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International Journal of Immunopathology and Pharmacology
1. Vol. 20, no. 1 (S1), 1-4 (2007)
ENZYMATIC ANALYSIS OF THE GINGIVAL CREVICULAR FLUID IN HYPOXIA OF HIGH ALTITUDE (EVEREST) P. TRENTINI, M. FERRANTE, M. DOLCI, L. CIAVARELLI, A. TONDI and G. SPOTO Department of Stomatology and Oral Sciences, Medical and Dental Schools, University of Chieti-Pescara, Chieti, Italy The aim of this study is to determine the qualitative and quantitative changes of alkaline phosphatase (ALP) that occur in the Gingival Crevicular Fluid (GCF) in hypobaric-hypoxic conditions (high altitude). Hypoxia affects systemic adaptation responses in different organs. We examined 17 Caucasians subjects, of whom 13 were mountain climbers (1 female and 12 males), and 4 Tibetans (2 females and 2 males) following exposure to the hypoxia environment of high altitude. The study was conducted at different altitudes (0 m control, 1000 m, 5200 m above sea level) on Mount Everest. The protocol consisted of withdrawing crevicular fluid through the use of cones made of endodontic paper size 30 sectioned to 15 mm from the apex, inserted for 30 seconds in the gingival sulcus (about 2 mm). The analyzed sites were the mesial and distal, buccal and palatal of tooth 1.1 and 2.1. Blood exams were performed on the subjects using I-Stat, furnishing analysis in real time (about 2 mins). In agreement with other results reported in literature, in all the subjects we found an increase in the hematocrit and hemoglobin with a large range of values between them, and with significant differences, as analysed with the Fisher, Scheffe and Bonferroni/Dunn statistical methods. The enzymatic analysis of the GFC showed an increase of the levels of ALP at each altitude studied. With this preliminary study we show that hypoxic environment determines not only the well known cardiovascular systemic responses, but also crevicular fluid adaptation.
2. Vol. 20, no. 1 (S1), 5-7 (2007) CASE REPORTMULTIPLE CHEMICAL SENSITIVITY: CURRENT CONCEPTS G. ROSSI, E. NUCERA1, G. PATRIARCA1, P.F. MANICONE, L. RAFFAELLI, A. PESCOLLA, D. BERARDI2 and G. PERFETTI2 Institute of Clinical Dentistry, Catholic University, Rome; 1Department of Allergology, Catholic University, Rome; 2Department of Stomatology and Oral Sciences, Medical and Dental Schools, University of Chieti-Pescara, Chieti, Italy Multiple Chemical Sensitivity (MS) is characterized by a wide range of symptoms when affected patients come into contact with several chemical products. Very little is known of either the diagnosis or the suitable treatment. In this study we report the case of a 38-year-old woman, previously diagnosed as suffering from MCS, who was referred for an oral health evaluation. After removing all the existing restorations and extracting the diseased teeth, a removable partial denture without metal structure was made after testing her hypersensitivity to these materials. The one year follow-up of the patient did not show any remarkable reaction, confirming the reduction of a large number of MCS symptoms and the increase in her quality of life.
3. Vol. 20, no. 1 (S1), 9-12 (2007)
REVIEW ARTICLE BIOLOGICAL CONSIDERATIONS ON THE USE OF ZIRCONIA FOR DENTAL DEVICES P.F. MANICONE1, P. ROSSI IOMMETTI1, L. RAFFAELLI1, M. PAOLANTONIO2 G. ROSSI1, D. BERARDI2 and G. PERFETTI2 1Institute of Clinical Dentistry, Catholic University, Rome 2; Department of Stomatology and Oral Sciences, Medical and Dental Schools, University of Chieti-Pescara, Italy Zirconium oxide, known as zirconia, is a ceramic material with optimal esthetical and mechanical properties. Zirconia stabilized with yttrium oxide has the best properties for medical uses. A stress on ZrO2 surface creates a crystalline modification that opposes to propagation of cracks. Zirconia core for fixed partial dentures (FPD) on anterior and posterior teeth and on implants are now available. Clinical evaluations after 3 years report good percentage of success for zirconia fixed partial denture. Zirconia biocompatibility was studied in vivo and in vitro by orthopedic research; no adverse responses were reported on insertion of ZrO2 samples in bone or muscle. In vitro experimentation showed absence of mutation and a good viability of cells cultured on this material.
4. Vol. 20, no. 1 (S1), 13-17 (2007)
DENTAL IMPLANTS WITH LOCKING TAPER CONNECTION VERSUS SCREWED CONNECTION: MICROBIOLOGIC AND SCANNING ELECTRON MICROSCOPE STUDY S. PAPPALARDO, I.MILAZZO1, G. NICOLETTI1, O. BAGLIO, G. BLANDINO1, L. SCALINI2 F. MASTRANGELO3 AND S. TETÈ3 Dipartimento Specialità Medico-Chirurgiche, 1Dipartimento di Scienze Microbiologiche e Ginecologiche-Sezione di Microbiologia, Policlinico Università di Catania; 2D.S.B. Francavilla al Mare, AUSL Chieti, 3Dipartimento Scienze Odontostomatologiche, Università di Chieti, Italy The aim of this study is to carry out an analysis of the Fixture-Abutment Interfaces (FAI), comparing different connection systems, to evaluate the role of geometric discrepancy, which is present between the abutment and the fixture, in favoring the permeability to bacterial colonization. Two types of commercially available FAI were studied, 16 screwed FAI (Sweden-Martina Italia) (4 of Ø 3.8 mm, 4 of Ø 4.7 mm, 4 of Ø 5.7 mm and 4 of Ø 6.7 mm) and 4 FAI (Bicon) (Ø 3.5mm). The assays were carried out in vitro, placing the different dental implants in contact with broth culture of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Streptococcus pyogenes to test the infiltration inside the FAI. Furthermore, scanning electron microscope (SEM) analysis was carried out to evaluate the gap at the fixture-abutment interface. In all the locking taper FAI and in the screwed FAI with a diameter of 3.8 mm there was no trace of bacterial infiltration of the species examined. In the screwed FAI with a diameter of 4.7 mm, 5.7 mm and 6.7 mm there was an increasing level of bacterial infiltration in relationship to the diameter. Therefore, this paper shows that there exists an important correlation between the diameter of the screwed implant and the permeability to microbic infiltration that is directly proportional to the diameter of the implant.
5. Vol. 20, no. 1 (S1), 19-22 (2007)
SEM AND FRACTOGRAPHY ANALYSIS OF SCREW THREAD LOOSENING IN DENTAL IMPLANTS A. SCARANO, M. QUARANTA1, T. TRAINI, M. PIATTELLI and A. PIATTELLI Department of Stomatology and Oral Sciences,Medical and Dental Schools, University of Chieti-Pescara, Chieti; 1Dental School, University of Rome “La Sapienza”, Italy Biological and technical failures of implants have already been reported. Mechanical factors are certainly of importance in implant failures, even if their exact nature has not yet been established. The abutment screw fracture or loosening represents a rare, but quite unpleasant failure. The aim of the present research is an analysis and structural examination of screw thread or abutment loosening compared with screw threads or abutment without loosening. The loosening of screw threads was compared to screw thread without loosening of three different implant systems; Branemark (Nobel Biocare, Gothenburg, Sweden), T.B.R. implant systems (Benax, Ancona, Italy) and Restore (Lifecore Biomedical, Chaska, Minnesota, USA). In this study broken screws were excluded. A total of 16 screw thread loosenings were observed (Group I) (4 Branemark, 4 T.B.R and 5 Restore), 10 screw threads without loosening were removed (Group II), and 6 screw threads as received by the manufacturer (unused) (Group III) were used as control (2 Branemark, 2 T.B.R and 2 Restore). The loosened abutment screws were retrieved and analyzed under SEM. Many alterations and deformations were present in concavities and convexities of screw threads in group I. No macroscopic alterations or deformations were observed in groups II and III. A statistical difference of the presence of microcracks were observed between screw threads with an abutment loosening and screw threads without an abutment loosening.
6. Vol. 20, no. 1 (S1), 23-26 (2007)
A. SCARANO, F. CARINCI1, A. QUARANTA2, D. DI IORIO, B. ASSENZA and A. PIATTELLI Medical and Dental Schools, University of Chieti-Pescara; Department of Stomatology and Oral Sciences, University of Chieti-Pescara, Chieti; 1University of Ferrara, Ferrara; Dental School, 2University of Rome “La Sapienza” Rome, Italy Background: Few studies have investigated the influence of drilling on bone healing. After the drilling of bone and placement of dental implants a sequence begins of cellular and molecular events which represents a combined response of wound healing. The bone healing around dental implants is a complex phenomenon and influences the proliferation and differentiation of pre-osteoblasts into osteoblasts, together with the activation of periosteal and endosteal lining cells, and initiates the production and mineralization of osteoid matrix followed by the organization of the bone-implant interface. The objective of this study is to quantify the temperature changes in cortical bone and marrow spaces during implant site preparation in bovine rib bone. A total 10 harvested bovine ribs and 6 10.5 x 3.5 new drills for implant insertion with external irrigation (Bone System, Milano, Italy) were used in this study. The implant sites were prepared with 10 mm long drills at 500 rpm under abundant external irrigation with saline solution at 37°C. Each drill was used for 10, 30, 60, 90 and 120 implant site preparations; each drill was then observed under SEM for evaluation of the damage of the cutting edge after 10, 30, 60, 90 and 120 preparations. There was an higher and statistically significant increase in the temperature in the cortical bone; this increase in temperature increases with the number of the times of drill use. The drill wear seemed to play a major role in heat production and could explain the observed increased temperature of the bone.
7. Vol. 20, no. 1 (S1), 27-32 (2007)
NOS EVALUATIONS IN HUMAN DENTAL PULP-CAPPING WITH MTA AND CALCIUM-HYDROXIDE C. D’ARCANGELO, F. DI NARDO-DI MAIO, C. PATRONO1 and S. CAPUTI Department of Stomatology and Oral Sciences, University of Chieti, Chieti; 1Department of Pharmacology, University of Rome La Sapienza, Rome, Italy The aim of this study is to compare mineral trioxide aggregate (MTA) with calcium hydroxide when used as pulp-capping material in human teeth. 40 teeth were divided into groups based on clinical diagnosis: healthy and hyperaemic. The teeth were pulp capped with MTA and calcium hydroxide. We localized the eNOS and iNOS by immunohistochemistry, tested their mRNA expression by RT-PCR and protein levels by western blots. The evaluation of the samples was based on the cell inflammatory response and on the pulp tissue organization. In particular, evaluation of eNOS and iNOS differences between the various groups and the cellular evolution after the first 7 days from the treatment, and at a distance of 28 days. Our results suggest that there are differences in localization and expression between eNOS and iNOS in dental pulp. Our study has helped us to better understand the effects that calcium hydroxide and MTA have on pulp tissue.
8. Vol. 20, no. 1 (S1), 33-36 (2007)
CORRELATION BETWEEN IMPLANT STABILITY QUOTIENT (ISQ) WITH CLINICAL AND HISTOLOGICAL ASPECTS OF DENTAL IMPLANTS REMOVED FOR MOBILITY A. SCARANO, 1F. CARINCI, 2A. QUARANTA, G. IEZZI, M. PIATTELLI and A. PIATTELLI Department of Stomatology and Oral Sciences, Medical and Dental Schools, University of Chieti-Pescara, Chieti; 1University of Ferrara, Dental School, Ferrara; 2University of Rome “La Sapienza” Rome, Italy Dental implants are a successful treatment modality for missing teeth; however, failures do occur. These failures can occur early in the healing process after primary stability has been achieved at the time of implant placement, or after initial bone remodeling and new bone growth have taken place. The ability to detect implants that are failing or will fail is still not possible. The aim of the present study is to see if correlations exist between RFA values and histologic and histochemical evaluation of the human retrieved implants for failure. In a 5 year period, 37 root form implants were retrieved because of mobility and underwent histological examination. Thin ground sections were obtained from each implant. All the implants had been removed with a 5 mm trephine. In all cases a peri-implant radiolucency was present. Before implant retrieval, the implant stability was evaluated with OsstellTM (Integration Diagnostics AB, Gothenburg, Sweden). All the implants were not osseointegrated clinically and mobility was present. Radiographically, bone loss was observed around the implants and the mean ISQ values was 37 (+/- 2.7). A scarce inflammatory cell infiltrate was present in the connective tissue of some specimens. In about 10% of specimens, the epithelium tended to surround the total perimeter of the implant. These data suggest that implants with an ISQ <40 are irretrievably lost and there is no possibility to save them. A statistically significant correlation was found between an ISQ<36 and irretrievably failed implants.
9. Vol. 20, no. 1 (S1), 37-41 (2007) BONE MICROSTRUCTURE EVALUATION NEAR UNLOADED DENTAL IMPLANTS COMBINING CONFOCAL SCANNING LASER MICROSCOPY, CIRCULARLY POLARIZED LIGHT MICROSCOPY, AND SEM BACKSCATTERED ELECTRONS IMAGING T. TRAINI, M. DEGIDI1, G. MURMURA, A. PIATTELLI and S. CAPUTI Department of Stomatology and Oral Sciences, School of Dentistry, University “G. d’Annunzio”, Chieti; 1Private practice Bologna, Italy The aim of this report is to present a new investigative approach to implant dentistry based on the correlation of qualitative and quantitative data reported on the same figure by overlapping different images collected on the specimen with different investigative systems. Six unloaded titanium dental implants retrieved with peri-implant bone from the mandible of 2 patients after a 6 month period were used in this study. Samples of the peri-implant tissues embedded in resin were imaged by scanning electron microscopy using backscattered electrons signal (SEM BSE), confocal scanning laser microscopy (CSLM) and circularly polarized light microscopy (CPLM). The SEM BSE images were used to identify the different levels of mineral density. The CSLM images provided all the information on cells and bone marrow spaces. The CPLM images gave the collagen fibre orientation. To overlap the images we used a program introduced by Alan Boyde, based on a linear transformation matrix which projects one system onto the other. The total bone area investigated was of 695x103 pixels. The low mineral density index was 40.1, with an extension area of 344x103 ± 23x103 pixels (mean ± SD) while the high mineral density index was 54.8 with an extension area of 317x103 ± 22x103 pixels (mean ± SD). Transverse collagen fibers showed an extension area of 201x103 ± 25x102 pixels (mean ± SD) (28.9%), while the area for longitudinal orientation was 282x103 ± 19x102 pixels (mean ± SD) (40.6%). The marrow spaces showed an extension of 113x103 ± 24x102 pixels (mean ± SD) (16.3%). This method demonstrated that bone near unloaded implants showed almost the same extension for longitudinal and transverse collagen fibre with a predominantly low mineral density index closest to the implant surface.
10. Vol. 20, no. 1 (S1), 43-47 (2007) MODIFICATION OF CONDYLE ANATOMY FOLLOWING A MONOLATERAL BITE RISE: A HISTOLOGICAL STUDY IN RAT M. D’ATTILIO, A. SCARANO, A. QUARANTA1, F. FESTA, S. CAPUTI and A. PIATTELLI Department of Stomatology and Oral Sciences, Medical and Dental Schools, University of Chieti-Pescara; 1University of Rome “La Sapienza”, Rome, Italy The aim of this study is to evaluate the histologic modifications of rat articular capsules, after compression and strain. Fifty adults Sprague Dawley rats were used in this study. The rats were divided into 3 groups: a dysfunction group, treatment group and a Control group. In the rats in the first two groups an occlusion hump, made of composite and less than 0,5 mm high, was applied to the upper right molar. The rats were anesthetized with an intraperitoneal injection of benzodiazepine (0.5-1mg for 100 g. of body weight). The composite used consisted of a hollow, plastic cylinder 0.5 mm high, spread over the whole occlusal surface of the right upper molar. The dysfunction group therapy wore the occlusion hump for a week, at the end of which the animals in this group were killed and their temporomandibular joint removed. In the treatment group a second occlusion hump was applied to the left upper molar, in order to obtain a distraction of the previously compressed temporomandibular joint. The rats of the second group wore the second occlusion hump for one week. The rats were then killed with an intraperitoneal injection of Tanax, and the block sections, containing the temporo-mandibolar joint, were retrieved with a diamond disk, and surrounding tissues were washed in saline solution and immediately fixed in 4% formalin for 4 days. In the control group, no treatment was applied. In the first group, bone resorption was observed in the left temporomandibular joint; no osteoclast were, however, present. No other tissue alterations were present. Newly formed bone undergoing remodelling was intensely stained with acid fuchsin. In the second and third groups, no bone remodelling areas were observed. In conclusion, the compression of the temporomandibular joint determined a remodelling of the bone structure of the condyle.
11. Vol. 20, no. 1 (S1), 49-53 (2007) REMOVAL TORQUE VALUES OF TITANIUM IMPLANTS INSERTED INTO BONE DEFECTS FILLED WITH HYDROXYAPATITE: A HISTOLOGIC AND HISTOMORPHOMETRIC ANALYSIS IN RABBIT A. SCARANO, F. CARINCI1, C. MANGANO2, A. QUARANTA3 and A. PIATTELLI Medical and Dental Schools, University of Chieti-Pescara, Department of Stomatology and Oral Sciences, University of Chieti-Pescara, Chieti; 1University of Ferrara, Ferrara; 2Private Practice, Gravedona, Como; 3University of Rome “La Sapienza”, Rome, Italy The successful clinical use of implants with microrough titanium surfaces has paved the way for the further development of surface topographies to promote enhanced peri-implant bone apposition during the early stages of bone regeneration. The aim of this study is to determine the torque resistance of the implant-bone interface of plasma sprayed titanium endosseous implants placed in the rabbit tibia in three different situations. Hydroxyapatite (HA) particles with a size ranging from 250 to 450 μm were used in the present study to fill out 6 mm bony defects created in rabbit tibia. Fourteen mature New Zealand white male rabbits, weighing about 2.5 Kg., were used in this study. The test sites were filled with HA and the non-grafted sites were used as control. A total of 28 bone defects (14 without HA and 14 with HA.) were created. Implants with plasma-spray surface were subsequently inserted. Six additional rabbits were used; in these animals no bone defects were created. The implant sites were divided into three groups: 1) implants inserted in the tibia without bone defects; 2) implants inserted in the tibia with bone defects not filled with HA; 3) implants inserted in the tibia with bone defects filled with HA particles. The purpose of this study is to measure reverse-torque in three different situations of clinically similar implant geometry in the articulation of rabbits. The null hypothesis stated that there is a difference in reversal torque between the bone regeneration with HA, native bone and bone defect without bone regeneration. Additionally, comparison between these 6-month data and the 3-month data from a previous study led to the following conclusions: a significant difference exists in the removed torque for the TPS implants in the bone regenerated by HA and native bone; increase in removal torque values was seen for the implant inserted in bone regenerated by HA compared to the implant nated in bone without biomaterials. In conclusion, bone regenerated with biomaterials possesses different mechanical characteristics to native bone.
12. Vol. 20, no. 1 (S1), 55-60 (2007) VASCULAR ENDOTHELIAL GROWTH FACTOR EXPRESSION (VEGF) IN SALIVARY GLANDS OF DIABETIC RATS V. PERROTTI, A. PIATTELLI, M. PICCIRILLI, G. BIANCHI1, C. DI GIULIO1 and L. ARTESE Medical and Dental Schools, University of Chieti-Pescara, Department of Stomatology and Oral Sciences, University of Chieti-Pescara; 1Department of Biomedical Sciences, University of Chieti-Pescara, Chieti, Italy This study is aimed at evaluating vascular endothelial growth factor (VEGF) expression in the salivary glands of diabetic rats. Our study was carried out on 1 group of male Wistar rats and 1 group of male Bio Breeding Wistar (BB/W) pre-diabetic rats. The first group (control) was composed of 11 rats (4 months old), and the other (test) of 11 rats (4 months old) which showed diabetes at day 85 of life. This kind of diabetes can be compared to human diabetes mellitus type 1. The submandibular glands were removed and processed for immunohistochemical analysis of VEGF. Diabetes increased salivary gland VEGF expression in the rats. The tissues analyzed (vascular endothelium, ductal endothelium, mucinous glands) always expressed VEGF, thus demonstrating that not only vascular endothelial cells, but also the other elements evaluated, have a role in the neoangiogenesis process. In both control and diabetic rats, the VEGF expression was constantly negative only in serous acini; thus demonstrating that serous acini are not involved in the neoangiogenetic processes. The vascular growth is a fundamental part of normal salivary gland development, therefore we speculate that strategies aimed at preservation or promotion of salivary gland VEGF expression may mitigate or attenuate diabetic-induced gland microvascular injury.
13. Vol. 20, no. 1 (S1), 61-67 (2007) ROLE OF THE FRICTION FREE DISTALIZE APPLIANCE (2FDA) PAT IN THE MOLAR DISTALIZATION: PHOTOELASTIC ANALYSIS AND ALKALINE-PHOSPHATASE (ALP) ACTIVITY ON FIRST MOLAR AND BICUSPID M. D’ATTILIO, S. TECCO, T. TRAINI, G. SPOTO and F. FESTA Department of Stomatology and Oral Sciences, Medical and Dental Schools, University of Chieti-Pescara, Chieti, Italy Maxillary molar distalization is an increasingly popular option for the resolution of Class II malocclusions. This study describes the effects of one particular molar distalizing appliance, the Friction Free Distalize Appliance (2FDA), in a sample of 20 consecutively treated and growing patients to verify the osteoblastic activity in the compression and traction sites of both the molars and the bicuspids when used as the anchorage teeth. The 2FDA appliances were constructed utilizing a Nickel Titanium open coil spring of 200 gr force in order to distalize the maxillary first molar. The reaction force was controlled utilizing the principle of low/free friction. The results show that the resin around the root of the bicuspid did not discolour at all, which indicates an absence of a force load. On the other hand, on the molar, the resin around the root of the molar became discoloured due to the fact that an orthodontic force was involved with the tooth. To better understand whether the quantity of force that reached the tooth was able to produce osteoblastic recruitment in the sites of tension of the molar and the bicuspid, we quantified an enzyme, the alkaline phosphatase (ALP), present. This measurement allowed us to verify a regular increase of the ALP on the site of molar traction. We also elaborated a mathematical model to evaluate the quantity of force of reaction that produces the device on the bicuspid. Such force results as being 8.34 grams which equals half the pressure of the capillaries of the parodontal ligament (18 grams). The 2FDA appliance compares favourably with other intra-oral distalization devices for the resolution of patients with Class II malocclusions, and is the only distalizing appliance that does not determine osteoclastic/osteoblastic recruitment on the “anchorage tooth”.
14. Vol. 20, no. 1 (S1), 69-74 (2007) PHARMACOLOGIC MODULATION OF CLODRONATE IN LOCAL THERAPY OF PERIODONTAL AND IMPLANT INFLAMMATION R.VOLPI, F. ROSSI1, P. TRISI2, T. TESTORI3, D. BERARDI1 and G. PERFETTI1 Italian Association for the Study of Bisphosphonates in Odontostomatology; 1Medical and Dental School, Department of Stomatology and Oral Sciences, University of Chieti-Pescara; 2Biomaterial Clinical Research Association, BioCRA and 3Department of Implant Dentistry and Oral Rehabilitation, University of Milan, Department f Odontology, Istituto Ortopedico Galeazzi I.R.C.C.S., Italy Bisphosphonates are drugs used in the treatment of a variety of osteometabolic diseases. Recently they have been the object of research and studies on their potential application in dentistry and orthopedics. In particular, clodronate (non-aminobisphosphonates) has been studied, due to its reversible activity in comparison to apoptotic osteoclasts, the intrinsic action which stimulates the differentiation and activity of the osteoblasts, their antinflammatory activity, antipain and antioxidant action, represent the rational to estimate their clinical efficacy, for local use in dentistry, implatology, orthopaedic, rheumatology, oncology and dermatology.
15. Vol. 20, no. 1 (S1), 75-79 (2007) SEM ANALYSIS OF ORAL LICHEN PLANUS BEFORE AND AFTER TREATMENT WITH 13 cis-RETINOIC ACID F. MASTRANGELO, M. DOLCI, L. STUPPÌA1,2, M. PAOLANTONIO, L. SALINI3, V. ZIZZARI, M. TRANASI, A. PATRONO4 and S. TETÈ Department of Stomatology and Oral Sciences, 1Center of Excellence of Aging (CESI), 2Department of Biomedical Sciences, University G. d’Annunzio, Chieti; 3DSB Francavilla-a-Mare, AUSL, Chieti; 4Departments of Biomorphology, University G. d’Annunzio, Chieti, Italy Cancer of the oral cavity is a frequent worldwide neoplasia, averaging 4% in men and 2% in women. Cancer of the oral cavity is often preceded by particular epithelial lesions, called “precancerous lesions”. The aim of this study is to evaluate, by SEM microscope analysis, before and after treatment with 0.1% 13-cis-retinoic, the morphostructural variation of the surface of the oral mucous affected by lichen planus in respect to healthy oral mucous. Following topical therapy with 0.1% 13-cis-retinoic acid for 8 weeks, a restoration of the physiological morphostructure was observed by SEM, demonstrating the efficaciousness of the treatment and the SEM analysis for identifying the lesions of oral epithelium.
16. Vol. 20, no. 1 (S1), 81-86 (2007) DENTAL PULP STEM CELLS BIOADHESIVITY: EVALUATION ON MINERAL-TRIOXIDE-AGGREGATE O. TRUBIANI, C. D’ARCANGELO, D. DI IORIO, F. DI NARDO DI MAIO and S. CAPUTI Department of Stomatology and Oral Sciences, University of Chieti, Italy Stem cells are undifferentiated cells that have the capacity to self-renew. They have been discovered in many adult tissues, including teeth. Dental Pulp Mesenchymal Stem Cells (DP-MSCs) are involved in dental repair by activation of growth factors, released after caries and have the ability to regenerate a dentin-pulp-like complex. The molecular/cellular research gives the possibility to grow new tissues and biological structures for clinical applications, providing cells for therapies including cell transplantation and tissue engineering. In this study DP-MSCs were derived from dental pulp of 10 donors. To evaluate material toxicity, after in vitro isolation, the cells were seeded on mineral trioxide aggregate (MTA). Initial light microscopy investigation of cells revealed no signs of cell death due to toxicity or infection, on the contrary the scaffolds supplied an excellent support for cell structures, the cells proliferated and adhered to substrate. Similar observation was seen in scanning electron microscopy, in particular the cells had proliferated and spread, covering a considerable part of the surface of the biomaterials investigated, with an elaborate form of attachment, in fact, the cells formed a continuous layer on the upper surface of the MTA. In conclusion, the aim of this study is to demonstrate that DP-MSCs combined with MTA could be a potential source for regenerative medicine, encouraging further study to evaluate the new-dentin formation.
17. Vol. 20, no. 1 (S1), 87-91 (2007)
THE PERFORMANCE OF HUMAN PERIODONTAL LIGAMENT MESENCHYMAL STEM CELLS ON XENOGENIC BIOMATERIALS O. TRUBIANI, A. SCARANO, G. ORSINI, D. DI IORIO, C. D’ARCANGELO, M. PICCIRILLI, M. SIGISMONDO and S. CAPUTI Department of Stomatology and Oral Sciences, University of G. d’Annunzio Chieti-Pescara, Italy Mesenchymal stem cells from periodontal ligament (PDL-MSCs) hold great promise for bone regeneration. Most studies regarding the osteogenic differentiation of stem cells from periodontal tissue suggest that PDL cells may have many osteoblast-like properties, including the ability to form calcified nodules in vitro. This study investigated the morphological and histochemistry aspects of human PDL-MSCs, induced for osteogenic differentiation and seeded on a xenogenic porcine bone substitute in vitro, at different times of incubation. This biomaterial seems physically identical to human bone, and it has been reported to be osteoconductive. Our results indicated that the cells had a high affinity for the three-dimensional biomaterials; in fact, cellular proliferation and colonization was evident, and after 21 days the adherent cells started to detach themselves from the substrate, and at 30 days of incubation in differentiation medium, the cells completely lost the adhesion to the Petri’s disk , englobing all bioparticles. In conclusion, the in vitro behaviour of PDL-MSCs and their relationship with three-dimensional scaffold biomaterials encourage in vivo investigations for their use in dental tissue regeneration.
18. Vol. 20, no. 1 (S1), 93-96 (2007)
DEMINERALIZING ACTION OF EGTA IN ENDODONTICS D. TRIPODI, S. D’ERCOLE, P. DE FAZIO and G. SPOTO1 Department of Stomatology and Oral Sciences, Dental School and 1Laboratory of Dental Materials and Biochemistry, Department of Endodontics, Chieti University, Italy The demineralization of dentin obtained by treatment with a chelating agent ethylene diamminotetracetic acid (EDTA) or ethylene glycol-bis(β-aminoethyl ether)-N-tetraacetic acid (EGTA), is a dynamic process involving chelation and solubilization. The actions of the EDTA and EGTA on dentin are influenced by the pH. Increasing mM concentrations of EDTA or EGTA the equivalent pH decreases in a similar slope to 80 mM chelator concentration. Increasing the chelator concentration different data were obtained: with EGTA the pH decreases slightly while with EDTA goes back up to the initial values. After 80 mM, EDTA reduces the activity on the dentin, and EGTA continues to work at higher concentrations. We demonstrated that EGTA solubilized more of 60% of dentin while EDTA gives about 20% at the maximal of the solubility.
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