ABSTRACT
Context: Gracey curettes are the most frequently used manual instruments in periodontal treatments. Aim: This study aimed to evaluate morphology of working ends of standard and modified Gracey curettes no. 1-2. Materials and Methods: Using scanning electron microscopy, four batches of unused standard curettes from seven manufacturers and modified curettes from 6 manufacturers were investigated for blade length, blade width, blade thickness, toe morphology, surface roughness, and cutting-edge morphology. Results: Working ends of the standard Gracey curettes were longer than the modified ones, with mean lengths of 5.65 ± 0.68 and 4.42 ± 0.82 mm, respectively. However, both standard and modified Gracey curettes had comparable widths and thicknesses, with the mean width of 0.86 mm and the mean thickness of 0.71 mm. Most samples had acceptably symmetrical toes, except those from three manufacturers which had unacceptable toes with angulations. Moreover, only two manufacturers produced curettes with smooth blades on all their surfaces. In addition, sharp or functional wire edges were seen in cutting edges of curettes from three manufacturers. Conclusions: Working ends of standard and modified Gracey curettes could have different morphological features if they were from different manufacturers or different batches. It is suggested that dentists or dental hygienists make a purchase decision based on their knowledge on morphology of a good curette in relation to its intended use in dental practice, rather than their familiarity or the curette's price. Furthermore, the curette needs to be examined using a widely available magnifying device when possible.
ABSTRACT
OBJECTIVE: This study sought to investigate the toothbrush-dentifrice abrasion of dental sealants. MATERIALS AND METHODS: Weight loss (∆W) and depth loss (∆D) were used as abrasion indicators. Sealant samples from nine products were soaked in dentifrice slurry and abraded by using a toothbrushing machine with a brushing force of 300 g. The mean percentages of ∆W and mean values of ∆D after 24,000 and 48,000 strokes of brushing were compared by using paired t-test. A comparison of these mean values among sealant products was performed by using one-way ANOVA and multiple comparison analysis (Scheffe's test). RESULTS: Abrasive wear was observed in all sealants. Teethmate F-1 (Kuraray Noritake, Tokyo, Japan)-a fluoride-releasing unfilled sealant-exhibited the maximum abrasive wear, with ∆W and ∆D values of 1.14% ± 0.37% and 12.84 ± 4.28 µm, respectively. Delton (Dentsply Sirona, Charlotte, North Carolina, United States), a light-cured unfilled sealant, showed the minimum abrasive wear, with ∆W and ∆D values of 0.41% ± 0.09% and 2.93 ± 1.23 µm, respectively. No statistical differences were observed among unfilled sealants except when compared with Teethmate F-1. Similarly, no differences were observed when comparing among filled sealants and flowable composite. CONCLUSION: Abrasive wear occurred in all sealants after brushing with dentifrice. Almost all unfilled sealants showed less wear compared with both filled sealants and flowable composite. However, the low abrasive values of all sealants after brushing with dentifrice implied that there is no clinical significance to this finding.
ABSTRACT
OBJECTIVES/AIMS: This study aimed to improve effectiveness of red protective shields in filtering unwanted light using window films. MATERIALS AND METHODS: Red protective shields were modified by placing V-Kool (VK), Scotchtint (ST) or Hüper Optik (HP) window films on both sides. Percentage transmittance (%T) of light with a wavelength of 190-990 nm was determined using a double-beam ultraviolet (UV) and visible spectrophotometer. RESULTS: In UV light (190-390 nm) and visible light (430-590 nm) ranges, %T in all modified groups and the control was below 2.5%. An increase in %T was observed at the wavelength of 630 nm, when all the modified shields showed superior effectiveness in light filtration over the control. In the infrared spectrum (700-990 nm), %T in the control was constantly high, ranging from 86 to 91%, compared to %T of 2-38% in all the modified groups, with the application of VK on both sides being the most effective group, followed by a combination of VK and HP. CONCLUSION: This study has introduced an economical and simple, yet highly effective, means of enhancing the efficiency of a red plastic protection shield in filtering unwanted infrared light, thereby additionally providing protection for dental personnel from potential ocular damages.
