Use of supercharged cover screw as static magnetic field generator for bone healing, 1st part: in vitro enhancement of osteoblast-like cell differentiation.

Since 1979, Pulsed electromagnetic fields (PEMFs) have been approved by the Food and Drug Administration as an effective method in the treatment of non-unions. As well as PEMFs, also static magnetic fields (SMFs) have been widely investigated in orthopaedic studies. Even if the exact mechanism of action is not well understood, a large number of studies showed specific effects both at cellular and tissue levels. As bone fracture healing and osseointegration share the same biological events, the application of magnetic field stimulation in order to facilitate the osseointegration process has been suggested. In this study we investigated the proliferation rate and gene expression profile of MG63 osteoblastic-like cells after a 24, 48 and 72-hour SMF stimulation, generated by a small, customized cover screw-shaped neodymium-iron-bore magnet placed in the inner cavity of a dental implant. As a result, we found that the application of a SMF to osteoblastic-like cells does slightly decrease cell proliferation rate while enhancing the expression of those genes correlated to differentiation and mineralization. Our findings represent, to our knowledge, the first clinical ready technique for dental implants showing the ability of SMF to promote the osteogenesis process in vitro.

Use of supercharged cover screw as static magnetic field generator for bone healing, 2nd part: in vivo enhancement of bone regeneration in rabbits.

In 1979, Pulsed electromagnetic fields (PEMFs) were approved by the Food and Drug Administration as an effective method in the treatment of non-unions. As well as PEMFs, also static magnetic fields (SMFs) have been widely investigated in orthopaedic studies. Even if the exact mechanism of action is not well understood, a large number of studies showed specific effects both at cellular and tissue levels. As bone fracture healing and osseointegration share the same biological events, the application of magnetic field stimulation in order to facilitate the osseointegration process has been suggested. In this study we investigated BIC and newly formed bone volume around dental implants inserted in the tibia of New Zealand rabbits after SMF stimulation, generated by a small-customized cover-screw-shaped neodymium-iron-bore magnet placed in the inner cavity of dental implants. As a result, we found that the SMF field generated around dental implants enhanced bone healing in the animal model. Our findings represent, to our knowledge, the first ready clinical technique for dental implants showing the ability of SMF to promote the osteogenesis process in vivo.

Pre-clinical evaluation of a new coral-based bone scaffold.

Coral is used worldwide for bone reconstruction. The favorable characteristics that make this material desirable for implantation are (i) osteoinduction, (ii) and osteoconduction. These proprieties have been demonstrated by in vivo studies with animal models and clinical trials over a twenty-year period. Also poly(2-hydroxyethylmethacrylate) [poly(HEMA)] is a widely used biomaterial. By using coral and poly(HEMA), a scaffold for bone reconstruction application has been recently synthesized. Cytological, histological and genetic analyses were performed to characterize this new alloplastic material. Four samples were analyzed: (a) white coral (WC), (b) red coral (RC), (c) WC plus polymer (WCP) and (d) RC plus polymer (RCP). Quantification of mitochondrial dehydrogenase activity by MTT assay was performed as indirect detector of cytotoxicity. In vivo effects were revealed by implanting corals and coral-based polymers in rabbit tibia. Samples were collected after 4 weeks and subjected to histological analysis. To evaluate the genetic response of cells to corals and coral-derived polymers an osteoblastlike cell line (i.e. MG63) was cultured in wells containing (a) medium, (b) medium plus corals and (c) medium plus two types of scaffolds (RCP or WCP). RNAs extracted from cells were retro-transcribed and hybridized on DNA 19.2K microarrays. No cytotoxicity was detected in corals and coral-based biopolymers. No inflammation or adverse effect was revealed by histological examination. By microarray analysis 154 clones were differentially expressed between RC and WC (81 up and 73 down regulated) whereas only 15 clones were repressed by the polymer. Histological evaluation not only confirmed that coral is a biocompatible material, but also that the polymer has no adverse effect. Microarray results were in agreement with cytological and histological analyses and provided further data regarding the genetic effects of RC, WC and the new polymer.

Osteopontin, osteocalcin and OB-cadherin expression in Synthetic nanohydroxyapatite vs bovine hydroxyapatite cultured Osteoblastic-like cells.

Calcium phosphate ceramics have been applied in bone replacement for several decades due to their excellent biocompatibility, bioactivity, osteo-conductivity and mechanical strength. Several studies have demonstrated that porous hydroxyapatite (HA) is an excellent scaffold for osteogenic proliferation and differentiation of the osteoprogenitor cells. However, different methods of synthesis and production of HA ceramic-based materials may have considerable effect on the physical and biological properties. In the present work, two hydroxyapatite-based materials, a natural hydroxyapatite ceramic of bovine origin and a synthetic nano-cristalline hydroxyapatite were tested in vitro with MG63 cell line. The results displayed that both the materials demonstrated a good biocompatibility. The immunocytochemical stain revealed a different positivity of the osteogenic markers between the cultures with the biomaterials, and the control culture. Western blot data confirmed the immunocytochemical stain. Both the materials tested in the present study demonstrated a good biocompatibility with the osteoblastic cells allowing, at the same time, the osteogenic differentiation, and they may be useful in clinical use.

Expression of poly(ADP-ribose) polymerase in bone regeneration.

Poly(ADP-ribose) polymerase (PARP) is a 116kDa enzyme catalysing the synthesis of ADP-ribose polymers from NAD+. PARP is activated in response to DNA strand breaks and plays a critical role in the maintenance of genomic integrity. However, considering its role also in transcription, proliferation as well as apoptosis in biological process, in the present study the role of PARP in bone regeneration was evaluated, in particular in bone cell proliferation and differentiation processes. Thus, formalin fixed paraffin embedded specimens of 10 human bone samples after sinus lift were collected and investigated by immunohistochemistry using a mouse monoclonal anti-human PARP antibody. PARP was expressed in cells with morphological features of osteoblasts in the areas of new bone formation at the junction between mineralized and unmineralized tissue, between osteoid tissue and bone. Few osteoclasts were observed and showed only focal nuclear expression of PARP, while osteocytes showed no positivity for PARP. Our data showed an overall involvement of PARP enzyme in human bone tissues, in particular during bone regeneration process.

Laparoscopic versus laparotomic approach to endometrial cancer.

OBJECTIVE: The aim of our study was to compare the feasibility, morbidity, long-term safety, disease-free survival, and overall survival of the laparoscopic (LPS) approach to early-stage endometrial cancer (EC) compared to the traditional laparotomic approach. METHODS: We reviewed retrospective data of patients who underwent primary surgery from 1997 to 2009. We recorded clinical parameters, surgical stage, histological type, operative and peri-operative complications, time to resumption of normal functions, conversion to laparotomy, overall survival, and disease-free survival. RESULTS: LPS, did not increase operative risk and peri-operative complications even in obese and older women. The number of pelvic lymph and aortic nodes removed was similar for the two groups. One hundred and eight patients had a follow-up of 60 months. The two groups were similar for disease-free survival and overall survival. CONCLUSIONS: Laparoscopic approach to EC provides a reduction in postoperative complications and hospital stay compared to the laparotomic approach.

Videoendoscopic assisted curettage of central giant cell granuloma of the maxilla in pediatric age.

Giant cell granuloma is an uncommon bony benign lesion that generally involves the mandible and maxilla. It may be locally aggressive and result in extensive tissue destruction in advanced cases. Surgery is the traditional and still the most accepted treatment for giant cell granuloma. We report a pediatric case of central giant cell granuloma of the maxilla treated with videoendoscopic assisted surgical excision.

Fiber-reinforced composite inlay fixed partial dentures: the influence of restorative materials and abutment design on stress distribution investigated by finite element model.

AIM: Fiber-reinforced composite may be successful used to fabricate inlay fixed partial dentures. This study used a finite element model to investigate three-dimensional stress distribution in a 3-unit fiber-reinforced composite fixed partial denture, and compared three types of fiber and three abutment configurations. METHODS: A finite element model of a 3-unit fixed partial denture was used to investigate stress distribution in three different fiber-reinforced composite systems (1) Ribbond Triaxial plus Sinfony; 2) EverStick plus Sinfony; 3) Vectris Pontic/Frame plus Sinfony) and in three different abutment configurations (minimal distal-occlusal and mesial-occlusal preparation; extensive distal-occlusal and mesial-occlusal preparation; mesial-occlusal-distal preparation of both abutment teeth). Maximum load of 196 N was applied at the center of the occlusal and buccal surfaces of the pontic. Stress distribution was calculated in the tooth/restoration complex and in the abutment preparation. RESULTS: When a vertical load was applied, no substantial differences between stress amount in the molar and in the premolar connectors was found. When a lateral load was applied, the stress was greater in the premolar connector than in the molar connector. In all designs investigated, stress was concentrated at the cervical margins of the proximal boxes adjacent to the pontic; no stress concentrated at the occlusal box preparation surface. CONCLUSIONS: Within the limitations of this study, the results suggest that different fiber-reinforced composite systems show similar pattern of stress distribution. Stress concentrates at the connector areas and in the prepared teeth. Peak stress is at the cervical margin of the boxes adjacent to the pontic.

Coeliac disease: oral ulcer prevalence, assessment of risk and association with gluten-free diet in children.

AIMS: Oral mucosal lesions may be markers of chronic gastrointestinal disorders, such as those causing malabsorption. Our objectives were to assess the prevalence of recurrent oral aphthous-like ulcers in coeliac disease patients living in the Mediterranean area, and to evaluate the impact of a gluten-free diet. METHODS: A test group of 269 patients (age range 3-17 years) with coeliac disease confirmed both serologically and histologically was compared with a control group of 575 otherwise clinically healthy subjects for the presence, or a positive history of aphthous-like ulcers. Coeliac disease patients with aphthous-like ulcers were re-evaluated 1-year after starting a gluten-free diet. RESULTS: Aphthous-like ulcers were found significantly more frequently in coeliac disease, in 22.7% (61/269) of patients with coeliac disease versus 7.1% (41/575) of controls (p=<0.0001; chi-square=41.687; odds ratio=4.3123; 95% confidence interval=2.7664:6.722). Most coeliac disease patients with aphthous-like ulcers and adhering strictly to gluten-free diet (71.7%; 33/46) reported significant improvement on gluten-free diet, with no or reduced episodes of aphthous-like ulcers (p=0.0003; chi-square=13.101; odds ratio=24.67; 95% confidence interval=2.63:231.441). CONCLUSIONS: The epidemiological association found between coeliac disease and aphthous-like ulcers suggests that recurrent aphthous-like ulcers should be considered a risk indicator for coeliac disease, and that gluten-free diet leads to ulcer amelioration.

In vitro retentive strength of metal superstructures cemented to solid abutments.

AIM: The aim of this study was to evaluate the effect of sandblasting on the retentive strength of metal single crowns luted with a resin cement to Straumann implant/abutment assemblies. METHODS: Fifty 4.1 mm-wide Straumann solid screw implants were mounted in self-polymerizing soft resin. Standard 5.5 mm-high, 8 degree tapered solid abutments were placed on each implant and torqued to 35 Ncm. Fifty metal castings were made using prefabricated burn-out caps. Each implant/abutment assembly and its corresponding metal casting was numbered and they were divided into two groups of 25. In the test group, the external surface of the abutments and the cavosurface of the corresponding metal casting were sandblasted. In the control group, neither the implant abutment nor the metal casting underwent sandblasting. Each metal casting was cemented onto its respective implant/abutment assembly using Panavia 21 (Kuraray Europe GmbH, Dusseldorf, Ger-many) resin cement. Specimens were then subjected to a pull-out test using a universal Instron testing machine. The load required to dislodge each crown was recorded and mean values were calculated for each group. Retention values were analyzed using the ANOVA test. RESULTS: The test group showed a higher mean retention value (83.78 kgf+/-19.61) than the control group (44.03 kgf+/-9.45) and the difference was statistically significant. CONCLUSION: Within the limitations of this in vitro study, the results suggest that sandblasting treatment significantly increases mechanical retention of crowns cemented using a resin cement. It is at the clinician's discretion to evaluate whether additional retention is desired in cementing an implant-supported fixed partial denture.

Activatory properties of lysophosphatidic acid on human THP-1 cells.

Excessive leukocyte proliferation and proinflammatory mediators release represent common phenomena in several chronic inflammatory diseases. Multiple evidences identify lysophosphatidic acid (LPA), a small lipid endowed with pleiotropic activities, as an important modulator of both proliferation and activation of different cell types involved in several inflammation-associated pathologies. However, its possible role on monocyte proinflammatory activation is not fully understood yet. Aim of the present study was to investigate LPA effects on THP-1 cells in terms of proliferation, reactive oxygen intermediates (ROI) production and release of arachidonic acid-derived inflammatory mediators. Actually, LPA significantly increased both DNA synthesis and ROI production as well as prostaglandin E(2) release and the upregulation of LPA(3) receptor expression. These findings identified LPA as both a growth factor and a triggering mediator of proinflammatory response in THP-1 cells.

A rare case of synovial otorrhea of iatrogenic nature in dentistry.

The authors describe a unique case of left synovial otorrhea in a masticatory phase, occurring in a 64-year-old patient after a long dental sitting. The otoscopic examination and the transverse CT of the ear revealed the fracture of the anterior wall of left external auditory canal and the presence of a small bone fragment on the external side of the glenoid fossa. This situation, at present, has been judged inoperable by otologists due to the close relationship between this area and the head of the left condyle, probably responsible for the fracture. The therapy used was based on the use of a masticatory bite plate, with the aim of increasing the vertical dimension of the jaws during mastication and, so, to keep the condyle in a forward position. The result obtained was the decrease and then the halting of the liquid exit in the auricle, through an increase of the bite plate height determined by the ex iuvantibus method. This temporary therapy could bring about a spontaneous healing of the fracture, thanks to the masticatory increase of the bite plate; but if this is not possible, a fixed prosthetic solution should then be provided for the patient. Research into the literature revealed no similar observations.

Raloxifene covalently bonded to titanium implants by interfacing with (3-aminopropyl)-triethoxysilane affects osteoblast-like cell gene expression.

Since Raloxifene, a drug used in osteoporosis therapy, inhibits the osteoclast functions but not osteoblast functions, it could improve the recovery during implant surgery. This preliminary report describes a simple method to link, through a covalent bond, Raloxifene to titanium by interfacing with (3-aminopropyl)-Triethoxysilane as assessed by the IR-FT and SEM. To evaluate the biological response of osteoblast-like cells to this implant, we compared expression gene profiling of cell cultures on Raloxifene conjugated implant and normal implant by DNA microarray. By using DNA microarrays containing 19,200 genes, we identified differently expressed genes in osteoblast-like cell line (MG-63). Surface Raloxifene conjugated implants have been shown to have a relevant importance in modifying cell response. This result could be an interesting starting point for the use of an immediate functional loading of implants.

Oral ulcer by Sphingomonas paucimobilis: first report.

The first case of an oral infection caused by Sphingomonas paucimobilis is reported. A 73-year-old man presented with a gingival ulcer with bone exposure affecting the attached gingiva in the anterior maxillary region. He reported pain during chewing and the presence of fever. Since the first case of S. paucimobilis infection was reported in 1977, involving a leg ulcer, the number of reports related to this organism has been increasing, indicating that the bacterium should be considered an emerging pathogen. It is possible that other non-classical pathogens of the oral cavity may be responsible for infectious lesions, which represents a diagnostic and therapeutic challenge.

Saliva as a diagnostic matrix for drug abuse.

Scientific interest in saliva as a diagnostic matrix has greatly increased over the last decade. The Triage screening test (Biosite Diagnostics), a rapid immunological test used to detect recreational drugs in the urine, was used to compare two biological matrixes: a non-conventional one, saliva, and a traditional one, urine. Twenty-one drug abusers collected one urine and one saliva specimen, both of which were tested with the Triage kit. Data were validated by gas-chromatography-mass-spectrometry (GC-MS). Results were positive for methadone in 9 saliva and 14 urine specimens, for opiates in 2 and 10, respectively, and for barbiturates in 2 specimens. Saliva specimens were negative for cannabis, THC, benzodiazepines and tricyclic antidepressants, although the GC-MS analysis revealed low concentrations of these drugs in the saliva. The study demonstrates the possibility of using saliva as a diagnostic matrix to test for drug-taking; however, the Triage kit must be improved before being used with saliva.

Activatory properties of lysophosphatidic acid on human THP-1 cells.

Excessive leukocyte proliferation and proinflammatory mediators release represent common phenomena in several chronic inflammatory diseases. Multiple evidences identify lysophosphatidic acid (LPA), a small lipid endowed with pleiotropic activities, as an important modulator of both proliferation and activation of different cell types involved in several inflammation-associated pathologies. However, its possible role on monocyte proinflammatory activation is not fully understood yet. Aim of the present study was to investigate LPA effects on THP-1 cells in terms of proliferation, reactive oxygen intermediates (ROI) production and release of arachidonic acid-derived inflammatory mediators. Actually, LPA significantly increased both DNA synthesis and ROI production as well as prostaglandin E(2) release and the upregulation of LPA(3) receptor expression. These findings identified LPA as both a growth factor and a triggering mediator of proinflammatory response in THP-1 cells.

Oral health conditions of the elderly in Ancona: a population-based study.

AIM: Information currently available regarding the oral health of elderly people is poor, especially in Italy. The aim of this study was to evaluate oral health conditions in older people in the city of Ancona, Italy. The usefulness of a dedicated medical record, specifically designed for older people, was tested. METHODS: A total of 124 elderly subjects aged between 65 and 95 years, all autonomous and self-sufficient, were recruited for this study. The specific medical/dental record, designed for older people, was used to collect data and was divided into three parts. The first part lists the patient's demographics. The second part was devoted to general medical history. The third part includes the dental history and the dental visit. As regards the oral conditions, injury to the soft tissues, degree of oral hygiene, presence of caries, periodontal diseases, missing teeth, presence of the prosthesis, and presence of xerostomia, were noticed. RESULTS: Among the examined subjects 53% were male and 47% were female. The most prevalent medical condition was hypertension (64.5%); 74.2% of the examined population took up to 3 drugs/day, while the 25.8% more than 3 drugs/day. Only 9.6% of patients had soft tissues lesions and only 33.3% had sufficient oral hygiene; 45.1% of patients suffered decayed teeth; 44% of patients had fewer than 8 missing teeth, the 33.4% had the number of missing teeth including between 9 and 15, and 22.6% had more than 16 missing teeth. Only 7 patients were completely edentulous; 32.3% of the patients had fixed partial dentures, 17.7% had removable partial dentures, 22.6% had both fixed partial dentures and removable partial dentures, 4% removable total dentures and 23.4% do not have any dentures. Only 29.1% patients had xerostomia. CONCLUSION: The most important data from this study are the following: 1) the majority of elderly patients is hypertensive; 2) the majority of elderly patients take up to 3 drugs/day; 3) the majority of elderly patients has insufficient oral hygiene; 4) the majority of elderly patients do not have removable dentures but fixed dentures. Therefore, it is important to preserve and take care of the teeth of the older people, especially of the autonomous and self-sufficient elderly patients. Further visits are therefore necessary in order to make a complete epidemiological study in Ancona.

P-cadherin expression predicts clinical outcome in oral squamous cell carcinomas.

P-cadherin, a transmembrane molecule similar to E-cadherin involved in the cell-cell adhesion, and catenins form complexes between its cytoplasmic domain and the cytoskeleton. Five cell lines, 108 specimens of oral squamous cell carcinomas (OSCC), 9 metastasis and 10 of normal oral mucosa were examined to evaluate P-cadherin expression and cellular localization by immunohistochemistry and western-blotting. In normal oral mucosa there was a membranous expression only in basal and parabasal layers. 91 cases (84%) showed membranous/cytoplasmic positivity, whereas 17 cases (16%) were negative. In particular, while well-differentiated carcinomas showed P-cadherin upregulation, the protein was homogeneously hypo- or unexpressed in low-differentiated carcinomas. There was a statistically significant correlation between P-cadherin expression and tumour grading: G3 tumours had a lower score than G1-G2 tumours (P<0.05). When analysed for prognostic significance, patients with no P-cadherin expression (score 0) had poorer overall and diseases-free survival rates than the P-cadherin-expressing group (score 1) (P=0.0463 and P=0.0471, respectively). Western blotting analysis of cell lines and tissue samples confirmed immunohistochemical findings. When cell staining pattern of positive cases was examined, 52 cases showed a prevalent membranous pattern, while 39 had a prevalent cytoplasmic pattern. Cases with prevalent cytoplasmic staining showed high rates of lymph node metastases (P>0.05), and regional relapse (P <0.05) and poorer survival rates than the group with prevalent membranous expression (P<0.0001). An absent P-cadherin expression could constitute a hallmark of aggressive biological behaviour in oral squamous cell carcinoma.

The NM23 gene and its expression in oral squamous cell carcinoma.

The murine nm23, a putative metastasis suppressor, has three human homologues, NM23-H1, -H2, and -H3b. Several reports have suggested a low metastatic potential for neoplasms with a high expression of NM23-H1 gene, while other studies have not shown this relationship. These apparent differences in the role of NM23 in metastasis suppression might be explained by unability to discriminate between the expression of the two genes NM23-H1 and NM23-H2. The NM23-H2 product is not related to tumor progression and metastasis suppression. Two studies on human oral squamous cell carcinoma (OSCC) have been reported, both showing the NM23 product to be a metastasis suppressor factor. However, none of these two studies distinguished NM23-H1 from NM23-H2. The aim of this study was to detect the protein expression pattern of NM23-H1 product in 24 OSCCs by immunohistochemistry in paraffin-embedded tissues using a monoclonal antibody non-cross-reactive with NM23-H2. The NM23-H1 positive group showed lower frequency of lymph node metastasis, and a better grading than the NM23-H1 negative group supporting the role of NM23-H1 as metastasis suppressor factor which may be useful for predicting tumor metastasis in OSCC.