A pilot study applying digital radiography for estimating ratio of supported single-root surface area.
BACKGROUND
The prognosis of a tooth with periodontitis is affected by the amount of supporting bone. A key factor in retaining a tooth is the ratio of supported root surface. Currently, root surfaces cannot be accurately measured using conventional dental radiographs, which only measure the length of bone support on proximal surfaces.


METHODS
Eight extracted, single-rooted teeth were 3-dimensionally digitized using a contact technique for true surface area measurements. Root length, projection area, and pixel values were then measured on digital radiographs. The accuracy of the ratio estimation of supported surface area from linear, area, and pixel values was calculated and compared.


RESULTS
The mean error from linear estimation was 7.9%; the mean error from area estimation was 1.0%; and the mean error from pixel value estimation was 1.3%. One-way analysis of variance (ANOVA) showed significant differences in all estimations while Scheffé's analysis further revealed significant differences only in the linear estimation.


CONCLUSIONS
A three-dimensional digitizing device could be used as a non-destructive method of measuring root surface area. The ratio of supported single-root surface area could be estimated with high accuracy from the projected area data acquired on the digital dental radiographs. The thickness data as reflected from the pixel values in the digital images did not improve the estimation accuracy. Estimations using only length data yielded significantly less accuracy. Digital dental x-ray images provide the potential for estimating the ratio of supported root surface efficiently.
Chen
Ssu-Kuang
SK
School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan.
Pan
Ju-Hung
JH
Lin
Chi-Hao
CH
Leu
Liang-Jenq
LJ
Chen
Chung-Ming
CM
Jeng
Jeng-Ywan
JY
D000704:Analysis of Variance; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D009811:Odontometry / Q000379:methods*; D010865:Pilot Projects; D019252:Radiography, Dental, Digital; D015203:Reproducibility of Results; D014092:Tooth Root / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*