Ultrasonik olarak aktive edilen obturasyon tekniği esnasındaki kök yüzeyi sıcaklıklarının kızılötesi termal analizi

Abstract

OBJECTIVE: To evaluate the temperature changes on the external root surfaces of mandibular premolar teeth during ultrasonic condensation of gutta-percha in the root canal. MATERIALS AND METHOD:Ten extracted mandibular premolar teeth were selected. The roots were cut to a uniform length of 14 mm. Root canal treatments were performed using the ProTaper system, and the master apical file was a ProTaper F3 instrument. After the root canal preparations, cone-beam computed tomography images were taken to detect the thinnest dentinal area on the root. Each root was embedded in acrylic plates. For temperature measurements, the specimens were placed in a stainless steel device that was specially designed for this study. Temperature changes during obturation (warm lateral condensation using ultrasonics as the experimental group and cold lateral condensation as control) were then recorded using a thermal camera. Unpaired ttest was performed using a statistical software (α=0.01).RESULTS: There were significant differences between the groups. The mean obturation times of the specimens were 232.8 s for the experimental group and 102.5 s for the control. The mean value of the temperature increase in the experimental group was 49.96±11.12°C; and no temperature increase was recorded for control group. The maximum temperature rises was 68.9°C, and the minimum was 35.9°C. The average cooling time of all samples were 17 s and did not exceed 1 min.CONCLUSION: High temperatures that may cause hazardous effects on periodontium were observed; however, average cooling times of the samples were in normal ranges (less than 1 min). Further investigations are needed for testing different power settings. KEYWORDS: Endodontics INTRODUCTIONCold lateral condensation is a commonly preferred root canal filling technique in endodontic practice.1,2 In this technique, gutta-percha is used in conjunction with a root canal sealer in order to attain an entirely filled root canal. Although root canal filling may lack homogeneity, 3 the cold lateral condensation technique has the advantage of controlled placement of gutta-percha into the root canal. 4Heat and solvents have been used for softening and improving the adaptation of gutta-percha both to root canal walls and the cones to each other without the need for excessive forces. 5,6 A number of thermoplastic techniques have these advantages, such as continuous wave of condensation, thermo-mechanic compaction and injection of thermoplasticized gutta-percha. 2,7,8 Furthermore, the use of ultrasonically-activated spreaders as an aid for lateral condensation of gutta-percha cones has been shown to be superior to the conventional lateral condensation technique in vitro. 9,10 In endodontic practice, ultrasonic devices are used without water cooling for softening gutta-percha in root canal filling; this may result in heat generation. A greater than 10°C increase sustained for 1 min may cause irreversible bone injury and lead to resorption and ankylosis.11-13 To our knowledge, only one study has evalu...