Digital Subtraction Radiography for Monitoring Dental Demineralization

The aim of the present study was to evaluate the assessment of progression of demineralization by digital subtraction radiography. In each of 14 extracted human teeth, 2 approximal enamel demineralization lesions were induced in vitro to simulate dental caries. A modified tunnel preparation with glass ionomer fillings was performed on one lesion of every tooth as a model of caries inhibition. Every week, radiographs were obtained under standardized conditions over a period of 42 days. The radiographs were digitized and calibrated for grayscales. Reference landmarks were chosen and aligned for the different pictures by computer–assisted imaging to adjust the images for projective distortions. The images of the 7th, 14th, 21st, 28th, 35th and 42nd day were subtracted from the baseline radiograph. The mean value of gray values of the subtraction images was calculated and ANOVA tests for repeated measurements and paired t tests were used for statistical analysis. The results of the present study indicate that statistically significant gray level changes due to progression of demineralization could be detected in the radiographic images by subtraction analysis. Differences between glass ionomer–filled and nonfilled lesions failed to reach significance. The introduced method may have the potential to detect and document minute caries progression.

[1]  Gröndahl Hg.  The influence of observer performance in radiographic caries diagnosis. , 1979 .

[2]  H. Gröndahl.  The influence of observer performance in radiographic caries diagnosis. , 1979, Swedish dental journal.

[3]  H G Gröndahl,et al.  Subtraction radiography for the diagnosis of periodontal bone lesions. , 1983, Oral surgery, oral medicine, and oral pathology.

[4]  S. Socransky,et al.  A method for the geometric and densitometric standardization of intraoral radiographs. , 1983, Journal of periodontology.

[5]  J. Boffa,et al.  A longitudinal analysis from bite-wing radiographs of the rate of progression of approximal carious lesions through human dental enamel. , 1984, Archives of oral biology.

[6]  D. Retief,et al.  Enamel and cementum fluoride uptake from a glass ionomer cement. , 1984, Caries research.

[7]  H G Gröndahl,et al.  Influence of variations in projection geometry on the detectability of periodontal bone lesions. A comparison between subtraction radiography and conventional radiographic technique. , 1984, Journal of clinical periodontology.

[8]  T. Okano,et al.  Diagnostic accuracy on detection of proximal enamel lesions in nonscreen radiographic performance. , 1985, Oral surgery, oral medicine, and oral pathology.

[9]  R. L. Webber,et al.  A robust digital method for film contrast correction in subtraction radiography. , 1986, Journal of periodontal research.

[10]  N. Pitts,et al.  Image analysis of bitewing radiographs: a histologically validated comparison with visual assessments of radiolucency depth in enamel , 1986, British Dental Journal.

[11]  M S Reddy,et al.  Extraoral control of geometry for digital subtraction radiography. , 1987, Journal of periodontal research.

[12]  Swift Ej.  An update on glass ionomer cements. , 1988 .

[13]  U Brägger,et al.  Digital imaging in periodontal radiography. A review. , 1988, Journal of clinical periodontology.

[14]  M. Cohen,et al.  False positive rates in the determination of changes in probing depth-related periodontal measurements. , 1988, Journal of periodontal research.

[15]  A Wenzel.  Effect of manual compared with reference point superimposition on image quality in digital subtraction radiography. , 1989, Dento maxillo facial radiology.

[16]  J van Aken,et al.  The effect of in-vivo-occurring errors in the reproducibility of radiographs on the use of the subtraction technique. , 1989, Journal of clinical periodontology.

[17]  Swift Ej.  Effects of glass ionomers on recurrent caries. , 1989 .

[18]  J. Mann,et al.  Assessment of the DMF-S index with the use of bitewing radiographs. , 1989, Oral surgery, oral medicine, and oral pathology.

[19]  E. Swift.  Effects of glass ionomers on recurrent caries. , 1989, Operative dentistry.

[20]  D. Benn.  Limitations of the digital image subtraction technique in assessing alveolar bone crest changes due to misalignment errors during image capture. , 1990, Dento maxillo facial radiology.

[21]  J. Gornbein,et al.  Prediction of efficacy of bitewing radiographs for caries detection. , 1990, Oral surgery, oral medicine, and oral pathology.

[22]  E. Kidd,et al.  A reappraisal of the value of the bitewing radiograph in the diagnosis of posterior approximal caries , 1990, British Dental Journal.

[23]  A Wenzel,et al.  Sources of noise in digital subtraction radiography. , 1991, Oral surgery, oral medicine, and oral pathology.

[24]  A. Firestone,et al.  Computer-based Image Analysis of Natural Approximal Caries on Radiographic Films , 1992, Journal of dental research.

[25]  D A Tyndall,et al.  Assessment of external root resorption using digital subtraction radiography. , 1992, Journal of endodontics.

[26]  W D McDavid,et al.  Digital subtraction radiography in artificial recurrent caries detection. , 1992, Dento maxillo facial radiology.

[27]  E. Bronkhorst,et al.  Applicability of Receiver Operating Characteristic (ROC) analysis on discrete caries depth ratings. , 1993, Community dentistry and oral epidemiology.

[28]  L C Carpio,et al.  Evaluation of a simple modified radiographic alignment system for routine use. , 1994, Journal of periodontology.

[29]  E Hausmann,et al.  Studies on the angular reproducibility of positioning patients adjacent to an x-ray tube. 2. A new electronically guided, force-sensitive sensor-based alignment system. , 1995, Journal of periodontal research.

[30]  W. Tay.  An update on glass-ionomer cements. , 1995, Dental update.

[31]  A. Farman,et al.  Observer differentiation of proximal enamel mechanical defects versus natural proximal dental caries with computed dental radiography. , 1996, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[32]  P. Eickholz,et al.  A method to monitor dental demineralisation in vitro. , 1996, Caries research.

[33]  P. Eickholz,et al.  Progression of dental demineralization with and without modified tunnel restorations in vitro. , 1997, Operative dentistry.

[34]  M K Jeffcoat,et al.  Semiautomated image registration for digital subtraction radiography. , 1998, Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics.

[35]  S. Hassfeld,et al.  Digital Radiography of Interproximal Caries: Effect of Different Filters , 1999, Caries Research.

[36]  J. Berg.  Glass ionomer cements. , 2002, Pediatric dentistry.