Plugger temperature of cordless heat carriers according to the time elapsed

Comparative Analysis of Temperature Variation with Three Continuous Wave Obturation Systems in Endodontics: An In Vitro Study

The aim of this study was to assess temperature changes with different continuous wave obturation systems when downpacking to 2 mm and 4 mm from the apical foramen in an open system not simulating the surrounding biological structures at body temperature. Sixty single-rooted teeth were divided into three groups: (A) Dia-Duo® (DiaDent Group International, Cheongju-si, Korea), (B) Elements Free® (Kerr Corporation, Orange, CA, USA) and (C) Calamus® (Dentsply Sirona, Ballaigues, Switzerland). The root canals were instrumented with Protaper Gold (Dentsply Sirona, Ballaigues, Switzerland) to size F2 (25.08). The root canals were filled by a continuous wave using an AH Plus® sealer (Dentsply Sirona). Temperatures during the obturation procedure were measured by a thermal imaging camera (Testo 875-1®) perpendicular to a vice where the teeth were held at −2 mm and −4 mm from the apical foramen. Comparisons were made by applying Student’s t-test and ANOVA (p = 0.05). The continuous wave technique at −2 mm with the Dia-Duo system® emitted average temperatures of 37.3 °C, Elements Free® emitted 39.85 °C and Calamus® emitted 40.16 °C. At −4 mm, the Dia-Duo system® emitted average temperatures of 34.81 °C, Elements Free® emitted 33.73 °C and Calamus® emitted 32.91 °C. There were significant differences between continuous waves at −2 mm and at −4 mm (p < 0.05). Dia-Duo® was the only system that did not present significant differences between the two lengths (p = 0.197). Regarding the heat emitted, the best system was Elements Free®, since, at −2 mm, it emitted the highest temperature without going above 47 °C. The Dia-Duo® system had lower temperatures. It could be concluded that not all systems transmit the same temperature to the apex and, therefore, to the periapical tissues. The surrounding conditions, such as temperature and humidity, have not been considered in this study.

Effect of Heat Softening versus Ultrasonic Removal of Root-End Gutta-Percha on the Quality of Root-End Preparation for Endodontic Microsurgery

This study is aimed at comparing the efficacy of heat softening and ultrasonic removal of root-end gutta-percha during retrograde preparation for root apical microsurgery. Recently extracted single-rooted premolars (n = 40) were prepared with standardized endodontically treated and root-end resection and then randomly divided into four groups that received root-end cavity preparation using four different instruments: a diamond-coated ultrasonic tip (AS3D; SACTEON, Paris, France), AS3D with the modified plugger of cordless heat carrier (MSE; B&L Biotech, Bala Cynwyd, PA, USA), stainless steel ultrasonic tip (Jetip-2; B&L Biotech, Bala Cynwyd, PA, USA), or Jetip-2 with MSE. The time required for root-end preparation was recorded. The root apex samples were examined by scanning electron microscopy to assess root surface microcracks and marginal integrity. The remnants of gutta-percha on the cavity walls were evaluated using a stereomicroscope. Statistical analysis was performed using Student's t-test and Wilcoxon rank-sum test (P < 0.05). Usage of MSE with Jetip-2 significantly reduced preparation time from 99.8 ± 6.8 s to 32.4 ± 1.0 s (P = 0.009), the number of microcracks from 42 to 13 (P = 0.036), and the remnants of gutta-percha from 80% to 20% (P = 0.041). Similar results were observed for AS3D with MSE. The heat softening of MSE was effective in cleaning gutta-percha, thus greatly improving the efficiency of the root-end preparation, thereby producing a root-end cavity with fewer microcracks and better marginal integrity.