Fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses after artificial aging.

This study compared the fracture resistance of monolithic and veneered all-ceramic four-unit posterior fixed dental prostheses (FDPs) generated by computer-aided design/computer-aided manufacturing (CAD/CAM) after aging in a mastication simulator. Four-unit FDPs were designed from six different all-ceramic systems: 1) monolithic lithium disilicate (M-E), 2) monolithic zirconia (M-TZI), 3) veneered zirconia by conventional layering (V-L), 4) veneered zirconia by lithium disilicate pressing (V-P), 5) veneered zirconia by lithium disilicate fusing (CAD-F-E), and 6) veneered zirconia by feldspathic ceramic cementing (CAD-C-CB). The specimens were divided into control and aging groups (n = 10 per group). The aging process included both thermocycling and mechanical loading and was followed by fracture resistance testing. All specimens in the M-E, M-TZI, and V-L groups survived; however, all specimens in the V-P group were fractured during artificial aging. The highest fracture resistance values were observed in the M-TZI group. According to the fracture resistance test, connector fractures were the most frequent type of failure. M-TZI and M-E FDPs revealed no failures during aging and showed higher fracture resistance than the veneered groups. Among the veneered zirconia framework groups, V-L FDPs showed the highest success rate during aging, while the fracture resistance was similar among all the veneered zirconia groups.

A pilot study to evaluate the adhesion of oral microorganisms to temporary soft lining materials.

The aim of the study was to compare the adhesion of oral microorganisms to different types of soft liner and acrylic resin surfaces. Three different soft lining materials were applied to cavities formed on the fitting surfaces of prostheses in 17 patients. On days 1, 7 and 14, the specimens were taken out and immediately processed for bacteriological evaluation. The numbers of adhering microorganisms were calculated and the specimens were compared among each other and also with a control group (acrylic resin). Data were analyzed by two-way ANOVA and least squares differences at a significance level of P < 0.05. Among the four materials tested the total number of oral microorganisms adhering to Softliner material was the greatest after each of the time periods tested. Higher numbers of oral bacteria and Candida were shown to adhere to soft lining materials than to acrylic resin. Microbial coverage increased continuously with time and the differences between days 1 and 14 were statistically significant (P < 0.05). Temporary soft lining materials are not resistant to adhesion and possible surface damage caused by oral bacteria, and therefore their use should be limited to short-term periods.

Antibacterial and antifungal properties of polyether impression materials.

The aim of this study was to evaluate the antibacterial and antifungal properties of polyether impression materials using the agar diffusion test. Three different types of polyether impression materials (P2, Penta Soft and Penta) were tested to determine their ability to inhibit the growth of Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The areas of inhibition zones were measured visually with a 0.1-mm incremental Boley gauge. In all groups, none of the samples of the P2 polyether impression material exhibited antibacterial or antifungal activity against any of the microorganisms. All Penta Soft and Penta samples exhibited antibacterial activity against E. faecalis and S. aureus, and only Penta samples exhibited antifungal effect against C. albicans, which decreased progressively as the setting time of the material increased.

Aesthetic reconstruction of large scalp defects by sequential tissue expansion without interval.

Tissue expansion is indicated in the reconstruction of various scalp defects when there is inadequate adjacent tissue to allow either primary closure of the defect or repair with a local flap. It is the most important armamentarium for aesthetic hair-bearing scalp reconstruction in cases of congenital or required defects. This technique was used sequentially without interval to achieve scalp reconstruction for 12 patients with a defect ranging from 30% to 75% of the scalp (average, 55%). For 12 patients, 32 expansion treatments were undertaken between September 1997 and January 2002. The 12 patients included 3 women, 4 men, and 5 children with a mean age of 20 years (range, 45 days to 36 years). All patients had more than one period of treatment. The most common conditions treated were burns (n=7), trauma (n=1), congenital naevi (n=2), and male pattern baldness (n=2). Reconstruction of 12 large scalp defects has been performed with a 3.1% rate of major complications. Results show that tissue expansion is a safe and efficient but time-consuming technique for aesthetic scalp reconstruction, especially in the case of "sideburn" scenario or large defects. There was no significant alteration in ratio of complications although tissue expansions were made sequentially.

The use of lower turbinate bone grafts in the treatment of saddle nose deformities.

Saddle nose reconstruction is based on the use of support grafts to manage aesthetic and functional problems. Bone (calvarial, iliac crest, costal, nasal hump, ulnar, and heterogeneous origin), cartilage (septal, costal, heterogeneous), and synthetic materials (silicon, silastic, polyethylene) were used as support grafts. Three patients have been included in this study to define the surgical management and long-term aesthetic and functional results of patients undergoing rhinoplasty with support grafts for a saddle nose deformity. Open rhinoplasty was employed. Both the lower turbinates were excised and the bone dissected from the soft tissues in two cases and in one case, only mucosa was removed. The amount of support needed was measured by using bone wax. The bone was used shaped in layers, according to the defect, and sutured to each other by vycril suture, and wrapped around by surgicell. The graft was then inserted in its place and fixed with external prolene sutures. Results were satisfactory in both function and aesthetics. Ten to 16-month follow-ups had no complications. Saddle nose surgery basically requires the use of a support graft to repair the nasal dorsum. A lower turbinate bone graft procedure has some advantages: it is cheap and safe, it is ready to use and not time-consuming, there is no donor area and no additional donor site morbidity, and it enlarges the airway and the passage to prevent nasal airway obstruction.

Spontaneous cerebrospinal fluid rhinorrhea associated with chronic renal failure--case report.

A 39-year-old woman was admitted with complaints of headache and nasal discharge on the left for 3 months which was later on proved to be cerebrospinal fluid (CSF). Neurological examination found no abnormalities except bilateral papilledema. Neuroimaging demonstrated enlargement of the lamina cribrosa foramina through which the olfactory nerves pass, as well as empty sella and cerebral cortical atrophy. Bone mineral densitometry showed osteopenia. CSF Ca++ and blood parathyroid hormone levels were elevated. CSF pressure was 280 mmH2O. Bilateral frontal craniotomy was performed to expose the anterior fossa. Foraminal enlargement at the lamina cribrosa was confirmed, and islands of extra-osseous calcifications on the arachnoid membrane were identified. The base of the anterior fossa was repaired intradurally with fascial graft and fibrin glue on both sides. No CSF leakage was noted at 1-year follow up. Spontaneous CSF leakage probably resulted from enlargement of the foramina at the lamina cribrosa due to Ca++ mobilization from bones and pseudotumor cerebri not to the extent of hydrocephalus caused by poor CSF absorption at the arachnoid granulations obliterated by extra-osseous calcareous accumulation.

Solitary plasmacytoma of the calvarium.

A solitary plasmacytoma of the calvarium was removed radically without postoperative radiotherapy. A 69-year-old female patient was operated for a giant solitary plasmacytoma in the frontal region and the follow-up over 10 years revealed no recurrence. The authors discuss that solitary plasmacytoma of the calvarium may have a good prognosis if radically removed and the radiotherapy may not be necessary.

Bilateral vertebral artery occlusion following cervical spine trauma--case report.

A 41-year-old female presented with a rare case of bilateral vertebral artery occlusion following C5-6 cervical spine subluxation after a fall of 30 feet. Digital subtraction angiography showed occlusion of the bilateral vertebral arteries. Unlocking of the facet joint, posterior wiring with iliac crest grafting, and anterior fusion were performed. The patient died on the 3rd day after the operation. This type of injury has a grim prognosis with less than a third of the patients achieving a good outcome.

Cerebral alveolar hydatidosis: case report.

A young male patient, who previously was presumed inoperable due to an existing hepatic mass with multiple cerebral metastases, was referred to us from an oncology clinic ith signs of transtentorial herniation. An operation was performed promptly; the right parietal mass, which was totally removed, proved to be an alveolar hydatid cyst. He refused the operation proposed for the hepatic lesion and was discharged.

Solitary eosinophilic granuloma of the lumbar spine in an adult. Case report.

Eosinophilic granuloma of bone is the localised and most benign form of Langerhans-cell histiocytosis, previously known as histiocytosis X and is characterised by lytic lesions of one or more bones. It is a disease of children and adolescents, and very rarely affects adults. We report a 34-year-old patient with a solitary eosinophilic granuloma involving the fifth lumbar vertebra which produced sciatica. Operative treatment performed by a single extended posterior approach consisted of total resection of the tumour with hemicorporectomy, L4-5 and L5-S1 discectomy, interbody fusion with an iliac bone graft, and interpedicular fixation. Postoperatively, the symptoms resolved and the patient continues to do well at 2 1/2 years follow-up.

Distal posterior inferior cerebellar artery aneurysm association with multiple aneurysms.

A rare case of distal aneurysm of the posterior inferior cerebellar artery (d PICA) found in association with distal anterior cerebral artery (d ACA) and middle cerebral artery (MCA) aneurysms is described. d PICA aneurysm causing subarachnoid hemorrhage was successfully clipped. The aneurysmal sac was excised and examined pathologically; no infectious etiology was found. Aneurysms at other locations were not operated. The association of vascular anomalies with d PICA aneurysms is discussed.

Primary multiple hydatid cysts of the brain: case report.

Primary multiple hydatid cyst in the brain is uncommon. We report two large primary multiple hydatid cysts of the brain in an adult, which were removed without rupture by two separate operations.

Lipid peroxidation in experimental spinal cord injury: time-level relationship.

Damage which occurs following spinal traumas is often irreversible. During recent years free oxygen radicals formed due to the pathological changes following neural tissue ischemia have been identified as being responsible for the ethio-pathogenesis of such damage. In our experimental study, model lesions are formed in spinal cords of rats by standard trauma. Malondialdehyde (MDA), a lipid peroxidation product, was measured in the spinal tissues distal to the trauma in order to examine indirectly the time-quantity relationship of free oxygen radicals in the area. For this study 60 rats in six groups, including one control group, were used to determine the formation of MDA. Under a surgical microscope, the spines of all rats were exposed by C5-Th6 laminectomy, and pressure was applied to the spinal cords of animals, except the members of the control group, at the level of C7 by a Yasargil aneurysm clip. MDA was measured in spinal cord tissues in order to determine free oxygen radicals at the first and fifteenth minutes and at the first, second, and fourth hours. The statistical evaluation of the findings revealed a significant increase in MDA, starting from the 15th minute after the compression, reaching a maximum at 1 hour, and then decreasing. This observation may provide an important guide for studies on prevention of neural destruction.

Von Hippel-Lindau disease: analysis of two families.

In this report we present two families with von Hippel-Lindau syndrome. We operated on haemangioblastomas in two members, one from each, in our clinic. In the first family we saw 17 lesions in 9 members. Although in the first family carcinoma of the kidney was often observed, in the second family retinal haemangioma was found to be predominant, namely, in eight out of nine patients. In both families there were 11 patients with retinal haemangioma; of these, 9 patients were blind (82%). In 6 patients with retinal haemangioblastoma blindness was unilateral and bilateral only in one. All the patients with renal carcinoma were male and died young. In one of our patients with renal carcinoma we found metastatic lesions in the distal and proximal parts of the femur, vertebral arch, cranium and the thoracic wall. In these two families 23 members had 32 lesions, from which eleven were retinal haemangiomas (3 + 8), nine haemangioblastomas of CNS (5 + 4), one a renal cyst (0 + 1), eight renal carcinomas (7 + 1), two pancreatic cysts (1 + 1) and one liver cyst (0 + 1).

Skull base amyloidoma. Case report.

A mass lesion of amyloid involving the central nervous system is a rare finding. A 64-year-old woman presented with a large amyloidoma at the skull base causing neural tissue compression. The only accompanying disease was an asymptomatic renal cyst. The mass had caused destruction of the bone elements and pathological calcification as seen on x-ray films, computerized tomography (CT) scans, and magnetic resonance (MR) images, and was enhanced after injection of contrast medium on both CT scans and MR imaging.

Familial hemangioblastoma and von Hippel-Lindau's disease: case report.

Thirty-five members of a family affected with von Hippel-Lindau's disease (VHL) were examined and lesions were found in nine of them. Four of the lesions were located in the central nervous system; two cerebellar, one spinal, one cerebral. Eye lesions were present in eight of the nine patients and complications developed in seven; six unilateral and one bilateral blindness. Both mortality and morbidity were found to be higher than in other series. This is attributed to insufficient screening of the patients with familial VHL, the late diagnosis was established only after the onset of complications. The importance of screening tests in VHL risk patients is emphasized.

Entrapment neuropathy of the median nerve at the level of the ligament of Struthers.

The presence of a supracondylar process and Struthers' ligament is a rare congenital anomaly that may cause compression of either the median nerve, the brachial artery, or both. The authors present a case in which the supracondylar process and Struthers' ligament compressed both the median nerve and the brachial artery. This case is unusual, in that the symptoms of compression of the brachial artery increased--namely, the pulse intensity decreased and the pain increased with elbow flexion.