Die Funktionsdauer von Brucken mit Rucksicht auf Umgebungsfaktoren

Most, kao fiksno-protetsko sredstvo za nadomještanje zubi, morao bi, u tehničkom smislu, imati gotovo neograničenu trajnost. Bazirajući izradu mosta na suvremenim principima fiksne protetike i uz primjenu materijala, koji nam danas stoje na raspolaganju, ova tvrdnja, u velikoj većini slučajeva, dobiva svoju potvrdu. Međutim, budući da se most sastoji i od dijelova, koji pripadaju živom organizmu zuba nosača i koštanog fundamenta, a postavlja se u jedan funkcionalno i fiziološki izrazito aktivan i promjenama podložan medij, opravdano je uvesti pojam uporabne trajnosti mosta, koja bitno ovisi o okolnim faktorima, za razliku od samo tehničke trajnosti, koja ovisi o konstrukciji i materijalu. U svom radu, autori upozoravaju na učestalost i važnost faktora okoline, oslanjajući se na dio opsežnijih vlastitih istraživanja. Zaključno, naglašavaju, kao doktrinski stav, potrebu stalnog nadzora nad izrađenim mostovima, s ciljem pravodobnog otkrivanja utjecajnih faktora okoline, na njihovu uporabnu trajnost.The bridge as a fixed prosthetic means for substituting teeth should be of unlimited duration in technical sense. This claim has been confirmed by a number of cases in which bridge production is based on modern principles of fixed prosthetics and the application of materials available nowadays. However, as a bridge consists also of the parts belonging to the living organism i. e. bearer tooth and bony basis and it is placed in an extremely active functional and physiological environment subject to changes it is justifiable to introduce the term of permanent usability of the bridge which esentially depends on environmental factors unlike its technical duration determined by construction and material. In this paper the authors point at the incidence and importance of environmental factors on the ground of their more comprehensive studies. In conclusion the need for a constant control of produced bridges is emphasized as a doctrinal attitude with the purpose of an early detection of the effects of environmental factors on their permanent usability.Die Brücke als fixer prothetischer Ersatz müsste im technischen Sinne eine fast unbegrenzte Dauerhaftigkeit haben. Hergestellt aufgrund zeitgemässer Prinzipien der fixen Prothetik und bei Anwendung der uns heute zur Verfügung gestellten Materialien, ist diese Behauptung für die Mehrzahl der Fälle stichhältig. Da jedoch die Brücke mit lebendem Gewebe-Zähnen und knöchernen Grundlage in enger Beziehung steht, und in ein funktionell und physiologisch sehr aktiven und Veränderungen ausgesetztem Medium, eingesetzt wird, ist es berechtigt den Begriff Funktionelle Beriützungs-dauer« einzuführen. Diese ist wesentlich von den Umgebungsfaktoren abhängig, zum Unterschied von der bloss technischen Dauerhaftigkeit, die von der Konstruktion und den Materialien abhängt. Aufgrund eigener grösserer Erfahrungen weisen die Autoren auf die Häufigkeit und Wichtigkeit des Umweltfaktors, hin. Die Bedeutung der ständigen Beaufsichtigung und Kontrolle der eingesetzten Brücken, wegen rechtzeitiger Entdeckung des Einflusses der Umweltfaktoren, wird besonders hervorgehoben

Die Grundprobleme in der anfertigung einer Fasettenkrone vom standpunkt unserer Erfahrungen

Ovaj rad predstavlja zbir aktualnih znanja o problematici pravilne izrade fasetirane krunice, kao najvažnijeg i najčešće primjenjivanog estetskog fiksnoprotetskog konstrukcijskog elementa. Na, mijenjen je stomatologu praktičaru, a pripremljen je na temelju višegodišnjeg vlastitog iskustva i podataka iz literature. Osnovni problemi koji se razmatraju i prikazuju vezani su uz preparaciju bataljka, retenciju nemetalne ljuske (fasete), ekstenziju nemetalne ljuske i materijala za izradu ljuske. Problem preparacije bataljka razmatra se u odnosu na: zadovoljenje potreba tehnike u pogledu debljine i retencije nemetalne ljuske, na zadovoljenje minimuma fiksacijske površine krunice i oblika baatljka, na očuvanje pulpe od oštećenja te na izradu cervikalne stepenice. Problem retencije fasete razmatra se sa stajališta osnovne ili primarne retencije i dopunske ili sekundarne retencije. Problem ekstenzije raspravlja se s obzirom na alternative, da li unutar okvira metalnog ormarića, ili preko granica okvira u kojim smjerovima. S obzirom na upotrebljavani nemetal za izradu ljuske, razmatraju se problemi potrebe različito pripremljene retencijske forme ležišta.This work presents the sum total of our actual knowledge concerning the problems of correct fabrication of facette crowns as the most important and the most frequently used aesthetic fixed prosthetic construction element. It is intended for the practicing stomatologist and has been compiled on the basis of our own experiences of several years standing and data from the literature. The basic problems which are discussed and reviewed are associated with the problems of preparing the stumps, retention of the non-metal shell, extension of the non-metal shell and material for the facette. The problem of preparing the stump is discussed with a view to satisfying the technical requirements with regard to the thickness and retention of the non-metal sihell, the minimum of fixation surface of the crown and the form of the stump, to preservation of the pulp from injury and to providing a cervical step. The retention problem of the facette is discussed from the point of view of the basic or primary retention and the supplementary or secondary retention. The problem of extension is discussed with regard to alternatives, whether within the metal case or over the margins of the frame and in what directions. With regard to the non-metal used for the facette the necessity of different preparation of the retention form for the base is considered.Diese Arbeit stellt eine Zusammenfassung der aktuellen Erkentnisse über die Problematik der richtigen Anfertigung der Fasettenkrone als wichtigstes und am häufingsten angewendeten ästhetischen Konstruktionselements in der fixen Prothetik, dar. Sie ist dem Praktiker zugedacht, aufgrund vieljähriger eigener Erfahrung und Angaben aus der Literatur, verfasst. Die vorgebrachten Grundprobleme sind Probleme der Stumpfpräparation, der Retention der Fasette, der Extension der nichtmetallischen Fasette und des dazu verwendeten Materials. Die Stumpfpräparation wird inbezug auf die genügende Schichtdicke und Retention der Fasette, inbezug auf die mindest-nötige Haftfläche der Krone und Stuimpfform, inbezug auf die Schonung der Pulpa und inbezug auf die cervikale Stufe, behandelt. Die Retention der Fasette ist vom Stanardpunkt der Haupt- und der zusätzlichen Retention dargestellt. Die Extension der Fasette ist alternativ, ob innerhalb des metallischen Rahmens oder ausserhalb des metallischen Rahmens, zu begutachten. Mit Rücksicht auf das verwendete Fasettenmaterial werden die verschiedenen Retentionsformen des Lagers kritisch betrachtet

Dimensional Stability of Elastomeric Impression Materials Disinfected in a Solution of 0.5% Chlorhexidine Gluconate and Alcohol

Dezinfekcija elastomernih materijala za otiske može prouzročiti njihove dimenzijske promjene. Na našoj se klinici kao dezinficijens najčešće upotrebljava 0,5% klorheksidin glukonat. Svrha rada bila je izmjeriti i usporediti linearne dimenzijske promjene koje nastaju u trima elastomerima nakon uranjanja u spomenuti dezinficijens. Radni kalup napravljen je prema ADA specifikaciji br.19. Testirani su Panasil (adicijski silikon), Blend-a-scon (kondenzacijski silikon) i Impregum (polieter). Uzorci su izloženi dezinficijensu, vodi i zraku u četiri razdoblja (10 min., 30 min., 60 min. i tijekom 24 sata). Linearne dimenzijske promjene izmjerene su bezkontaktnim digitalnim alatnim mikroskopom. Rezultati su pokazali najmanje dimenzijske promjene adicijskog silikona s tendencijom širenja. Kondenzacijski silikon skvrčio se unutar tolerantnoga raspona od 0,2 - 0,4%, prema DIN 13913, a polieter je znatno nabubrio. Može se zaključiti da testirani polieter nije prikladno dezinficirati uranjanjem u klorheksidin glukonat, a druga dva materijala pokazuju klinički prihvatljive linearne dimenzijske promjene unutar 24-satne imerzije.Disinfection of elastomeric impression materials used in prosthetic dentistry can cause dimensional changes in the impression materials. 0.5% chlorhexidine gluconate is usually used for disinfection of impressions at the School of Dental Medicine in Zagreb. The purpose of this study was to measure and compare linear dimensional changes of three elastomeric impression materials after their immersion in a certain disinfectant. The master dies were made according to the ADA specification no 19. The tested materials were Panasil (addition silicone), Blend-a-scon (condensation silicone) and Impregum F (polyether). Twelve samples were immersed in disinfectant, twelve in water and twelve left in the air for four different periods of time (10 min., 30 min., 60 min and 24 hours). Linear dimensional changes were measured by a non-contact digital tool microscope. The smallest changes were noticed in addition silicone with the least tendency to expansion. The condensation silicone contracted within a tolerant range of 0.2 - 0.4%, according to DIN 13913. Polyether expanded in the disinfectant significantly. Our results show that the tested polyether is not appropriate for disinfection by immersion in chlorhexidine gluconate, while the other two materials underwent 24-hour immersion with linear dimensional changes within a clinically acceptable range

Masticatory forces and oral status

Na uzorku od 4.857 ispitanika od kojih je bilo 2.204 muškaraca i 2.653 žena u dobi od 18 — 20 godina, autori su ispitivali odnose karijesa, ispuna, protetskih radova i gingivitisa s individualnim, maksimalno izraženim žvačnim silama. U tu svrhu usna šupljina podijeljena je u tri segmenta, — desni, prednji i lijevi, u kojima nije nađeno više od dva ekstrahirana zuba uz uvjet, da nisu jedan do drugoga. Uz uobičajeni klinički pregled izvršena su u svakog ispitanika mjerenja žvačnih sila našim gnatodinamometrom i to obostrano lateralno i sprijeda. Rezultati upućuju da izučavanje žvačnih sila uvijek zahtijeva i registraciju kompletnog dentalnog statusa, a posebno stanja prednjeg segmenta, u kojem međutim ni sanacija bilo konzervativna ili protetska, ne omogućuju postizanje prirodno očekivane razine intenziteta žvačnih sila.Relationships between caries, fillings, prosthetic appliances and gingivitis, and individual maximally pronounced masticatory forces, were studied in a sample consiting of 4,857 subjects (2,204 males and 2,653 famales), mean age 18— 20 years. The oral cavity was divided into three segments, i. e. the right, frontal and left segments, in which not more than two extracted teeth were found, provided they were not situated next to each other. In addition to the usual clinical examination, masticatory forces were bilaterally and frontally measured using our gnathodynamometer in all the subjects. The results have shown that a study of masticatory forces should always include registration of the complete dental status, and of the frontal status in particular, because in this segment neither conservative nor prosthetic corrections can restore the natural intensity of masticatory forces

The oral health status and the prosthetic therapy required in the examinees of postipubertal age

Autori su istraživali skupinu od 5.665 studenata prve godine Zagrebačkog sveučilišta, sa ciljem da se ustanovi posljedično stanje oralnog zdravlja i stupanj hendikepiranosti žvačnog aparata uzrokovanog karijesom i parodontopatijama, te uobičajene više ili manje uspješno provedene stomatološke terapije. Posebna pozornost usredotočena je na istraživanje obima potreba za provođenjem protetske terapije na žvačnom organu ispitanika. Dobiveni rezultati ukupne frekvencije KEPa od 11,71 po ispitaniku, ukazali su da su oštećenja žvačnog organa oko 30\u27% od njegove optimalne biološke vrijednosti u ovoj životnoj dobi. Potvrđena je potreba da se pojača mjere preventive i sanacijskih programa već i dječje dobi, a poglavito i kvantifikacija potrebnih protetskih intervencija.The study was carried out in 5.665 first-year students at the Zagreb University, in order to establish the consequential oral health status and the degree of hindrance to the masticatory system due to caries and periodontopathies, as well as the usual, more or less successfully performed stomatological therapy. Attention was especially focused on the extension of the required prosthetic therapy of the subjects organs of mastication. The results obtained on the total frequency of DMF of 11.71 per a subject showed the impairments of the masticatory system to be about 30% of those expected at this age. This study has confirmed the need of preventive and therapeutic programs to be conducted already during childhood, whereas in the student population the need of prosthetic interventions is particularly emphasized

The oral health status and the prosthetic therapy required in the examinees of postipubertal age

Autori su istraživali skupinu od 5.665 studenata prve godine Zagrebačkog sveučilišta, sa ciljem da se ustanovi posljedično stanje oralnog zdravlja i stupanj hendikepiranosti žvačnog aparata uzrokovanog karijesom i parodontopatijama, te uobičajene više ili manje uspješno provedene stomatološke terapije. Posebna pozornost usredotočena je na istraživanje obima potreba za provođenjem protetske terapije na žvačnom organu ispitanika. Dobiveni rezultati ukupne frekvencije KEPa od 11,71 po ispitaniku, ukazali su da su oštećenja žvačnog organa oko 30\u27% od njegove optimalne biološke vrijednosti u ovoj životnoj dobi. Potvrđena je potreba da se pojača mjere preventive i sanacijskih programa već i dječje dobi, a poglavito i kvantifikacija potrebnih protetskih intervencija.The study was carried out in 5.665 first-year students at the Zagreb University, in order to establish the consequential oral health status and the degree of hindrance to the masticatory system due to caries and periodontopathies, as well as the usual, more or less successfully performed stomatological therapy. Attention was especially focused on the extension of the required prosthetic therapy of the subjects organs of mastication. The results obtained on the total frequency of DMF of 11.71 per a subject showed the impairments of the masticatory system to be about 30% of those expected at this age. This study has confirmed the need of preventive and therapeutic programs to be conducted already during childhood, whereas in the student population the need of prosthetic interventions is particularly emphasized

Einfluss der Unterlage auf Farbveränderungen der Akrylaten und keramischen Krone

Problem debljine nemetalnih estetskih krunica u literaturi se često rješava preporukom da stijenka krunice mora imati debljinu od najmanje 1 milimetar. Jedan od razloga za takvu uputu je zaštita krunice od promjene boje zbog utjecaja cementa ili podloge. Međutim, u praksi se pokazuje, osobito pri izradi akrilatnih krunica, da vrlo kontrastne podloge mogu prosijavati i kroz 1 milimetar debelu stijenku, a s druge strane, uvijek nije miti moguće niti potrebno ostvariti ovu debljinu. Autori su pristupačnim metodama ispitivali utjecaj podloge u odnosu na sloj akrilata i došli do zaključka da ni propisana debljina stvarno nije dovoljna zaštita od vrlo kontrastnih podloga te da je mnogo važnije i jednostavnije pravilnim izborom boje cementa isključiti utjecaj podloge, što zadovoljava i tamo gdje je iz mehaničko-statičkih razloga dopuštena i izrada tanje krunice.The problem of the thickness of non-metal aesthetic dental crowns has often been solved in the literature by the recommendation that the wall of the crown must be at least 1 mm thick. One of the reasons for such a recommendation is to protect the crown from changes in colour due to the effect of cement or the foundation. However, practice has shown, especially when making acrylic crowns, that highly contrasting bases may show through a wall of even 1 millimeter thickness and on the other hand it is not always possible nor necessary to achieve this thickness. The authors investigated the effect of the base in relationship to the layer of acrylic and reached the conclusion that not even the recommended thickness offers in fact sufficient protection from the greatly contrasting base and that it is much more important and simpler too to eliminate the effect of the base by the correct choice of the cement colour. This has proved satisfactory even in cases where for mechanical and statical reasons it was permissible to make thinner crowns.Die Dicke der nichtmetallischen aesthetischen Krone wird in der Literatur mit der mindest Wanddicke von 1 mm angegeben. Dieser Vorschlag wird wegen der Verfärbung durch den Einfluss des Zements oder anderer Unterlagen, begründet. Die Praxis jedoch ergibt, insbesondere für Akrylatkronen, dass selbst sehr kontrastreiche Unterlagen durch eine 1 mm dicke Wand durchschimmern können, andererseits ist es nicht immer möglich, noch nötig, diese Dicke herzustellen. Die Autoren haben den Einfluss der Unterlage auf die Akrylatschichte untersucht und kamen zum Ergebnis, dass die vorgeschriebene Wandstarke von 1 mm keinen genügenden Schutz vor kontrastreichen Unterlagen gewährleistet. Viel wichtiger und einfacher ist es durch eine richtige Auswahl der Zementfarbe den Einfluss der Unterlage auszuschalten, was auch dort zufriedenstellende Ergebnisse zeitigt, wo aus mechanisch-statischen Gründen eine dünnere Kronenwand ausgeführt wird

The intensity of masticatory forces in front-teeth

Intenzitet izraženih žvačnih sila ovisi između ostalog, o stanju zubi i njihovih potpornih struktura. Autori, na osnovu uočenih fenomena u dosadašnjem izučavanju žvač­nih sila i njihova mjerenja, istražuju odnose između stanja zubi prednjeg segmenta i maksimalno izraženih žvačnih sila. Primjenom kanoničke korelacijske analize dobivene su visoke pozitivne korelacije žvačnih sila s intaktnim zubima u sva tri segmenta, s najvišim vrijednostima u prednjem segmentu: 0.62 u muških, a 0.51 u ženskih is­pitanika. Međutim, u prednjem segmentu pojavljuju se relativno visoke ali ne­gativne korelacije žvačnih sila s ispunima i protetskim radovima, koje u muških ispitanika iznose (—0.36) za obje varijable, a u ženskih ispitanika (—0.19) i (—0.20). Rezultati upućuju na zaključak, da osim patološkog nalaza, i terapijska sredstva koja se primjenjuju na prednjim zubima pokazuju negativne korelacije sa žvačnim silama u sva tri segmenta.The intensity of masticatory forces depends, among other factors, on the status of the teeth and their supporting structures. Relationship bet­ween the state of the anterior segment of teeth and maximally expressed masticatory forces was studied on the basis of the phenomena observed in the investigation of masticatory forces and their determination repor­ted. Employing the cannon correlation analysis, high positive correlations between masticatory forces and intact teeth in all the three segments were obtained, with the highest values observed in the anterior segment, i. e. 0.62 and 0.51 in males and females, respectively. In the anterior segment, however, relatively high negative correlations were recorded between masticatory forces on the one hand, and fillings and prosthetic constructions on the other. In males, they were —0.36 for both variables, whereas in females they were —0.19 and —0.20 for fillings and prostheses, respectively. Thus, the results suggest a conclusion that besides apathologic finding, therapeutic tools used in anterior teeth also produce negative correlations with masticatory forces in all the three segments

Innervation of the Human Periodontal Ligament

Istraživanje smo izvršili na materijalu izdvojenom tijekom kirurških zahvata radi sanacije malignih tumora u donjoj čeljusti i to na četiri pretkutnjaka i dva kutnjaka koje smo ispreparirali zajedno s pripadajućom alveolom i susjednim dijelovima čeljusti, te ih dekalcinirali u mravljoj kiselini. Svrha ovog rada bila je istražiti distribuciju i vrstu senzoričkih živčanih vlakana i različitih živčanih završetaka u periodontalnom ligamentu odrasla čovjeka. Ustanovili smo da živčana vlakna ulaze u periodontalni ligament prolazeći dnom alveole, dok njihov tok prate krvne žile. Periodontalni ligament je najbolje inerviran u području apikalne trećine korijena zuba, za razliku od srednje i cervikalne trećine, gdje je nazočan daleko manji broj vlakana. U periodontalnom ligamentu odrasla čovjeka nismo dokazali postojanje slobodnih živčanih završetaka odnosno grmastih završetaka koji su opisani kod različitih životinjskih vrsta. Istraživanje upućuje na prisutnost velikog broja specijaliziranih živčanih završetaka koji po svojim morfološkim karakteristikama odgovaraju Meissnerovim tjelešcima, a uklopljeni su u sustav Sharpeyevih vlakana. Najveći broj tih specijaliziranih završetaka, za koje pretpostavljamo da su pravi mehanoreceptori, smješten je u srednjoj i cervikalnoj trećini desmodonta.The aim o f this study was to analyze the distribution and forms o f nerve fibres and endings in the periodontal ligament o f the adult man. The material for this investigation was obtained at routine autopsies and consisted o f four lower premolar and two molar tooth prepared together with belonging alveola and neighbouring parts o f the mandibula. The material was decalcinated in the formic acid, embedded in paraplast, sectioned 20 micrometers thick in bucco- lingual direction and stained with modified Ungewitter’s silver nitrate method. It was found that nerve fibres enter the periodontium passing through the bottom o f the bony socket. The nerve fibres follow the course o f the blood vessels in periodontium. The richest innervation o f the periodontium was found in the apical third o f the tooth root and less fibres were present in the upper and middle third. In the periodontium o f the adult man we were not able to found free endings o f nerve fibres in the form o f bush-like terminations that were described in previous investigations in lower mammals. On the other hand, we found the presence o f the large number o f specialized nerve endings that according to their morphological characteristics could be Meissner corpuscules embedded in Sharpey’s ligaments. The largest number o f these endings may belong to real mechanoreceptors situated in the upper and middle part o f the periodontium

Innervation of the Human Periodontal Ligament

Istraživanje smo izvršili na materijalu izdvojenom tijekom kirurških zahvata radi sanacije malignih tumora u donjoj čeljusti i to na četiri pretkutnjaka i dva kutnjaka koje smo ispreparirali zajedno s pripadajućom alveolom i susjednim dijelovima čeljusti, te ih dekalcinirali u mravljoj kiselini. Svrha ovog rada bila je istražiti distribuciju i vrstu senzoričkih živčanih vlakana i različitih živčanih završetaka u periodontalnom ligamentu odrasla čovjeka. Ustanovili smo da živčana vlakna ulaze u periodontalni ligament prolazeći dnom alveole, dok njihov tok prate krvne žile. Periodontalni ligament je najbolje inerviran u području apikalne trećine korijena zuba, za razliku od srednje i cervikalne trećine, gdje je nazočan daleko manji broj vlakana. U periodontalnom ligamentu odrasla čovjeka nismo dokazali postojanje slobodnih živčanih završetaka odnosno grmastih završetaka koji su opisani kod različitih životinjskih vrsta. Istraživanje upućuje na prisutnost velikog broja specijaliziranih živčanih završetaka koji po svojim morfološkim karakteristikama odgovaraju Meissnerovim tjelešcima, a uklopljeni su u sustav Sharpeyevih vlakana. Najveći broj tih specijaliziranih završetaka, za koje pretpostavljamo da su pravi mehanoreceptori, smješten je u srednjoj i cervikalnoj trećini desmodonta.The aim o f this study was to analyze the distribution and forms o f nerve fibres and endings in the periodontal ligament o f the adult man. The material for this investigation was obtained at routine autopsies and consisted o f four lower premolar and two molar tooth prepared together with belonging alveola and neighbouring parts o f the mandibula. The material was decalcinated in the formic acid, embedded in paraplast, sectioned 20 micrometers thick in bucco- lingual direction and stained with modified Ungewitter’s silver nitrate method. It was found that nerve fibres enter the periodontium passing through the bottom o f the bony socket. The nerve fibres follow the course o f the blood vessels in periodontium. The richest innervation o f the periodontium was found in the apical third o f the tooth root and less fibres were present in the upper and middle third. In the periodontium o f the adult man we were not able to found free endings o f nerve fibres in the form o f bush-like terminations that were described in previous investigations in lower mammals. On the other hand, we found the presence o f the large number o f specialized nerve endings that according to their morphological characteristics could be Meissner corpuscules embedded in Sharpey’s ligaments. The largest number o f these endings may belong to real mechanoreceptors situated in the upper and middle part o f the periodontium