An in vitro comparative study of apically extruded debris resulting from conventional and three rotary (Profile, Race, FlexMaster) instrumentation techniques.
(25/129)
Canal preparation is one of the most important stages of endodontic therapy, and various techniques have been applied for it. The present study was conducted to compare the quantity of debris extruded from the apical foramen during canal preparation during the manual technique and with the use of three rotary systems (Profile, Race, FlexMaster). One hundred single-rooted premolars were divided into four groups of 25 teeth each. For collection of debris, vials containing distilled water and weighed before canal preparation were used. Groups H, P, R and F were prepared by the manual step-back technique, and with the use of the Profile system, Race system and FlexMaster system, respectively. After canal preparation, the vials were dried thoroughly and reweighed. The difference between the weights of the vials at the two stages was taken as the debris weight. The mean debris weights were compared by one-way ANOVA. Group H had the highest mean debris weight, which was significantly different from those of the rotary groups (P < 0.001). The lowest mean debris weight was related to group R, which was significantly different from that of group F but not significantly different from that of group P. It was concluded that the Race system induces less extruded debris than the manual technique and the FlexMaster system. (+info)
Cutting characteristics of dental diamond burs made with CVD technology.
(26/129)
The aim of this study was to determine the cutting ability of chemical vapor deposition (CVD) diamond burs coupled to an ultrasonic dental unit handpiece for minimally invasive cavity preparation. One standard cavity was prepared on the mesial and distal surfaces of 40 extracted human third molars either with cylindrical or with spherical CVD burs. The cutting ability was compared regarding type of substrate (enamel and dentin) and direction of handpiece motion. The morphological characteristics, width and depth of the cavities were analyzed and measured using scanning electron micrographs. Statistical analysis using the Kruskal-Wallis test (p < 0.05) revealed that the width and depth of the cavities were significantly greater when they were prepared on dentin. Wider cavities were prepared when the cylindrical CVD bur was used, and deeper cavities resulted from preparation with the spherical CVD bur. The direction of handpiece motion did not influence the size of the cavities, and the CVD burs produced precise and conservative cutting. (+info)
Surveillance of viral contamination of invasive medical instruments in dentistry.
(27/129)
OBJECTIVE: To investigate the viral contamination of invasive medical instruments in dentistry and to provide health administrative institutions with surveillance data. METHODS: Sterilized samples were randomly collected from the department of dentistry to detect HBV-DNA, HCV-RNA, HIV-RNA and HBsAg. RESULTS: Of the invasive medical instruments that were sterilized with 2% glutaraldehyde, one of the samples was positive for HBV-DNA, and another sample was positive for HBsAg. CONCLUSION: Though massive virus contamination of invasive medical instruments in dentistry has been reduced to a low level, the occurrence of contamination still remains. (+info)
Student occupational exposure incidence: perception versus reality.
(28/129)
Reports of clinical injuries made to a dental school Office of Occupational Health and Safety at the time of their occurrence were compared to self-reports on a survey for dental students in five classes at various times over their educational careers. The majority of injuries were from needlesticks and mishaps with hand instruments. Underreporting at the time of injury was approximately one-third in the first clinical year and one-half in the final clinical year of the three-year program. Students reported a greater perceived likelihood of injury later in their education than at the beginning but a decreased fear of such injuries. Female students reported more needlesticks and a greater fear of injury than did male students. It is hypothesized that a personal interpretation of the meaning of clinical injuries influences reporting behavior. (+info)
Injury reports in a dental school: a two-year overview.
(29/129)
As teaching institutions, it is vital for dental schools to collect data on accidental injuries to identify potential problems, improve the quality of care of patients, and educate future practitioners about risk management. Our data reveal important trends concerning such injuries. These data were compiled over a two-year period (2001-03) from accident reports at one dental school. We categorized the accidents as follows: source (instrument causing the injury), recipient of injury, time of day, location within the dental school where the injury occurred, and body part injured. The population examined in this study consisted of predoctoral and postdoctoral dental students, staff, faculty, and patients of the dental school. The majority of injuries occurred in the predoctoral clinic toward the middle to the end of the scheduled clinic periods. The instrument most likely involved was a needle, and the body part most commonly injured was a finger. The collection and analysis of injury data may be used to identify trends that will aid in the prediction and prevention of these injuries and, at a national level, serve as a benchmark that other dental schools can employ to assess their relative frequency of injury. (+info)
A biomechanical analysis of applied pinch force during periodontal scaling.
(30/129)
One of the factors associated with the high prevalence of upper extremity musculoskeletal disorders, such as carpal tunnel syndrome, among dental practitioners is the repeated high pinch force applied during periodontal scaling. The goal of this study was to determine the relationship between the pinch force applied during periodontal scaling and the forces generated at the tip of the tool. A linear biomechanical model that incorporated tool reaction forces and a calculated safety margin was created to predict the pinch force applied by experienced and inexperienced dentists during periodontal scaling. Six dentists and six dental students used an instrumented scaling tool while performing periodontal scaling on patients. Thumb pinch force was measured by a pressure sensor, while the forces developed at the instrument tip were measured by a six-axis load cell. A biomechanical model was used to calculate a safety factor and to predict the applied pinch force. For experienced dentists, the model was moderately successful in predicting pinch force (R(2)=0.59). For inexperienced dentists, the model failed to predict peak pinch force (R(2)=0.01). The mean safety margin was higher for inexperienced (4.88+/-1.58) than experienced (3.35+/-0.55) dentists, suggesting that students apply excessive force during scaling. (+info)
Percutaneous injuries among dental professionals in Washington State.
(31/129)
BACKGROUND: Percutaneous exposure incidents facilitate transmission of bloodborne pathogens such as human immunodeficiency virus (HIV), hepatitis C virus (HCV) and hepatitis B virus (HBV). This study was conducted to identify the circumstances and equipment related to percutaneous injuries among dental professionals. METHODS: We used workers' compensation claims submitted to the Department of Labor and Industries State Fund during a 7-year period (1995 through 2001) in Washington State for this study. We used the statement submitted by the injured worker on the workers' compensation claim form to determine the circumstances surrounding the injury including the type of activity and device involved. RESULTS: Of a total of 4,695 accepted State Fund percutaneous injury claims by health care workers (HCWs), 924 (20%) were submitted by dental professionals. Out of 924 percutaneous injuries reported by dental professionals 894 (97%) were among dental health care workers in non-hospital settings, including dentists (66, 7%), dental hygienists (61, 18%) and dental assistants (667, 75%). The majority of those reporting were females (638, 71%). Most (781, 87%) of the injuries involved syringes, dental instruments (77, 9%), and suture needles (23%). A large proportion (90%) of injuries occurred in offices and clinics of dentists, while remainder occurred in offices of clinics and of doctors of medicine (9%), and a few in specialty outpatient facilities (1%). Of the 894 dental health care workers with percutaneous injuries, there was evidence of HBV in 6 persons, HCV in 30 persons, HIV in 3 persons and both HBV and HVC (n = 2) exposure. CONCLUSION: Out of hospital percutaneous injuries are a substantial risk to dental health professionals in Washington State. Improved work practices and safer devices are needed to address this risk. (+info)
Reproducibility of pixel values for two photostimulable phosphor plates in consecutive standardized scannings.
(32/129)
The objective of the present study was to determine the reproducibility of the pixel values obtained with the Digora system (Soredex, Finland). Exposures were standardized, with variation in exposure and scanning time of two photostimulable phosphor plates containing a stepwedge image. The smallest variation in pixel values ranged from 50 to 75%, with the widest variations being observed in less dense steps. A significant difference in pixel values was observed in terms of X-ray exposure and scanning times and between the two plates themselves (ANOVA, p < 0.01). Using the present methodology, the reproducibility of pixel values was not satisfactory for the tested white photostimulable plates. This wide variation in digitalization might be influenced by the amount of X-rays that sensitized the plates. It may be important to establish the reproducibility of the pixel values in quantitative studies using digital image. (+info)