Comparative evaluation of morbidity and alveolar healing after surgical extraction of impacted lower third molar teeth using piezosurgery and rotational instruments

Surgical extraction of impacted lower third molars is a frequently performed procedure in oral surgery, and post-operative complications can adversely affect patients' quality of life. Individual biological differences, the size of the alveoli and the amount of trauma during extraction are among the factors affecting the healing of the tooth extraction socket and surrounding tissues. Rotational instruments are generally used in impacted tooth extraction operations. However, they may not be preferred due to overheating or fragmentation of bone and damage to adjacent tissues. Piezosurgery is a selective micrometric technique in which an incision is made using ultrasonic frequency. It is reported that postoperative pain, trismus, edema and neurological complications can be reduced with the use of the piezo device, and animal studies show that a good bone healing can be achieved with this technique. The disadvantage is the increase in operational time. The aim of our study is to compare the duration of the operation as well as the pain, trismus, edema, infection, neurologic complications and healing of the alveolar bone after surgical extractions of impacted lower third molars using piezosurgery and conventional rotary instruments. In our study, bilateral impacted lower third molars which were classified according to Pell-Gregory Classification such as class 2 position B mesioangular and vertical, in individuals aged between 18-32 years were involved. All impactions revealed to be the same surgical difficulty. This study was performed on bilaterally located 42 teeth, of 21 patients. All impacted teeth were radomly extracted with the aid of piezosurgery on one side and conventional rotary instruments on the other. So as not to interfere with postoperative symptoms in the same individuals, all operations were performed at intervals of 2 weeks. Postoperative pain was measured with the VAS scale, edema was measured preoperatively and on days 1, 3 and 7 by measuring the distance between the mandiblar angle and the tragus, eye margin, nose wing, lip corner, and the tip of the chin. Mouth opening values were measured as the distance between the lower and upper incisors preoperatively and postoperatively on 1st, 3rd and 7th days. Neurological complications and infection was evaluated during the follow-up period. In order to evaluate the healing of the alveolar bone, a panoramic film was taken from the patients at the 3rd and 6th months. The grayness values were compared with the Histogram tool of Adobe Photoshop application. SPSS 26 package program was used in data analysis. Shapiro Wilk which is one of the normality tests, was used to determine whether the data showed a normal distribution. To compare the results, paired samples t test from parametric methods as well as ANOVA methods were used to evaluate repeated measurements. Dependent groups t-test was used to compare two different average measurements only for a single group, and ANOVA was used for comparing repeated measurements. In piezosurgery, the operation time revealed to be longer when compared than the traditional method. In the traditional method, postoperative edema on the 1st, 3rd and 7th days was found to be significantly higher when compared to the pre-operative period. In the piezosurgery, postoperative edema increased on the 1st and 3rd days however disappeared on the 7th day. When the amount of edema was compared between the two methods, only the postoperative value of Angulus-Tragus measurements were found to be higher on the 1st, 3rd and 7th in the traditional method. In the traditional method, it was observed that edema is maximum on the postoperative 3rd day and minimum on the 7th day. In piezosurgery, evaluation of edema revealed to be similar on the postoperative 1st and 3rd day and to be minimum on the 7th day. Mouth opening decreased significantly on the 1st, 3rd and 7th days after the operation in the traditional method in comparisson to the pre-operative period. In piezosurgery, mouth opening decreased significantly on the 1st and 3rd days after the operation and reached the preoperative value on the 7th day. The comparisson of the postoperative mouth opening between the two methods showed that postoperative mouth opening is significantly higher in piezosurgery. Mouth opening increased significantly from day 1 to day 7 in both methods. The comparisson of postoperative pain levels between these methods showed that, pain from the 6th hour to the 4th day postoperatively is higher in the traditional method than piezosurgery. There is no difference on 5th, 6th and 7th days. In both methods, the pain decreased from the 6th hour to the 4th day. Reduction of pain after the 4th day showed no significancy. Histogramic evaluation of postoperative alveolar bone healing at 3rd and 6th month, mean values for both groups were similar, however on the piezosurgery side, the alveolar bone healing was statistically higher at the 3rd and 6th months when compared to the traditional operation side. Temporary paresthesia occurred in 1 patient where extraction was performed with traditional method and in this case recovery was observed after 2 weeks. No neurological complications occurred after extractions performed with piezosurgery. No signs of any kind of infection was observed in both methods. As a result, it can be stated that the developement of fast piezo devices over time will reduce the operation time which is a disadvantage of this technique as well as the number of complications that may occur due to the differences in duration between two methods. As a result, piezosurgery appears to be a safe technique, especially in areas of difficult anatomic locations.