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To prevent contamination of the light guide on a dental curing light, barriers such as disposable plastic wrap or covers may be used. This study compared the effect of 3 disposable barriers on the spectral output and power density from a curing light. The hypothesis was that none of the barriers would have a significant clinical effect on the spect...
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Using the push-out test, this study evaluated the bond strength of the composite resin Z250 (3M/ESPE) photoactivated with the XL2500 (3M/ESPE) quartz-tungsten-halogen light-curing unit with different curing protocols: soft-start (150 mW/cm² for 2 s (S2), 3 s (S3), 5 s (S5), 10 s (S10) or 15 s (S15), followed by 700 mW/cm² for 15 s; pulse-delay (150...
This study investigated the effects that disposable infection control barriers and physical damage through use had on the power output from dental light curing units (LCUs) and light curing tips (LCTs). Five disposable infection control barriers were tested on a number of LCUs and LCTs. Testing involved the repeated measurement of power output of L...
Citations
... Professionals should know that such exposure may be avoided using orange goggles, which filter 99% of blue light (Price, 2017). This equipment allows the operator to verify light-curing unit positioning during light-curing, improving the amount of light supplied to the restoration (Scott, Felix & Price, 2004;Price, 2017;Rueggeberg et al., 2017). ...
... Some barriers, including latex-based ones, decrease irradiance by up to 40% (Sword, Do, Chang & Rueggeberg, 2016) and should therefore be avoided (Price, 2017). Barriers need to be transparent and adequately fitted over the light-curing unit light tip to minimally interfere with light emission (Scott et al., 2004;Sword et al., 2016;Price, 2017). ...
Composite resin is versatile material for performing several dental procedures in dentistry, and its use has already been consolidated in this field. The clinical success of adhesive restorations is directly related to the knowledge of restorative material properties and light-curing unit factors, among others. The aim of the study was to assess the knowledge about the technical characteristics of light-curing devices and the forms of use and maintenance employed by undergraduate dental students. A total of 230 students answered a questionnaire containing six questions on technical data, use, and maintenance of light-curing units. Of the total number of participants, the majority were students from private educational institutions attending the last two years. With 59.1% of them unaware of the ideal irradiance of a light-curing unit, 73.0% were careful to position the light-curing unit as close as possible to the restoration, and 42.6% followed the light-curing time recommended by textbooks and theoretical texts. As for use and maintenance, 50.4% used the protector attached to the light-curing unit, 57.4% used safety barriers, and 63.0% sanitized the light tip after use. The evaluation suggests that student’s knowledge of “light-curing resin materials” is incomplete. Therefore, it can be inferred that the students have a good understanding of biosafety precautions when using light-curing units, but more knowledge is needed about the technical and clinical aspects of the devices.
... 7,[12][13][14] There is a large volume of published studies describing the impact of infection control barriers on light output from dental curing lights. [15][16][17][18] Recent evidence suggests that the method of application of plastic barriers significantly influences the amount of reduction in light output. Soares and colleagues (2020) found that correctly applied plastic barriers reduced the light output by 5-8% compared to the incorrectly applied (14-26%). ...
... It is rather disappointing considering that a great deal of the previous work has reported a reduction of light intensity related to the use of gloves or other opaque barriers. [15][16][17][18] Limitations of the study The small sample size and low response rate threatens the internal validity of this study. ...
It is generally accepted that inadequately sterilized dental curing light guides pose risks of infection and cross contamination.To determine the presence and level of bacterial contamination among curing light guides used by students during patient care at a dental school in South Africa and to describe students’ knowledge and awareness of measures used to maintain their sterility. A two-part descriptive study consisting of microbiological testing and a cross-sectional survey. Swabs were collected from curing light guide tips before and after use for aerobic culture and a questionnaire was used to collect data pertaining to students’ knowledge and awareness of measures used to maintain their sterility. The prevalence of contamination increased after use (54.5% vs 45.5%). Grades of bacterial growth higher than 1+ were not detected. Isolated bacteria were contaminants. The response rate for the questionnaire was 42.5%. Fifth-year students were overall more knowledgeable than fourth-year students (81.6% vs 67.5%) and were more aware of the existence of the different types of disposable barriers (27.5% vs 12.8%) and the impact of infection control barriers on curing light intensity (52.4% vs 15%). Contamination occurred despite high levels of knowledge and awareness of the risk.
... 7,[12][13][14] There is a large volume of published studies describing the impact of infection control barriers on light output from dental curing lights. [15][16][17][18] Recent evidence suggests that the method of application of plastic barriers significantly influences the amount of reduction in light output. Soares and colleagues (2020) found that correctly applied plastic barriers reduced the light output by 5-8% compared to the incorrectly applied (14-26%). ...
... It is rather disappointing considering that a great deal of the previous work has reported a reduction of light intensity related to the use of gloves or other opaque barriers. [15][16][17][18] Limitations of the study The small sample size and low response rate threatens the internal validity of this study. ...
INTRODUCTION: It is generally accepted that inadequately sterilised dental curing light guides pose risks of infection and cross-contamination. AIMS AND OBJECTIVES: To determine the presence and level of bacterial contamination among curing light guides used by students during patient care at a dental school in South Africa and to describe students' knowledge and awareness of measures used to maintain their sterility. DESIGN: A two-part descriptive study consisting of microbiological testing and a cross-sectional survey. Methods: Swabs were collected from curing light guide tips before and after use for aerobic culture and a questionnaire was used to collect data pertaining to students' knowledge and awareness of measures used to maintain their sterility. RESULTS: The prevalence of contamination increased after use (54.5% vs 45.5%). Grades of bacterial growth higher than 1+ were not detected. Isolated bacteria were contaminants. The response rate for the questionnaire was 42.5%. Fifth-year students were overall more knowledgeable than fourth-year students (81.6% vs 67.5%) and were more aware of the existence of the different types of disposable barriers (27.5% vs 12.8%) and the impact of infection control barriers on curing light intensity (52.4% vs 15%). CONCLUSION: Contamination occurred despite high levels of knowledge and awareness of the risk.
... Many methods have been employed in this regard to minimize the spread of infection. The common methods include wiping the light guide with a disinfectant, using autoclavable or disposable guides and by covering it with a barrier 3,4 . Each of these methods has some implication associated with it. ...
Aim: To evaluate the effect of different cross infection control barriers on the intensity of the curing light. Study Design: In-vitro experimental study. Place and duration: Department of Operative and Pediatric Dentistry, The University of Lahore from January to March 2022. Methodology: The intensity of the light-curing unit was measured using a radiometer. The intensity of light without using any barrier was taken as control. Four barriers were used; polythene glove, latex glove, cling film wrap and standard barrier tape. Ten measurements for each group were performed after placing each type of protection barrier and the average was taken. The data was analyzed using SPSS v 22. Results: The mean value for light intensity without using any barrier was found to be 737.6 mW/cm2. The light intensity was maximum for cling film, polythene glove, barrier tape and latex glove with mean values of 720.6 mW/cm2, 581.2 mW/cm2, 541.7 mW/cm2 and 255.06 mW/cm2 respectively. A comparison of the output values without barrier and with different barriers showed a statistically significant difference with all barriers except cling film. Conclusion: It was found that cling film, polythene glove and barrier tape could serve as a barrier to cover the tip of the light curing unit. Keywords: Dental curing light, cross-infection, composite resin
... 12,13 Another factor that could affect polymerization efficiency is the protective barriers used to maintain the sterility of the light guide. [14][15][16] However, the use of protecting barriers is strongly recommended because the LCU tip may be a cross-infection agent, due to the possibility of contact with contaminating oral fluids, saliva, and blood. For this reason, the main centers for the control and prevention of infectious diseases around the world establish biosafety protocols with strict determinations regarding the use of instruments or dental equipment. ...
Objective
To evaluate the influence of different protective barriers as a function of the photoactivation distances on the radiant exposure of several light-curing units (LCU). The influence of the protective barriers on the degree of conversion of an adhesive resin was also evaluated.
Methods
Five LCUs were evaluated: Valo Cordless— used in standard mode (Ultradent, South Jordan, USA); Radii-cal—used in continuous mode (SDI, Bayswater, AU); Emitter D—used in continuous mode (Schuster, Santa Maria, BR); Bluephase N— used in high-intensity mode (Ivoclar Vivadent, Schaan, LI); and Rainbow Curing Light—used in continuous mode (Axdent, Guangdong, CN). For each LCU, radiant exposure was measured with a spectrometer (MARC Resin Calibrator) using three different protective barriers (low-density polyethylene, polyvinyl chloride, or Radii-cal barrier sleeves) and five photoactivation distances (0, 2, 5, 10, and 20 mm). The degree of conversion of an adhesive resin (Adper Scotchbond Multi-Purpose, 3M ESPE, St. Paul, USA) was measured through Fourier-transform infrared spectroscopy. The translucency parameter of protective barriers was measured with a spectrophotometer. For all statistical tests, a significance level of α = 0.05 was set.
Results
For all LCUs tested, radiant exposure was found to be significantly influenced by both protective barriers and curing distance (p≤0.001). In general terms, all the protective barriers significantly decreased the radiant exposure. Radii-cal barrier sleeves were the protective barrier that most decreased the radiant exposure. Irrespective of the protective barrier used, none of the LCU equipment reached the required minimum radiant exposure of 16 J/cm2 at 10 mm of curing distance. The degree of conversion was not effected by either LCU or a protective barrier (p≥0.211).
Conclusions
Protective barriers and photoactivation distance reduced the radiant exposure emitted by different LCUs.
... 7,8 Studies have shown that latex barriers, thick barriers, and barriers applied with folds or air bubbles can attenuate or spread the light emitting from the curing unit. [8][9][10][11] However, none of these studies has evaluated the most recent LED curing devices, which are able to emit higher irradiance values than older devices. ...
... In contrast, Scott et al observed no significant differences between the PVC film group and their control group. 9 The discrepancies between the present study and the findings of Scott et al are likely associated with differences in the types of barriers and curing units used. [8][9][10] Barriers made with latex, for example, should be avoided, as they considerably decrease light transmission; however, barriers made with PVC, such as those used in the present study, do not influence light transmission. ...
... 9 The discrepancies between the present study and the findings of Scott et al are likely associated with differences in the types of barriers and curing units used. [8][9][10] Barriers made with latex, for example, should be avoided, as they considerably decrease light transmission; however, barriers made with PVC, such as those used in the present study, do not influence light transmission. [8][9][10] The lowest irradiance values were found when the misfit PVC barriers were used, probably because successive layers of the barrier caused light scattering. ...
This study aimed to analyze the effects of polyvinyl chloride (PVC) film and oxygen-blocking gel (OBG) on the irradiance from an LED source and the depth of cure of a composite resin. Irradiance was measured with a curing radiometer, and curing depth was evaluated according to the methods described by the International Organization for Standardization (ISO 4049). Twelve experimental conditions were investigated in a 3 × 4 factorial design (n = 5 specimens per condition): no PVC film at the tip of the device, fitted PVC film, or misfit PVC film; and no OBG or a 1-, 2-, or 3-mm-thick layer of OBG. The data were analyzed using analysis of variance and Tukey tests (P < 0.05), and a linear regression test was performed between the variables (P < 0.05). The analyses showed that the variables under study influenced the irradiance (P < 0.05) but not the curing depth (P > 0.05). The 3 groups that did not have the PVC film and either did not have the OBG or had the OBG in a thickness of 1 or 2 mm were not significantly different from each other (P > 0.05) but presented the highest irradiance values among all the groups (P < 0.05). The use of the misfit PVC film with a 3-mm layer of OBG led to the lowest irradiance values (P < 0.05). The variables did not influence each other (P > 0.05). The results of this study indicated that the presence of PVC film, especially misfit film, reduced the irradiance. In addition, the greater the thickness of the OBG, the lower the irradiance. None of the PVC film barrier conditions or OBG thicknesses had an effect on the depth of cure.
... It was observed that the light intensity of the device could be reduced to 50% of the original value after 3 times autoclaving of the tip (10,11). If the LCU tips are polished after autoclaving, the light intensity may return to its original value (12). Although polishing can restore light transmission, autoclaving and polishing the tip take time. ...
... It is reported that the hygienic barrier can reduce the light output by 5-10% in the Valo manual. On the other hand, studies have shown that light intensity can be reduced by up to 35% when some plastic sheaths were used (11,12,14). Similarly, according to the result of the present study, the usage of the hygienic sheaths reduced the light output of two LCU's, thereby microhardness of the samples. ...
... Thus, the first null hypothesis was rejected. These findings were consistent with the studies of Warren et al. and Scott et al. (7,12). However, McAndrew et al. (26). ...
Objective: The aim of this study was to evaluate the effect of disposable sheaths on microhardness of resin composites. Methods: A total of 40 resin composite specimens were fabricated with perspex molds (5x2 mm). Specimens were divided into 4 groups: Irradiated by 1-Elipar LCU only (EL), 2-Elipar LCU with sheath (ELS), 3-Valo LCU only (VL), 4-Valo LCU with sheath (VLS), (n=10). The specimens were subjected to surface microhardness (SMH) test (Tronic, Digital Microhardness Tester DHV-1000) on the top and bottom surfaces under 200 g load applied for 10 s with a Vickers indenter. The specimens were stored in the distilled water at 37 °C for 24 hours and the same measurements were repeated. One-way ANOVA test, Tukey and Tamhane post-hoc tests were used for intergroup comparisons. Also paired sample t-test was used for comparisons of the different time results. Results: According to the 1st-hour data from the top and bottom SMH measurements, EL and VL groups gave significantly higher microhardness values than VLS and ELS groups (p
... A barrier must be used to cover LCUs. However, these plastic barriers will reduce the irradiance from the LCU, so the light exposure time must be increased accordingly [18]. e distance between the light-curing unit tip and the surface of the resin material is one of the important factors to be considered since a reduction in radiance power was observed when the distance was increased [19]. ...
Objectives:
Light curing is crucial when applying composite resin restorations. Complete polymerization of the resin depends on delivering adequate light energy to it. Dental clinicians may be unaware of the importance of proper light-curing techniques. This study aimed at evaluating and comparing the level of knowledge of general practitioners (GPs) and specialists (SPs) regarding light-curing units.
Materials and methods:
An electronic survey was conducted online among GPs and SPs of various specialties, working in the governmental sector in Riyadh, Saudi Arabia. Collected data were analyzed for statistical significance.
Results:
310 dentists were included in the study. Nearly half of the GPs (45.9%) and more than half of SPs (56.8%) use light-emitting diode (LED) type light-curing units (LCUs). 36.9% of GPs and 29.6% of SPs were unsure about the type of LCUs they use in their dental clinics. 10.8% of GPs and 8.5% of SPs knew the proper term of the power output of LCU. 52.2% of the GPs and 55.7% of SPs were wrong about advancements in technology of LED LCUs. Regarding the use of radiometer, 48.2% of SPs and 35.1% of GPs had responded wrongly, and 37.7% of SPs and 52.3% of GPs were not familiar with the device, showing a statistical significance (p=0.040). There was no statistical significance observed in the responses pertaining to their years of experience, expected for two questions.
Conclusion:
Both GPs and SPs displayed inadequate knowledge regarding the use of LCUs. Further educational programs are recommended to spread awareness about the handling of LCUs among dental clinicians.
... Assim, após o polimento foi possível observar um aumento na média da irradiância de 650,6 mW/cm 2 , para 719,1 mW/cm², o que representou um aumento de 9,5%. Entretanto, é importante ressaltar que polimentos frequentes podem causar danos permanentes nas ponteiras e devem ser evitados 30 . ...
... Segundo Ajaj et al. 23 , o uso de barreiras de proteção possui baixo custo e demanda menor tempo clínico para a utilização do que outros métodos, tais como a esterilização e polimento frequente das ponteiras. É possível adquirir barreiras de diversos materiais como: polietileno, polietileno de baixa densidade, cloreto de polivinil (PVC) ou poliuretano 22,30 . ...
... Diversos trabalhos na literatura têm avaliado os diferentes tipos de barreiras de proteção e mostraram que o filme de PVC obteve os melhores resultados 21,22,30 . Este foi um dos motivos que levou o presente trabalho a escolher duas barreiras de filme de PVC, bem como o fato de ser de baixo custo e utilizado por um grande número de dentistas 31 . ...
Objetivos: Mensurar a quantidade de resíduos impregnados nas ponteiras condutoras de luz utilizadas nos fotopolimerizadores; aferir a irradiância antes e após a realização de limpeza e polimento das ponteiras; avaliar o efeito do uso de barreiras de proteção nos valores de irradiância. Materiais e métodos: A quantidade de resíduos nas ponteiras foi avaliada a partir de fotografias, nas quais foi sobreposta uma grade quadriculada, de modo a se calcular a porcentagem de resíduos em cada ponteira. A irradiância foi mensurada com auxílio de um radiômetro RD-7 (Exel®), antes e após seu polimento. Cada ponteira foi polida utilizando discos de pedra montada de granulação fina e extra-fina, seguido de ponta chama Optimize (TDV®), escova de pêlo de cabra com pasta de polimento Universal Polishing (Ivoclar®) e disco de feltro com pasta Enamelize (Cosmedent®). Por fim, a irradiância foi novamente aferida utilizando dois protetores distintos: incolor e amarelado. Os dados foram analisados estatisticamente pelo programa BioEstat 5.0. Resultados: Os resultados mostraram que a quantidade média de resíduos foi de 23,67%, estando localizados, predominantemente, na periferia da área circunferencial das ponteiras. Após o polimento, houve aumento significativo da irradiância (p<0,05). O protetor incolor não causou redução estatisticamente significante nos valores de irradiância (p>0,05), enquanto o protetor amarelado promoveu significativa diminuição (p<0,05). Conclusão: A emissão de luz através das ponteiras é reduzida pela presença de resíduos, porém aumenta após a limpeza e polimento. O uso de barreiras de proteção pode afetar a quantidade de luz que é emitida pela ponteira, dependendo de sua coloração.
... Thus, the use of protective materials during the use of the laser is essential for the photobiomodulation therapy to be performed safely. An economical and effective way to protect this equipment is the use of physical barriers, such as PVC [7,13] or PEAD [14][15][16][17]. However, it is important that its use do not interfere with the output power of the laser, not compromising negatively the final result of the therapy. ...
Biosafety materials used in the correct handling of low power laser equipment may interfere on the power delivered at the target tissue and, possibly, on the effects on biological tissues. The aim of this study was to evaluate the interference of the use of polyvinyl chloride (PVC) and polyethylene (PEAD) protection materials on the output power of low power lasers. Two low power diode laser devices with different wavelengths (red and infrared) were used. For each wavelength, two protection materials and two evaluation times (before and after protection) were considered. The output power (mW) was measured with the tip positioned in close contact with the power meter receiver. Parametric statistical test, two-way ANOVA for repeated measures (protection material and time), was performed considering the level of significance of 5%. In respect to “time”, all groups had the output power reduced after placing the protective material (p < 0.05). Comparing the protection materials, the PEAD showed a greater reduction in output power than the PVC for both red and infrared wavelengths. It was concluded that, among the biosafety materials tested, PVC is the most suitable for the protection of the tip of the low power lasers.
