<ORIGINAL REPORT>Visual properties of dental local anesthetic injection needles can increase discomfort and anxiety

P(論文)We tested visual factors related to dental injection needles by evaluating discomfort and anxiety levels, to develop a visually comfortable dental local anesthetic injection needle and to provide more comfortable dental care for dental phobic or needle phobic patients. The subjects used in this study were people with high levels of trait-anxiety using the STAI valuation bases. The injection needles were obtained in a complete range of outside diameters and lengths, as follows : (A) 25G (0.5×30mm, color of syringe adaptor : green), (B) 27G (0.4×21mm, light brown), (C ) 30G (0.3×21mm, yellowish green), (D) 31G (0.28×16mm, gray), (E) 31G (0.28×12mm, pink) (Fig. 1). The subjects sitting in a dental chair were shown the five types of dental injection needles with dental cartridge syringes on a stainless steel tray with the bevels pointing at the volunteers' faces. The discomfort was evaluated by VAS (100-point scale, 100-mm width. No discomfort zero points, Unbearable discomfort 100 points) and anxiety levels by FAS (minimum score 0 and maximum score 5, scores of 2 and higher are equivalent to high levels of state-anxiety in the STAI valuation bases) (Fig. 2). The data were presented as a mean±S.E.. Statistical analysis was performed with Wilcoxon signed-rank tests. Ap-value of less than 0.05 was considered to show significance. The results showed that the VAS in descending point order were : A : 47.3±12.6, B : 37.6±12.6, D : 34.1±11.1, C : 32.1±11.3, E : 27.3±9.9 ; the A value was significantly higher than E (Table 1). The FAS in descending score order were : A : 2.84±0.49, B : 2.62±0.52, D : 2.49±0.49, C : 2.38±0.51, E : 1.98±0.42. Except E, all classified as high state-anxiety levels, because the FAS scores were higher than 2 (Table 2). The effect of the color of the syringe adaptor must also be considered as discomfort increased when changing it to silver (Table 3). In conclusion, our data suggest that dental or needle phobic patients feel strong discomfort and anxiety when seeing a metal dental cartridge syringe with a dental injection needle with outside diameter above 0.28mm and more than 16mm long.departmental bulletin pape