Orthodontic Pliers Research Articles

Microbiological evaluation of ultraviolet C light-emitting diodes for disinfection of medical instruments

BackgroundDespite the many guidelines for reprocessing of medical instruments, challenges persist such as microbial resistance to biocides, corrosive effects on materials, and time-consuming reprocessing procedures. Ultraviolet (UV) C light-emitting diode (LED) chambers might provide a solution but the integration in healthcare is still in its infancy. Here, we evaluated the efficacy of a novel ZAPARAY™ UVC LED chamber as a time and energy-efficient alternative for reprocessing of medical instruments for which current disinfection protocols exhibit limitations. MethodsWe verified the disinfection efficacy of the UVC LED chamber on a Petri dish and contaminated several medical devices with Staphylococcus aureus ATCC 25923. The bacterial reduction was assessed after 5 min of UVC LED exposure. Additionally, we investigated the impact of rinsing before UVC exposure. ResultsWe demonstrated a bacterial reduction of 9 log10 on a Petri dish. Non-rinsed dental tools exhibited varied reduction levels ranging from a 3.23 log10 to a 6.25 log10 reduction. Rinsing alone yielded an average reduction of 2.7 log10 and additional UVC exposure further reduced the bacterial load by an average of 3.65 log10. We showed an average 4.90 log10 reduction on thermistors, 2 log10 or less on orthodontic pliers, and no reduction on handpieces. ConclusionsThis study demonstrates that UVC LED chambers may be used as a standardized substitute for specific (manual) disinfection procedures of certain medical devices, offering a time-efficient and more sustainable alternative. However, its use should be preceded by efficacy testing for each specific type of instrument.

UV-C light as an alternative for disinfecting orthodontic pliers

Objective: Orthodontists use orthodontic pliers continuously, and these tools have a strong potential for nosocomial infections. This study aimed to compare the efficiency of three methods for disinfecting orthodontic pliers. Material and Methods: The active tips of 26 orthodontic pliers (distal end cutters and Weingart pliers) were contaminated with S. aureus, E. coli, and C. albicans microorganisms, viruses, and spores. The microbial control methods were 70% alcohol disinfection, glass bead sterilization (250 °C dry heat), and ultraviolet light irradiation (250 nm UV-C) for 30 and 60 seconds. The number of colony-forming units (CFU) and plaque-forming units (PFU) was quantified and compared for each microorganism after incubation in culture plates. Results: All tips of the pliers in the groups that received ultraviolet light or were subjected to glass bead sterilization showed a significantly lower number of spores, bacteria, and fungi than their respective control samples (p<0.001). Physical disinfection with UV-C light may represent a reliable alternative compared to other chemical and physical methods due to the increase in microorganisms resistant to chemical products and the emission of harmful by-products after chemical treatment. Conclusion: The tested microbial control methods were effective in the disinfection of orthodontic pliers, making ultraviolet-C light a promising alternative to eliminate microorganisms from pliers. KEYWORDS Biosafety; Contamination; Disinfection; Microorganisms; Ultraviolet light.

Do different orthodontic pliers used in bracket debonding have different effects on pain and sensitivity? A prospective split-mouth study

The assessment of whether different orthodontic pliers used in bracket debonding have different effects on pain and sensitivity experience. Thirty-three patients (17 females, 16 males) with metal brackets were included in the study. Compressed air and freshly melted ice water were applied to each tooth (6-6) in upper and lower arch before bracket debonding (T0), just after debonding (T1), and 1week after debonding (T2). Bracket remover plier (BRP) and Weingart plier (WP) were used to debond brackets. A numeric rating scale (NRS) was used to assess sensitivity for each tooth at T0, T1, and T2. Tooth pain was assessed for each tooth using NRS during bracket debonding. Statistically higher pain scores were found in teeth U4 (upper first premolar) (p = 0.017) and L6 (lower first molar) (p = 0.026) in Weingart plier group. No statistically significant difference was found during debonding in the other teeth between groups. Statistically high sensitivity score was found at T1 time point in tooth U3 (upper canine) by applying air stimulus in Weingart plier group (p = 0.024). There was no statistically significant difference between the sensitivity scores measured at T2 time point by applying air and cold stimuli between groups. Although the debonding pain scores were statistically significant in two teeth and the sensitivity score in one tooth, there was no clinical significance between the two pliers in terms of pain and sensitivity. Both debonding pliers gave clinically similar results in terms of pain and sensitivity.

Efficacy of Anti-Rusting Agents on Sterilization of Instruments used in Orthodontic Practice

Autoclaving (a process of sterilization) of instruments can lead to rust formation and corrosion especially the cutting instruments because they have a carbide steel tip. The aim of this study was to check the microbial load of instruments after treatment with any of these agents viz. sodium hypochlorite, vinegar, lemon and coconut oil followed by autoclaving and to assess the instruments for corrosion treated by these above mentioned agents followed by autoclaving. A sample of twenty five orthodontic pliers and cutters were selected for evaluation. They were divided into five groups depending on the agent used. After ultrasonic cleaning of these pliers, they were immersed in the respective solutions for 10 minutes, dried and then subjected to autoclaving. Microbial swabs were collected at two stages: before treating the instruments(T0) with anti rusting agents and after autoclaving(T1). Quantitative culture was performed using standard technique. The working edge of each instrument was examined visually on the amount of corrosion seen. The mean difference in colony forming units of each group were sodium hypochlorite-48.6, vinegar-32.2, coconut oil-31.4, lemon-7.4 and control group-16.8. In this study, use of additive agents like sodium hypochlorite, vinegar, lemon and coconut oil did not alter the process of sterilization, wherein, the CFU’s of all the four experimental groups were similar to the control group. Visual examination reveals that the anti-rusting property of coconut oil is far superior compared to all other agents used.

A Simplified Spring winder For Clinical Application

Introduction: The fabrication of coils using heavy gauge stainless steel wire for use in appliances such as the Churro Jumper can be a tedious task and can often result in spaced coils that lead to more flexibility than can be desired, leading to a decreased force application and hence overall lengthened treatment time. Using well placed, tightly adherent coils the force of which can be controlled by placement of the desired number of coils can help to mitigate this shortcoming. Technique: The spring winder described here is easy to fabricate using easily available stationary articles which can be repurposed to form an efficient winder that can coil springs with reduced effort as compared to that would have been required when using orthodontic pliers only. The stationary repurposed for this winder is the electric etching pen which provides a good framework for fabricating the winder. In addition, clear acrylic is used along with a syringe body to hold the winding components. The syringe is filled up with clear acrylic and winding rods are laid down within the acrylic which holds it firmly in place. In addition, the syringe body is embedded into the electric pen handle which allows for easy turning the winder so as to exert effective force while reducing operator effort and fatigue. This also allows for winding of heavy gauge orthodontic wire with little effort. Conclusion: A simplified spring winder can be best indicated for the fabrication of coils for fixed functional appliances like Churro Jumper.

Ativação de alinhadores ortodônticos com alicates – uma alternativa para obtenção de resultados

The great demand for aesthetics has led to the development of increasingly discreet orthodontic appliances. For this reason, treatments with orthodontic aligners have become a reality in daily practice and the understanding of their biomechanics and especially the resources to obtain the desired results is of fundamental importance. Therefore, this work aims to demonstrate how the activation of the aligners through orthodontic pliers can be performed in order to help complement the movement, especially when only a force exerted by the aligners is not sufficient for the desired tooth movement.

In vitro comparison of peracetic acid and autoclave sterilization in the corrosion of orthodontic pliers: a pilot study.

ABSTRACTIntroduction: The most currently recommended method for sterilization of orthodontic pliers is the autoclave, while peracetic acid has also been shown to be effective in the chemical sterilization process. Objective: This study sought to compare the corrosive effects of peracetic acid and autoclave sterilization process of orthodontic pliers. Methods: Four active tungsten carbide (WC) stainless steel tie-cutting pliers from the manufacturers Quinelato (Rio Claro, SP, Brazil) and ICE (Cajamar, SP, Brazil) were selected. The active ends of the pliers were sectioned, and six active tips were obtained and distributed into the following groups: 1) control group (no sterilization); 2) AC group (two active pliers tips submitted to 100 autoclave sterilization cycles); and 3) AP group (two active pliers tips submitted to 100 cycles of sterilization by immersion in 2% peracetic acid solution for 30 minutes). Results: Chemical analysis using X-ray dispersive energy spectroscopy showed that after autoclave sterilization, only the ICE pliers presented oxidation corrosion (Δ[O] = +24.5%; Δ[Fe] = +5.8%; Δ[WC] = -1.9%). In comparison, following peracetic acid sterilization, both manufacturers ICE (Δ[O] = +1.8%; Δ[Fe] = +18.0%; Δ[WC] = -1.1%) and Quinelato (Δ[O] = +5.3%; Δ[Fe] = -10.4%; Δ[WC] = -15.2%) showed corrosion. The morphological analysis revealed that peracetic acid caused a pitting and localized corrosion in both brands, while the autoclave caused uniform surface corrosion on the ICE pliers. Conclusion: Autoclave application was the sterilization method that generated less corrosive damage to the orthodontic cutting pliers, when compared to the immersion in 2% peracetic acid.

Opuntia ficus-indica as a durable and eco-friendly corrosion inhibitor on AISI 410 stainless steel in $$0.5~\hbox {M}\,\hbox {H}_{{2}}\hbox {SO}_{{4}}$$

In the dental office, surgical instruments must be sterilized for each patient, following their contamination by saliva and blood. Repeated sterilization cycles cause corrosion. A worn out and corroded instrument may cause toxicity to the patient. The aim of our study is to improve the corrosion resistance of orthodontic pliers during sterilization using green inhibitors. The behaviour of AISI 410 stainless steel with respect to corrosion was studied in a $$0.5~\hbox {M H}_{{2}}\hbox {SO}_{{4}}$$ , using cladodes of Opuntia ficus-indica (OFI) as a green inhibitor. Temperature effect on OFI efficacy was studied for different ranges (25, 35 and $$45^{\circ } \hbox {C}$$ ). The study was carried out using the weight loss method, the stationary electrochemical techniques (polarization curves), the transients (electrochemical impedance spectroscopy), and the scanning electron microscopy associated with X-ray dispersive energy spectroscopy (SEM–EDX) and atomic force microscopy (AFM) observations. OFI behaves as a mixed inhibitor, with a physisorbed adsorption obeying to Langmuir isotherm and, with an efficacy ranging from 95.12 to 15% (v/v) obtained after 12 h immersion at a temperature of $$25^{\circ } \hbox {C}$$ . The SEM–EDX and AFM observations confirm the obtained results. In conclusion, OFI improves corrosion resistance of AISI 410 stainless steels in $$0.5~\hbox {M H}_{{2}}\hbox {SO}_{{4}}$$ at $$25^{\circ } \hbox {C}$$ .

Various Disinfecting Methods of Orthodontic Pliers in Daily Clinical Practice: A comparative Study

Introduction: Orthodontic pliers are essential armamentarium in every orthodontic office and should be used
 once for one patient, then autoclaved before next use. Clinical orthodontics with higher volume of patients,
 requires a quick chair side disinfection method for pliers, also in rural centres with minimum infrastructure
 it is a challenge to maintain sterilisation protocols. Various disinfecting agents include alcohols , quaternary
 ammonium salts, formaldehyde, chloramine, sodium hypochlorite, spirit, glutaraldehyde etc. are available.
 Out of these we compared the commonly available disinfectants including ethyl alcohol, 5% glutaraldehyde,
 and 6% sodium hypochlorite to assess their disinfection efficacy after clinical use.
 Materials and method: 20 orthodontic pliers were inoculated with Coagulase negative streptococci. The
 pliers were divided in 4 groups with 5 pliers in each group. Each group was subjected to different disinfectant
 solution with one group aiding as control. The disinfectants used were: spirit (group 1), 5% glutaraldehyde
 (group 2), 2% sodium hypochlorite (group 3) and distilled water (control group).
 Results: spirit and 5% glutaraldehyde have shown to be potent disinfectants.
 Conclusions: Based on these results, we concluded that among the tested methods, disinfection of orthodontic
 pliers with spirit and 5% glutaraldehyde are the efficient methods for chair-side disinfection.

Effectiveness of Various Disinfectant Protocols on Orthodontic Pliers � An In-Vitro Study

Disinfection of the instruments used in orthodontic clinic is essential in order to prevent the transmission of disease to the practitioner, auxiliary staff and patients. Present study aims to evaluate the effectiveness of 2% Glutaraldehyde solution, quaternary ammonium compound based wipes and foam sprays on the disinfection of orthodontic pliers. Methodology: The efficacy of disinfection methods of orthodontic pliers used in everyday practice by orthodontists was evaluated using 30 sterile pliers. They were contaminated in vitro with bacteria commonly found in the oral cavity, Streptococcus salivarius [ATCC 13419], Staphylococcus aureus [ATCC 25923] and Pseudomonas aeruginosa [ATCC27853]. Following contamination of the pliers, each of ten pliers underwent one of the three disinfectant protocols in a solution of 2% Glutaraldehyde, alcohol-free wipes containing quaternary ammonium compounds and spraying a foam containing quaternary ammonium compound. The plier heads were spread on the surface of sterile blood agar plates after contamination and after disinfection. Results: 2% Glutaraldehyde solution, quaternary ammonium compound based wipes and foam sprays were found to be effective with regards to disinfection of orthodontic pliers. Conclusion: As per the results of our study, we conclude that 2% Glutaraldehyde solution, quaternary ammonium compound based wipes and foam spray were found to be effective with regards to disinfection of orthodontic pliers contaminated with standard strains of Pseudomonas aeruginosa , Staphylococcus aureus and Streptococcus salivarius .

Micrographic evaluation of different widia compositions of orthodontic pliers submitted to peracetic acid and intensive use

Abstract Introduction The sterilization and disinfection procedures should be adapted to the chemical profile of the metal alloys present in the instruments. Objective This study aimed to perform a micrographic assessment on the surface characteristics of the widia of orthodontic pliers with two alloy compositions subjected to the action of 0.2% peracetic acid and intensive use. Material and method Twenty distal cutting pliers were divided into two groups (n=10) according to widia composition (%wt): W1- 85% to 87% of tungsten carbide (TC) and other components in the proportion of 13% to 15% and W2 – 87.5% to 88.5% of tungsten carbide and 11.5% to 12.5% for other components. All the pliers were assessed in a stereoscopic magnifying glass (32x) after three treatments: before use (T0); after cutting 100 segments of rectangular stainless-steel wires – intensive use (T1); and after 100 sterilization cycles in 0.2% peracetic acid and intensive use (T2). The cutting sites of all pliers were standardized. Widia regions were defined by line “A” representing T1 and line “B” representing T2. A frequency distribution table and Fisher’s exact test (α=0.05) was performed. We assessed two widia from each composition and treatment in SEM and energy-dispersive X-ray spectroscopy (EDS/SEM). Result The results showed that W1 pliers presented significantly fewer defects after the sterilization cycles with peracetic acid and intensive use than W2 pliers (p=0.0198). There were no differences between both pliers after intensive use (p=1.000). Conclusion The SEM images and EDS analyses showed changes in widia surfaces after the different treatments. Widia composition affected the resistance of the orthodontic pliers after sterilization cycles with 0.2% peracetic acid and intensive use.

Biosafety conducts adopted by orthodontists.

ABSTRACTObjective: This cross-sectional observational study was designed to assess the biosafety conducts adopted by orthodontists, and possible differences regarding training time. Methods: Both the application of methods for sterilization/disinfection of instruments and materials, and the use of personal protective equipment (PPE) were collected through questionnaires via e-mail. Results: The questionnaires were answered by 90 orthodontists with a mean age of 37.19 ± 9.08 years and mean training time of 13.52 ± 6.84 years. Regarding orthodontic pliers, 63.23% use an autoclave, except 1 who does not perform any procedure. All participants use autoclave to sterilize instruments, and 95.6% of respondents perform cleaning with chemicals prior to sterilization. Most of them (65.56%) use an autoclave to sterilize orthodontic bands, with some still associating disinfection methods, while few (18.89%) do nothing at all. There was a high incidence of the answer “nothing” for the methods used for elastic, accessories, bandages, metal springs, and arches. All respondents use mask and gloves in attendance, 78.92% use aprons, 58.92% use protective goggles, and 50.01% use cap. Training time significantly influenced (p = 0.003) only the use of glutaraldehyde for sterilization/disinfection of pliers. Conclusions: The sterilization and cleaning of pliers, instruments, and bands, besides the use of PPE, received more uniform and positive responses, while other items suggest disagreements and possible failures. Only orthodontists trained for more than 13 years choose using glutaraldehyde for pliers sterilization/disinfection, the only adopted method with a significant difference in relation to training time.

Clinical Instrument Refurbishment-A Chair side Technique.

A pin and ligature and distal end cutter are some of the most commonly used instruments in orthodontic practice. These instruments are also prone to tip damage on account of heavy usage as well as repeated sterilization. Steam sterilization is most common and the quickest method of sterilization; however, it causes corrosion and rusting of orthodontic pliers and damages the cutting edges [1]. When the tips of these instruments break, a clinician is usually left with no option other than replacing the instruments with new ones at considerable cost or getting the instruments retipped or repaired by sending them back to the manufacturer which again entails expense and time loss. In India, this facility of retipping is at present not provided by most of the manufacturers and this means that the instrument has to be discarded and a new one to be purchased.

Evaluation of disinfection methods of orthodontic pliers

INTRODUCTION: In recent years, a strong behavior change regarding the control of cross infection during dental treatment was perceived, except among some orthodontists who insist in the misconception that Orthodontics is a specialty of low risk in the transmission of infectious and contagious diseases. OBJECTIVE: The objective of this study was to evaluate the methods used by orthodontists for disinfection of pliers in their daily practice. METHODS: The bacteria Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus salivarius were inoculated in vitro in 30 orthodontic pliers. The pliers were divided into 3 groups (n = 10) and disinfected in different ways. Group 1: Brush, soap and water; Group 2: Cotton soaked in ethyl alcohol 70%; Group 3: Immersion in a solution of 2% glutaraldehyde for 30 minutes and then rinsed with water. RESULTS: The results showed that the ethyl alcohol 70% (Group 2) kept 20% of the pliers infected, being more efficient than the soap and water (Group 1), which maintained 60% of contaminated pliers. Only immersion in 2% glutaraldehyde was able to decontaminate all pliers and was statistically superior to the aforementioned methods (p = 0.030). CONCLUSION: Based on these results, we concluded that among the tested methods, disinfection of orthodontic pliers with 2% glutaraldehyde is the only efficient method.

Análises microbiológicas de alicates ortodônticos

OBJETIVO: avaliar a contaminação bacteriana presente na ponta ativa de alicates ortodônticos utilizados no meio acadêmico. MÉTODOS: selecionou-se 34 alicates, 17 do modelo 347 e 17 do modelo 139. O grupo controle foi composto por 3 alicates de cada modelo, previamente autoclavados. Os alicates do grupo experimental, após o uso, foram imersos em 10ml do meio de cultura líquido Brain-Heart Infusion (BHI) por 2 minutos, seguido de cultivo a 37°C (24 a 48h) e semeadura (duplicata) em diferentes meios de cultura sólidos à base de ágar, para detecção e identificação de agentes microbianos. RESULTADOS: as análises microbiológicas revelaram contaminação em ambos os tipos de alicates ortodônticos. Observaram-se variadas formas bacterianas, predominando estafilococos e cocos isolados gram-positivos. Os alicates removedores de anéis apresentaram maiores índices de contaminação, com médias entre 2,83 x 10(9) e 6,25 x 10(9) UFC/ml, variando de acordo com o tipo de meio de cultura. Os alicates 139 também continham bactérias da microbiota bucal, com variações entre 1,33 x 10(8) e 6,93 x 10(9) UFC/ml, sendo que a maior média obtida refere-se ao meio de cultura próprio para desenvolvimento de estafilococos, indicando, em certos casos, presença da espécie Staphylococcus aureus, microrganismos que não fazem parte da microbiota bucal normal, sendo comumente encontrados na cavidade nasal e superfícies epiteliais das mãos. CONCLUSÃO: constatou-se que os alicates ortodônticos apresentam-se contaminados, como qualquer outro instrumental odontológico, após serem empregados em atendimentos clínicos. Em razão disso, há necessidade de submetê-los previamente aos procedimentos de esterilização após cada utilização em pacientes.

Avaliação microbiológica da contaminação residual em diferentes tipos de alicates ortodônticos após desinfecção com álcool 70%

OBJETIVO: o objetivo deste trabalho foi verificar, por meio de análises microbiológicas, a contaminação de diferentes tipos de alicates ortodônticos (139, Weingart, removedor de bandas e de corte distal) após a lavagem com água e sabão e fricção de álcool 70% por um minuto. MÉTODOS: todos os alicates foram, inicialmente, esterilizados em autoclave durante 20 minutos, a 121ºC e pressão de 1atm. Após o atendimento ortodôntico, os alicates utilizados foram depositados individualmente em recipientes estéreis tipo béquer, fechados com papel kraft e transportados ao laboratório de Microbiologia. Esses alicates foram submetidos, numa primeira etapa, à coleta imediata de microrganismos e à semeadura para contagem de bactérias. Posteriormente, os mesmos alicates foram lavados com água corrente e sabão, e friccionados por um minuto com gaze (esterilizada) embebida em álcool 70% (P/P). Novos testes bacteriológicos foram, então, realizados. Os alicates esterilizados do grupo controle foram submetidos aos mesmos testes bacteriológicos, todavia não haviam sido utilizados na clínica. RESULTADOS: os resultados demonstraram uma grande quantidade e variedade de bactérias residuais após a realização da desinfecção com o álcool 70%. CONCLUSÕES: mesmo alicates que não são inseridos na cavidade bucal do paciente, como o 139, mas que são pegos pelo ortodontista, cujas luvas entram em contato com saliva e/ou sangue, devem ser esterilizados, pois somente a desinfecção não é suficiente para impedir a potencial infecciosidade desses instrumentos.

Esterilização em Ortodontia: eficácia do esterilizador com esferas de vidro

OBJETIVO: avaliar a efetividade do esterilizador com esferas de vidro Steri® 350, quanto ao controle de infecção das partes ativas dos alicates ortodônticos. METODOLOGIA: foram utilizados nove alicates ortodônticos, previamente esterilizados em autoclave à temperatura de 121ºC, durante 20 minutos. Posteriormente, as partes ativas dos alicates foram contaminadas com Bacillus stearothermophilus. Logo após, as pontas dos alicates foram colocadas no Steri® 350, durante os períodos de 3, 5, 10, 15, 20, 30 e 40 segundos, em temperatura de 255ºC, para avaliar a eficácia da esterilização. RESULTADOS E CONCLUSÕES: o esterilizador com esferas de vidro mostrou-se eficaz no controle do crescimento de Bacillus stearothermophilus nas partes ativas dos alicates ortodônticos, a partir de 10 segundos de exposição à temperatura de 255ºC.

Evaluation of failure characteristics and bond strength after ceramic and polycarbonate bracket debonding: effect of bracket base silanization

The objectives of this study were to evaluate the effect of silanization on the failure type and shear-peel bond strength (SBS) of ceramic and polycarbonate brackets, and to determine the type of failure when debonded with either a universal testing machine or orthodontic pliers. Silanized and non-silanized ceramic and polycarbonate brackets (N = 48, n = 24 per bracket type) were bonded to extracted caries-free human maxillary central incisors using an alignment apparatus under a weight of 750 g. All bonded specimens were thermocycled 1000 times (5-55 degrees C). Half of the specimens from each group were debonded with a universal testing machine (1 mm/minute) to determine the SBS and the other half by an operator using orthodontic debonding pliers. Failure types of the enamel surface and the bracket base were identified both from visual inspection and digital photographs using the adhesive remnant index (ARI) and base remnant index (BRI). As-received ceramic brackets showed significantly higher bond strength values (11.5 +/- 4.1 MPa) than polycarbonate brackets [6.3 +/- 2.7 MPa; (P = 0.0077; analysis of variance (ANOVA)]. Interaction between bracket types and silanization was not significant (P = 0.4408). Silanization did not significantly improve the mean SBS results either for the ceramic or polycarbonate brackets (12.9 +/- 3.7 and 6.3 +/- 2.7 MPa, respectively; P = 0.4044; two-way ANOVA, Tukey-Kramer adjustment). There was a significant difference between groups in ARI scores for ceramic (P = 0.0991) but not polycarbonate (P = 0.3916; Kruskall-Wallis) brackets. BRI values did not vary significantly for ceramic (P = 0.1476) or polycarbonate (P = 0.0227) brackets. Failure type was not significantly different when brackets were debonded with a universal testing machine or with orthodontic debonding pliers. No enamel damage was observed in any of the groups.

Effective Disinfection of Orthodontic Pliers

Pathogenic microbes may be transmitted directly from the orthodontist to the patient or from the patient to the doctor, and indirectly from patient to patient. The latter may occur via contaminated instruments or surfaces, and is referred to as cross-contamination. The objective of this study was to evaluate the extent of bacterial contamination of orthodontic pliers and the efficacy of the disinfection techniques applied after clinical use. We also sought to examine under standardized conditions the virucidal, bactericidal and fungicidal effects of disinfection techniques used in practice. The efficacy of various disinfection methods was determined after clinical use in-vivo on 10 test subjects and in-vitro with deliberate contamination. The following disinfection methods were tested: 1. Iso-Septol spray 2. Incidur spray 3. Trough disinfection in combination with 5% Sekusept Plus solution 4. Ultrasound bath in combination with 5% Sekusept Plus solution 5. Thermal disinfection For in-vitro contamination we used the test organisms Staphylococcus aureus, Escherichia coli, Candida albicans, Coxsackie virus B4, HSV 1, and Adenovirus type 5. The tests were carried out six to eight times for each organism. The Weingart pliers and distalend cutters were tested. The criteria for effective disinfection were a reduction in infectiosity of five log steps (for bacteria and fungi) or four log steps (viruses). Statistical analysis was carried out using the Wilcoxon and Whitney U-test. The presence of contamination following clinical use was not adequately eliminated with all disinfection methods. The spray methods exhibited shortcomings in disinfection. For the type of contamination defined, trough disinfection with 5% Sekusept Plus and the Incidur and Iso-Septol spray disinfection methods provided insufficient disinfection. Conversely, the ultrasound bath with 5% Sekusept Plus solution and steam disinfection met the criteria for effective disinfection for all microbes. No statistically significant difference was found between the oiled and unoiled states. In some cases, there were slightly higher rates of contamination with the Weingart pliers as with the distalend cutters. However, these were not statistically significant. It should be possible to disinfect lipophilic viruses and the usual bacterial infections adequately with all methods, provided that the use of sprays and trough disinfection is preceded by cleaning with brush and water, followed by drying. With hydrophilic viruses, however, the spray and trough disinfection methods are limited in their efficacy and cannot be considered adequate. Exclusively chemical methods are therefore less effective than thermal or physical-chemical methods. Thermal disinfection and the ultrasound bath in combination with 5% Sekusept Plus are clearly superior to spray disinfection and trough disinfection alone. The ultrasound bath and thermal disinfection can therefore be recommended for the disinfection of orthodontic pliers. We recommend that the pliers be cleaned beforehand due to their uneven surfaces.

Corrosion of Orthodontic Pliers Using Different Sterilization Procedures

The aim of this study was to investigate the corrosion resistance of orthodontic pliers from several manufacturers following different sterilization procedures, namely heat sterilization and the use of a disinfectant agent (Sekusept Extra N in an ultrasonic bath. Employed in this study were ten distal-end cutters and ten Weingart pliers manufactured by Aesculap, ETM and Hu-Friedy, examined under electron microscopy for evidence of corrosion following 500 sterilization cycles. The corrosion data were recorded photographically and graphically. Metallographic microsections were prepared from each pair of pliers and were then analyzed by means of EDX measurements to assess the chemical alloy composition. The light and electron microscopic evaluation showed that both heat sterilization and high level disinfection caused corrosive changes on the pliers. However, the type of corrosion differed between the two sterilization methods. The main type of corrosion with Sekusept Extra N was pitting, while with heat sterilization it was surface corrosion. Heat sterilization was the type of corrosion that caused the most corrosive changes, regardless of which type of corrosion was considered. However, these results must be viewed critically, because pitting corrosion is obviously a more severe problem than surface corrosion. In comparing the pliers of various manufacturers, differences were noted. However, it was difficult to rank them when the correct maintenance regime was adhered to. The soldered joint gap was revealed to be a specific weak point, and that area proved to be inadequate due to qualities related to their production, particularly in the Hu-Friedy pliers. This study showed that heat sterilization leads to less corrosion than cold disinfection. Corroded pliers can be restored to a useable condition by re-polishing, though it is important that the instructions for their care be strictly adhered to.