Dental Surface Texture Characterization Based on Erosive Tooth Wear Processes.

The differential diagnosis of dental wear lesions affects their clinical management. We hypothesized that surface texture parameters can differentiate simulated erosion, abrasion, and erosion-abrasion lesions on human enamel and dentin. This in vitro study comprised 2 parts (both factorial 4 × 2), with 4 lesion types (erosion, abrasion, erosion-abrasion, and sound [no lesion; control]) and 2 substrates (enamel and dentin). Flattened/polished dental specimens were used in part 1, whereas natural dental surfaces were used in part 2. Testing surfaces were evaluated in blind conditions, using average surface roughness (Sa) and the following scale-sensitive fractal analysis parameters: area-scale fractal complexity (Asfc), exact proportion length-scale anisotropy of relief (eplsar), scale of maximum complexity (Smc), and textural fill volume (Tfv). Two-way analyses of variance, followed by Fisher's protected least significant difference tests (α = 0.05), were used to evaluate the effects of lesion and substrate. Classification trees were constructed to verify the strength of potential associations of the tested parameters. In part 1,Asfc, Sa, and Tfv were able to differentiate erosion and erosion-abrasion lesions from the sound (no lesion) control in both substrates; only Asfc differentiated erosion and erosion-abrasion enamel lesions (allP< 0.05). The best association of parameters correctly classified up to 84% and 94% of the lesions on enamel and dentin, respectively. In part 2, only Asfc differentiated erosion and erosion-abrasion lesions from the sound (no lesion) control in both substrates, whereas eplsar was able to differentiate erosion from erosion-abrasion (allP< 0.05). The association of parameters correctly classified up to 81% and 91% of the lesions in enamel and dentin, respectively.Asfc, Sa, and Tfv were able to differentiate erosion and erosion-abrasion lesions, despite their complicated surface textures. The association of parameters improved the differentiation of lesions for both enamel and dentin in polished or natural surfaces.

Should echocardiography be performed to assess effects of antihypertensive therapy? Test-retest reliability of echocardiography for measurement of left ventricular mass and function.

OBJECTIVES: The purpose of this study was to determine the test-retest stability of echocardiography for the measurement of left ventricular mass and function in patients with hypertension. BACKGROUND: Determination of changes in left ventricular mass may be impaired by study variability. The amount by which variables of mass and left ventricular function must change in an individual patient to exceed temporal variability has not been determined in a multicenter trial. METHODS: Ninety-six patients with hypertension had two-dimensional targeted, M-mode Doppler echocardiography repeated at 6 +/- 8 days by the same technician utilizing the same machine. Left ventricular mass and variables of systolic and diastolic function were measured. Test-retest reliability and the width of the 95% confidence intervals of variable change, as well as the contributions of age, study quality and body size to measurement reliability, were determined. RESULTS: Despite excellent reliability (intraclass coefficient of correlation 0.86), the 95% confidence interval width of a single replicate measurement of left ventricular mass was 59g, exceeding usual decreases in mass during treatment. Study quality, which was dependent on age and weight, influenced test reliability. Although the confidence interval width for ejection fraction was narrow (5 U), those for peak early (E) and late (A) diastolic velocities were wide, resulting in a confidence interval width for the E/A ratio of 1.5. CONCLUSIONS: The temporal variability, particularly in obese or elderly patients, or both, of echocardiography for measurement of left ventricular mass precludes its use to measure changes in mass of the magnitude likely to occur with therapy. Measurement stability is affected by study quality, and age and body weight both influence study quality. Although ejection fraction shows little temporal variability, the large width of the confidence interval of the Doppler E/A ratio impairs its use to serially measure diastolic function.

Comparative analysis of noninvasive cardiac parameters in the detection and evaluation of adriamycin cardiotoxicity.

Serial electrocardiograms, phonocardiograms and echocardiograms were recorded in a prospective study of 45 closely-followed patients receiving chemotherapy with Adriamycin (doxorubicin hydrochloride, Adria Labs.). QRS voltage, systolic time intervals (STI), echocardiographic ejection fraction (EF) and rate of ventricular circumferential fiber shortening (Vcf) were compared as indicators of Adriamycin cardiotoxicity. Seven patients (16%) developed a decline in left ventricular function. Four of these seven patients (57%) developed symptoms and signs of congestive heart failure (CHF). The pre-ejection period/left ventricular ejection time (PEP/LVET) was earliest to change and was the least specific of the noninvasive parameters. The ejection fraction was the most specific parameter in predicting clinical cardiotoxicity. In every case of congestive heart failure, significant changes in ejection fraction, Vcf and PEP/LVET preceded the onset of symptoms, suggesting that measurement of the ejection fraction and systolic time intervals will allow early prediction and avoidance of heart failure. A fall in the ejection fraction of greater than or equal to 10% may represent sufficient grounds for discontinuing Adriamycin.