title: [Comparison of clinical effect between spectrophotometric and conventional visual shade].
abstract: OBJECTIVE
  To study the feasibility of clinical application of the Crystaleye spectrophotometer, and compare the clinical effect of Crystaleye spectrophotometer with conventional visual shade.
  
  
  METHODS
  63 patients in need of an anterior or a first premolar Ni-Cr porcelain-fused-to-metal crown were enrolled in this study randomly. 2 crowns (crown V and crown S) were prepared for each patient. Crown V was made via conventional visual matching by a commercial shade guide, Vitapan classical method. Crown S was made via a new computer system, Crystaleye spectrophotometer. Crystaleye spectrophotometer was also applied to measure the color of the natural teeth and crowns. The color difference values (DeltaE) between the contralateral natural tooth and each of the 2 crowns were calculated in the middle regions. A paired-samples t test was performed based on the DeltaE using SPSS13.0 software package. The color reproducibility of crown V and crown S was evaluated by patients (p) and prosthodontists (d) visually using double-blind method (Vp,Vd,Sp,Sd). The results were evaluated by Chi-square test.
  
  
  RESULTS
  There was significant difference in the mean DeltaE between crown V(3.13+/-0.80) and crown S (2.68+/-0.72)(P<0.01). Results of visual evaluation were as follows: no significant difference was found between crown Vp and crown Sp (P=0.035); significant difference was found between crown Vd and crown Sd (P<0.01) there was also significant difference between crown p and crown d(P<0.01).
  
  
  CONCLUSIONS
  According to this clinical study, the crowns fabricated based on a dedicated spectrophotometer have a better color matching compared to the ones fabricated via a conventional shade-matching method. Crystaleye spectrophotometer is proved to be a promising instrument for determining tooth color in clinic.
authors: Department of Dental Implantology, Stomatology Hospital of Tianjin Medical University, Tianjin 300070, China. scarlett911@163.com
authors: Xia-heng
authors: XH
authors: Wang
authors: Li-min
authors: LM
authors: Chen
authors: Ping
authors: P
authors: Gao
mesh_terms: D003116:Color; D003442:Crowns; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D004311:Double-Blind Method; D006801:Humans; D008437:Maxilla; D008963:Molar; D015203:Reproducibility of Results; D013053:Spectrophotometry; D019228:Tooth Crown
chemical_list: D003776:Dental Porcelain