In order to overcome the limitations of old-style ultrasonic surgery in which the conventional piezoelectric equipment was used, Tomaso Vercellotti et al. began to develop ideal ultrasonic technology for incision of the bone. The results of the experimental phase of laboratory investigations on animals’ bone created a primary prototype, called piezosurgery [28]. In other studies [29], the therapeutic effects of laser procedures (Er:YAG) were investigated, which affected the old-style ultrasonic methods.
According to the present results, the pain immediately after surgery and 2 days and 7 days after surgery was higher in the laser group that there was no significant difference in any periods. Also, the swelling immediately after surgery and 2 days after surgery was significantly higher in the laser group, but the swelling at 7 days after surgery in the piezosurgery group was higher; there was no significant difference. The amount of mouth opening immediately after surgery and 2 days and 7 days after surgery was significantly lower in the laser group than in the piezosurgery group, indicating significantly higher trismus in the laser group. Moreover, the total duration of surgery and duration of osteotomy were significantly longer in the laser group.
Rud [20] in a prospective study investigated the impacted mandibular third molar surgery in 52 patients using conventional surgery via drilling (group A) and surgery by the piezoelectric device (group B) using the Parant scale with simple and complex categories. They reported that when complex extraction of the mandibular third molar was carried out, assessment of pain and surgery duration was recorded shorter, and when the extraction was simple, the duration of surgery was similar in both groups. Nevertheless, the pain in the first day of surgery procedure by drilling was much higher than that of other methods. Osteonecrosis of the bone was observed only in the rotational group and a high level of alkaline phosphatase enzyme in the piezoelectric group. Finally, it was reported that in the longer interventions, the pain after extraction and third molar surgery problems would be much more.
Sortino et al. [21] conducted a study on 100 patients with the mandibular third molar problem, in which 50 patients using rotational osteotomy technique (group A) and 50 patients using piezoelectric osteotomy technique (group B) were treated. The treatment protocol was the same, and the facial swelling and trismus were examined 24 h after surgery. They reported that the average duration of surgery was 17 min in group A and 23 min in group B. The swelling level in the rotational osteotomy group (7.04 mm vs. 4.22 mm) and trismus (16.7 mm vs. 12.5 mm) were much more than in the piezoelectric group. Postoperative trismus and facial swelling in the piezoelectric osteotomy group (group B) showed a significant decrease while the longer surgery duration is required. Finally, it was reported that the piezoelectric osteotomy technique (group B) within 24 h after surgery was very effective in reduction of swelling and trismus, in line with our results.
In the study of Basheer et al. [30], 30 adults requiring treatment of third molars were divided into two groups of 15. The first group was treated with the piezoelectric osteotomy technique and the second group with the rotational osteotomy technique. The rotary dental instrument was with a rotational speed of 35,000 rpm, and the piezoelectric instrument was with the frequencies of 25 to 29 kHz with microvibration of 60 to 200 mm/s. The mean age of the patients in the piezosurgery group was 28 years and in the rotational group was 30 years. The results reported that the surgery duration in the rotational technique was shorter than that in the piezoelectric technique and the pain intensity in the rotational group was higher up to 4 days after surgery. However, the amount of mouth opening in the piezoelectric group was significantly better than that in the rotational group (rotary dental bur) up to 7 days after surgery. Finally, it was reported that on the piezosurgery day, postoperative pain, trismus, and swelling were reduced and may also play an important role in increasing the bone density in the extraction cavity and reducing bone loss from adjacent teeth in the distal area, which is similar to the obtained results of the present study.
Al-Moraissi et al. [31] carried out a systematic review and meta-analysis aiming to respond to the question of whether or not the piezoelectric surgical procedure has less postoperative complications in third molar surgery compared to the common rotational surgical procedure. They reported that a significant difference was found between piezoelectric surgery and rotational surgery regarding the postoperative complications including edema, trismus, and pain, as well as the total number of sedative consumed to reduce the pain. They showed that piezosurgery technique significantly reduces these complications. However, the increase in the duration of surgery was very clear and significant in the piezosurgery group.
The study of Jiang et al. [32] investigating possible complications of piezosurgery and conventional rotary instrument technique in third molar surgery in a clinical trial showed that the duration of surgery in the piezosurgery technique was higher than that in the other techniques, including rotary instruments (4.13 min). As well, the postoperative pain, swelling, and trismus in the piezosurgery group at 1, 3, 5, and 7 days were significantly lower. Finally, it was reported that the piezosurgery technique is a promising alternative technique to extract impacted molar.
In the study of Bartuli et al. [33] conducted on the surgical procedures for impacted third molar with high speed by piezosurgery technique and handpiece, 192 patients were selected and studied surgical techniques were randomly applied on the subjects. Analgesic treatment with 1000-mg paracetamol tablets and postoperative pain questionnaire (Wong-Baker FACES pain rating scale questionnaire) were used. Finally, it was found that the mean duration in the handpiece technique was much lower than that in the piezosurgery technique (34 min vs. 54 min), while the pain level was the same for both techniques. As a result, it can be concluded that osteotomy by traditional techniques can still be a golden standard in impacted molar surgery; piezosurgery can be considered particularly to maintain the anatomical structure of the bone.
Pippi and Alvaro [34] reported in their study that piezosurgery can be a highly effective technique for the removal of third molars. Its only weakness is the long surgery duration, which is considered lower than the piezoelectric instrument due to the power outages; such a result was also obtained in the study of Abu-Serriah et al. [22], and it warns about the longer duration of surgery in patients undergoing laser surgery.
Romeo et al. [35] indicated that third molar surgery by YAG laser can significantly decrease pain, trismus, and swelling compared to the rotational osteotomy; also, the longer surgery duration in the rotational osteotomy group was highly significant, which indicates that laser can be used as an alternative technique to conventional rotational surgery.
In the study of Passi et al. [24], it was reported that the amount of pain, hemorrhage, and swelling in the laser group was less than that dental bur and rotational surgery group, but the passed time in the laser group was double compared to the group of incision with dental rub. Also, Romeo et al. [36] stated faster healing and the incidence of thermal damage in the laser-test group.
Based on the reviewed researches, the piezosurgery technique can be a promising method to the surgical treatment of impacted third molars. However, its long duration of surgery has been investigated in these studies, but studies indicate that the piezosurgery method can be more effective to reduce the pain, trauma, and trismus compared to the conventional surgical techniques (dental burs or rotary). Concerning laser surgery, it can be concluded that the studies indicate that laser surgery and piezosurgery will improve the future of third molar surgeries. The only problem of these surgeries for surgeons is its long duration, but since the purpose is to reduce the pain and complications in the patients, the long duration of these procedures can be justified.
Given the rising demand for impacted molar surgery, this study suggests that laser surgery and piezosurgery techniques can improve the future of the impacted molar surgery. These approaches are more efficient in reducing postoperative complications compared to the conventional surgeries. Although the duration of surgery can be increased in these operations, it can be justified by reducing these surgical complications.