Radiological Evaluation of the Healing of Bone Defects Filled with Tricalcium Phosphate (Bioresorb) after Cystectomy of the Mandible

Trikalcijev fosfat -Ca3(PO4)2 - resorbilna je i biokompatibilna kalcijeva fosfatna keramika vrlo velike čistoće s omjerom atoma kalcija i fosfata vrlo sličnim prirodnom koštanom mineralu, pa se u tkivu ponaša poput vlastita koštanog transplantata. Postupno se resorbira tijekom pregradnje kosti i nadomješta novim koštanim tkivom, a u oralnoj se kirurgiji uglavnom primjenjuje kod većih defekata kostiju nakon operacija cista i tumora te u dentalnoj implantologiji. Svrha je rada opisati dva slučaja cijeljenja koštanih defekata čeljusti nakon operacije čeljusnih cista punjenih granulatom beta-trikalcijeva fosfata (Bioresorb Macro Pore - Oraltronics). Postupak je obavljen na hospitaliziranim pacijentima, uz njihovu suglasnost, u Kliničkom zavodu za oralnu kirurgiju Kliničke bolnice Dubrava. Koštani su defekti punjeni potrebnom količinom granulata veličine zrnaca od 1000 do 2000 μm. Rezultati cijeljenja subjektivno su procijenjeni raščlambom kontrolnih snimaka nakon dva, četiri i šest mjeseci te uspoređeni s cijeljenjem slične koštane šupljine koja je nastala nakon što je uklonjena radikularna koštana cista liječena metodom Partsch II i trajnom poslijeoperacijskom sukcijom. Preliminarni rezultati primjene Bioresorb Macro Porea u liječenju velikih cista donje čeljusti pokazali su vrlo dobru prihvatljivost materijala bez komplikacija - znači bez infekcije ili poteškoća s cijeljenjem rana - a obnova koštane strukture bila je završena u razdoblju od četiri i šest mjeseci nakon zahvata. Opisani slučajevi i njihova usporedba s trećim primjerom govore u prilog primjene resorbilnog trikalcijeva fosfata. Može se pretpostaviti da se na taj način brže uspostavlja očekivana građa kosti negoli kod ostalih poznatih metoda.Tricalcium phosphate -Ca3(PO4)2- is a resorbable and biocompatible calcium phosphate ceramic with the ratio of calcium and phosphate atoms very similar to natural bone mineral and consequently in the tissue it behaves like an autogenic bone transplant. It is gradually resorbed during remodelling of the bone and substituted with new osseous tissue. In oral surgery it is mainly used for large bone defects which develop during operations for cysts and tumours and in dental implantology. The purpose of the study was to present two cases of the healing of bone defects after operation of jaw cysts filled with granulate beta-tricalcium phosphate (Bioresorb Macro Pore - Oraltronics). The method was performed on hospitalised patients with their prior consent in the Department of Oral Surgery, University Hospital “Dubrava”. Bone defects were filled with the required amount of granulate, granules 1000 - 2000 µm in size. The results of healing were subjectively evaluated by analysis of radiographs after 2, 4 and 6 months and compared with the healing of a similar cavity after enucleation of a bone cyst treated by Partsch II method with permanent postoperative suctions. The preliminary results of the application of Bioresorb Macro Pore in the treatment of large mandibular cysts showed very good acceptability of the material, with no complications with regard to infection or problematic healing of the wound, and restoration of the bone structure was completed within a period of 4 and 6 months after the operation. The examples presented and their comparison with a third example support the application of resorbable tricalcium phosphate. By this method the anticipated bone structure is achieved faster than by other known methods

Toxicity of Metal Ions Released from a Fixed Orthodontic Appliance to Gastrointestinal Tract Cell Lines

The mechanism of toxicity and cellular response to metal ions present in the environment is still a very current area of research. In this work, which is a continuation of the study of the toxicity of metal ions released by fixed orthodontic appliances, eluates of archwires, brackets, ligatures, and bands are used to test the prooxidant effect, cytotoxicity, and genotoxicity on cell lines of the gastrointestinal tract. Eluates obtained after three immersion periods (3, 7, and 14 days) and with known amounts and types of metal ions were used. Four cell lines—CAL 27 (human tongue), Hep-G2 (liver), AGS (stomach) and CaCo-2 (colon)—were treated with each type of eluate at four concentrations (0.1×, 0.5×, 1.0×, and 2.0×) for 24 h. Most eluates had toxic effects on CAL 27 cells over the entire concentration range regardless of exposure time, while CaCo-2 proved to be the most resistant. In AGS and Hep-G2 cells, all samples tested induced free radical formation, with the highest concentration (2×) causing a decrease in free radicals formed compared to the lowest concentrations. Eluates containing Cr, Mn, and Al showed a slight pro-oxidant effect on DNA (on plasmid φX-174 RF I) and slight genotoxicity (comet assay), but these effects are not so great that the human body could not “resist” them. Statistical analysis of data on chemical composition, cytotoxicity, ROS, genotoxicity, and prooxidative DNA damage shows the influence of metal ions present in some eluates on the toxicity obtained. Fe and Ni are responsible for the production of ROS, while Mn and Cr have a great influence on hydroxyl radicals, which cause single-strand breaks in supercoiled plasmid DNA in addition to the production of ROS. On the other hand, Fe, Cr, Mn, and Al are responsible for the cytotoxic effect of the studied eluates. The obtained results confirm that this type of research is useful and brings us closer to more accurate in vivo conditions

Phacelia bipinnatifida Michx.

https://thekeep.eiu.edu/herbarium_specimens_byname/13340/thumbnail.jp

Symptoms of titanium and nickel allergic sensitization in orthodontic treatment

The study aimed to evaluate to which extent self-reported symptomatology, age, and sex are predictors of titanium and nickel allergic sensitization in patients in treatment with fixed orthodontic appliances. Methods The study analyzed 228 subjects aged 11–45 years (median 18, interquartile range 16–22); 68% of them were females, and 52% were adolescents. The allergic sensitization testing included epicutaneous patch test to titanium, titanium dioxide, titanium oxalate, titanium nitride, and nickel sulfate. The questionnaire on symptoms potentially linked to titanium and nickel sensitization was used. Results Prevalence of the allergic sensitization to titanium in patients undergoing orthodontic treatment was 4% (2% only to titanium without nickel) while to nickel 14% (12% nickel without titanium). Hypersensitivity to both metals at the same time was present in 2% of subjects. Sensitization to nickel was more common in females than in males (17 vs. 8%) and much more common in adults than in adolescents with small effect size (20 vs. 8%; p = 0.013). Sensitization to titanium was more common in females than in males (6 vs. 1%) with no difference in age. Multiple logistic regression analysis revealed that adult age increases the odds for being sensitized to nickel for 2.4 × (95% CI 1.1–5.6; p = 0.044) while watery eyes for 3.7 × (95% CI 1.2–11.1; p = 0.022). None of the symptoms were significant predictors of titanium sensitization. Conclusion Allergic sensitization to titanium and nickel are not very frequent in orthodontic patients, and self-reported symptomatology is a weak predictor of those sensitizations

Comparison of laparoscopic and classic appendectomy at Clinical hospital center Rijeka over a ten year period

BACKGROUND: The aim of this paper was to compare laparoscopic and classic appendectomy over a ten-year period to the complications and recovery rate of patients. METHODS: In the period from the beginning of 2007 to the end of 2016, a total of 1480 patients with laparoscopic approach and 1220 patients with classic approach (including 65 patients converted to open appendectomy - 2.4%) were operated at Clinical Hospital Center Rijeka, Croatia. 43% (1161 patients) of the total number of patients were female and the remaining were men (1539 patients, 57%). RESULTS: Out of 1480 patients with laparoscopic approach, 212 (14%) had peritonitis due to perforated appendicitis, compared to 193 (16%) among 1220 patients with classic approach. Among the laparoscopic appendectomies there were 242 (16%) gangrenous appendicitis without perforation, and 220 (18%) among the classic appendectomies. Other patients had acute phlegmonous appendicitis. Postoperative wound infection was the most common complication in 83 (5.6%) patients operated by laparoscopic approach and in 105 (8.6%) of classic operated patients. Postoperative hematoma of the wound had 25 (2%) of the classic operated patients versus 4 patients (0.2%) operated by laparoscopic approach. Douglas abscess had 92 (7.5%) of the classic operated patients, and 42 (2.8%) of the patients operated by laparoscopic surgery. The average duration of hospitalization in laparoscopic operated patients was two days, in the classic operated three days. CONCLUSIONS: Laparoscopic appendectomy is a less invasive operation with shorter recovery time, minor complications, and faster early onset of per os nutrition and return to everyday life

Oral antiseptics and nickel–titanium alloys: mechanical and chemical effects of interaction

The effect of oral antiseptics on the corrosion of nickel-titanium (NiTi) alloys with various coating was investigated. Uncoated, titanium nitride-coated and rhodium-coated NiTi archwires (0.020 × 0.020″) were tested in interaction with artificial saliva pH 4.8 and oral antiseptics based on hyaluronic acid (Gengigel), chlorhexidine (Curasept) and essential oils in alcohol base (Listerine). The dynamics of nickel and titanium ions release were recorded during 28 days. Springback ratio and modulus of resilience were assessed by three-point bending test. The results showed that corrosion of NiTi is related to type of antiseptic mouth rinse and coating formulations. Exposure to an artificial saliva and antiseptics tend to reduce flexibility and resilience of NiTi archwires. The influence of the media is more significant than the influence of the type of the alloys coating. The largest release of nickel ions is in the first 3 days. Antiseptics do not cause further deterioration of the elastic properties in uncoated NiTi compared to saliva. As a result of exposure of nitrified NiTi wires in Listerine, there is bigger release of nickel ions, decrease in elastic properties and lower force delivery in unload. Listerine tends to reduce elastic properties of rhodium- coated wires also. In conclusion, except for Listerine, changes of mechanical characteristics induced by antiseptics are small and would not have a clinically important impact. Generally, Curasept would be the most suitable option

Effect of oral antiseptics on the corrosion stability of nickel‐titanium orthodontic alloys

The aim was to explore the influence of the interaction of oral antiseptics and various coatings on the corrosion behavior of nickel‐ titanium (NiTi) orthodontic alloys. NiTi archwires with uncoated, rhodium‐coated, and nitride‐coated surface were exposed to artificial saliva pH 4.8 at the temperature of 37 °C, and to saliva with the addition of three commercial oral antiseptics (Curaspet, Gengigel, and Listerine). Electrochemical impedance spectroscopy and cyclic polarization were performed. Released nickel and titanium ions after a period of 7 days were measured by inductively coupled optical emission spectroscopy. Results demonstrate that the rate and degree of corrosion mainly increase with the addition of antiseptics. Electrochemical impedance spectroscopy indicates the biggest corrosion resistance in Gengigel. Rhodium‐coated NiTi demonstrates higher corrosion rate in saliva and in all antiseptics than uncoated and nitride‐ coated NiTi. The highest tendency toward localized corrosion is seen in rhodium‐coated NiTi in all media, and least in nitride‐coated NiTi. The release of titanium ions mainly supports findings of general corrosion rate. These results indicate that both antiseptics and coating modify corrosion

Smell and Taste in Titanium and Nickel Allergic Sensitization in Orthodontic Patients

Objective: To assess the prevalence of allergic sensitization to titanium and nickel in orthodontic patients and to evaluate alterations of smell and taste. Subjects and Methods: A total of 250 subjects were invited to participate, 245 accepted. The age range was 11‐45 years, 68% were females and 52% adolescents. An epicutaneous patch test was performed. Of the positive subjects in the patch test, 26 participated in the taste and smell testing and were matched by age and sex with 26 negative subjects. Results: The prevalence of hypersensitivity to titanium and/or nickel in orthodontic patients was 15.5%. Taste and smell were more impaired in sensitized subjects (P ≤ .025), taste was more affected than smell and the tastes most affected were sour and bitter tastes, while the sweet taste was least impaired. Conclusion: The allergic sensitization to titanium is more uncommon than to nickel, with altered smell and taste related to those hypersensitivities

Cytotoxicity of Metal Ions Released from NiTi and Stainless Steel Orthodontic Appliances, Part 1: Surface Morphology and Ion Release Variations

Despite numerous studies on ion release from orthodontic appliances, no clear conclusions can be drawn due to complex interrelations of multiple factors. Therefore, as the first part of a comprehensive investigation of cytotoxicity of eluted ions, the objective of this study was to analyze four parts of a fixed orthodontic appliance. Specifically, NiTi archwires and stainless steel (SS) brackets, bands, and ligatures were immersed in artificial saliva and studied for morphological and chemical changes after 3-, 7-, and 14-day immersion, using the SEM/EDX technique. Ion release profiles were analyzed for all eluted ions using inductively coupled plasma mass spectrometry (ICP-MS). The results demonstrated dissimilar surface morphologies among parts of the fixed appliance, due to variations in manufacturing processes. The onset of pitting corrosion was observed for the SS brackets and bands in the as-received state. Protective oxide layers were not observed on any of the parts, but adherent layers developed on SS brackets and ligatures during immersion. Salt precipitation, mainly KCl, was also observed. ICP-MS proved to be more sensitive than SEM/EDX and exhibited results undetected by SEM/EDX. Ion release was an order-of-magnitude higher for SS bands compared to other parts, which was attributed to manufacturing procedure (welding). Ion release did not correlate with surface roughness