Spectral distributions of dental colour-matching lamps (original) (raw)
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Aim: To evaluate the influence of three lighting conditions on the accuracy of tooth shade matching. Materials and methods: Ten prosthodontists participated in this study after being tested for color deficiency using Ishahara’s tests. Ten patients were selected for shade matching procedure. Shade of tooth 11 were taken under three lighting conditions (incandescent light, fluorescent light and hand-held full spectrum light). Using spectrophotometer (Easy Shade ,VITA Zahnfabrik H, Germany), shade of tooth 11 was recorded as control. Delta E was calculated for each reading according to the CIE L*a*b* formula, between visually and digitally recorded shades. Results: The percent of correct color matching choices with Incandescent light scored the highest number of correct color matching (15), followed by hand-held full spectrum light (7) then fluorescent light (6). Kruskal-Wallis test revealed significant differences in shade matching under the three light sources (P Value = 0.0006). One-way ANOVA revealed significant difference between fluorescent light and incandescent light (P Value= 0.039) while no significant difference was found among other groups. Conclusion: Different lighting conditions affect color-matching procedure. Hand-held full spectrum light did not improve shade-matching procedure. Incandescent light showed better lighting condition than both fluorescent light and Hand-held full spectrum light. KEYWORDS: Shade matching, Light source, Shade guide, incandescent light, fluorescent light, hand-held full spectrum light, digital shade analysis, spectrophotometer.
Comparison of colour differences in visual versus spectrophotometric shade matching
South African Dental Journal, 2015
Introduction: The challenge of achieving accurate colour matching in restorative dentistry is central to success in aesthetics. For many years selection of tooth colour in both restorative and prosthodontic dentistry have relied on shade guides which present a number of tabs of differing hue. Signal difficulties do arise with their use, notably in terms of accuracy and variability under differing circumstances. The use of a digital device to evaluate and record tooth colour offers an advanced option. Aim: There is merit in assessing the extent of agreement between the digital and the human assessment methods. Method: Twenty five patients were selected who had all upper anterior teeth, with the right central being pristine. Colour assessments were undertaken using a variety of guides and devices. The measurements were recorded and subjected to statistical comparisons. Results: In general there were significant differences recorded between the systems but it appears that these results...
Irradiance Uniformity and Distribution from Dental Light Curing Unitsj erd_318 86
Problem: The irradiance from dental light-curing units (LCUs) is commonly reported as a single number, but this number does not properly describe the light output. Purpose: This study examined the irradiance uniformity and distribution from a variety of LCUs as well as the effect of different light guides. Materials and Methods: Five LCUs representing quartz-tungsten-halogen, plasma arc, and light emitting diode units were evaluated. One LCU was evaluated using two different light guides (Standard or Turbo style). The total power emitted from each LCU was measured and the irradiance calculated using conventional methods (ICM). In addition, a beam profiler was used to determine the optically active emitting area, the mean irradiance (IBP), the irradiance distribution, and the Top Hat Factor (THF). Five replications were performed for each test and compared using analysis of variance with Fisher's PLSD tests at a pre-set alpha of 0.05. Results: The spatial distribution of the irradiance from LCUs was neither universally symmetrical nor was it uniformly distributed across the tip end. Significant differences in both the emitted power and THF were found among the LCUs. The THF values ranged from a high of 0.74 Ϯ 0.01 to a low of 0.32 Ϯ 0.01. Changing from a standard to a turbo light guide increased the irradiance, but significantly reduced beam homogeneity, reduced the total emitted power, and reduced the optical tip area by 60%. Conclusions: Using different light guides on the same LCU significantly affected the power output, irradiance values, and beam homogeneity. For all LCUs, irradiance values calculated using conventional methods (ICM) did not represent the irradiance distribution across the tip end of the LCU. CLINICAL SIGNIFICANCE Irradiance values calculated using conventional methods assume power uniformity within the beam and do not validly characterize the distribution of the irradiance delivered from dental light curing units.
Irradiance Uniformity and Distribution from Dental Light Curing Units
Journal of Esthetic and Restorative Dentistry, 2010
Problem: The irradiance from dental light-curing units (LCUs) is commonly reported as a single number, but this number does not properly describe the light output. Purpose: This study examined the irradiance uniformity and distribution from a variety of LCUs as well as the effect of different light guides. Materials and Methods: Five LCUs representing quartz-tungsten-halogen, plasma arc, and light emitting diode units were evaluated. One LCU was evaluated using two different light guides (Standard or Turbo style). The total power emitted from each LCU was measured and the irradiance calculated using conventional methods (ICM). In addition, a beam profiler was used to determine the optically active emitting area, the mean irradiance (IBP), the irradiance distribution, and the Top Hat Factor (THF). Five replications were performed for each test and compared using analysis of variance with Fisher's PLSD tests at a pre-set alpha of 0.05. Results: The spatial distribution of the irradiance from LCUs was neither universally symmetrical nor was it uniformly distributed across the tip end. Significant differences in both the emitted power and THF were found among the LCUs. The THF values ranged from a high of 0.74 Ϯ 0.01 to a low of 0.32 Ϯ 0.01. Changing from a standard to a turbo light guide increased the irradiance, but significantly reduced beam homogeneity, reduced the total emitted power, and reduced the optical tip area by 60%. Conclusions: Using different light guides on the same LCU significantly affected the power output, irradiance values, and beam homogeneity. For all LCUs, irradiance values calculated using conventional methods (ICM) did not represent the irradiance distribution across the tip end of the LCU. CLINICAL SIGNIFICANCE Irradiance values calculated using conventional methods assume power uniformity within the beam and do not validly characterize the distribution of the irradiance delivered from dental light curing units.
An Overview of Shade Selection in Clinical Dentistry
Applied Sciences
The selection of an accurate tooth shade has always been a challenging task for dental practitioners in restoring the natural appearance of teeth. Various factors can influence shade selection, such as different lighting conditions, clearness and opaqueness of teeth, eye fatigue, aging and color vision problems. It is imperative to have a sound knowledge about the concept of shades and its selection protocol for obtaining good esthetics outcomes. To attain the best esthetics, four elementary contributing factors are essential: exact position, shape, surface texture and shade. The current analysis focuses on several features of shade, sensitivity of shades, optical properties of the teeth, visual and innovative instrumental techniques for shade selection, protocols for shade selection and factors affecting dental shade selection.
The Journal of Prosthetic Dentistry, 2018
Tooth shade matching is mostly a trial and error method influenced by clinician proficiency, visual fatigue, and surrounding light source. 1 Accurate color reproduction with a restorative material is challenging. 2-7 Furthermore, patient expectations for the outcomes of the restorative treatment are often high. 8-10 Shade selection in dentistry can be performed by using both visual methods with a shade guide and instrumental methods such as using a spectrophotometer, a colorimeter, and, more recently, an intraoral digital scanner. 1,4,11 The human eye is efficient in detecting small differences in tooth color. 12,13 However, communicating such differences to the dental technician is complex. 12 The wide range of different tones, translucency, opacities, and characterizations of a tooth may not be detected. Visual shade matching is subject to variables such as age, sex, experience, type of scale used, different degrees of light exposure, eye fatigue, and physiological variables such as color deficiency, which may lead to inconsistencies. 14-21 Light-correcting devices are available to minimize lighting interference and to allow neutral clarity to assist
World Journal of Advanced Research and Reviews
Objective: The purpose of this study was to determine the intensity of the light power and the integrity of the active part of the curing lights of the Faculty of Dentistry Clinic of the University of Cuenca in the March-August 2022 term. Lack of knowledge of light-curing units, leads dentists to purchase low-quality equipment, thinking that they all work with the same efficiency, compromising the long-term success of restorations. Therefore, it is important to know the ideal characteristics of a light-curing lamp. Materials and methods: This is a descriptive and observational study whose sample is made up of 72 light-curing lamps assigned by the clinic and the lamps of each student who is attending the clinic. For the development of the project, a radiometer was used. Results: Of the 72 lamps analyzed, 54 (75%) are LED devices and they correspond to the students. Of which, 47 (87.03%) are effective because they have a power greater than 800 𝑚𝑊/𝑐𝑚2. On the other hand, the 18 (25%) a...