Piezosebészeti eszköz és a sagittalis csontfűrész intraossealis hőtermelésének in vitro összehasonlító vizsgálata.

Vizsgálatunkban in vitro körülmények között összehasonlítottuk a piezosebészeti eszköz és a sagittalis csontfűrész által termelt hőmennyiséget. Sertésbordába K-típusú hőérzékelőt rögzítettünk, amitől 1 mm távolságra, "legyezőszerű" folyamatos mozgással 30-30 bordát vágtunk át sagittalis fűrésszel (S-8 S - Elcomed, W&H) és piezosebészeti eszközzel (B6 - Piezomed, W&H). Utóbbival hűtési ciklusokat közbeiktatva 30 mintán szakaszos vágást is végeztünk. Sagittalis fűrésszel végzett osteotomia során nem mértünk 47°C feletti értéket. Piezoelektromos eszközzel "legyezőszerű", folyamatos mozgással végzett vágás mellett a mérési eredmények 16,2 +- 3,53%-a elérte a kritikus hőmérséklet-értéket, hűtési ciklusok közbeiktatásával ez az érték 2,6 +- 0,96%-ra csökkent (p < 0.001). A hőmérséklet egyetlen esetben sem haladta meg a 47°C-ot több mint 20 másodpercig. A piezosebészeti eszköz biztonságosan használható, azonban az osteonecrosis kialakulásának esélyét tovább csökkenthetjük hűtési ciklusok közbeiktatásával, intermittáló műszerhasználattal és maximális vízhűtéssel

A Renox szuperoxid-termelő enzim vizsgálata emlős sejtekben = Characterization of the Renox superoxide-producing enzyme in mammalian cells

1. Kifejlesztettünk egy Nox4 (Renox)-deficiens egérmodellt. Az eddigi vizsgálataink szerint a Nox4 jelenléte nem nélkülözhetetlen az élethez és az állatok konstitutív vérképzése is normálisnak tűnik. 2. Kimutattuk, hogy az eddig ismeretlen funkciójú p50RhoGAP fehérje fontos szerepet játszhaz a Rho és a Rab G-fehérjék jelátviteli útvonalainak összekapcsolásában. 3. Dr Thomas Leto laboratóriumával együttműködésben megállapítottuk, hogy a Rac1 kismólsúlyú GTP-kötő fehérje fontos szerepet játszik a Nox1-et és Nox3-at tartalmazó NADPH oxidázok szabályozásában. 4. A Nox4 élettani funkcióját kutatva sikerült azonosítanunk egy olyan új emberi peroxidázt amely fontos szerepet játszhat a reaktív oxigénszármazékok hatásának közvetítésében. | 1. We have developed a Nox4 (Renox)-deficient mouse model. Preliminary analysis of this model indicates that the function of Nox4 is not essential for life and Nox4 has no role in the regulation of constitutive haematopoiesis. 2. We have shown that the p50 Rho-GAP protein provides a link between Rho- and Rab GTPases. 3. In collaboration with Dr Thomas Leto we have shown that the small GTPas Rac1 has an important role in the regulation of Nox1- and Nox3-based NADPH oxidases. 4. While searching for the physiological function of Nox4 we have identified a novel human peroxidase which might have an important role in the mediation of the effects of reactive oxygen species

Assessment of heat provocation tests on the human gingiva: the effect of periodontal disease and smoking.

Periodontal inflammation is associated with morphological changes in the blood vessels which may influence the regulation of gingival blood flow (GBF). Our aim was to adapt the heat provocation test to the human gingiva to assess vascular reactivity in periodontal inflammation. METHOD: GBF was recorded by Laser Doppler Flowmetry before and after heat provocation in healthy volunteers (n = 50). Heat was generated either by warm saline or a halogen lamp. The latter method was also utilized for a heat test in non-smoking and smoking patients with periodontal inflammation. The circulatory parameters were correlated to the inflammatory marker, i.e. gingival crevicular fluid (GCF) production measured by Periotron. RESULTS: Local application of heat caused a rapid, significant and transient increase in GBF regardless of the method used. The increase in the speed and not in the concentration of moving blood cells was responsible for increased GBF. Higher GCF values were correlated with increased peak flow, flux pulse amplitude and faster restoration of GBF after the test in non-smokers, but not in smokers. CONCLUSIONS: The heat test could be a valuable tool to check the vascular reactivity of gingival vessels. Moderate periodontal inflammation may facilitate gingival vascular responsiveness which can be suppressed by smoking

Intraosseous arterial alteration of maxilla influencing implant-related surgeries.

OBJECTIVES To investigate the intraosseous arterial pathways and anastomoses in the alveolar aspects of the maxilla in order to better understand the arterial scattering pattern. MATERIALS AND METHODS Eleven cadavers were selected for macroscopic intraosseous arterial analyses by corrosion casting. The red-colored acrylic resin was injected into the external carotid arteries. The specimens were kept in an enzymatic solution at 36 °C for about 60 days, depending on the process progression. After removal of the soft tissues and drying, the bone was macerated by potassium hydroxide to analyze the course and the mean diameters of the intraosseous anastomoses. RESULTS Vertico-oblique and horizontal intraosseous arteries and anastomoses between the greater palatine-, posterior superior alveolar-, and infraorbital arteries were detected. The vertico-oblique anastomoses were found on the anterolateral wall of the maxilla and the alveolar crest with a mean diameter of 0.46 mm; nevertheless, the horizontal (transalveolar) anastomoses were identified in the interdental septum/alveolar crest with the mean diameter of 0.41 mm. From the horizontal anastomoses, small intraseptal branches supplied the territory of the alveolar socket in various directions. CONCLUSIONS The localization of intraosseous arterial anastomoses is critical in implant-related surgeries, predominantly to maintain proper circulation. CLINICAL RELEVANCE Based on vertico-oblique and transalveolar anastomoses, simultaneous buccal- and palatal flap elevation (particularly on the palatal side) should be avoided to minimize patient morbidity and intra- or postoperative complications. Moreover, preserving transverse loops in the interdental septum is essential during implant surgeries, which can significantly influence collateral periosteal and osteal circulation to prevent ischemia

Comparing the trueness of seven intraoral scanners and a physical impression on dentate human maxilla by a novel method

Intraoral scanner (IOS) accuracy is commonly evaluated using full-arch surface comparison, which fails to take into consideration the starting position of the scanning (scan origin). Previously a novel method was developed, which takes into account the scan origin and calculates the deviation of predefined identical points between references and test models. This method may reveal the error caused by stitching individual images during intraoral scan. This study aimed to validate the novel method by comparing the trueness of seven IOSs (Element 1, Element 2, Emerald, Omnicam, Planscan, Trios 3, CS 3600) to a physical impression digitized by laboratory scanner which lacks linear stitching problems

Evidence of spreading vasodilation in the human gingiva evoked by nitric oxide

Spreading vasodilation is an important means of increasing local blood flow effectively during increased metabolic demands or in case of vascular injury. Our aim was to develop a technique proving the presence of spreading vasodilation in the human keratinized gingiva.Local vasodilation was evoked by the application of nitric oxide (NO) donor nitroglycerin into a well, fixed 2 mm above the marginal gingiva, in 20 subjects with healthy periodontal tissue. Either 1 or 8 mg/mL nitroglycerin solutions were dropped into the test well at the upper right second incisor, and saline was applied into the control well at the upper left first incisor. The gingival blood flow (GBF) was recorded for 15 minutes by a laser speckle contrast imager below the well and in the surrounding area in the mesial, distal, apical and coronal directions. Gingival thickness was measured by an ultrasonic biometer.Peak GBF increase was similar after 1 mg/mL and after 8 mg/mL nitroglycerin application in the well (51% ± 12% vs 42% ± 8%) and in the apical region (33 ± 9% vs 55% ± 13%). While the lower dose of nitroglycerin increased GBF only in the apical region around the well, the higher dose induced significant elevations in all surrounding regions, with apical prominence. Hyperaemia lasted 10-14 minutes in the low-dose group whereas it extended beyond the observation period in the high-dose group. Neither the baseline nor the NO-induced peak GBF were correlated with gingival thickness.The role of the direct effect of NO in the regulation of perfusion was demonstrated in the human gingiva as well as the propagation of local vasodilation to distant, especially apical areas, probably by the mechanism of flow-mediated dilation. This mechanism may have a clinical importance for flap survival or wound healing

Evaluation of Laser Speckle Contrast Imaging for the Assessment of Oral Mucosal Blood Flow following Periodontal Plastic Surgery: An Exploratory Study

The laser speckle contrast imaging (LSCI) is proved to be a reliable tool in flap monitoring in general surgery; however, it has not been evaluated in oral surgery yet. We applied the LSCI to compare the effect of a xenogeneic collagen matrix (Geistlich Mucograft®) to connective tissue grafts (CTG) on the microcirculation of the modified coronally advanced tunnel technique (MCAT) for gingival recession coverage. Gingival microcirculation and wound fluid were measured before and after surgery for six months at twenty-seven treated teeth. In males, the flap microcirculation was restored within 3 days for both grafts followed by a hyperemic response. During the first 8 days the blood flow was higher at xenogeneic graft comparing to the CTG. In females, the ischemic period lasted for 7-12 days depending on the graft and no hyperemic response was observed. Females had more intense and prolonged wound fluid production. The LSCI method is suitable to capture the microcirculatory effect of the surgical intervention in human oral mucosa. The application of xenogeneic collagen matrices as a CTG substitute does not seem to restrain the recovery of graft bed circulation. Gender may have an effect on postoperative circulation and inflammation

Idegi, valamint endothel eredetű mediátorok szerepe és kölcsönhatása a gingiva keringésének szabályozásában = Action and interaction of neural and endothelial mediators in the regulation of blood supply to the gingiva

Vazoaktív mediátorok keringésszabályozó szerepét tanulmányoztuk ép és gyulladt fogínyben patkányban. Humán gingiván a fogorvosi beavatkozások hatását vizsgáltuk. Adataink szerint patkány marginális gingiva erekben érszűkítő adrenerg alfa1, alfa2, valamint endotheliális ETA receptorok találhatók. A vaszkuláris endotheliális növekedési faktor (VEGF) a gingiva bazális keringésszabályozásában nem vesz részt, de azt az íny VEGF-2 érreceptorain keresztül befolyásolhatja. Primer neurogén gyulladás szisztémás antiinflammációs hatása a gingivában is leírható. E hatásban a nitrogénoxid szerepe valószínű. Megvizsgáltuk a gyomornedvből izolált gasztrikus pentadekapeptid BPC157 hatását ép, ill. gyulladt fogínyre. BPC157 vazokonstriktor, kísérletes parodontitisben gyulladáscsökkentő. Az alveoláris csontállományra protektív hatású. Az ínybarázda (gingivális sulcus) kemomechanikai tágítása a fogorvoslásban alkalmazott eljárás. Vizsgálataink szerint a használatos adrenalin koncentrációval átitatott tágító fonal a sulcusfolyadék elválasztást nem befolyásolja. Barázdatágításra a 0,1 %-os adrenalin oldat a leghatékonyabb. Bölcsességfogak pulpájából, ill. parodontiumából tenyésztéssel sejtkultúrát nyertünk, melyben vizsgáltuk a fogászati anyagok sejtproliferációra gyakorolt hatását. A pozitív STRO-1 immunreaktivitás sejtkultúránkban mesenhymalis őssejtek jelenlétére utal. A hemostatikumok, ill. retrakciós szerek klinikumban használt koncentrációi toxikusak. Emdogain a sejtproliferációt fokozta. | The role of vasoactive mediators has been studied in blood flow regulation to the sound/inflamed rat gingiva. The gingival effects of dental treatment were also detected in human. According to our data vasoconstrictor alpha1, alpha2 and endothelial ETA receptors localize in the blood vessels of the marginal gingva. Although the vascular endothelial growth factor (VEGF) does not participate in the basal flow regulation to the gingiva, exogenous VEGF evokes an enhanced gingival blood perfusion by the means of local VEGF2 receptors. The systemic anti-inflammatory effect of primary neurogenic inflammation can be observed also in the gingiva. Nitric oxide is probably involved in this process. The effect of gastric juice pentadecapeptide BPC157 on the sound/inflamed gingiva was also studied. BPC157 induces vasoconstriction and decreases inflammation in experimental periodontitis. The chemo-mechanical exposure of the gingival sulcus is a procedure commonly used in dentistry. Among the concentrations of epinephrine we used 0.1% was the most effective one, without any effect on crevicular fluid production. In order to study the effect of dental materials on the cell proliferation tissue culture was gained using the cells of dental pulp and connecting periodontium of wisdom teeth. The positive STRO-1 immunreactivity observed in our tissue culture refers to the presence of mesenchymal stemm cells. Clinically used concentrations of hemostatic and vasoconstrictor retraction solutions are toxic for the cultured cells. Emdogain shows a cellproliferative effect

Application of intraoral scanner to identify monozygotic twins

DNA base identification is a proper and high specificity method. However, identification could be challenged in a situation where there is no database or the DNA sequence is almost identical, as in the case of monozygotic (MZ) twins. The aim of this study was to introduce a novel forensic method for distinguishing between almost identical MZ twins by means of an intraoral scanner using the 3D digital pattern of the human palate

Blood flow kinetics of a xenogeneic collagen matrix following a vestibuloplasty procedure in the human gingiva-An explorative study

The aim of the present study was to investigate temporal and spatial blood flow patterns following vestibuloplasty procedures using a collagen matrix (CM) to get an insight into the timing and direction of neovascularization in the CM.Five patients were treated using a modified apically repositioned flap combined with a CM. Intraoral photographs and blood flow measurements by laser speckle contrast imaging were taken for 12 months. Thirty regions of interest in the graft and the surrounding mucosa were evaluated. The clinical parameters were assessed after 6 and 12 months. VEGF expression was analyzed in the wound fluid on days 2 and 4.At 6 months, the mean width of keratinized gingiva increased, but the thickness was unchanged. Scar formation was observed in all cases. Perfusion in the graft began to increase at the lateral and coronal edges and then spread concentrically toward the center. The apical side showed a significant delay in perfusion, the highest VEGF expression, and wound fluid production as well as the most abundant scar formation.Neovascularization occurs mainly from the lateral and coronal edges, which may limit the extent of the surgical area. Abundant scar formation may be explained by increased VEGF expression induced by prolonged ischemia in this area