ABSTRACT
Osteomas are generally benign tumors of the skull that affect all age groups and are diagnosed in the fourth or fifth decade of life, and are rare in childhood. Surgical resection is curative and malignant transformation is very rare. A 12-year boy who had undergone a craniotomy for resection of a parietal osteoma four years ago, followed by a cranioplasty with methylmethacrylate bone cement, presented to our clinic with an expanding mass overlying the cranioplasty. Upon reoperation, the mass was totally excised, and the parietal cranial defect was repaired using methylmethacrylate bone cement. On histologic examination, the mass was found to be a recurrent osteoma overlying the methylmethacrylate bone cement. In this report, we discuss the etiologies of recurrence of osteoma and treatment options of these rare cases. We believe that this recurrence resulted from contamination of the surgical area and cranioplasty materials with osteoma material. Extensive washing of the cranioplasty materials and perioperative area may prevent recurrence of such tumors
ABSTRACT
PURPOSE: In this study, the shear bond strengths (SBS) of luting cements to fixed superstructure metal surfaces under various seating forces were investigated. MATERIALS AND METHODS: Seven different cements [Polycarboxylate (PCC), Glass-Ionomer (GIC), Zinc phospahate (ZPC), Self-adhesive resin (RXU), Resin (C&B), and Temporary cements ((RXT) and (TCS))] were bonded to a total number of 224 square blocks (5×5×3 mm) made of one pure metal [Titanium (CP Ti) and two metal alloys [Gold-Platinum (Au-Pt) and Cobalt-Chrome (Co-Cr)] under 10 N and 50 N seating forces. SBS values were determined and data were analyzed with 3-way ANOVA. Pairwise comparisons and interactions among groups were analyzed with Tukey's simultaneous confidence intervals. RESULTS: Overall mean scores indicated that Co-Cr showed the highest SBS values (1.96±0.4) (P .05). The PCC cement showed the highest mean SBS score (3.59±0.07) among all cements tested (P < .00), while the resin-based temporary luting cement RXT showed the lowest (0.39±0.07) (P < .00). CONCLUSION: Polycarboxylate cement provides reliable bonding performance to metal surfaces. Resin-based temporary luting cements can be used when retrievability is needed. GIC is not suitable for permanent cementation of fixed dental prostheses consisting of CP Ti or Au-Pt substructures.
Subject(s)
Alloys , Cementation , Dental Prosthesis , Metals , Polycarboxylate Cement , ZincABSTRACT
To investigate acute changes of systemic parameters following experimental subarachnoid hemorrhage [SAH] and cerebral vasospasm conditions created by intracistonal injection of fresh autologous blood in arabbit model the study was carried out at th neuro surgery clinic, Izmir Training and research Hospital, Izmir, Turkey between April 2002 and March 2005. Thirty-two male rabbits were divided into the following 4 groups: group one with mild hemorrhage received 0.5 cc of blood, group 2 with moderate hemorrhage received 0.7 cc of blood, group 3 with severe hemorrhage received 1 cc of blood, and the sham-operated group 4 with no blood. The clinical parameters of all animals were monitored 2 hours after the operation, and blood analysis was performed just after hemorrhage. A series of systemic parameters such as rectal temperature, systolic and diastolic blood pressure, and blood gas analysis were measured before and after administration of blood injection. Results were compared by analysis of variance and paired t-tests, and -P values less than 0.05 were considered significant. The systolic blood pressures were significantly different in groups 1, 2, and 3 before and after the bleeding period. The diastolic blood pressures were also considerably different. This study suggests that the presence of a blood clot and different amounts of blood in the subarachnoid space can evoke a series of changes in both local and systemic states in experimental models