enlargement of only 1 socket wall by using specially designed inserts ( Fig. 2 ).
Ridge splitting techniques: Classic ridge splitting involved using chisels with rotation and oscillating saws. These techniques were time consuming, technically more difficult, and carried a higher risk of damage to adjacent soft tissues and teeth. The piezo has made this procedure easier and safer to perform with lower risk of thermal necrosis and vertical cusp can be made without damaging adjacent soft tissues and teeth ( Fig. 3 ).
Maxillary sinus lifts : This procedure can be accomplished via a lateral window approach with less risk of perforation of the Schneiderian membrane. Reports show perforation with conventional techniques ranging from 14% to 56%, with the percentage decreasing to as low as 5% with the piezo in some papers in the literature. The bony access window can be created with a diamond-coated square or ball insert, and the sinus membrane can be elevated with rounded and soft tissues inserts ( Fig. 4 ).
Inferior alveolar nerve lateralization technique: These are an alternative to augmentation techniques if implants are planned in edentulous jaws. This decreases the risk of damage to the nerve at the osteotomy lines. Schaeren and colleagues showed that direct exposure of a nerve to piezosurgery does not dissect the nerve, but only induces some structural or functional damage. In most cases, the nerve is able to regenerate with the perineurium intact, in contrast with conventional drills or oscillating saws ( Fig. 5 ).
Maxillary and mandibular osteotomies in orthognathic surgery : This technique is particularly useful when doing a multiple piece maxillary surgery and maintaining vitality of the teeth in the line of osteotomy. Beziat and colleagues in 2007 provided one of the largest studies of the use of the piezo in craniomaxillofacial surgery including 144 cases of Lefort 1 and 134 cases of bilateral sagittal split osteotomies, as well as other osteotomies used to treat craniofacial disorders. The conclusion from their article was that the piezo allows for precise cutting and spares soft tissue such as the brain, dura mater, and palatal mucosa. There have also been reports of less blood loss from an average of 772 mL in conventional orthognathic surgery versus 537 mL in piezo orthognathic surgery. Landes and colleagues showed that inferior alveolar nerve neurosensation was retained in 98% of their piezo bilateral sagittal split osteotomy cases versus 84% of their conventional bilateral sagittal split osteotomy cases at 3 months postoperative ( Fig. 6 ).
Aesthetic facial surgery: This technique is particularly useful for lateral osteotomies in rhinoplasty procedures with less likelihood of lacerating the nasal tissues and damaging associated vessels. It can also be used in otologic procedures.
Distraction osteogenesis: The piezo creates precise osteotomies owing to micrometric and linear vibrations. There is also less flap damage, which means better vascularization that leads to more successful bone formation by this process ( Fig. 7 ).