Glass bead sterilization of orthodontic pliers

The study on sterilization of orthodontic pliers by using glass bead sterilizer at 450 F was performed. Microorganisms used in this experiment were Staphylococcus aureus ATCC 25933, Bacillus subtilis ATCC 6633, Candida albicans ATCC 10231 and mixed microorganisms in human saliva. The result showed that after the pliers were scrubbed with alcohol and sterilized for 3 minutes with glass bead sterilizer, all vegetative cells and bacterial spores were killed in every test. This study indicated that glass bead sterilizer is capable of sterilizing orthodontic pliers and can be a useful adjunct when rapid chairside sterilization is desired.     

Cytotoxicity of orthodontic elastic chain bands after sterilization by different methods

IntroductionThe aim was to verify the hypothesis that orthodontic elastics in chain form become more cytotoxic after the sterilization process.Materials and methodsOrthodontic elastic in chain form with six links each was divided into eight groups according to the sterilization method to be performed. The following groups were formed: Control, alcohol 70, autoclave, glutaraldehyde, microwave, ultraviolet, ethylene oxide and gamma rays. Three additional groups were used, cell control, positive control consisting of cellular detergent Tween 80, and negative control consisting of phosphate buffer solution (PBS). After this, the elastics were immersed in culture media for 24 h to release possible toxic substances. After this period elapsed, the medium was placed in contact with L929 cells for 24 h. Next, the cells were stained and analyzed in a spectrophotometer with regard to their cell viability. The data obtained were analyzed by the analysis of variance (ANOVA) and the Tukey's test.ResultsThe groups of elastic sterilized by chemical means (alcohol 70 and glutaraldehyde) and thermal means (autoclave and microwave) led to an increase in cytotoxicity of the studied elastics, presenting statistically significant differences from the groups sterilized with ethylene, ultraviolet and gamma rays (p < 0.05).ConclusionThe hypothesis was partly confirmed, since some of the sterilization methods increased the cytotoxicity of the elastics and others did not.     

Decontamination of tried-in orthodontic molar bands

Molar bands are commonly used to retain orthodontic attachments on posterior teeth and due to the variation in the size of such teeth, it is usually necessary to 'try in' several bands before the correct one is selected. A possible concern with re-using such bands is the lack of cross-infection control, even following autoclaving, due to the presence of one or more small bore lumen (the archwire and headgear tubes). The aim of this experiment was, therefore, to determine whether such bands could be successfully decontaminated so that they could be re-used without a cross-infection risk. Two hundred orthodontic molar bands that had previously been tried in patients' mouths, but not cemented into place, were tested. Each band was decontaminated using an enzymatic cleaner/disinfectant and then sterilized using either a downward displacement (n = 100) or a vacuum cycle autoclave (n = 100). Following autoclaving each band was inoculated into brain heart infusion culture broth and incubated at 37 degrees C for 5 days. None of the decontaminated bands exhibited growth after 5 days. It would appear that, using this methodology, there is little risk of a cross-infection hazard occurring with the re-use of previously tried-in and decontaminated molar bands.     

Instrument sterilization in orthodontic offices.

1. Three different quaternary ammonium compound solutions remained bactericidal against specific vegetative bacteria in three orthodontic offices over a ten day working period. However, no spore formers or viruses were tested. 2. Bacterial contaminants were cultured on pliers and scalers at the chair at least once in each of three orthodontic offices sampled twice a day for ten working days. 3. Sampled chairside instruments wiped with an alcohol sponge only, between patients, were contaminated an excessive 32.5% of the time, too frequently to be seriously considered for routine disinfection of pliers. 4. Chairside instruments, sampled regardless of other means of disinfection or sterilization used, were contaminated from 3.5 to 15% of the time. Therefore, storage and handling of orthodontic instruments must be evaluated and upgraded to prevent recontamination of previously sterilized instruments. 5. Staff personnel need courses in sterilization and disinfection procedures to prevent cross contamination from patient to patient and to protect themselves. These courses should be related specifically to orthodontic practice procedures.     

Upgrading sterilization in the orthodontic practice

In today's orthodontic practice, disease control must undergo major reevaluation and restructuring. The knowledge of the natural history and treatment of many highly transmissible diseases to which orthodontic personnel are at high risk is changing rapidly. Among these diseases are acquired immune deficiency syndrome (AIDS), hepatitis B virus, and the herpesvirus complex (currently five types). If barrier techniques are not in place, it is possible to cross-infect orthodontic personnel and patients alike. Clinical orthodontics, with its higher volume of patients (on a daily basis) than other dental practices, requires a custom-made sterilization schema tailored to each office. Proper organization of instruments to permit orderly processing, storing, and use is even more important than before. Turnaround time of processing instruments, corrosion control, and minimizing of dulling of cutting edges are critical. Treatment of surfaces and chair/unit facilities with improved disinfection techniques is a necessity. Protection of hands and eyes by appropriate means is discussed with practical guidelines for the use of gloves by chairside personnel. Many fomites (inanimate disease transmitters) lurk in the orthodontic office and must be eliminated. Finally, the most important ingredient to any change--the orthodontic office staff--must be enlightened, trained, and supervised by the orthodontist to effectively and efficiently switch from the old to the new.     

Glass bead sterilisation of surgical dental burs

Since burs used in OMF surgery are a source of microbial contamination, sterilisation of the burs is an important aspect of infection control. A two-part study was performed to evaluate the efficacy of using the glass bead steriliser to sterilise long-shank burs. The laboratory and clinical studies indicated that the glass bead steriliser was effective in sterilising long-shank burs in 60 s.     

Dental instrument sterilization by glass bead conduction of heat.

Long handle dental instruments were inoculated with oral organisms or with B subtilis and immersed in a glass bead sterilizer at 400 F (204 C). It required from 12 to 14 minutes to sterilize the instruments at that temperature.     

Sterilization of orthodontic instruments and bands in cassettes

The purpose of this study was to determine whether orthodontic instruments and bands contaminated with blood or saliva and bacterial spores can be heat sterilized while contained in OMS-ASAPsys instrument and band cassettes. Hinged and nonhinged instruments and bands were contaminated and dried, placed in the cassettes, ultrasonically cleaned, rinsed, and dried. The cassettes were wrapped and then processed through standard steam, chemical vapor, or dry-heat sterilizing cycles. Each instrument and band was then cultured for the presence of live spores. The results showed that the residual spores on the instruments and bands after ultrasonic cleaning and rinsing had indeed been killed in all cases. The three types of sterilization were equally effective. The results indicate that contaminated orthodontic instruments and bands can be sterilized within OMS-ASAPsys cassettes.     

Retention of orthodontic bands with new fluoride-releasing cements

The prevalence of enamel decalcification beneath orthodontic bands has indicated the need for a fluoride-releasing, enamel-adhesive orthodontic luting cement. The purpose of this study was to compare the retentive bond strengths of orthodontic bands cemented with two new fluoride-releasing cements, a zinc polycarboxylate and a glass ionomer, with the retentive bond strength of bands cemented with the standard orthodontic cement zinc phosphate. The site of cement failure was also evaluated. One hundred eighty extracted human molar teeth were embedded in resin blocks and randomly assigned to three cement groups. Adapted bands were cemented by a clinically acceptable technique. The cemented teeth were then assigned to one of three time intervals--24 hours, 7 days, and 60 days--and thermocycled in synthetic saliva. The force required to initially fracture the cement bond was used as a measure of cement retention. By means of the Instron, a tensile load was applied to each cemented band. The maximum retentive strength (cement failure) was interpreted from the stress-strain curve at the point where linearity deviated. The failure site was judged subjectively: between cement and enamel, within the cement, or between cement and the band. Using stress at failure, an analysis of variance showed no significant differences among the retentive strengths of the three cements. The chi-square test revealed a significant difference (P less than 0.01) between failure sites of the zinc phosphate and glass ionomer cements. Significantly more bands cemented with the glass ionomer failed at the cement/band interface, leaving the cement adhered to the tooth.(ABSTRACT TRUNCATED AT 250 WORDS)     

Decontamination of orthodontic bands following size determination and cleaning

OBJECTIVE: To measure the effectiveness of ultrasonic cleaning for decontaminating orthodontic molar bands following size determination using a quantitative antibody capture assay technique. DESIGN: A prospective, cross-sectional, clinical and laboratory investigation. SETTING: The Orthodontic Department of the Charles Clifford Dental Hospital and the Microbiology Laboratory of the School of Clinical Dentistry, Sheffield. PARTICIPANTS: Thirty-two patients about to start orthodontic treatment with fixed orthodontic appliances. METHODS: Four first molar bands were tried in the mouth and then removed. They were randomly assigned either for no decontamination (control) or to be decontaminated in an ultrasonic cleaning bath for 15 minutes (experimental). The bands were placed in a predetermined volume of phosphate-buffered saline (PBS) and assayed by enzyme-linked immunosorbent assay (ELISA) for albumin, to detect the presence of blood and amylase, to detect the presence of saliva. RESULTS: Fifty per cent of decontaminated molar bands showed detectable amounts of amylase, albumin or both. The quantity of detectable amylase was significantly reduced on the cleaned compared with uncleaned bands (P = 0.036); however, the reduction in the quantity of albumin was not statistically significant (P = 0.074). CONCLUSIONS: Ultrasonic cleaning for 15 minutes reduces, but does not always eliminate, salivary proteins (amylase) from tried-in bands. It is less effective at removing serum protein (albumin). There is a need, therefore, to investigate effective means of cleaning organic material from orthodontic bands if they are to be adequately sterilized and reused.     

Effects of orthodontic bands on microbiologic and clinical parameters

The aim of this study was to evaluate the effect of placement of orthodontic bands on the gingival tissues and the microbial composition of dental plaque. Ten subjects undergoing orthodontic treatment completed the study. In each subject four sites were examined: two test sites with orthodontic bands and two control sites free of bands. Clinical and bacterial examinations were performed before the beginning of the treatment and 5, 7, 47, 72, and 90 days after placement of the orthodontic appliances. Plaque index (Pl I) and bleeding scores increased significantly on banded teeth as compared with control sites. Probing depth remained within normal values for both test and control groups. The composition of dental plaque determined by dark-field microscopy showed significant shifts in the test sites after banding. Changes consisted of an increase in the percentage of spirochetes, motile rods, filaments, and fusiforms; conversely, a decrease in cocci was noted. During the same period no significant changes in the bacterial distribution were observed in the control group.