Determining cutting efficiency of nickel-titanium coronal flaring instruments used in lateral action.

AIM: To develop a method to evaluate the cutting behaviour of nickel-titanium (NiTi) coronal flaring instruments. METHODOLOGY: BioRaCe BR0 (BR), HyFlex CM 1 (HY), ProFile OS No. 2 (PF) and ProTaper Sx (PT) instruments were used in simulated coronal flaring using a lateral action against bovine dentine blocks, at 250 and 500 rpm. Cutting efficiency was assessed by three methods: first, areas of notches produced by instruments were directly measured under a stereomicroscope. Second, dentine specimens were then analysed by surface profilometry to determine the maximum cutting depth and finally by microcomputed tomography to assess the volume of removed dentine. Data were compared using parametric tests with the significance level set at 0.05. RESULTS: For all three methods, HY and PF were the most and the least cutting-efficient instruments, respectively (P < 0.05). Significant differences were detected between 250 and 500 rpm for HY and PT (area); for BR, HY and PT (depth); and for BR and HY (volume). There were strong positive correlations between the results obtained with those three different methods with r-values ranging from 0.81 to 0.92. CONCLUSION: Measuring the amount of material removed in a specific time under stereomicroscopy is a simple and rational way to assess the cutting behaviour of NiTi rotary instruments in lateral action. HyFlex, manufactured with thermomechanically treated NiTi wire, was the most efficient instrument, and increased rotational speed was associated with increased cutting efficiency.

Micro-Raman spectroscopic investigation of dental calcified tissues.

The purpose of this study was to determine if dental calcified junctions (DEJs/CDJs) in human teeth contain different compositional phases compared to the adjacent dental calcified tissues. Peak positions and intensities were determined from micro-Raman spectra for PO(3-) (4) and the C--H modes and compared among the mineralized tissues and their junctions. Values of width were determined from the intersections of intensity regression lines through the junctions and in the adjacent tissues. The peaks were measured in 1-microm steps along a l00-microm line across the junction. High-resolution analysis revealed that PO(3-) (4) band peaks for dentin, the DEJ, enamel, the CDJ, and cementum were at the same position (959 cm(-1)), while for the C--H stretching mode a significant shift of 4.6 cm(-1) was found between enamel, the DEJ, and dentin. The mean width of the DEJ was 7.6 (+/- 2.8) microm using the PO(3-) (4) band and 8.6 (+/- 3.6) microm using the C--H stretching mode. Across the DEJ, the mineral content monotonically decreased from enamel to dentin while the organic component monotonically increased. The DEJ width was in agreement with prior nanoindentation studies. No width estimate was possible for the CDJ because the compositional differences between cementum and dentin were small.

Selective diagnostic uroradiography for trauma.

Fifteen years of personal experience have yielded 157 penetrating and 225 blunt urological injuries, including only 2 instances of simultaneous upper and lower tract involvement (0.5 per cent). A similar review of 2,750 cases from the urological literature has yielded only 17 patients with simultaneous upper and lower tract injuries (0.6 per cent). Blunt trauma was responsible in all but 1 of these 17 patients (95 per cent). Based upon these observations, it is suggested that comprehensive radiographic evaluation of traumatic hematuria or suspected occult urological trauma unnecessarily may be expensive and dilatory, and that evaluation may be limited routinely to the area of maximum injury.

Ventral bladder hernia following Marshall-Marchetti-Krantz procedure for stress urinary incontinence.

Ventral herniation of the bladder occurred in 2 patients following Marshall-Marchetti-Krantz procedures for stress incontinence. Symptoms included suprapubic pain, urgency, incontinence, and a ventral abdominal hernia. The diagnosis was easily established by cystography in both patients. Possible etiologic factors included postoperative wound infection in 1 patient and possibly suspension of the anterior bladder to the pubis in the other.

Evaluating the undescended testis.

This problem is often associated with other anomalies which, if present, are usually evident on the initial examination. Therapy before age two is mandatory to preserve fertility. The malignant potential of undescended testes is well established. Placement of the testes into the scrotum facilitates frequent examinations. All postpubertal patients with intra-abdominal testes, as well as patients who have inguinal testes and are between puberty and age 50, should be referred for orchiectomy.

Encrustation and stone formation: complication of indwelling ureteral stents.

Severe encrustation and stone formation on indwelling ureteral stents in 2 patients with a lithogenic history are reported. In both cases this complication occurred in the presence of sterile urine and treatment required pyelolithotomy in one and renal pelvic irrigation with urologic G solution in the other. Analyses of these stones revealed struvite and apatite, respectively. Dissolution of encrustations and stones via renal pelvic irrigation is suggested as a viable alternative to surgical intervention for this problem. A review of the literature shows a correlation between chronic stone formers and stent encrustation, rather than from bacteriuria alone. Long-term antibiotic suppression, more frequent followup with abdominal roentgenograms, and shorter periods of internal stenting are suggested for patients with a lithogenic history.

Urethral duplication and complete bladder exstrophy.

Urethral duplication is a rare anomaly that has been classified into epispadiac, hypospadiac, spindle, Y-duplications and collateral varieties. We report a case of an accessory urethra associated with complete bladder exstrophy in which the accessory urethra was integrated into the epispadias repair. To our knowledge this is the first case reported of urethral duplication associated with bladder exstrophy.

Use of scrotal skin to cover cutaneous defects resulting from palliative lymph node dissections in groin and suprapubic area.

Scrotal skin was employed to cover skin defects resulting from palliative groin and suprapubic dissections designed to remove large masses of tumor which had eroded the skin. This technique provides a simple and effective alternative to more complex procedures using rotational skin and myocutaneous flaps to achieve primary skin closure in similar circumstances.