Analysis of Heat Generation Using Ultrasonic Vibration for Post Removal

Abstract

This study measured the temperature of the root surface and post during the application of ultrasonic vibration to cemented posts to simulate post removal procedure. Root canal therapy was performed on ten extracted maxillary incisors. A stainless steel Parapost was cemented into each prepared post space. Ultrasonic vibration was applied to the post and temperatures were recorded at the coronal post and the cervical root surface. Data were analyzed with ANOVA using the independent variables of (a) time of ultrasonic application (15, 30, 45 and 60 s) and 2) location (post and root surface). Greater temperature increase was observed at the post (52.6 degrees C, SD 11.1; 82.6 degrees C, SD 20.1; 111.0 degrees C, SD 29.1; 125.3 degrees C, SD 33.2) compared to the root surface (9.5 degrees C, SD 4.6; 17.5 degrees C, SD 4.8; 25.4 degrees C, SD 7.3; 32.2 degrees C, SD 8.1) for each time period, P < 0.001. Ultrasonic application to the post for longer than 15 s generates high temperature on the root surface.

Sterilization of extracted human teeth: A comparative analysis

“…Our results are in accordance with observations made by Kumar et al, 12 Lolayekar et al 10 and Dominici et al, 13 who also observed 10% formalin, 5.25% sodium hypochlorite and autoclaving were the best methods of sterilization. These procedures did not seem to affect the "feel" and cutting characteristics of the teeth.…”

“…These procedures did not seem to affect the "feel" and cutting characteristics of the teeth. 13,14 However, a study by Abdul-Rahman et al 15 showed that the immersion of the extracted teeth for 7 days in 2.5% sodium hypochlorite, autoclaving at 121 C, 15 lbs for 15 min and the use of the microwave for 6 or 3 min were effective in disinfecting the extracted human teeth. In the present study, formalin, 5.25% sodium hypochlorite and autoclaving were more effective than other chemical and physical methods for sterilization and disinfection.…”

“…Impervious gloves and goggles should be worn to prevent skin and eye exposure. 13,18 Autoclave requires a continuous source of heat in the form of electricity and strict adherence to time, temperature and pressure settings. It has been reported that sodium hypochlorite may increase enamel porosity by deproteinization and alter dentin structure, by removing or modifying the proteic matrix, which could nullify the use of teeth stored in this solution.…”

In Vitro Infrared Thermographic Assessment of Root Surface Temperatures Generated by High-Temperature Thermoplasticized Injectable Gutta-Percha Obturation Technique

“…It appears that in vivo root surface temperature rises may be lower because of periodontal ligament, bone and microvasculature (21,26,30). Despite this, the relatively high temperature rises recorded on the root surface of mandibular incisors suggest however that caution should be exercised when using the high-temperature thermoplasticized injectable gutta-percha obturation technique to fill the teeth with thin remaining root dentin.…”

A Comparison of Different Methods for Disinfection or Sterilization of Extracted Human Teeth to be Used for Dental Education Purposes

“…1 It is also possible that the thermal cycling may cause teeth with amalgam restorations to fracture due to their differences in coefficient of thermal expansion. 13 Infection control guidelines for use of extracted teeth in dental educational settings: 2 Extracted teeth used for the education of dental health care workers should be considered infective and classified as clinical specimens because they contain blood.…”