Ultrasound of Salivary Glands

Ultrazvuk je jednostavna i neinvazivna metoda, neškodljiva za bolesnika, razmjerno je jednostavna i pruža mogućnost da se pregled ponovi. Omogućuje brz uvid u morfologiju žlijezda slinovnica. Sama metoda se temelji na transmisiji energije u žlijezdano tkivo, primanju te energije pošto je ona bila reflektirana od tkiva, te njezina bilježenja, tako da se može interpretirati. Budući da se kod bolesti mijenja veličina, oblik i hitološka građa, mijenja se i ehostruktura same slinovnice. Na temelju te promjene zaključuje se da je riječ o patološkom procesu. Cilj je da ultrazvuk odmah nakon kliničkoga pregleda postane prva pretraga u dijagnostičkome postupku. Kod upalno promijenjenih žlijezda slinovnica, na temelju ehogenosti može se razlikovati akutna od kronične upale. Kod akutne upale parenhim je smanjene ehogenosti (hipoehogen), a kod kronične upale pokazuje pojačanu ehogenost (hiperehogen je). Benigni tumori su obično smanjene ehogenosti s pojačanim odjecima iza stražnje stijenke. Ultrazvučna slika pokazuje lokaciju, veličinu, ograničenost strukture i odnos tvorbe s okolnim tkivima i organima. Kod malignih tumora na slici je bitno uočiti je li tvorba ostala ograničena na tkivo žlijezde ili je infiltrirala u okolna tkiva, te jesu li povećani limfni čvorovi. Moguća je raščlamba drugih parenhimatoznih organa (jetre, slezene, limfnih čvorova abdomena). Vrijednost je ultrazvučne slike kod kamenaca žlijezda slinovnica u mogućnosti odgovarajućega slikovnog prikaza popratnih patomorfologijskih promjena u parenhimu žlijezda. Ultrazvučni aparat je uređaj koji daje slike presjeka unutrašnjosti ljudskoga tijela ravninom kojom se ultrazvučni snop širi. Ultrazvučni aparat emitira kratke impulse ultrazvuka visoke frekvencije (između 2 i 10 MHz) u unutrašnjost tijela uz pomoć odgovarajućeg pretraživača. Uspješnost ultrazvučne pretrage ovisi prvenstveno o kakvoći uređaja i pretraživača, a zatim o vještini liječnika i o vrsti patoloških promjena žlijezda slinovnica. Također je pod kontrolom ultrazvuka moguća ciljana punkcija pri kojoj se igla koso uvodi u željezdano tkivo ispred pretraživača u snop ultrazvučnih valova. Na taj način igla se vidi u cijeloj dužini, a vrh igle je usmjeren u područje iz kojeg se želi dobiti uzorak za citološku raščlambu. Iako ultrazvučna dijagnostika na spada u temeljne i uobičajene metode pretrage u stomatološkoj praksi, ona pomaže stomatologu da na osnovi ultrazvučne slike lakše spozna etiologiju procesa, odredi dijagnozu i po potrebi uputi pacijenta na daljnju spcijalističku pretragu.Ultrasound is a simple and non-invasive method with no negative effects on the patients health. It is also relatively cheap and enables patients to repeat the examination. It allows quick access into salivary gland morphology. This method is based on the transmission of energy into glandular tissue.The energy is then reflected from the tissue and subsequently received and recorded in order to be interpreted. Since the size, shape and histologic structure are altered by disease, the echostrukture of the salivary gland it self is altered as well, thus revealing a pathological process. The ultrasound should be used immediately after clinical examination as the first stage of diagnostic procedure. By echogenity of inflamed salivary glands acute inflammation can be differentiated from chronic. Unlike acute inflammation in which the parenchyma echogenity is decreased (hypoechogenic), chronic inflammation shows increased echogenity (hyperechogenic). Benign tumors usually show lower echogenity with intensified echoes behind the back wall. The ultrasound image reveals the location, margins, structure dimensions as well as its relation to the surrounding tissues and organs. In a malignant tumor image it is important to observe whether the tumor has spread into the surrounding tissues or it has remained within the glandular tissue. Also it is essential to check whether the lymph nodes are enlarged. An anlysis of other parenchymatous organs such as the liver, spleen and lymph nodes of the abdomen is also possible. Ultrasound of the sialolites of the alivary glands can indicate corresponding pathomorphological changes in glandular parenchyma. The ultrasound is a device which produces crosssection images of the inner parts of the human body spreading an ultrasound wave across the plane. The ultrasound device emits short ultrasound impulses of high frequency (2-10 MHz) into the human body by means of an adequate scanner. The effects of the ultrasound examination depend primarily on the quality of both the device and the scanner, in the physicians skill as well as on the pathologic changes of the salivary glands. When performing a needle biopsy, the ultrasound device also anables the needle to be inserted at a certain angle into the glandular tissue in front of the scanner and directly into the ultrasound waves. In this way, the needle can be seen across its whole lenght, its tip being directed into the area from which the sample for biopsy should be obtained. Although ulatrasound diagnostics is not included in the common methods of dental exmination, it allows the dentist to get better insights into etiology of the process. It also helps in making the diagnosis and, if necessary, referring the patient to further specialist examination

Promjene u zdravlju usne šupljine tijekom rane faze ortodontske terapije

The aim of the study was to assess the influence of fixed orthodontic appliance on Streptococcus (S.) mutans and S. sobrinus counts in orthodontic patients with regard to their previous caries experience (Decayed, Missing and Filled Teeth (DMFT ) index) during the first 12 weeks of orthodontic treatment. Twenty-two patients that satisfied inclusion criteria (healthy systemic and periodontal condition, avoidance of antibiotic therapy and antiseptic mouthwashes in the past three months) were included. All clinical measurements took place prior to and 12 weeks after fixed orthodontic appliance placement, in the following order: 1) stimulated saliva flow (SS); 2) Simplified Oral Hygiene I ndex (OHI -S); and 3) DMFT . The method of polymerase chain reaction (PCR) was used to detect the presence of S. mutans and S. sobrinus at T1 and T2. T-test showed significant increase in DMFT index and SS between T1 and T2. Results also indicated significant improvement in OHI -S index. By use of the PCR method, S. mutans was detected in two patients at T1. At T2, two more patients had S. mutans, but the increase was not statistically significant. Using the same method, S. sobrinus was detected only in two patients at T2. In conclusion, fixed orthodontic appliances did not induce statistically significant changes in caries microflora even in the presence of enhanced oral hygiene habits.Svrha istraživanja bila je utvrditi utjecaj fiksnih ortodontskih naprava na broj kariogenih bakterija Streptococcus (S.) mutans i S. sobrinus u ortodontskih pacijenata s obzirom na njihov kariogeni status (indeks DMFT ) tijekom prvih dvanaest tjedana ortodontske terapije. U istraživanju je sudjelovalo 22 ispitanika koji su zadovoljili kriterije za uključenje: uredno opće i parodontno zdravlje, izbjegavanje antiseptika za ispiranje usne šupljine i antibiotika u prethodna tri mjeseca. Sva klinička mjerenja napravljena su prije (T1) i 12 tjedana nakon (T2) postavljanja fiksne ortodontske naprave sljedećim redoslijedom: 1) količina stimulirane sline (SS), 2) Simplified Oral Hygiene Index (OHI -S) i 3) DMFT . Reakcija lančane polimeraze (PCR) je korištena za otkrivanje prisutnosti S. mutans i S. sobrinus prilikom T1 i T2. T-test je pokazao značajan porast indeksa DMFT i SS između T1 i T2. Rezultati također pokazuju značajno poboljšanje indeksa OHI -S. Koristeći PCR metodu S. mutans je otkriven kod dvoje ispitanika na T1. Nakon 12 tjedana fiksne ortodontske terapije došlo je do porasta broja ispitanika kod kojih je otkriven S. mutans, ali porast nije bio statistički značajan. Istom metodom S. sobrinus je otkriven tek u dvoje ispitanika na T2. U zaključku, tijekom prvih 12 tjedana fiksne ortodontske terapije nije došlo do statistički zančajne promjene u kariogenoj mikroflori. Primjena individualnih edukativnih i preventivnih mjera oralne higijene može spriječiti nastanak štetnih nuspojava tijekom fiksne ortodontske terapije

Salivary Electrolytes in Patients with Metallic and Ceramic Orthodontic Brackets

Svrha: Iz postojeće literature poznato je da metalni ioni iz ortodontskih naprava mogu korodirati zbog djelovanja sline i bakterija u usnoj šupljini. Rezultati većine studija upućuju na to da se razina nikla i kroma u slini ne povisuje nakon postavljanja ortodontskih naprava. No nema istraživanja o razini titanija, kobalta, bakra i cinka u slini ortodontskih pacijenata. Ispitanici i postupci: Razina nikla (Ni), titanija (Ti), kroma (Cr), kobalta (Co), bakra (Cu) i cinka (Zn) mjerena je u slini četrdeset i dvoje pacijenta s keramičkim metalnim bravicama i isto toliko njih s konvencionalnima i to prije postavljanja ortodontskih naprava s pomoću induktivne spregnute plazme/masene spektrometrije i šest mjeseci poslije toga. U statističkoj analizi korištena su dva testa – Wilcoxonov signed rank i Mann-Whitneyev s razinom značajnosti od 0,05. Rezultati: Rezultati su pokazali da se razina titana u slini povisila šest mjeseci nakon postavljanja ortodontskih naprava. Razina kroma i cinka, pak, značajno se snizila nakon postavljanja ortodonskih naprava. Nije bilo statistički značajne razlike u razini nikla, titanija, kroma, bakra, kobalta i cinka u slini između pacijenata s metalnim i keramičkim ortotontskim bravicama. Zaključak: Možemo zaključiti da se razina titanija u slini značajno povisila šest mjeseci nakon postavljanja ortodontskih naprava za razliku od razine kroma i cinka koja se značajno snizila šest mjeseci poslije njihova postavljanja, bez obzira na vrstu korištenih bravica.Objectives: It is known from the existing literature that metal ions within orthodontic appliances are prone to corrosion due to the salivary and bacterial interplay in the oral cavity. The results from the most studies show that levels of salivary nickel and chromium do not increase after the installment of orthodontic appliances. Material and methods: However, there are no studies on salivary levels of titanium, cobalt, copper and zinc in these patients. Salivary levels of nickel (Ni), titanium (Ti), chromium (Cr), cobalt (Co), copper (Cu) and zinc (Zn) were measured in 42 patients with ceramic brackets and in 42 patients with metal conventional brackets prior to insertion of orthodontic appliances and six months after insertion of orthodontic appliances by means of inductive coupled plasma/mass spectrometry. Statistical analysis was performed by use of Wilcoxon signed rank test and Mann Whitney test with level of significance set at 0.05. Results: The results showed that salivary level of titanium increased significantly six months after installment of orthodontic appliances. Salivary level of chromium and zinc significantly decreased after installment of orthodontic appliances. There were no significant differences in salivary levels of nickel, titanium, chromium, copper, cobalt and zinc between the patients with metallic and those with ceramic brackets. Conclusion: We might conclude that the salivary level of titanium increased significantly six months after installment of orthodontic appliances unlike salivary levels of chromium and zinc which significantly decreased after installment of orthodontic appliances, regardless of bracket type which was used

Clinical and Salivary Findings in Patients with Different Types of Orthodontic Brackets

Cilj: Podatci o kliničkim i salivarnim nalazima pacijenata s različitim vrstama ortodontskih bravica i vezanja (ligacije) doista su oskudni. Zbog toga je cilj ove studije bio usporediti kliničke i salivarne nalaze pacijenata s različitim vrstama fiksnih ortodontskih naprava. Ispitanici i postupci: Indeks karioznih i ekstrahiranih zuba te zuba s ispunom (KEP indeks), indeks plaka, količina sline, pH sline i prevalencija bijelih mrlja određena je za 83 pacijenta s različitim vrstama ortodontskih bravica i vezanja (metalne pasivne samovezujuće bravice, konvencionalne metalne bravice, monokristalne bravice i polikristalne aktivne samovezujuće bravice), prije početka ortodontske terapije i poslije toga tretmana. Pacijenti su, u razdoblju od dvije godine, birani u privatnoj stomatološkoj ordinaciji. Skupinu su činila 83 pacijenta (srednja dob 15,14 ± 1,66 godina) – 52 žene (srednja dob 15,8 ± 1,68) i 31 muškarac (srednja dob 15,24 ± 1,64). Statistička analiza rađena je primjenom t-testova za zavisne i nezavisne uzorke te jednosmjernog testa ANOVA-e, Wilcoxonova signed rank testa i Kruskal-Wallisova testa. P-vrijednost manja od 0,05 (p < 0,05) smatrana je statistički značajnom. Rezultati: KEP indeks i količina sline pokazali su značajan porast, a pH sline značajno se snizio u promatranom razdoblju kod svih pacijenata, neovisno o vrsti bravica i ligacije. Nije nađena statistički značajna razlika u promatranim parametrima među pacijentima s različitim ortodontskim bravicama. Zaključak: Iako je količina salivacije povećana kod pacijenata s fiksnim ortodontskim napravama, što može imati protektivni protukarijesni učinak, KEP indeks također raste, a pH sline pada šest mjeseci nakon početka tretmana, neovisno o materijalu bravica i načinu vezanja. Svi pacijenti trebali bi dobiti detaljne pute o oralnoj higijeni i prehrambenim navikama prije početka fiksne ortodontske terapije i na svakom kontrolnom pregledu.Aim: Data regarding different types of orthodontic brackets and ligation and various clinical and salivary findings are scarce. Therefore, the aim of this study was to compare clinical and salivary findings in patients with different types of fixed orthodontic appliances. Subjects and methods: Decayed, missing and filled teeth index (DMFT) and plaque index, salivary flow rate, salivary pH and prevalence of white spot lesions were determined in 83 patients with different types of orthodontic brackets and ligation (metal passive self-ligating brackets, conventional metal brackets, mono-crystal brackets and polycrystalline active self-ligating brackets), before and six months after the beginning of fixed orthodontic treatment. The patients were recruited in a private dental office, in the period of two years. The group comprised 83 patients (mean age: 15.14 ± 1.66 years), including 52 women (mean age: 15.08 ± 1.68) and 31 men (15.24 ± 1.64). Statistical analysis was performed by use of dependent and independent samples t-test as well as one way ANOVA, Wilcoxon signed rank test and the Kruskal Wallis test. P-values below 0.05 (p<0.05) were considered significant. Results: DMFT and salivary flow have shown a significant increase, while salivary pH has shown a significant decrease in the observed time interval, in all patients irrespective of type of brackets and ligation. Among patients with different bracket material, no significant differences were found in any of the observed parameters. Conclusion: Although salivary flow rate is increased in patients with fixed orthodontic appliances which can have caries-protective effect, DMFT also increases and salivary pH decreases six months after the beginning of the treatment independently of bracket material or ligation type. All patients should receive instructions for precise oral hygiene and dietary habits before the beginning of fixed orthodontic therapy and at every dental check-up

CONCESSION

Koncesija u pravnom smislu predstavlja dozvolu za obavljanje djelatnosti koje su uvjetovane posebnim odobrenjem. Koncesija je također i pravni dvostrani odnos koji se uvijek razvija između dviju strana, odnosno između davatelja koncesije i koncesionara. Postoje neke vrste koncesija, a to su koncesija za gospodarsko korištenje općeg ili drugog dobra, koncesija za radove te koncesija za usluge. U ovom radu će se spomenuti i mnoge druge stvari vezane uz koncesiju, kao što su obilježja koncesije, razvoj koncesije, ugovori o koncesijama te će se navesti primjer koncesije. Da bi se zasnovao koncesijski odnos, potrebno je pored odluke o koncesiji, sklopiti ugovor o koncesiji kojim se određuju prava i obveze davatelja koncesije i koncesionara. Davatelj koncesije dužan je kontinuirano nadzirati rad koncesionara i izvršavanja njegovih obveza iz ugovora o koncesiji. U Republici Hrvatskoj se uz Zakon o koncesijama primjenjuju i drugi propisi, kao što su Zakon o pomorskom dobru i morskim lukama, itd.A concession in the legal sense is a license to perform an activity that is subject to a special approval. A concession is also a legal bilateral relationship and always develops between the two parties, between the grantor of the concession and the concesssionaire. There are some types of concessions, such as concessions for the economic use of common ot other goods, concesions for works and concessions for services. This paper will mention many other things related to the concession, such as the chararacteristics of the conseccion, the development oft he concession, concession agreements and will give an example of a concession. In order to establish a concession relationship, it is necesarry, in addition to the decision on the concession, to enter into a concession agreement which determines the rights and obligations of the grantor and the concessionaire. The concession grantor is obliged to continuosly monitor the work of the concessionaire and the execution of its obligations under the concession agreement. In the Republic of Croatia, in addition to the Concessions Act, other regulations apply, such as the Maritime Property and Seaports Ac

Hiding Data in Images Using Steganography

Steganografija je postupak skrivanja podataka u multimedijskim datotekama, najčešće u slikama, tako da ljudska osjetila ne primijete razliku između originalne datoteke i one s umetnutim podacima. Najčešće korištena metoda za umetanje podataka u slike naziva se LSB metoda. To je supstitucijska metoda koja bitove podataka koji se umeću sprema u bitove najmanje važnosti slike u koju se umeće. Mijenjanje samo najmanje važnih bitova slike osigurava da promjene u bojama piksela budu što manje uočljive. U sklopu ovog rada dana je implementacija LSB metode kojom je moguće u sliku sakriti tekst ili drugu sliku te pročitati te skrivene podatke iz slike i rekonstruirati ono što je u nju bilo skriveno.Steganography is a proccess of hiding data in multimedia files, most often images, in a way that human senses do not notice the difference between the original file and the one with the inserted data. The most commonly used method for inserting data into images is called the LSB method. It's a substitution method that stores the bits of inserted data into the least significant bits of the image in which it's inserted. Changing only the least significant image bits ensures that changes in pixel colors are as unnoticeable as possible. In this paper, an implementation of the LSB method is given. Using this implementation it is possible to hide text or another image in an image and to also read the hidden data from an image and reconstruct what was hidden

Hiding Data in Images Using Steganography

Steganografija je postupak skrivanja podataka u multimedijskim datotekama, najčešće u slikama, tako da ljudska osjetila ne primijete razliku između originalne datoteke i one s umetnutim podacima. Najčešće korištena metoda za umetanje podataka u slike naziva se LSB metoda. To je supstitucijska metoda koja bitove podataka koji se umeću sprema u bitove najmanje važnosti slike u koju se umeće. Mijenjanje samo najmanje važnih bitova slike osigurava da promjene u bojama piksela budu što manje uočljive. U sklopu ovog rada dana je implementacija LSB metode kojom je moguće u sliku sakriti tekst ili drugu sliku te pročitati te skrivene podatke iz slike i rekonstruirati ono što je u nju bilo skriveno.Steganography is a proccess of hiding data in multimedia files, most often images, in a way that human senses do not notice the difference between the original file and the one with the inserted data. The most commonly used method for inserting data into images is called the LSB method. It's a substitution method that stores the bits of inserted data into the least significant bits of the image in which it's inserted. Changing only the least significant image bits ensures that changes in pixel colors are as unnoticeable as possible. In this paper, an implementation of the LSB method is given. Using this implementation it is possible to hide text or another image in an image and to also read the hidden data from an image and reconstruct what was hidden

THE PREVALENCE OF WHITE SPOT LESIONS IN THE PATIENTS DURING FIXED ORTHODONTIC TREATMENT

Uvod: Trenutačno u literaturi ne postoji longitudinalno kliničko istraživanje koje bi pratilo promjene mikrobioloških i fizikalnih parametara sline u pacijenata koji imaju ortodontske bravice različitog dizajna i materijala. Materijali i metode: Svaka skupina od 21 pacijenata razlikovala se po tipu bravica (estetske konvencionalne i estetske samovezujuće, metalne konvencionalne i metalne samovezujuće) i kod kojih je određen pH plaka, prisutnost inicijalnih karijesnih lezija s pomoću Diagnodent pen-a, salivarni elektroliti (titanij, nikal, bakar, cink, krom i kobalt), količina i vrsta bakterija s pomoću masene spektrometrije, indeks KEP-a, prehrambene i oralne-higijenske navike. Rezultati: Na 28,57 % zuba pogoršao se nalaz bijelih mrlja, a svi su ispitanici, njih 24, dobili novu bijelu leziju. pH plaka bio je znakovito alkalniji tijekom drugoga mjerenja. Indeks plaka pogoršao se (ali ne znakovito) u drugome mjerenju, neovisno o vrsti bravice. pH plaka i količina izlučene sline znakovito su bili viši šest mjeseci nakon postavljanja fiksne ortodontske naprave. Indeks KEP-a znakovito se pogoršao šest mjeseci nakon postavljanja fiksne ortodontske naprave neovisno o tipu bravice. Salivarne koncentracije titana bile su znakovito veće šest mjeseci nakon početka terapije, a kroma i cinka manje. Nije bilo razlika u drugim salivarnim elektrolitima. Velika razlika postoji o upotrebi interdentalnih četkica prije uporabe i šest mjeseci poslije. Nije bilo očitih razlika tijekom početnog mjerenja i šest mjeseci poslije s obzirom na konzumiranje obroka, međuobroka, slatkiša, slatkih pića, upotrebe gume za žvakanje, pranje zuba i upotrebu zubnog konca. Zaključci: Ortodontsko liječenje pridonosi promjeni sastava dentobakterijskog plaka, nastanku bijelih mrlja i utječe na povećanje indeksa KEP-a, količinu izlučene sline i pH plaka. Plak indeks nije pokazao znakovite promjene. Ispitanici nisu pokazali promjene u prehrambeno-higijenskim navikama, osim u korištenju interdentalnih četkica. Vrsta bravica utjecala je jedino na salivarne razine titanija i količinu izlučene sline.Background and objectives: It is known that orthodontic therapy might alter various oral and salivary findings, especially if patients do not impose better oral hygiene practices at home as well as certain dietary habit changes. Therefore, it is expected that certain bacterial rods would be more frequent in these patients, especially when correlated to the white spot lesions development. Furthermore, changes in the pH of the saliva and plaque is expected as it was suggested from the previous finding of various authors. This might result in the worsening of the DMFT index. At present there are no recorded longitudinal clinical trials monitoring the changes of microbiological and physiological parameters of saliva in patients with orthodontic brackets of various designs and materials. Materials and methods: Each study group consisted of 21 patients with different type of fixed orthodontic appliance - aesthetic conventional and aesthetic self-ligating brackets, metal conventional and metal self-ligating brackets. For all patients the following was determined: pH of plaque, presence of initial carious lesions (by means of Diagnodent), salivary levels of electrolytes (titanium, nickel, copper, zinc, chromium and cobalt) by use of inductively coupled plasma mass spectrometry, the number and species of the bacteria present (by means of mass spectrometry), the DMFT index, dietary habits and oral hygiene by use of questionnaire with eight questions. Statistical analysis was performed by use of Kolmogorov Smirnov test in order to determine normality of the data distribution. As the data were normally distributed, T-test for dependent samples was applied for the measurment immediately after bracket installment and six months later. In order to determine differences between boys and girls as well as differences between various bracket types, T-test for independent samples was used. P-values lower than 0.05 (p < 0.05) were considered as statistically significant. Results: Overall, 28,57% of teeth showed deterioration in white spot finding and the total of 24 patients developed a new white spot lesion. White spot lesion at first measurement were noticed on the 17.86 % of the teeth, while on the second measurment they were present on 46.43 % teeth. There were no significant differences in the occurrence of white spot lesions regarding the features of the brackets. There was a significant difference in pH of the plaque Antonija Jurela, disertacija after the brackets were inserted no matter which ones. On the first measurment, pH of the plaque was 6.0, whereas on the second measurment pH of the plaque was 6.25, which means that it was more alkaline. It seems that the patients implemented better oral hygiene measures when they got orthodontic appliances. Plaque index deteriorated after the brackets were inserted, however the difference did not reach statistical significance, regardless of the type of the bracket. The DMFT index increased after insertion of the fixed orthodontic appliance, regardless of the bracket type. Salivary flow rate increased after the brackets were inserted, expecially in patients with aesthetic conventional brackets. Salivary concentrations of titanium were significantly higher after six months of treatment. Salivary titanium levels were higher in patients with metallic conventional brackets when compared to the ones with metallic self-ligating brackets. Salivary chromium and zinc concentrations were significantly higher at the first measurment when compared to the second one. Bacterial composition of the plaque determined by use of mass spectrometry showed continuous presence of the following bacteria: Capnocytophaga, Veilonella, Streptococcus parasanguinis and Streptococcus mutans. New bacteria which appeared together with deterioration of white spot lesions was Campylobacter. Significant difference was observed in the usage of interdental brushes before the treatment and six months after the insertion of orthodontic appliance. The initial measurement and the second measurement found no significant differences regarding food consumption habits (meals, snacks, sweets, sweetened drinks, chewing gums) and oral hygiene practices (brushing and flossing) regardless of the bracket type. Conclusions: Orthodontic treatment leads to an increased tendency to formation of white spot lesions and an increase in the DMFT index, salivary flow rate and pH of the plaque although plaque index do not change significantly. It seems that the participants did not change their eating habits, only increased use of interdental brushes was noticed. It seems that bracket type does not influence any of the examined parameters except salivary titanium levels and salivary flow rate

THE PREVALENCE OF WHITE SPOT LESIONS IN THE PATIENTS DURING FIXED ORTHODONTIC TREATMENT

Uvod: Trenutačno u literaturi ne postoji longitudinalno kliničko istraživanje koje bi pratilo promjene mikrobioloških i fizikalnih parametara sline u pacijenata koji imaju ortodontske bravice različitog dizajna i materijala. Materijali i metode: Svaka skupina od 21 pacijenata razlikovala se po tipu bravica (estetske konvencionalne i estetske samovezujuće, metalne konvencionalne i metalne samovezujuće) i kod kojih je određen pH plaka, prisutnost inicijalnih karijesnih lezija s pomoću Diagnodent pen-a, salivarni elektroliti (titanij, nikal, bakar, cink, krom i kobalt), količina i vrsta bakterija s pomoću masene spektrometrije, indeks KEP-a, prehrambene i oralne-higijenske navike. Rezultati: Na 28,57 % zuba pogoršao se nalaz bijelih mrlja, a svi su ispitanici, njih 24, dobili novu bijelu leziju. pH plaka bio je znakovito alkalniji tijekom drugoga mjerenja. Indeks plaka pogoršao se (ali ne znakovito) u drugome mjerenju, neovisno o vrsti bravice. pH plaka i količina izlučene sline znakovito su bili viši šest mjeseci nakon postavljanja fiksne ortodontske naprave. Indeks KEP-a znakovito se pogoršao šest mjeseci nakon postavljanja fiksne ortodontske naprave neovisno o tipu bravice. Salivarne koncentracije titana bile su znakovito veće šest mjeseci nakon početka terapije, a kroma i cinka manje. Nije bilo razlika u drugim salivarnim elektrolitima. Velika razlika postoji o upotrebi interdentalnih četkica prije uporabe i šest mjeseci poslije. Nije bilo očitih razlika tijekom početnog mjerenja i šest mjeseci poslije s obzirom na konzumiranje obroka, međuobroka, slatkiša, slatkih pića, upotrebe gume za žvakanje, pranje zuba i upotrebu zubnog konca. Zaključci: Ortodontsko liječenje pridonosi promjeni sastava dentobakterijskog plaka, nastanku bijelih mrlja i utječe na povećanje indeksa KEP-a, količinu izlučene sline i pH plaka. Plak indeks nije pokazao znakovite promjene. Ispitanici nisu pokazali promjene u prehrambeno-higijenskim navikama, osim u korištenju interdentalnih četkica. Vrsta bravica utjecala je jedino na salivarne razine titanija i količinu izlučene sline.Background and objectives: It is known that orthodontic therapy might alter various oral and salivary findings, especially if patients do not impose better oral hygiene practices at home as well as certain dietary habit changes. Therefore, it is expected that certain bacterial rods would be more frequent in these patients, especially when correlated to the white spot lesions development. Furthermore, changes in the pH of the saliva and plaque is expected as it was suggested from the previous finding of various authors. This might result in the worsening of the DMFT index. At present there are no recorded longitudinal clinical trials monitoring the changes of microbiological and physiological parameters of saliva in patients with orthodontic brackets of various designs and materials. Materials and methods: Each study group consisted of 21 patients with different type of fixed orthodontic appliance - aesthetic conventional and aesthetic self-ligating brackets, metal conventional and metal self-ligating brackets. For all patients the following was determined: pH of plaque, presence of initial carious lesions (by means of Diagnodent), salivary levels of electrolytes (titanium, nickel, copper, zinc, chromium and cobalt) by use of inductively coupled plasma mass spectrometry, the number and species of the bacteria present (by means of mass spectrometry), the DMFT index, dietary habits and oral hygiene by use of questionnaire with eight questions. Statistical analysis was performed by use of Kolmogorov Smirnov test in order to determine normality of the data distribution. As the data were normally distributed, T-test for dependent samples was applied for the measurment immediately after bracket installment and six months later. In order to determine differences between boys and girls as well as differences between various bracket types, T-test for independent samples was used. P-values lower than 0.05 (p < 0.05) were considered as statistically significant. Results: Overall, 28,57% of teeth showed deterioration in white spot finding and the total of 24 patients developed a new white spot lesion. White spot lesion at first measurement were noticed on the 17.86 % of the teeth, while on the second measurment they were present on 46.43 % teeth. There were no significant differences in the occurrence of white spot lesions regarding the features of the brackets. There was a significant difference in pH of the plaque Antonija Jurela, disertacija after the brackets were inserted no matter which ones. On the first measurment, pH of the plaque was 6.0, whereas on the second measurment pH of the plaque was 6.25, which means that it was more alkaline. It seems that the patients implemented better oral hygiene measures when they got orthodontic appliances. Plaque index deteriorated after the brackets were inserted, however the difference did not reach statistical significance, regardless of the type of the bracket. The DMFT index increased after insertion of the fixed orthodontic appliance, regardless of the bracket type. Salivary flow rate increased after the brackets were inserted, expecially in patients with aesthetic conventional brackets. Salivary concentrations of titanium were significantly higher after six months of treatment. Salivary titanium levels were higher in patients with metallic conventional brackets when compared to the ones with metallic self-ligating brackets. Salivary chromium and zinc concentrations were significantly higher at the first measurment when compared to the second one. Bacterial composition of the plaque determined by use of mass spectrometry showed continuous presence of the following bacteria: Capnocytophaga, Veilonella, Streptococcus parasanguinis and Streptococcus mutans. New bacteria which appeared together with deterioration of white spot lesions was Campylobacter. Significant difference was observed in the usage of interdental brushes before the treatment and six months after the insertion of orthodontic appliance. The initial measurement and the second measurement found no significant differences regarding food consumption habits (meals, snacks, sweets, sweetened drinks, chewing gums) and oral hygiene practices (brushing and flossing) regardless of the bracket type. Conclusions: Orthodontic treatment leads to an increased tendency to formation of white spot lesions and an increase in the DMFT index, salivary flow rate and pH of the plaque although plaque index do not change significantly. It seems that the participants did not change their eating habits, only increased use of interdental brushes was noticed. It seems that bracket type does not influence any of the examined parameters except salivary titanium levels and salivary flow rate