Number of the Dentinal Tubules as a Function of Cavity Dept

Svrha ovog istraživanja je utvrditi postoji li razlika između broja i promjera otvora eksponiranih dentinskih tubula te udjela površine otvora eksponiranih dentinskih tubula od ukupne površine poprečnog presjeka humanoga koronarnog dentina s obzirom na udaljenost prema caklinsko-dentinskom spojištu i pulpi. Scanning elektronsko-mikroskopska usporedbena raščlamba provedena je na 60 uzoraka humanoga koronarnog dentina razdijeljenih u tri skupine prema udaljenosti između pulpe i caklinsko-dentinskog spojišta. promatran je dentin na tri razine u području središnje fisure: 1. poprečni rez koronarnoga dentina, 1 mm ispod caklinsko-dentinskoga spojišta 2. poprečni rez koronarnoga dentina na polovini razmaka između caklinsko-dentinskoga spojišta i pulpne komore 3. poprečni rez koronarnoga dentina 1 mm iznad krova pulpne komore Izbrojeni su vidljivi dentinski tubulusi unutar kvadrata površine 50 µm x 50 µm. Dobiveni broj podijeljen je s 2500 da bi se dobio N/µm2 i pomnožen s 1.000.000 da bi se dobio N/mm2). Prosječan broj otvora eksponiranih dentinskih tubula na prvoj razini je 96000/mm2, na drugoj razini 27100/mm2, te na trećoj 58.300/mm2. Jednosmjernom raščlambom varijance dobiven je omjer MStretman/MS pogrješka 305,22, koji je veći od F 0,99 (2,57) 4,98. Rezultati upućuju da postoji statistički znatna razlika broja i promjera otvora eksponiranih dentinskih tubula i veličine površine koju zauzimaju sve tri promatrane skupine uzoraka.The aim of this study was to determine if there is any defference between the number of exposed dentinal tubules on the cross section of the coronal dentine. By scanning electron microscopy comparative observation was carried out on 60 specimens of human coronal dentine, divided into 3 groups, in relation to the distance from the enamel-dentine junction and the pulp. Coronal dentine in the region of the central fissure was observed on three levels: 1. Cross section of the coronal dentine, 1 mm from the enamel-dentine junction. 2. Cross section of the coronal dentine, half-distance between the enamel-dentine junction and the pulp. 3. Cross section of the coronal dentine, 1 mm from the roof of the pulp chamber. Openings of the exposed dentinal tubules were counted in a square size 50 x 50 µm of the dentinal surface. The number was divided by 2500 to obtain the number of the openings of the dentinal tubules in the square micrometer (N/µm2). This number was multiplied by 106 to obtain the number of the openings of the dentinal tubules in the square millimeter (N/mm2). The mean number of the openings of the dentinal tubules on the first level was 9600/mm2, on the second level 27100/mm2 and on the third level 58300/mm2. Using the one-way analysis of variance was found ratio MStreatment/MSerror 305.22, that was greater than F 0.99 (2.57) 4.98. The results showed that there is significant statistical difference in the number of exposed dentinal tubules between all three groups of specimens

Biological Based of Dentine Hybridization

Proučavanje građe i strukture dentina usko je povezano s pronalaskom i usavršavanjem tehnika istraživanja- svjetlosne mikroskopije i elektronske mikroskopije. Rezultati svjetlosne mikroskopije pružili su površan i necjelovit uvid u građu i strukturu dentina. Razvojem elektronske mikroskopije nastao je epohalan pomak u proučavanju građe i strukture tvrdih zubnih tkiva. Potanko poznavanje građe i strukture tvrdih zubnih tkiva temelj je u razvoju koncepcije suvremenog adhezijskog restorativnog postupka. Dok adhezija na caklinu nije predstavljala problem u eksperimentalnom, a niti u kliničkom radu, adhezija na dentin uključuje mnoštvo specifičnosti i varijabilnosti. Adhezija na dentin ovisi o nekoliko skupina čimbenika: 1. biološkoj osnovi supstrata za adheziju 2. stanju i odgovorima pulpo-dentinskog kompleksa na adhezijski restorativni postupak 3. izboru materijala. Suvremena koncepcija adhezije na dentin zasniva se na hibridnom sloju kao vezi između dentina i smole, zapravo tvrdih zubnih tkiva i restorativnoga materijala. Hibridni se sloj sastoji od monomerom infiltriranoga demineraliziranog dentina, ostataka zaostaloga sloja, polimerizirane smole, smolom infiltriranih kolagenih vlakana i kristala hidroksilapatita. Raspored i međusobni odnosi strukturalnih elemenata dentina imaju velik utjecaj na oblik i kakvoću hibridnoga sloja. Heterogena struktura dentina određuje specifična svojstva dentina: permeabilnost, vlažnost, fizikalna svojstva (tvrdoća, čvrstoća, elastičnost). Različitost strukture i fiziologije dentina određuje adheziju na dentin kao kompleksnu interakciju između biološkoga materijala (dentina) i adhezijskoga sustava. Većina zuba koji zahtijevaju adhezijski restorativni postupak imaju ili su imali karijesnu leziju. U dentinu i pulpi se kao rezultat karijesnog procesa događaju mnoge tkivne reakcije, kao što su stvaranje tercijarnog dentina i sklerozacija dentinskih tubula. Osim u karijesnom lezijom zahvaćenim dentinom, sklerozacija se javlja i u eksponiranom abradiranom cervikalnom dentinu. Obje vrste skleroziranoga dentina sprječavaju stvaranje smolastih produljaka. Vrijednosti čvrstoće veze su smanjene u usporedbi sa površinom normalnoga, fiziološkog dentina. Izbor adhezijskoga sustava vrlo je važan čimbenik za proces hibridizacije i trajnost veze. Svaki adhezijski sustav sadrži sljedeće sastavnice: kiselina, primer, adhezijska smola. Do godine 1994. upotrebljavali su se adhezijski sustavi koji se primjenjuju u više koraka. Prigodom hibridizacije dentina događaju se velike promjene volumnog omjera minerala, vode i smole. Udio kolagenih vlakana ostaje isti. Stvaranjem hibridnoga sloja nastaju nova kemijska i fizikalna svojstva dentina i smole.The picture of the dentine structure is closely connected with the discovery and improvement of research techniques- light microscopy and scanning electron microscopy. Results of light microscopy were limited. Rapid development of dentine structure investigation begins with the use of scanning electron microscopy. Detailed knowledge of the hard dental tissue structure was the basis for the development of the concept of modern adhesive restorative treatment. Adhesion to enamel was not the problem, either experimentall, or clinically. Adhesion to dentine has a great number of specific characteristics and varieties. Further factors are important regarding the adhesion to dentine: 1. Biological bases of the substrate, 2. Condition and response of the pulp/dentine complex to the adhesive restorative treatment, 3. Material selection. Modern concept of adhesion to dentine is based on the hybrid layer as a bond between dentine and resin, hard dental tissues and restorative materials respectively. The hybrid layer in the dentine consists of a monomer-infiltrated demineralized dentine, smears layer remnants, polymerized resin, resin-infiltrated collagen fibrils and hydroxyl- apatite crystals. Distribution and interrelationships between structural elements of dentine have great influence on the form and quality of the hybrid layer. Heterogenous structure if dentine determines further specific properties of the dentine: permeability, humidity, physical properties (hardness, strength, elasticity). This dentine structure and dentine physiology variety determines adhesion to dentine as a complex interaction between biologic material (dentine) and adhesion system. Most teeth that require adhesive restorative treatment are carious or have had a previous caries lesion. A number of tissue changes in the dentin and pulp take place as a result of caries (formation of tertiary dentine, sclerosis of the dentinal tubules, cellular changes in the pulp). Apart from caries-effected dentine, sclerosis takes place in the exposed, abraded, cervical dentine. Both types of dentine sclerosis prevent resin tag formation. Bond strength values are reduced in comparison to bond strenght on the normal, physiologic dentine surface. Adhesive system selection is a very important factor for hybridization and bond durability. Each adhesive system contents further components: acid, primer and adhesive resin. Multi-bottled adhesive system were used until 1994. These system required application in multiple steps. After chemical treatment, hybridized dentin is formed in the subsurface. There is greatest change in the volume ratio between minerals, water and resin. The rate of collagen fibrils reamins the same. New chemical and physical properties of dentin and resin are developed due to the formation of the hybrid layer

Erfahrungen mit kortikosteroid-antibiotischen Präparaten in der Endodontie

U višegodišnjem radu u Zavodu za dentalnu patologiju Stomatološkog fakulteta u Zagrebu, autori su ispitivali mogućnosti koritosteroid-antibiotskog preparata u suvremenom endodontskom tretmanu oboljele pulpe. Budući da ovi preparati imaju dva svojstva: antiflogističko i antibakterijsko, postoji osnova za njihovu primjenu u različitim oboljenjima zubne pulpe. Tim preparatima kod hiperemije i pulpitisa, naročito u bitnim intervencijama pacijenta brzo i efikasno rješavamo boli. U slijedećem posjetu kod pulpitisa je neophodno izvršiti biopulpektomiju totalis. U toku tretmana gangrene pulpe sa periapeksnim promjenama ili bez njih, kortikosteroid-antibiotski preparat je također pokazao dobra svojstva. Zaključno autori smatraju da taj preparat mogu preporučiti u suvremenim endodontskim tretmanima, ali uz strogu indikaciju i točnu dijagnozu.The authors have investigated the possibilities of applying corticosteroid-antibiotics in the course of modern endodontic treatment for a diseased dental pulp, doing research work over a number of years at the Institute for Dental Pathology of the Faculty of Dentistry in Zagreb. Since these drugs have two properties, i. e. the antiphlogistic and the antibacterial effect, possibilities exist for their application in different diseases of the dental pulp. Particularly in urgent interventions have these drugs proved effective in killing pain quickly and efficaciously in patients suffering from hyperemia and pulpitis. Biopulpectomy totalis must inevitably be carried out at the next visit to the dentist. In the course of the treatment of gangrene of the pulp with or without periapical changes, corticosteroid-antibiotics have also shown good results. Concluding, the authors consider that corticosteroid-antibiotics therapy may be recommended in modern endodontic treatment but with strict indications and only in cases where a precise diagnosis has previously been made.In mehrjähriger Arbeit haben die Autoren die Möglichkeit der Behandlung der erkrankten Pulpa mit kortikosteroid-antibiotischen Präparaten gerprüft. Die antiphlogistischen und antibakteriellen Eigenschaften dieser Präparate ergeben die Grundlagen für ihre Anwendung bei verschiedenen Pulpaerkramkungen. Bei Hyperämie und Pulpitis wirken sie rasch und sicher schmerzstillend, insbesondere bei akuten Interventionen. Bei Pulpitis muss unbedingt in der folgenden Visite die totale Biopulpektomie ausgeführt werden. Bei der Behandlung der gangränösen Pulpa, mit oder ohne periapikalen Veränderungen, sind diese Präparate auch von guter Wirkung. Zusammenfassend sind die Autoren der Meinung, dass diese Präparate für die zeitgemässe endodontische Behandlung, unter strenger Indikation und genauer Diagnose, empfohlen werden können

Die Experimentalle bewertung des Diakets und Zinkoxyphosphatzements als mittel fur die Wurzelkanalfullung

Autori su u eksperimentu na zubima psa histološki ispitivali efikasnost diaketa i cink oksifosfatnog cementa, kao sredstava za punjenje korijenskih kanala. Ustanovili su reaktivnu upalu u području periapeksa, kao posljedicu iritacije stranog tijela. Istovremeno su ustanovili degenerativne promjene upalnih stanica i proliferacija veziva. Polazeći sa stajališta da nema idealnog sredstva za punjenje korijenskih kanala, može se do daljnjega dopustiti upotreba diaketa i cink oksifosfatnog cementa za punjenje korijenskih kanala.The authors investigated the efficacy of Diaket and zinc oxyphosphate cement as suitable agents for the filling of root canals in experiments on the teeth of dogs. They found a reactive inflammation periapically as the result of irritation caused by the foreign body. Simultaneously degenerative changes of the inflammatory cells was established and proliferation of the connective tissue. Starting from the assumption that no ideal agent for the filling of root canals has so far been found, Diaket and zinc oxyphosphate cement may be used for the time being for the filling of root canals.Die Autoren haben an Hundezähnen die Wirkung des Diakets und Zinkoxyphosphatzements als M ittel für die Wurzelkanalfüllung histologisch untersucht. Es konnte eine reaktive Entzündung im Gebiet des Periapex als Folge des Fremdkörperreizes festgestellt werden. Gleichzeitig wurden degenerative Veränderungen an Zellen und Wucherungen des Bindegewebes festgestellt. Da es kein ideales Mittel für die Wurzelkanalfüllung gibt, kann die Anwendung des Diakets und Zinkoxyphosphatzements für die Wurzelkanalfüllung befürwortet werden

Caries of Croatian Army Recruits

Predmet je istraživanja pojavnost karijesa u novaka Hrvatske vojske s obzirom na osobitosti pojedinih društvenih zajednica. U 190 novaka karijes je utvrđen upotrebom DMFT indeksa. Ispitanici su podijeljeni prema prebivalištu (gradsko, prigradsko, seosko) i prema dobi. Zdrave zube imalo je 5 (2,6%) ispitanika. Prosječna DMFT vrijednost iznosi 7,76 (DT:2,03; MT:1,49; FT:4,25). Postoji statistički znatna razlika između DT (p = 0,009) i FT (p < 0,001) vrijednosti ovisno o prebivalištu. Za seosku sredinu iznosile su DT:2,59 i FT:2,87, a za gradsku DT:1,52 i FT:5,48. Vrijednosti ispitanika prema dobi bile su DMFT (p = 0,008), DT (p < 0,001), MT (p = 0,022) i FT (p < 0,001). Istraživanje čestoće karijesa u novaka poticaj je daljnjim sustavnim istraživanjima u manjim društveno-ekonomskim skupinama te upozorava da je potrebno poboljšati preventivne mjere u dječjoj i adolescentnoj dobi.The object of this study is the occurrence of caries in Croatian Army recruits with regard to specific qualities of certain social communities. Caries was diagnosed in 190 recruits by means of DMFT index. Subjects were classified according to residence (urban, suburban, rural) and age. Healthy teeth were determined in 5 (2.6%) subjects. The average DMFT value was 7.76 (DT:2.03; MT:1.49; FT:4.25). Statistically significant difference was found between DT (p = 0.009) and FT (p < 0.001) values depending on residence. For rural environment the following values were established DT:2.59 and FT:2.87, and for urban environment DT:1.52 and FT:5.48. Subject values according to age were DMFT (p = 0.008), DT (p < 0.001), MT (p = 0.022) and FT (p < 0.001). The study of caries frequency in recruits is incentive for further systematic studies in smaller socio economic groups and reveals the necessity for improvement in preventive program both during childhood and adolescence

Zeitgemässe Grundprinzipien bei der Präparation der Kavität

Osnovni cilj terapijske stomatologije je odstranjivanje kariozno promijenjenog tkiva i očuvanje zdrave zubne pulpe. Vodeći računa o prevenciji oboljenja tvrdih zubnih tkiva i zubne pulpe te pridržavajući se principa ergonomije u svakodnevnom ambulantnom radu i vodeći računa o pacijentovu vremenu, autori preporučuju određeni redoslijed prilikom preparacije kaviteta. Važan je svakako i pravilan izbor svrdla, odnosno dlijeta, za obradu kaviteta. Autori smatraju da je preparacija kaviteta odgovorna dužnost svakog stomatologa, a kako se vide dosta česte greške, kad je u pitanju oblik kaviteta, preventivna ekstenzija, osiguranje retencije i rezistencije ispuna te definitvno finiranje i poliranje rubova kaviteta, pokušali su upozoriti na odgovarajući potrebni redoslijed u obradi kaviteta i na pravilan izbor dijamantnih svrdla.The basic aim of therapeutic dentistry is to remove the tissue altered by caries and to preserve the dealthy dental pulp. Taking into account the need for the prevention of disease of the hard dental tissues and of the dental pulp and following the principle of ergonomy in our daily work with out-patients, placing particular emphasis on the time the patient has to spend in the doctor\u27s consultation room, the authors recommend a certain chronological order to be followed in the preparation of cavities. Certainly the right choice of a drill and chisel is of the utmost importance in preparing cavities. The authors consider that the preparation of cavities presents a responsible duty to every dentist and since mistakes frequently occur in shaping the cavity, in preventive extension, in securing retention and resistance of the filling and adding the final touch and polishing of the edges of a cavity, we have tried to draw attention to the chronological order which is necessary to follow in the preparation of cavities and we have emphasized the proper choice of diamond drills.Der Grundgedank bei der therapeutischen Stomatologie ist die Beseitigung des Kariös veränderten Gewebes und die Erhaltung der gesunden Zahnpulpe. Der Prävenz der Erkrankung der harten Gewebe und der Zahnpulpe Rechnung tragend und der Prinzipien der Ergonomie Rechnung tragend wie auch der Zeit des Pazienten empfehlen die Autoren in der alltägigen Ambulanzarbeit eine bestimmte Reihenfolge bei der Präparation der Kavität. Allerdingst auch die rechte Wahl des Bohrers und Meissels ist bei der Bearbeitung der Kavität von Wichtigkeit. Die Autoren sind der Meinung, dass die Präparation der Kavität verantwortliche Pflicht jedes Stomatologen ist und da Ziehmlich häufige Fehler zu Sehen sind, wenn in Frage stehen die Form der Kavität, die präventiv Extension, Sicherung der Retenz und die Resistenz der Füllung wie auch das definitive Finieren und Polieren der Ränder der Kavität, so haben sie versucht auf die entsprechende nötige Reihenfolge bei der Bearbeitung der Kavität aufmerksam zu machen, nicht weniger auch auf die rechte Wahl der Diamantbohrer

Endokarditis dentogen Verursacht

Autori iznose da se dijagnoza bakterijskog endokarditisa dentogenog porijekla postavlja na osnovu nalaza kardiologa, bakteriologa i stomatologa. Poznato je, da je oko 30% slučajeva bakteriijskog endokarditisa dentogenog porijekla, te da postoji predispozicija za ovo oboljenje kod 1% čitavog pučanstva.Prognoza oboljenja ovisi o brzini dijagnoze i terapije. Hemokultura je najvažniji dijagnostički elemenat. Do pojave bakterijskog endokarditisa dolazi često nakon nekog zahvata u usnoj šupljini, a najčešći uzročnik je streptokok. Uloga stomatologa se sastoji u otkrivanju i otklanjanju žarišta. Svaki zubno-medicinski zahvat u usnoj šupljini mora se izvršiti pod zaštitom antibiotika kod pacijenata koji boluju ili su preboljeli bakterijski endokarditis, ili pak postoji predispozija za bakterijski endokarditis. Iz svega prethodno iznesenog, jasno je da se svaki tretman kao i dijagnoza mora postaviti u uskoj suradnji kardiologa, bakteriologa i stomatologa.The authors state that the diagnosis of bacterial endocarditis of dentogenous origin is based on the findings of the heart specialist, bacteriologist and dental surgeon. It is known that about 30% of all cases of bacterial endocarditis are of dentogenous origin and that a predisposition for this affliction is present in 1 % of the entire population. The prognosis depends on the rapidity of the diagnosis and on the treatment. Hemoculture is the most important diagnostical aid element. Batcterial endocarditis often develops after an intervention in the oral cavity and the most frequent causative agent is the streptococcus. The task of the dental surgeon is to detect and to remove the focus. Every dental-medical intervention in the oral cavity must be undertaken under the protection of antibiotics in all patients who suffer from or who have just recovered from bacterial endocarditis or in cases where there exists a predisposition for bacterial endocarditis. All the aforesaid shows that the diagnosis and treatment must be undertaken in close cooperation of the heart specialist bacterilogist and dental surgeon.Die Autoren heben hervor, dass die Diagnose des bakteriellen Endocarditis dentogenen Ursprungs aufgrund der Befunde des Kardiologen, Bakteriologen und Stomatologen gestellt wird. Ungefähr 30% der Fälle von bakteriellen Endocarditiden sind dentogenen Ursprings, bei 1% der Bevölkerung besteht eine Prädisposition zu dieser Erkrankung. Die Prognose der Erkrankung hängt von der frühzeitigen Diagnose und Therapie ab. Die Erscheinung des bakteriellen Endocarditis ist häufig in Zusammenhang mit einem Eingriff in der Mundhöhle. Die häufigsten Erreger sind Streptococcen. Die Aufgabe des Stomatologen besteht in der Entdeckung und Beseitigung des Herdes. Jeder zahnärtztliche Eingriff in der Mundhöhle muss bei Patienten, welche an bakterieller Endocarditis erkranken, oder dazu prädistiniert sind, unter dem Schutz von Antibiotika erfolgen. Aus dem Dargestellten ist ersichtlich, dass jede Behandlung und Diagnose in enger Zusammenarbeit von Kardiologen, Bakteriologen und Stomatologe zu geschehen hat

Influence of Different Etching Times on Dentin Surface Morphology

The aim of this study is to investigate the influence of different etching times on demineralized dentin surface morphology using scanning electron microscopy and qualitative line microanalysis of chemical structure. Two sample groups, consisting of 30 first premolar teeth in each group, were established. Teeth were cut at the half-distance between the enamel-dentin junction and the pulp. The first group of specimens was etched for 10 seconds and the second group for 30 seconds. 37% ortophosphoric acid was used. SEM (scanning electron microscopy) was utilized to observe the following parameters: number and diameter of dentinal tubules, dentinal and intertubular dentinal surface percentage, appearance of the dentin surface porous zone containing smear layer and demineralized residual collagen particles with dentin demineralization products in acid globules, and dissolved peritubular dentin cuff. After calculating measurements of central tendency (X,C, Mo, SD), Kolmogorov-Smirnov and Student t-test were performed to confirm the quantitative results, and the c²-test was run to produce qualitative data. In contrast to the 10-second etching time, the increased etching time of 30 seconds resulted in the following findings: (1) an increased number of dentinal tubules (p<0.05), (2) an increase in dentinal tubule diameter (p<0.05), (3) an increase in dentinal tubule surface percentage (p<0.001), (4) a decrease in intertubular dentinal surface percentage (p<0.001), (5) appearance of dentin surface porous zone containing smear layer and demineralized residual collagen particles with dentin demineralization products in acid globules (p< 0.001), and (6) completely dissolved peritubular dentin cuff (p<0.001). Therefore, different etching times using the same phosphoric acid concentration result in different morphological changes in demineralized dentin surface. Moreover, based on a comparison with current studies, prolonged etching time causes morphological changes to dentin surface. Such changes, have, in turn, negative effects on the dentin hybridization process