Peripheral ameloblastic fibroma: a rare case report.

CASE REPORT: Ameloblastic fibroma is a rare mixed odontogenic tumour which involves mostly the posterior mandible. Its peripheral variant is very rare. Only eight cases have been reported worldwide. In this report, we described a case of peripheral ameloblastic fibroma occurring in the maxillary gingiva in a 10 year-old child. The lesion was excised with a conservative surgical approach and no recurrence has occurred. Peripheral ameloblastic fibroma should be considered in the differential diagnosis of a slow growing lesion involving the gingiva.

Soft tissue regeneration using leukocyte-platelet rich fibrin after exeresis of hyperplastic gingival lesions: two case reports.

INTRODUCTION: Leukocyte-platelet rich fibrin belongs to a second generation of platelet concentrates that does not need biochemical blood manipulation. It is used for tissue healing and regeneration in periodontal and oral-maxillofacial surgery. We report two cases of hyperplastic gingival lesions treated by exeresis and application of leukocyte-platelet rich fibrin membranes in order to improve and accelerate tissue healing. CASE PRESENTATION: Two patients (a 78-year-old Caucasian woman and a 30-year-old Caucasian man) were treated for hyperplastic gingival lesions. They underwent to exeresis of lesions and application of leukocyte-platelet rich fibrin membranes. Tissue healing was clinically evaluated after 1, 3, 7, 14 and 30 postoperative days. No recurrences were observed after 2 years of semi-annual follow up. CONCLUSIONS: We obtained rapid and good healing of soft tissues probably due to the elevated content of leukocytes, platelets and growth factors in the leukocyte-platelet rich fibrin. Based on our results we suggest the use of leukocyte-platelet rich fibrin to cover wounds after exeresis of oral neoformations such as hyperplastic gingival lesions.

Treatment of a post surgery defect of the lower lip: a case report.

We present the clinical case of a patient, CT of 35 years who came to our observation for the appearance of a recurrent mucocele on the lower lip. The mucocele or retention cyst is a benign lesion of minor salivary glands characterized by swelling, which can vary from a few millimeters to several centimeters, as determined by retention of secretion due to partial or total obstruction of an excretory duct. Current thinking is that the mucocele is formed due to traumatic events or inflammatory, malformation of the excretory duct or parenchyma of the minor salivary glands. Once framed the patient from a clinical point of view we performed surgery, which provides complete enucleation of the lesion by about 7 mm. The clinical suspicion was confirmed by histological diagnosis as extraductal mucocele. After about six months after surgery, at complete healing, resulted a residual imperfections with a loss of substance in the area. To eliminate this defect, poorly tolerated by the patient, we decided to use a filler of hyaluronic acid, which, although it is an absorbable material, results in an excellent appearance and does not expose to complications like the use of inducible permanent.

Effectiveness of a new decisional algorithm in managing mandibular ameloblastomas: a 10-years experience.

We present a new treatment algorithm aimed to assist surgeons to develop a rational diagnostic protocol and establish effective conservative surgical management in patients with mandibular ameloblastoma. Fifteen consecutive cases treated by conservative management were reviewed. Data collected included age, sex, symptoms and signs at diagnosis, anatomical distribution of the lesions, numbers and types of operations, number of recurrences, and duration of follow-up post-operatively. Curettage was the first operation for all patients and they were closely followed-up post-operatively. During the follow-up period (4-10 years), small recurrences were diagnosed early in 7 patients who were treated by radical surgery including marginal or "box" resection. No further recurrences were observed after the second operation. When detected early, recurrences are small and surrounded by a large amount of uninvolved normal bone so it is possible to manage them with a radical resection, so lowering the risk of further recurrence and avoiding severe cosmetic and functional problems.

Peri-implant tissue healing in implant placed in post-extraction sockets of maxillary premolars.

AIM: The aim of this study was the clinical and radiographic evaluation of peri-implant tissues healing associated with two-stage implants performed with one-stage surgery and placed into post-extraction sockets of maxillary premolars. METHODS: Ten natural tapered submerged titanium implants with double acid-etched surface were installed in post-extraction sockets of maxillary premolars showing no bone dehiscence or fenestrations. Implants were selected according to the greatest dimension compatible to vertical and horizontal diameters of the post-extraction sockets. Peri-implant defects showing more than 2 mm of distance between the marginal palatal bone and the implant margin, were not treated with a regenerative procedure but with a bone swaging technique by means of piezoelectric surgery. At 16 weeks osteointegration of implants was examined with a clinical and standardized radiographic evaluation. RESULTS: All patients showed good clinical healing without any complication. At 16 weeks all implants, either those with reduced marginal defect or those with modified crestal bone profile, were osteointegrated. CONCLUSIONS: The use of two-stage implants performed with one-stage surgery in 4 walls post-extraction sockets of maxillary premolars, seems to allow osteointegration both in reduced peri-implant horizontal defects as well as in defects larger than 2 mm. Furthermore, these procedures seem to simplify the management of soft peri-implant tissues.

Different titanium surfaces modulate the bone phenotype of SaOS-2 osteoblast-like cells.

Commercially pure titanium implants presenting a relatively smooth, machined surface or a roughened endosseous surface show a large percentage of clinical success. Surface properties of dental implants seem to affect bone cells response. Implant topography appears to modulate cell growth and differentiation of osteoblasts affecting the bone healing around the titanium implant. The aim of the present study was to examine the effects of 1cm diameter and 1mm thick titanium disks on cellular morphology, adhesion and bone phenotypic expression of human osteoblast-like cells, SaOS-2. SaOS-2 cells were cultured on commercially 1 cm pure titanium disks with three different surface roughness: smooth (S), sandblasted (SB) and titanium plasma sprayed (TPS). Differences in the cellular morphology were found when they were grown on the three different surfaces. An uniform monolayer of cells recovered the S surface, while clusters of multilayered irregularly shaped cells were distributed on the rough SB and TPS surfaces. The adhesion of SaOS-2 cells, as measured after 3h of culture, was not affected by surface roughness. ECM components such as Collagen I (CoI), Fibronectin (FN), Vitronectin (VN) and Tenascin (TN) were secreted and organized only on the SB and TPS surfaces while they remained into the cytoplasm on the S surfaces. Osteopontin and BSP-II were largely detected on the SB and TPS surfaces, while only minimal production was observed on the S ones. These data show that titanium surface roughness affects bone differentiation of osteoblast like-cells, SaOS-2, indicating that surface properties may be able to modulate the osteoblast phenotype. These observations also suggest that the bone healing response around dental implants can be affected by surface topography.

[In vitro effects on rough implant surfaces of different instrumentations used in the surgical therapy of peri-implantitis]. / Effetti in vitro su superfici implantari rugose di differenti strumentazioni in uso nella terapia chirurgica della peri-implantite.

BACKGROUND: In vitro evaluation of the effects of different mechanical and manual instruments on rough implant surfaces coated with hydroxyapatite (HA) or titanium plasma sprayed (TPS). METHODS: Fourteen cylindrical rough implants have been used, 7 HA coated and 7 TPS coated. 1 HA and 1 TPS implant have been used as control. Implants, splitted in two surfaces for a total of 24 experimental areas, have been treated by ultrasonic scaler tips, stainless-steel curettes, plastic curettes and air-powder polishing. Instrumented surfaces have been examinted under light microscope by different examiners and then evaluated under scanning electron microscope. RESULTS: All experimental procedures have determined alterations of rough implant surfaces. Ultrasonic scaler tips and stainless-steel curettes have modified the surface topography of the coating in almost all samples examinted under light microscope, while alterations induced by plastic curettes and air-powder polishing have been detected respectively in 30% and 60% of the treated surfaces. The type of alteration was related to implant coating material and to the procedures used, and it may consist in coating removal or decreasing of surface roughness. The effect of ultrasonic scaler tips, although more aggressive, seems to be more limited compared to the other procedures. CONCLUSIONS: Ultrasonic scaler tips may be used in conjunction with a magnification system to limit the instrumentation to areas with bacterial deposits extremely adherent or calcified.

Platelet 3H-imipramine binding in bipolar patients.

Platelet 3H-imipramine binding was investigated in 31 control subjects and 19 hospitalized bipolar patients, either in the hypomanic or the depressed phase of illness. The mean Bmax value in the bipolar depressed patients did not differ significantly from that in the control subjects or the hypomanic patients. Differences in timing of the assay after blood collection, membrane preparation, protein content used in the assay, or binding of radioactive ligand to the equipment do not appear to explain the discrepancy between these results and previous findings.

Glutamate dehydrogenase in human brain: regional distribution and properties.

Glutamate dehydrogenase (GDH) activity was studied in 17 regions of six human brains. Duration and conditions of the postmortem period did not affect enzyme activity. Specific activity ranged between 103 and 377 nmoles/min/mg protein at 25 degrees C and it was 10-fold higher than that found in leukocytes. Apart from exclusively white matter regions (corpus callosum and centrum ovale), there was a moderate regional distribution (2.5-fold variation), with highest values in the inferior olive and hypothalamus, and lowest in the cerebellum and lenticular nucleus. With alpha-ketoglutarate (alpha-KG), NADH, or NH4+ as variable substrate, the apparent Km values in human brain were Km alpha-KG = 1.9 X 10(-3) M, KmNADH = 0.21 X 10(-3) M, and KmNH4+ = 28 X 10(-3) M, and in leukocytes they were Km alpha-KG = 1.7 X 10(-3) M, KmNADH = 0.24 X 10(-3) M, and KmNH4+ = 28 X 10(-3) M. The effects of cofactors, inhibitor, and pH were similar in brain and leukocyte GDH.

No circadian rhythms of serotoninergic, alpha-, beta-adrenergic and imipramine binding sites in rat brain regions.

Bmax values of the specific binding of [3H]-WB 4101, [3H]-dihydroalprenolol, [3H]-spiperone and [3H]-imipramine to various rat brain regions were determined at 4 hr intervals over 24 hr under circadian conditions. No significant circadian rhythm of binding sites number was found for any receptor investigated in cerebral cortex, hypothalamus or brain stem. Some methodological issues are discussed.

Blood cells as biological trait markers in affective disorders.

Data are reviewed on platelet monoamine oxidase activity, red blood cell/plasma lithium ratio, and tritiated imipramine binding to platelet membranes as trait markers for affective disorders. The results of various studies are not in agreement. Differences in methodological procedure are probably central to such discrepancies. At the present time, no single biological abnormality of blood cells has proved to be a trait marker for affective disorders; thus their use to identify vulnerability to mood disorders or predict favourable response to pharmacological treatment appears to be premature.

Specific high-affinity binding of L-[3H]aspartate to rat brain membranes.

The binding of L-[3H]aspartate was investigated in washed membranes prepared from whole rat brain. We were able to differentiate two separate binding sites differing in their Na dependence. The Na-independent binding was saturable, reversible, and optimal at 20 degrees C and at pHs in the neutral range. The dissociation constant (Kd) at 20 degrees C was about 200 nM. This binding site seemed to be modulated by magnesium and calcium at physiological concentrations. None of the amino acids tested was a potent competitor for Na-independent L-[3H]aspartate binding. This binding site was unevenly distributed in the rat central nervous system: cerebellum = cerebral cortex greater than pons-medulla greater than spinal cord. Destruction of the intrinsic neurons of the cerebellum by injecting kainic acid 30 days before sacrifice resulted in a 53% reduction in Na-independent binding in this region. The Na-dependent binding of L-[3H]-aspartate (Kd = 4894 nM) was strongly inhibited by D-aspartate, L-glutamate, D,L-aspartate beta-hydroxamate; was unaffected by calcium and magnesium; and showed a different pattern of distribution: cerebral cortex greater than cerebellum = pons-medulla = spinal cord. This binding in cerebellum was unaffected by injections of kainic acid.

Is aspartic acid the neurotransmitter of the perforant pathway?

In order to determine whether an amino acid may act as a neurotransmitter in the perforant pathway we examined the effect of lesion of rat entorhinal cortex on the concentrations of various amino acids in the hippocampus proper and fascia dentata. Only the aspartic acid content was found significantly decreased after the lesion. This decreases is not due to a loss from target cells of the perforant pathway, but rather to a loss from its degenerating terminals.