In vivo and in vitro assessment of an intraoral dental colorimeter.

PURPOSE: The purpose of this study was to assess the performance of an intraoral dental colorimeter. MATERIALS AND METHODS: In vivo repeatability of an intraoral colorimeter was assessed by performing color measurements of 30 individuals' right maxillary central incisor. Three consecutive measurements from each individual were made. In the in vitro part of the study, 25 metal-ceramic and 25 all-ceramic specimens were prepared. Five shades of metal-ceramic and all-ceramic specimens were selected for color determination. A widely recognized in vitro colorimeter was used as the control group for the in vitro performance assessment of the in vivo colorimeter. The color differentiation capability of two colorimeters was compared with the readings obtained from ceramic specimens. DeltaE values between shade groups of ceramic specimens were calculated and statistically analyzed with Student's t-test. The repeatability of the intraoral instrument was evaluated statistically with Intraclass correlation coefficient. RESULTS: The in vivo evaluation results showed that the overall repeatability coefficient values of L*, a*, and b* notations of the intraoral colorimeter were "excellent." The color differences (DeltaE) calculated between the colorimeters were significant only between shades A(1)-B(1) for metal-ceramic specimens (p= 0.002); however, from 5 of 10 shade couples of all-ceramic specimens, the color differences obtained from the readings of the in vivo colorimeter were significantly different from that of the in vitro colorimeter (p < 0.001). For all specimens, the differences between DeltaE values were within clinically acceptable limits (<3.5). CONCLUSIONS: Within the limitations of this study, the intraoral colorimeter exhibited successful in vivo repeatability; however, the color difference detection performance of the device varied depending on the translucency of the specimens.

Assessment of bone density differences between conventional and bone-condensing techniques using dual energy x-ray absorptiometry and radiography.

OBJECTIVES: We used dual energy x-ray absorptiometry (DEXA) and periapical radiography to assess bone density differences after conventional and bone-condensing dental implant techniques. STUDY DESIGN: Single-tooth dental implants were placed by both conventional and bone-condensing techniques in 14 patients with bilateral missing teeth. Dual energy x-ray absorptiometry was used to calculate bone mineral density (BMD) and bone mineral content (BMC) before and 6 and 12 months after implant placement. Furthermore, photodensitometry of periapical radiographs was also assessed. RESULTS: The success rate was 92.9% for the conventional technique and 71.5% for the bone-condensing technique. The BMD was observed to be significantly higher 6 and 12 months after implant placement. The BMC and photodensitometry were significantly increased 6 months after implant placement but showed no further after 12 months. CONCLUSIONS: There were no significant differences in BMD, BMC, and photodensitometry between the two implant placement techniques. However, success rate of the conventional technique was greater than the bone-condensing technique, which may be the result of trabecular fracture associated with the bone-condensing.