Hanan Elgendy1, Rodrigo Rocha Maia2, Fredrick Skiff3, Gerald Denehy2, Fang Qian4. 1. Department of Operative Dentistry, College of Dentistry, University of Iowa, Iowa City, IA, USA. Hanan-elgendy@uiowa.edu. 2. Department of Operative Dentistry, College of Dentistry, University of Iowa, Iowa City, IA, USA. 3. Department of Physics and Astronomy, College of Liberal Arts & Sciences, University of Iowa, Iowa City, IA, USA. 4. Division of Biostatistics and Research Design, Iowa Institute for Oral Health Research and Department of Preventive and Community Dentistry, College of Dentistry, University of Iowa, Iowa City, IA, USA.
Abstract
OBJECTIVE: This study used three LASERs (red, green, and blue) with a spectrophotometer to compare the light propagation for the following: absorption (A), transmittance (T), attenuation (K), and scattering anisotropy coefficient (g) in dental tissues and nano-filled resin-based composites. This study used three distinct incremental build-up techniques, which included one shade (body), two shades (enamel and dentin), and three shades (enamel, transparent, and dentin). METHODS: Twenty human, un-erupted, recently extracted third molars (shade B1) were used to obtain 40 tooth slabs. The samples were randomized and equally distributed into four experimental groups. The Positive Control Group included dental tissues with enamel, dento-enamel junction DEJ, and dentin; the Technique 1 group (T1) included one shade tissues, B1B; the Technique 2 group (T2) included two-shades tissues, A2Dentin and B1Enamel; and the Technique 3 group (T3) included three shade tissues, A2Dentin, Transparent, and B1Enamel. Cavity preparation was standardized, and, using the spectrophotometer, each specimen was irradiated by three LASERs. A voltmeter recorded the light-output signal, and from this raw data, the following optical constants (A, T, K, g) were calculated. RESULTS: ANOVA, followed by a post hoc Tukey's test (p < 0.05), revealed that absorption and transmittance in dental tissues were significantly different when comparing the three build-up technique groups. However, when examining attenuation coefficient, there was no significant difference in dental tissues for T2 and T3 as analyzed by blue and red lasers. There was also no significant difference among the three lasers for T2 and T3. There was also no significant effect of the types of experiments on the value of scattering anisotropy factor g for blue laser among the four experimental groups. CONCLUSION: Within the limitations of this study, none of the build-up techniques were able to reproduce the dental tissues optical properties, and T2 and T3 resulted in a similar pattern of light propagation. CLINICAL SIGNIFICANCE: The clinical success of restorative procedures depends on selecting materials and techniques that emulate the natural tooth and provide long-term stability in color and optical properties.
OBJECTIVE: This study used three LASERs (red, green, and blue) with a spectrophotometer to compare the light propagation for the following: absorption (A), transmittance (T), attenuation (K), and scattering anisotropy coefficient (g) in dental tissues and nano-filled resin-based composites. This study used three distinct incremental build-up techniques, which included one shade (body), two shades (enamel and dentin), and three shades (enamel, transparent, and dentin). METHODS: Twenty human, un-erupted, recently extracted third molars (shade B1) were used to obtain 40 tooth slabs. The samples were randomized and equally distributed into four experimental groups. The Positive Control Group included dental tissues with enamel, dento-enamel junction DEJ, and dentin; the Technique 1 group (T1) included one shade tissues, B1B; the Technique 2 group (T2) included two-shades tissues, A2Dentin and B1Enamel; and the Technique 3 group (T3) included three shade tissues, A2Dentin, Transparent, and B1Enamel. Cavity preparation was standardized, and, using the spectrophotometer, each specimen was irradiated by three LASERs. A voltmeter recorded the light-output signal, and from this raw data, the following optical constants (A, T, K, g) were calculated. RESULTS: ANOVA, followed by a post hoc Tukey's test (p < 0.05), revealed that absorption and transmittance in dental tissues were significantly different when comparing the three build-up technique groups. However, when examining attenuation coefficient, there was no significant difference in dental tissues for T2 and T3 as analyzed by blue and red lasers. There was also no significant difference among the three lasers for T2 and T3. There was also no significant effect of the types of experiments on the value of scattering anisotropy factor g for blue laser among the four experimental groups. CONCLUSION: Within the limitations of this study, none of the build-up techniques were able to reproduce the dental tissues optical properties, and T2 and T3 resulted in a similar pattern of light propagation. CLINICAL SIGNIFICANCE: The clinical success of restorative procedures depends on selecting materials and techniques that emulate the natural tooth and provide long-term stability in color and optical properties.
Authors: Francesco Guido Mangano; Uli Hauschild; Giovanni Veronesi; Mario Imburgia; Carlo Mangano; Oleg Admakin Journal: BMC Oral Health Date: 2019-06-06 Impact factor: 2.757