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Rad je pregled novijih rezultata u području razgradnje akrilatnih polimera, prije svega na temelju metil-metakrilata, koji se primjenjuju u stomatološkoj praksi. Opisani su procesi razgradnje i starenja polimera tijekom uporabe protetskih nadomjestaka, i to biorazgradnja, toplinska razgradnja, razgradnja potaknuta zračenjem i mehaničkim djelovanjem. Raspravljen je utjecaj razgradnje na promjenu strukture polimera, molekulnu masu i izlučivanje produkata razgradnje u usnu šupljinu. Pri tome dolazi do promjene svojstava polimera, a niskomolekulni spojevi nastali razgradnjom mogu utjecati na zdravlje pacijenta. Raspravljeni su najnoviji rezultati utjecaja malih doza γ zračenja na strukturne promjene metakrilatnih nadomjestaka u pacijenata podvrgnutih radioterapiji.

Rad je pregled novijih rezultata u području primjene akrilatnih polimera u dentalnoj protetici. Opisana su najvažnija postignuća u pripravi i modificiranju polimera prije svega na temelju metil-metakrilata s poboljšanim svojstvima te fizičko-kemijska i mehanička svojstva važna u stomatološkoj praksi. Posebno je razmotren utjecaj polimerizacije na svojstva polimera, sadržaj i difuziju ostatnog monomera i drugih niskomolekulnih sastojaka u usnu šupljinu. Pozornost je posvećena i novijim metodama analize molekulne strukture i morfologije opisanih polimera radi boljeg razumijevanja njihova utjecaja na svojstva i vrijeme uporabe nadomjeska u usnoj šupljini.

Purpose: It is assumed that abutments of the FPD bear more load than homologous teeth as they also take loads from the missing units. The aim of this study was to evaluate bone density of FPD restorations being successfully in function several years and to compare it with homologous teeth. The hypothesis was that the abutments might present higher density than homologous teeth. Material and Methods: The bone density (expressed in equivalents of Cu stepwedge thickness, attached to the digital x-ray sensor), was measured at the mesial and distal side of the root of both, abutments and homologous teeth at the alveolar crest level, the middle of the root, the root apex, as well as bellow the apex. A total of 70 patients with 146 abutments participated. Mean age of satisfactory FPDs was 4.9 years. Results: The bone density increased from the alveolar crest towards the apex in both, the FPD abutments and the homologous teeth (p0.05). There was no significant effect of age, FPD material, type of abutment (single crown or bridge), abutment/pontic ratio (1:0.5 ; 1:1 ; 1:1.5 ; 1:2), and Ante’s law (p>0.05). Conclusions: Lower bone density at the level of alveolar crest mesially than distally in FPD abutments and homologous teeth should not be considered a pathological finding. It is attributed to the increase of bone volume towards distal parts of the alveolar bone. No difference of bone density between abutments and homologous teeth is attributed to the load distribution of the missing units through the interdental contact points over the dental arch. The findings of the present study emphasize the importance of interdental contact points in FPDs.

MATERIALS AND METHODS: CO•CR•MO ALLOY WAS CASTED AND AND ELECTROPOLISHED (EP) ; SOME SAMPLES HAD BEEN ADDITIONALLY MECHANICALY POLISHED USING ROTATING RUBBERS AND BRUSHES WITH POLISHING PASTE (MP). THE ROUGHNESS AND OTHER MORPHOLOGICAL FEATURES OF THE EP AND MP SURFACES WERE ASSESSED BY ATOMIC FORCE MICROSCOPE (AFM). THE EP AND MP SAMPLES WERE SOAKED IN PH 6.0 PHOSPHATE BUFFER (SALIVA), 3.5 PH PHOSPHATE BUFFER (ACID) AND PH 3.5 MIXTURE OF LACTIC, FORMIC AND ACETIC ACID (DENTOBACTERIAL PLAQUE), AND INCUBATED AT 37 0C FOR 7 DAYS. SIX SAMPLES OF EVERY SOLUTION WERE PREPARED. AAS-GF WAS USED FOR ANALYSIS OF THE RELEASED CO, CR AND NI. RESULTS: CO AND CR WERE RELEASED ; NI WAS NOT DETECTED. AFM REVEALED DIFFERENT MORPHOLOGICAL FEATURES IN EP AND MP SAMPLES WHERE Z RANGE WAS SIGNIFICANTLY HIGHER IN EP SAMPLES (P0.05). THERE WAS ALSO NO SIGNIFICANT DIFFERENCE IN ION RELEASE BETWEEN EP AND MP POLISHING TREATMENTS (P>0.05). DISCUSSION: ALTHOUGH THERE WERE MORPHOLOGICALLY DIFFERENT FEATURES BETWEEN THE RESPECTIVE STANDARD EP AND ADDITIONAL MP SURFACES, THEY DID NOT SIGNIFICANTLY AFFECT THE DIFFERENCE IN CO AND CR ION RELEASE FROM THE CO•CR•MO DENTAL ALLOY. CONCLUSION: ADDITIONAL MECHANICAL POLISHING DOES NOT INFLUENCE ION RELEASE AND DOES NOT REDUCE OR ENHANCE THE RISK OF POSSIBLE METAL TOXICITY.

Introduction: Inclination of the occlusal plane is responsible for the amount of forces directed towards the denture bearing area, and for the stability of dentures. The artificial occlusal plane should be as close as possible to the position once occupied by the natural teeth in order not to jeopardize proprioceptive and neuro-muscular mechanisms (1-3). Clinically occlusal plane orientation in edentulous patients is established using different soft and hard tissue landmarks (1-7). Aims: To compare the accuracy of three methods for establishment of the occlusal plane inclination: a) parallelism with the Camper’s plane, b) parallelism with the incisive papila-hamular notch plane, and c) termination at the level of the retromolar pad.Methods: Eighty eugnath subjects were photographed with the Fox Plane (44 females, 36 males). The angle between the Camper’s plane and the Fox plane was transferred to the callibrated paper. Alginate impressions were also made and the maxillary casts were mounted in the S.A.M. 2 articulator and the measurements were performed by a precise calliper. The natural occlusal plane was defined as the line connecting incisal margins of the maxillary central incisors and the mesiopalatal cusp sof the first molars. Also the plane connecting the midpoint of the incisive papilla and the hamular notches was defined (IP-HN). All the vertical and the horizontal values were transfered t o the calibrated paper and the inclination between the planes were measured . The third method to establish the artificial occlusal plane was its termination at the insertion of the pterygomolar fold at the retromolar pad. The plane connecting the incisal margins of the lower mandibular incisors and the insertion of the pterygomolar fold was measured and transferred to the calibrated paper. The angles were measured by a precise protractor. The statistical analysis comprised one-way Kolmogorov-Smirnov test, Student’’s t-test and one-way ANOVA. Results: 1.There was a significant difference between the OP determined by the three different methods (p0.05). Conclusion: The occlusal plane (OP) determined by the parallelism with the IPHN plane was superior to other two methods

Objectives: Oral health-related quality of life (OHRQoL) is an important patient-centered endpoint to be considered when assessing the impact of oral diseases in general population and evaluating the professional interventions. The aim of this study was to investigate and compare OHRQoL in different population groups in Croatia. Methods: The OHIP-CRO49 questionnaire was used and a total of 271 patients participated: General population wearing removable dentures (GPRD, n=42, mean age=47.60), General population without removable dentures (with their own teeth or fixed partial dentures) (GPNRD, n=140, mean age=44.31), Patients having acute dental pain (PAP, n=30, mean age=49.26) and the Control group-Healthy young population with all teeth and without any dental problems (CHP, n=59, mean age=22.31). Results: The scores of the OHIP-CRO49 and all seven subscales were significantly higher for GPRD (summary score=33.48) than for GPNRD (19.71). CHP had the lowest summary scores, as well as the 7 subscale scores (10.88), while the PAP had the highest OHIP-CRO49 summary scores and the 7 subscale scores (ANOVA, P

Introduction: Metal ions released from dental alloys may be of clinical concern due to allergogenic, mutegenic and cytogenicproperties. Corrosion behaviour in oral fluids is strongly influenced by microstructural characteristics and surface properties of a dental alloy. Aim of the study: To examine the surface of cast CoCrMo alloy prior and after exposure into different solutions mimicking oral conditions. Materials and Methods: The cast and electropolished specimens of CoCrMo alloy (Wironit® ; , extra hard) were examined by SEM with EDS and by AFM prior and after immersion into two solutions simulating saliva („ saliva“ ) and dentobacterial plaque („ plaque“ ) for 30 days at 37 º ; C. To find the same surface after immersion, each sample was marked prior AFM imaging and soaking. Results: The surface of cast and electropolished specimens prior the contact with corroding solutions was characterized with at least 3-4 different phases: undulating surface corresponding to dendrites (matrix), clusters of nanocrystallites (islands) corresponding to interdendritic phase and some high conical crystallites emerging from both, interdendritic space and the matrix. Also some very small crystallites could also be observed. The undulating surface (matrix) was twice richer with Co than Cr, while the interdendritic phase had almost equal contents og Co and Cr. However, some cristallytes were dissolved after corrosion, but some new phases (dense sprinkles of very small crystallites) appeared. The respective alloy peaks in the EDS spectrum revealed that new phases are the result of a corrosion - primarily of metal dissolution, break-down of an oxide layer and metal salt formation. The presence of some elements from the corroding solution was registered on the alloy surface, as well. Conclusions: Probably metal salts (anions from corroding solutions) were binded at the surface as a new phase. Electrochemical behaviour of CoCrMo alloys is clearly affected by pH and composition of the fluids. It is obvious that some complex mechanisms involving reactions between ionic species are dominating the interfacial processes, which in turn affect the morphology and the composition of the phases formed.

Dužina prosječnog životnog vijeka značajno se produžila u gotovo svim zemljama svijeta, pa tako i u Hrvatskoj. Osobe starije od 65 godina osim problema vezanih uz opće zdravstveno stanje, također imaju i različite probleme vezane uz oralno zdravlje. Česti problemi vezani uz stomatološko protetsko zbrinjavanje starijih su i: različite kliničke slike djelomične bezubosti, potpuna bezubost, stari i dotrajali protetski nadomjestci, karijes i nedostatna oralna higijena. Istraživanja gubitka zuba i opskrbe protetskim nadomjestcima obavljeno je na skupini od 1826 osoba starije životne dobi štićenika domova umirovljenika na području grada Zagreba. Ispitanici su podijeljeni na 6 dobnih skupina (65-69, 70-74, 75-79, 80-84, 90 i više godina). Klinički pregled proveden je sondom i ogledalom u improviziranom zubarskom stolcu. Potpuna bezubost utvrđena je kod 33.6% ženskih i 23.9% muških ispitanika. Istraživanjem je potvrđen statistički značajan porast bezubosti u odnosu na dob ispitanika. Tako je primjerice broj ekstrahiranih zuba u najmlađoj dobnoj skupini (65-69 god.) iznosio 15 kod žena i 16 kod muškaraca, au najstarijoj životnoj skupini (90 i više god.) 27 kod žena i 25 kod muškaraca. Gornju potpunu protezu posjedovalo je 45% žena i 35% muškaraca, a gornju parcijalnu protezu 10% ispitanika podjednako u oba spola. Gornji mostovi pronađeni su u 27% ženskih i 30% muških ispitanika. Donju potpunu protezu posjedovalo je 33% žena i 26% muškaraca, a donju parcijalnu protezu 16% ženskih i 24% muških ispitanika. Zaključno se može istaknuti da je veći broj protetskih nadoknada pronađen u gornjoj čeljusti, a da je donja čeljust češće ostala protetski nezbrinuta.

Uvod: Metalni ioni otpuštaju se iz svih dentalnih legura ; kvaliteta i kvantiteta otpuštenih iona ovisi o sastavu legure, hrapavosti površine i o veličini površine u kontaktu s vlažnim strukturama usne šupljine. Količina otpuštenih iona ne ovisi samo o postotku elementa u leguri, katkad se ioni otpuštaju i kad su prisutni samo u neznatnim količinama, pa čak i ako ih proizvođač ne spominje u deklaraciji. Svrha: Izmjeriti količinu otpuštenih iona Co, Cr i Ni iz CoCrMo legure ovisno o različitim završnim načinima poliranja i to u različite otopine koje imitiraju uvjete u usnoj šupljini. Materijal i Metode: Izliveni CoCrMo uzorci (8x8x2 mm) (Wironit®, extra hard, Bego, Germany) bili su ili samo elektropolirani (EP = 5 samples) ili EP i još polirani crnom rotirajućom četkom (BB = 5 samples). Uzorci su uronjeni u 3 otopine koje su simulirale slinu (fosfatni pufer pH 6), dentobakterijski plak (pH 3, 5) i kiselinu (fosfatni pufer pH 3, 5) kroz 7 i 30 dana na 37 ºC. Kvantiteta otpuštenih iona Co, Cr i Ni u otopine (mg/l) utvrđena je pomoću Perkin Elmer atomskog apsorpcijskog spectrofotometra (AAS) AAnalyst 700 (USA). Results: Bili su otpušteni ioni Co i Cr, ali nisu nađeni ioni Ni. Više iona otpušteno je u otopine niže pH vrijednosti (p

The aim was to compare the alveolar bone density obtained from intraoral retroalveolar digital radiographs of FPD abutments and homologous teeth. Material and Methods The bone density data were expressed as equivalents of 8 layers (0, 05-0, 7mm) Cu stepwedge thicknes, directly calculated from mean grey levels of regions of interest (ROIs) using the third order polinomial. A total of 69 patients having 130 abutment teeth participated. Mean age of FPDs was 5 years and clinical examination revealed that the FPDs were mostly satisfactory. A copper stepwedge was attached to the digital x-ray sensor. The results showed that the alveolar bone density became higher from the alveolar crest towards the apex of both, the FPD abutments and the homologous teeth (p0.05). No significant effect of age, jaw, FPD material, body mass index, interdental space width, type of abutment (single crown or bridge), abutment/pontic ratio, and Ante’ s law was registered (p>0.05). Conclusion Messially lower bone density at the level of alveolar crest in FPD abutments should not be considered as pathological findings.

U svrhu poduzimanja preventivnih mjera i određivanja opsega potreba za stomatološkim liječenjem osoba starije životne dobi na području Zagreba organizirani su tijekom 2007. gdine klinički pregledi osoba starije dobi i skupljanje podataka o njihovom oralnom statusu. Podaci za dijelove preliminarnog istraživanja koji se odnose na gubitak zuba, stanje parodonta i oralne bolesti prikupljeni su od pacijenata starije dobi iz baze podataka Stomatološke poliklinike Zagreb. Preliminarna studija obuhvatila je 171 funkcijski neovisnu stariju osobu oba spola (126 žena i 45 muškaraca) na području Zagreba. Oralne bolesti nađene su u 117 pacijenata (68, 5%), a najčešće dijagnosticirane su stomatopiroza i kserostomija. Podaci preliminarnih istraživanja gubitka zuba, stanja parodonta i oralne sluznice ukazuju na potrebu za poboljšanjem preventivne njege oralnog zdravlja u osoba starije dobi na prodručju Zagreba organiziranjem češćih kontrolnih pregleda.

Skraćen zubni luk (SZL) je naziv za stanje denticije kad nedostaju stražnji, tj. distalni zubi. Ovo se stanje često susreće zbog toga što se molari najčešće među prvima ekstrahiraju zbog destrukcije karijesom i/ili parodontne bolesti. U SZL-u preostali premolari mogu distalno migrirati, što može dovesti do sniženja okluzije i vertikalne dimenzije donje trećine lica i rezultirati povećanim opterećenjem prednjih zuba. Ovakva situacija smatra se nekompenziranim SZL-om. Međutim, kod mnogih pacijenata s gubitkom molara može nastati neznatna migracija prema distalno, koja je unutar granica prihvatljivosti, bez sniženja vertikalne dimenzije i bez nastajanja kontakata u području fronte i to se smatra kompenziranim SZL-om. Nedostatak lateralnih zuba ne igra važnu ulogu sa subjektivnog aspekta pacijenta, puno važniju ulogu imaju socio– psihološki i estetski faktori, a gubital stražnjih zuba ne narušava previše estetiku. Kod osoba starijih od 45 godina sa dobro raspoređenih 20 zuba, najpovoljnije od pretkutnjaka s jedne strane do pretkutnjaka s druge strane, žvačna sposobnost, te njihove potrebe u izgledu i funkciji su uglavnom zadovoljavajuće. Istraživanja su pokazala veliku razliku između profesionalne procjene potreba i subjektivne procjene tretmana, naročito kod starijih osoba. Tradicionalni koncepti liječenja su u mnogim slučajevima doveli do nepotrebno preopsežnog liječenja. Zdrava denticija je karakterizirana slijedećim biološkim kriterijima: nedostatak patoloških manifestacija, zadovoljavajuća funkcija, različitosti u obliku i funkciji i sposobnosti prilagodbe, tj. adaptivnom kapacitetu. Zato je kod kompenziranog SZLa moguće pacijenta samo pratiti, a intervenirati jedino ako se za to ukaže potreba, odnosno kad nastane nekompenzirani SZL. Kad je preostala denticija previše smanjena da osigurava zadovoljavajuću oralnu funkciju, vodilja bi trebala biti očuvanje alveolarne kosti i preostalih zuba.

U radu su prikazani preliminarni rezultati istraživanja stanja oralnog zdravlja u starijih osoba na području grada Zagreba.

The aim was to determine the distribution of fixed and removable prosthodontic appliances among the elderly population in the city of Zagreb, Croatia. The data on deliveries of 15 various types of fixed and removable prosthodontic appliances for the period 2002-2006 was obtained from the Croatian Institute for Health Insurance (CIHI). Total number of Zagreb citizens who used dental services in the period 2002-2006 covered by CIHI was 187 159, while the population of Zagreb determined in the 2001 counteed 779 145. Considering the overall number of prosthodontic appliances delivered in the Republic of Croatia, 24% was delivered in the city of Zagreb. Regarding the appliance type, removable prosthodontic appliance deliveries accounted for 65% (138.111), while 35% (75.083) of the overall number were fixed. The highest number of partial removable appliances (24.435) was observed in the age group of 60-70 year olds, and the highest number of fixed appliances (24.940) was in the age group of 70-80 year olds.

The aim of this study was to acquire a three-dimensional qualitative and quantitative nano-scale data of surface topology of electropolished CoCr dental alloy, actually of the two different solid solutions previously described as dendrites and interdendritic regions. Ten CoCr alloy samples (Wironit® ; extra-hard, Bego, Germany) were prepared, cast and electropolished. The surface of the samples was recorded and analysed by atomic force microscopy (AFM), as well as with optical microscope. The AFM imaging and analysis made possible to observe a surface of the CoCr dental alloy three-dimensionally. It has been understood that the dendritic surface structure of the CoCr alloy consists of clusters of nanocrystallites forming islands (corresponding the dark interdendritic regions on optical micrographs), which emerge from a smooth undulating surface (corresponding the light dendritic regions on optical micrographs). The 95% confidence interval (p

PURPOSE: To aquire the 3-D nanotopographic data of the CoCr alloy surfaces submitted to different polishing protocols using atomic force microscopy (AFM). METHODS & MATERIALS: 18 samples were divided into 3 groups of 6 samples. The first group was only electropolished (EP), and the second and the third were further mechanically polished using green rubber discs and afterwards a high shine polishing paste and a rotating black brush (BB), or a high shine polishing paste and a rotating deer-leather brush (DL). Optical micrographs and 5 AFM images of each sample were obtained. The roughness (RMS, Ra and maximum Z-range)and the section analysis were performed. Mean values of 5 scanned surfaces of each sample were accounted for statistical analysis (ANOVA, Scheffe post hoc, 95% probability level). RESULTS: In the EP samples 2 distinct forms of surface structure were identified: clusters of nanocrystallytes (alligned in parallel rows 160 or 320 mm apart, 90-150 nm high) forming islands (matching the dark zones in optical micrographs) and a smooth undulating surface (matching the light zones). Dramatic changes were induced by further mechanical polishing: The islands' height was reduced to 40 nm due to decrease in their roughness (the crystallite peaks were polished away) and scratches appeared in parallel fashion on the undulating surface. Optical micrographs at that stage showed islands as lighter and undulating surface as slightly darker zones with dark lines (scratches). Mechanical polishing caused change of reflectivity as saw-tooth cristallyte peaks were taken away. The maximum Z range of EP samples (918.0 nm) was significantly higher than that of BB (537.23 nm) and DL (616.17) (p0.05). The BB revealed the smoothest surface. CONCLUSION: Mechanical reduction of islands' height and roughness resulted in decrease of maximum Z range values. Surface roughness was also reduced, but not significantly due to appearence of shallow scratches on the undulating surface. BB surface smoothness was superior to EP and DL.

Objectives: Radiographic assessment of « ; ; bone quality» ; ; is of great value in planning any further dental treatment in different dental fields: orthodontics, prosthodontics, oral surgery etc. The aim of this study was to assess cortical thickness of the lower border of the mandible and to determine whether these linear radiomorphometric indices are correlated with different age, gender and malocclusion categories. Methods: Measurements were made by one experienced individual on 299 panoramic radiographs using a caliper (0.01 mm precision). Patients were divided in 3 age groups: 6 to 12 years (31.8%) ; 12 to 16 years (44.1%) and 16 to 18 years (24.1%), respectively. There were 151 males and 148 females. Twenty patients had Angle class II/2, 30 had Angle Class III, open bite was registered in 27 individuals and the other 222 patients had Angle Class I occlusal relationship. Results: The results revealed significantly higher values of gonion index (GI) on the right side of the mandible (p

Objectives: The aim was to assess dental status and prosthodontic treatment needs in urban Croatian population. Dental status, Community Periodontal Index (CPI), current prosthodontic status and needs were registered according to WHO criteria. Methods:In urban population (Zagreb) 1234 patients were examined (521 males and 713 fenales) divided in the 6 age groups (15-20, 21-30, 31-40, 41-50, 51-60, >61 years). Current dental status and CPI were registered, as well as status of prosthodontic appliances if present in patient mouth (which was assessed by a trained specialist of prosthodontics). Teeth with pockets > 6 mm were classified as teeth which would need extraction within a few years. Specialist of prosthodontics assessed that about 35 % patients needed new PAs mainly older than 40 years. Results: Until the age of 20 no prosthodontic appliances (PAs) were found and until 30 years only 6 % had fixed partial dentures (FPD). At the age of 40 more than 34 % had PAs, mainly FPDs. At the age of 50 more than 47 % Pas (10 % had removable dentures). At the age of 60 more than 52 % had Pas (FPDs begun to decrease (32 %) and removable partials (13 %) and complete dentures ( 9 %) begun to increase). In the age group > 61 % only 25 % had no Pas and more than 66 % had removable dentures. CPI revealed considerable percentage of periodontal pockets > 6 mm (11 %) in age 21-30, 32 % (31-40 years) reaching the peak (>52 %) in 41-50 year group. In older age group the percentage of pockets > 6 mm decreased. Conclusions: Need for prosthetic treatment was considerably high in Croatian urban population. Considerable need was registered after the age of 30 and the highest need was between 40-60 years.

Objectives: The residual ridge resorption (RRR) results in reduction of a face height and counterclockwise rotation of the mandible. So far, the etiology of RRR has not been not elucidated. The aim of this study was to analyse the extent of RRR in different regions of both jaws and changes of Go-angle within a 5 year period of complete denture wearing. Methods: The height of residual ridges was measured on lateral cephalograms at 5 different sites of the mandible and the maxilla at the delivery of the dentures, after one year and after the five year period using a calibrated grid. From a baseline of 100 individuals, only 32 responded after 5 years. Results: RRR was 2.5x greater in the mandible compared to maxilla after a period of one year and 2.0x greater in the mandible after 5 years. It was greater in frontal sites of the both jaws in comparison to lateral regions. After the first year of denture wearing, the rate of RRR decreased and during the next four years resorption was only twice as much as registered after the first year. Go-angle had not changed during 5 years (t=0, 295 ; p>0.05, N.S.). Conclusions: Considerable residual ridge resorption was observed. The rate od resorption was higher in frontal than in lateral regions. Vertical dimension of occlusion decreased 3.86 mm after 5 years. Go-angle did not change and was not responsible for the counterclockwise rotation of the mandible.

Objectives: Alveolar bone loss (RRR) is a continous process following tooth extraction. The RRR results in reduction of face height and counterclockwise rotation of the mandible. So far, the etiology of RRR has not been not elucidated. It has been speculated that both, systemic and local factors contribute. The aim of this study was to analyse RRR in different regions of both jaws to correlate such changes with factors such as number of years of edentulousness, nighttime wear of dentures, body mass index, gender, number of previous denture worn, surface of denture bearing area, density of cervical vertebra, etc. Methods: The height of residual ridges was measured on 50 lateral cephalograms at 5 different sites of the mandible and maxilla at the delivery of the dentures, after one year and after the five year period of denture wearing using a calibrated grid. Results: The results revealed significant RRR (p0.05). Conclusion: The only significant factor contributing to RRR was the period of edentulousnes.

OBJECTIVE: The aim was to assess dental status and prosthodontic treatment needs (PTN) in urban Croatian population. METHODS: A total of 1200 individuals, 491 males and 709 females (15-90 years) divided in 6 age groups (15-20 years, 21-30 years, 31-40 years, 41-50 years, 51-60 years and >61 years) were examined. Dental status, Community Periodontal Index (CPI), current prosthodontic status and needs were registered according to WHO criteria. RESULTS: There was no significant difference between genders. Until the age of 20 no prosthodontic appliances (PA) were found and until 30 years only 5% had fixed partial dentures (FPD). At the age of 40 more than 30% had PAs, mainly FPDs. At the age of 50 more than 45% had PAs (10% had removable dentures). At the age of 60 more than 50% had PAs (FPDs begun to decrease (30%) and removable partial (12%) and complete dentures (8%) begun to increase). In age group >61 only 25% had no PA and more than 65% had removable dentures. Additional PTN (replacement of more than 1 tooth) varied from 1% in the youngest group, 13% (21-30 years), and 27% (31-40 years) till 40% (41-50 years). In older groups additional PTN declined to 30% (51-60 years) and to 22% in >61 years. CPI revealed a considerable percentage of periodontal pockets >6 mm (10%) in age between 21-30 years, 30% (31-40 years), reaching the peak (>50%) in 41- 50 year group. In older age groups the percentage of pockets >6 mm decreased, mainly due to the fact that majority teeth had been already extracted. CONCLUSION: Including present prosthodontic status, current needs and anticipating extractions of teeth (pockets >6 mm), the population need for prosthodontic treatment in Croatia was considerably high. Greater emphasis on prevention and financial support for prosthodontic treatment are required.

Introduction: Digital photography is almost available to everybody. Proper artificial tooth selection is very important for aesthetic consideration of prosthetic appliance. Aim of this study: was to examine possibility of calculating the width of a missing central incisor using digital photographs as well as to determine best camera-object distance on accuracy of the calculated tooth dimension. Materials and methods: Digital photographs were obtained from 51 dentate subjects using a 3.1 Mega pixel digital camera from various distances: 35 cm, 70 cm, 1 m and 1.5 m. For the calculation of the width of maxillary left central incisor (MLI), the following equation was used: MLI(calculated) = Photographic width of MLI x IPD / photographic IPD. Statistical analysis was made (Kolmogorov-Smirnov test, dependent sample t-test, correlation and frequencies) using SPSS 10.0 for Windows. Results: Results revealed no significant difference between the calculated MLI (70 cm, 1 m and 1.5 m distance) and actual MLI. Calculated MLI from 35 cm distance was significantly different from the actual MLI value (p < 0.01). The highest correlation was between calculated MLI (70 cm distance) and actual MLI. However, the highest percentage of results from a distance of 70 cm also fitted within +/- 0.3 mm ; +/- 0.5 mm and +/- 1 mm difference from the actual MLI values. However, the results obtained from 1 m distance were also satisfactory. The technique of use of digital photography is of proven value in calculating the width of a maxillary central incisor. Conclusion: The photographs using a simple digital camera should be taken from a distance from 70 cm to 1 m. Digital photographs in a dental office may be helpful for calculating dimensions of artificial teeth in possible future reconstructive treatment.

Stomatološki materijali kao predmet u nastavi te sadržaj stručnih rasprava i znanstveno-istraživačkih radova srazmjerno je novijeg datuma. Međutim, bavljenje materijalima postoji od početka zubarstva i stomatologije, tj. od vremena prvih pronađenih zlatnih zubnih nadomjestaka iz doba Feničana i Etruščana, starih preko 2500 godina. U suvremenoj stomatologiji koristimo se preventivnim, terapijskim, korektivnim i restorativnim zahvatima. Po nekim procjenama, samo za restorativne zahvate u stomatološkoj djelatnosti potroši se od pola do tri četvrtine radnog vremena. Nadomještanje zuba, bez obzira na razloge zašto su izgubljeni, obično se provodi iz estetskih razloga i/ili uspostavljanja žvačne funkcije. Iz ovih okolnosti proizlazi nužnost i važnost poznavanja svojstava stomatoloških materijala te tehnologije njihove primjene.

Introduction: Aesthetics is an important issue for dentists and their patients (1). Therefore the selection of artificial teeth (dimension, shape and colour) is an important concern in complete denture construction. (2-4). Many attempts have been made to establish methods as aids for artificial tooth selection (2, 5-9), but none of them being completely satisfactory. It had been documented that artificial teeth were frequently too narrow and too long (10) in dentures. Therefore, attempts have been made to establish methods for selection of appropriate size of maxillary anterior teeth. Many investigators studied the relationship between dimensions of various landmarks on a subject's face and a size of maxillary anterior teeth (8, 11-13) with an idea to compute the maxillary first incisor’s width or length if the strong correlation existed. Purpose of the study:To determine a possibility of reconstruction of maxillary incisor's dimensions using the dimensions of the hard palate. Materials & Methods: A total of 82 dentate students participated (Angle class I occlussal relationship, minimal tooth rotations or compressions were allowed). Irreversible hydrocolloid impressions of a maxillary jaw were made (Alginoplast fast set, Heraeus Kulzer, Hanau, Germany) and casts were poured in the hard stone (ISO Type I, Vel-Mix Stone, Kerr Italia S. p. A., Salerno, Italy). Measurements were made on the casts using a precise caliper (0.1 mm precision) (TMA MEBA, Zagreb, Croatia). The incisal height (IH) and the incisal width (IW), the contact (CtW) and the cervical width (CW) of the maxillary first incisors (MCI) were measured, as well as an interhamular distance (HD) (distance between the left and the right hamular notch) and a distance between a centre of an incisive papilla and foveola palatina (IP-FP). Statistical analysis was made by SPSS 12 for Windows. Results: The distribution of the data was normal (p>0.05) (tested by the Kolmogorov-Smirnov test). Descriptive statistics (mean values, standard deviations) is presented in Figure 1 and Figure 2. There was no significant difference for any variable measured in this study between men and women (p>0.05) (independent t test). Significance of the difference between mean values of maxillary frontal teeth on the left and right side of the dental arch is tested by t test for dependent samples.There was no significant difference between the left and the right side maxillary first incisor’s widths (p>0.05). Maxillary first incisors on the left side were significantly higher than maxillary first incisors on the right side (p0.05), mean values for maxillary first incisor were calculated (Table 1). The ratios (factors) were computed: HD/IW (5.71), HD/CtP (5.69), HD/CW (5.51) and IP-FP/IH (4.76) (Table 2). In Table 3 the dimensions of the hard palate were calculated by multiplying the measured tooth dimensions (Table 1) and computed ratios (Table 2). Than the descriptive statistics and significance of the difference between measured and calculated hard palate dimensions were tested by Student's paired t test (p>0.05). Maxillary first incisor’s height had been calculated by dividing the hard palate length by the calculated ratio (4.76, Table 2). Mean values and standard deviations for the calculated maxillary first incisor’s length are presented in Table 4. In older age groups gingival margin migrates apically and the incisor’s crown becomes longer. For this reason, except the use of the calculated factor 4.76, the factor 4.0 was also used (palate length divided by 4). Discussion:After the extraction of the all teeth, it is very difficult to reconstruct the exact position of maxillary frontal teeth, since the rate of alveolar bone resorption is individual in each subject. At the other hand, hamular notches, incisive papila and foveae palatinae have been considered to be reliable landmarks since they have not been submitted to resorptive changes after teeth extraction (14). Their position has been determined by anatomical structures. Therefore the interhamular distance and the distance between the incisive papilla and fovea palatina have been chosen as reference distances for determination of the teeth dimensions. The ratios calculated in this study seem to be relevant for a choice of maxillary first incisor’s width (Table 4). For the height of the maxillary central incisor, dividing palate length with the calculated ratio 4.76 would lead to the choice of too short incisors (9.41 mm, Table 4) because in older age groups gingival recession is present, as well as a resorption of residual alveolar ridges in edentulous patients (15). The artificial maxillary incisors should be longer than the length of natural teeth to compensate for alveolar ridge resorption. However, artificial denture gums should also not be visible. Therefore the calculated ratio was modified to a 4.0 factor. The incisor’s length calculated by dividing palate length by 4 would lead to 1.7 mm longer incisors than measured (11.19 mm, Table 4). However, artificial teeth have to be grinded during a set up procedure and therefore factor 4 seems to be more appropriate for determination of the first maxillary incisor’s height for removable denture population than the calculated ratio 4.76. Conclusion: It is possible to calculate the maxillary central incisor’s width and height by measuring the patient’s palate. Interhamular distance should be divided by 5.71 for the cervical width between interdental papilas, by 5.69 for the incisal width and by 5.5 for the contact-point width of a maxillary central incisor. To calculate the length of the maxillary central incisor, a distance between foveolae palatine and incisive papilla should be divided by 4.

Introduction: The position of occlusal plane should be as close as possible to the position which was previously occupied by the occlusal plane of the natural teeth. Most textbooks on removable prosthodontics advocate that occlusal plane should be parallel to Camper's line. Aim of the study: To check the accuracy of using this method in a clinical practice. Materials and methods: Fifty seven dental students with complete natural dentition and Angle Class I participated. Left profile with a subject in a natural head position and clenching on a Fox plane were photographed from a distance of 1.5 m. There was no significant difference between the position of a Fox plane and quick-mounting face bow on digital photographs and between occlusal plane and articulator's horizontal plane (P>.05) of the same individuals, so this method was considered reliable. The angle between Fox plane and Camper's plane was measured on digital photographs. Statistical analysis was made (descriptives, one sample t-test). Results: Mean difference between Fox plane and Camper plane was: x = - 4.1o, SD = 5.6 o). The range of inclination between the 2 planes varied from - 15.0 to + 10.5 degrees. Males had significantly higher difference between the two planes tham females (P

The aim of this study was to clinically determine the thickness of masticatory mucosa in the hard palate and tuberosity as potential donor sites for subepitelial autotransplatation tissue for moderate ridge augmentation procedures to acheive better aesthetics of the pontics of fixed partial dentures. In 102 periodontally healthy fully dentate subjects the masticatory thickness was assessed by bone sonding with a periodontal probe. Seventeen measurement points were defined, 15 on hard palate located on 3 lines running at different distances parallel to gingival margin and 2 on tuberosity. Data were analysed to determine differences between gender, different body mass index and different shapes of hard palate, using t test and analysis of variance. The mucosa on the hard palate was significantly thicker than on the tuberosity. The thickest mucosa was registered on the second and the third line behind canines and on all 3 lines behind the first premolar, which are recomanded as potential donor sites. The thickness increased from the first line behind gingival margin towards the third line. Males had significanly thicker mucosa than females (p0, 05) where the mucosa was the thinnest in the both gender, which was attributed to the protuberance of the palatal root of the first molar. The same was with the body mass index. There was no significant differences in the thickness of the mucosa between the oval and the square palatal shapes (p>0, 05). Therefore canine-premolar palatal region is recommanded for harvesting free subepitelial autotransplatate tissue for moderate augmentation of alveolar ridges for achiving optimal aesthetics of the pontics.

The aim was to compare 3 methods for determination of vertical dimension, which are often used in clinical practise and to study influence of changing head position to interocclusal space. One hundred of healthy fully dentate subjects (18-36 yrs.) with Angle Class I were instructed to say "s", "mi" and to maintain postural rest position until the freeway space was measured. This was done in different head positions: straight, head leaned back and head leaned forward. Measurements were performed between upper and lower central incisors, canines and first molars. There was no significant differences between gender. Interocclusal space decreased from incisors towards molars. Head position had significant impact on the size of free-way space in postural rest position. During speech of "s" and "mi" the size of free-way space remained constant. These findings confirm that clinical determination of vertical dimension should include speech methods rather than relaxation. Results also revealed significant positive correlation between vertical overlap and interocclusal space during speech of "s" (r=0.7) and "mi" (r=0.5) and weak correlation during postural position (r=0.35).Horizontal overlap was significantly, but weakly associated with "s" pronunciation (r=0.2), while for "mi" and rest position of the mandible, there was no significant correlation.

Objectives: Alveolar bone loss (RRR) is a continous process following tooth extraction. The RRR results in reduction of face height and counterclockwise rotation of the mandible. So far, the etiology of RRR has not been not elucidated. It has been speculated that both, systemic and local factors contribute. The aim of this study was to analyse RRR in different regions of both jaws on lateral cephalograms of 50 complete denture wearers and to correlate such changes with factors such as number of years of edentulousness, age of present denture, nighttime wear of dentures, body mass index, gender, number of previous denture worn, surface of denture bearing area, etc. Methods: The height of residual ridges was measured on telerontgenograms on 5 different sites at the delivery of the dentures and a year later using a calibrated grid. Results: The results revealed significant RRR in one year period (p0.05). Conclusion: Hyerarhic regression analysis revealed that the most important factors for RRR were the period of edentulousnes and number of years of denture wearing.

We studied the metal ion release from Ni.Cr and Co-Cr-Mo dental alloy in a simulated oral saliva from one to thirty days. Co, Fe, Zn, Ni, and Cr were released from both dental alloys and to a different extent. The manufacturer didn't declare the presence of neither Ni, Zn and Fe from Co-Cr-Mo dental alloy, nor the release of Co and Zn from Ni-Cr dental alloy. The released amounts of Fe and Zn may only improve the subjects dietary status in respect to these elements, whereas Ni, Cr and Co are potent allergens which may impede the biological compatibility of the entire protethic structure in vivo.

Gold/platinum (Au/Pt) dental alloy was exposed in vitro to either simulated saliva (Saliva ; phosphate buffer pH 6.0), highly acidic medium resembling the extreme conditions in the oral cavity (Acid ; phosphate buffer pH 3.5), and in lactic acid at pH which occurs under the dental plaque (Plaque, lactic acid pH 3.5). The alloy was immersed in the Saliva, Acid, and Plaque solution for 1, 2, 3, 4, 5, 6, 7, 14, 21, and 30 days. The solution was analyzed for fifteen metals with the ICP-AES. We observed time and solution dependent leaching of Zn, Cu, Fe, and Cr (ANOVA, p

Zn, Cu, and Fe were released from the gold-platinum dental alloy ; only copper release was admitted by the manufacturers. All these elements are essential for human nutrition, but maz change the electrochemical forces in the oral cavity.

Uvod: Najčešći kriteriji za odabir legure su fizikalna svojstva i biokompatibilnost, ali i cijena. Neplemenita (bazna) NiCr legura upotrebljava se za metalno-keramičke radove. Svrha rada bila je ispitati koji se ioni otpuštaju iz nikal-krom legure u otopine različitih pH vrijednosti, te utvrditi utjecaj pH i trajanja izloženosti na otpuštanje iona. Materijal i metode: Ispitivana NiCr legura (Wiron 99&reg ; ; , BEGO, Njemačka) bila je in vitro izložena otopini koja je oponašala ljudsku slinu (fosfatni pufer pH 6.0), otopini koja je oponašala ekstremne uvjete u usnoj šupljini (fosfatni pufer pH 3.5) i otopini mliječne kiseline pH 3.5 koja je oponašala uvjete ispod dentobakterijskog plaka. Uzorci su bili uronjeni kroz 1, 2, 3, 4, 5, 6, 7, 14, 21 i 30 dana. Otopine su analizirane pomoću ICP-AES (Jobin Yvon 50 P, France). Bilo je ukupno 180 uzoraka, po 60 u svakoj otopini, po 6 za svaki ispitivani vremenski period. Rezultati: Otpušteni su ioni Ni, Cr, Co, Zn i Fe. Otpuštanje je ovisilo o vrsti otopine i dužini izloženosti (ANOVA, p

Uvod: Resorpcija rezidualnog alveolarnog grebena (RRR) je kontinuirani proces koji se nastavlja nakon ekstrakcije zuba i formiranja bezubog grebena. Etiologija RRR još uvijek nije do kraja razjašnjena. Smatra se da i sistemski i lokalni faktori doprinose resorpciji. Svrha ovog rada bila je analizirati iznos RRR na pet različitih područja obje čeljusti tijekom razdoblja od jedne godine te usporediti iznos resorpcije ovisno o različitim faktorima: vrijeme koje je proteklo od ekstrakcije poslijednjeg zuba, indeks mase tijela, nošenje proteza noću, veličina ležišta proteze, spol, itd. Materijal i metode: Visina rezidualnih grebena mjerena je na lateralnim telerengenogramima u 100 nosilaca totalnih proteza na 5 mjesta u gornjoj i donjoj čeljusti u dva vremenska perioda: prilikom predaje potpunih proteze i ponovo nakon razdoblja od jedne godine. Mjerenja su izvršena uz pomoć kalibrirane mrežice. Rezultati: Rezultati su pokazali postojanje statistički značajne razlike u iznosu resorpcije ovisno o vremenu bezubosti (ANOVA, p0.05), kao ni nošenje proteza noću, veličina ležišta proteze ili spolna pripadnost. Resorpcija je bila jače izražena u prednjim dijelovima obje čeljusti i kada su molari bili poslijednji izvađeni zubi, čime se objašnjava rotacija mandibule u smjeru suprotnom od kazaljke na satu. Resorpcija grebena bila je u donjoj čeljusti 2, 5 puta veća nego u gornjoj. Zaključak: Poznavanje faktora koji doprinose resorpciji pomaže u planiranju proteza kako bi smanjili resorpciju i očuvali ležište.

Uvod: Korozijska stabilnost i biokompatibilnost su glavni preduvjeti za upotrebu dentalnih legura u ustima. Svrha ovog rada bila je ispitati ponašanje AuPt legure u otopinama različite pH vrijednosti i različitog sastava kroz vremensko razdoblje od mjesec dana. Materijal i metode: AuPt legura in vitro je bila izložena otopini koja je oponašala ljudsku slinu (fosfatni pufer pH 6.0), kiseloj otopini koja je oponašala ekstremne uvjete u usnoj šupljini (fosfatni pufer pH 3.5) i otopini mliječne kiseline čija pH vrijednosti odgovara uvjetima koji nastaju ispod dentobakterijskog plaka (mliječna kiselina pH 3.5). Uzorci su bili uronjeni kroz 1, 2, 3, 4, 5, 6, 7, 14, 21 i 30 dana. Otopine su analizirane pomoću ICP-AES (Jobin Yvon 50 P, France). Bilo je ukupno 180 uzoraka, po 60 u svakoj otopini, po 6 za svaki ispitivani vremenski period. Rezultati: Analiza je pokazala da su se tijekom mjesec dana iz ispitivanih uzoraka slitine otpustili ioni Zn, Cu, Fe i Cr. Proizvođač u dekleraciji nije naveo prisustvo Cr, Fe i Zn. Otpuštanje iona ovisilo je i o vrsti otopine i o dužini izloženosti legure (ANOVA, p

Co, Fe, Zn, Ni, and Cr were released from the removable frame partial denture made from the cobalt-chromium-molybdenum dental alloy. However, the presence of Fe, Zn, and Ni in the Co-Cr-Mo dental alloy was not declared by the manufacturer. Zn and Fe are essential trace element for human nutrition but may affect the durability of Co-Cr- Mo dental alloy in the oral cavity, whereas nickel is a potent allergogen.

Gold/platinum (Au/Pt) dental alloy was exposed in vitro to either simulated saliva (Saliva ; phosphate buffer pH 6.0), highly acidic medium resembling the extreme conditions in the oral cavity (Acid ; phosphate buffer pH 3.5), and in lactic acid at pH which occurs under the dental plaque (Plaque, lactic acid pH 3.5). The alloy was immersed in the Saliva, Acid, and Plaque solution for 1, 2, 3, 4, 5, 6, 7, 14, 21, and 30 days. The solution was analyzed for fifteen metals with the ICP-AES. We observed time and solution dependent leaching of Zn, Cu, Fe, and Cr (ANOVA, p

Co, Fe, Zn, Ni and Cr are released from the nickel- chromium dental alloy. Iron and copper release was not declared by the manufacturer although they maz affect the life span of dental alloy in the oral cavity. Co, Ni, and Cr have a considerable allergogenic potential.

Uvod: Korozijska stabilnost i biokompatibilnost su najvažniji čimbenici za upotrebu neke legure u ustima. Svrha ovog rada bila je analizirati otpuštanje metalnih iona iz visoko plemenite zlatno-platinske (Au/Pt) legure u različite otopine koje imitiraju različite uvjete u usnoj šupljini. Materijali i metode: Zlatno-platinska (Au/Pt) legura bila je izložena in vitro otopini koja simulira slinu (Saliva ; fosfatni pufer pH 6.0), u jako kiselom mediju koji simulira ekstremne uvjete u usnoj šupljini (Ekstrem ; fosfatni pufer pH 3.5) i u mliječnoj kiselini pri pH 3, 5 što simulira uvjete ispod dentobakterijskog plaka (Plak, mliječna kiselina pH 3.5). Po 6 uzoraka tvorničke legure bilo je uronjeno u slinu, ekstrem i plak kroz 1, 2, 3, 4, 5, 6, 7, 14, 21 i 30 dana. Otopine su analizirane na 15 metalnih iona pomoću ICP-AES. Rezultati: Rezultati pokazuju da je otpuštanje iona Zn, Cu, Fe i Cr ovisno o vremenu izloženosti i o vrsti otopine i njenog pH (ANOVA, p

Svrha rada bila je ispitati ponašanje WIRONITR legure u fosfatnom puferu pH 6, 0 (kako bi se simulirala ljudska slina) kroz dulje vremensko razdoblje, te ustanoviti vrstu i količinu iona koji se otpuštaju iz legure. Također se željelo ustanoviti kako na otpuštanje iona utječe vrijeme izloženosti legure djelovanju fosfatnog pufera pH 6, 0. U tu svrhu ispitano je 60 neobrađenih tvorničkih uzoraka WIRONITR legure promjera 8 mm i visine 15, 8 mm. Otpuštanje iona mjereno je kroz deset vremenskih razdoblja: 1, 2, 3, 4, 5, 6, 7, 14, 21 i 30 dana. Analizom otopina u kojima su ležali uzorci ispitivane legure pomoću atomskog emisijskog spektrofotometra sa induciranom združenom plazmom (ICP-AES) utvrđeno je da su se tijekom mjesec dana otpustili ioni kobalta (Co), kroma (Cr), željeza (Fe), cinka (Zn) i nikla (Ni). Iz uzoraka bazne Co-Cr-Mo legure najviše se otpustilo iona kobalta, a najmanje iona željeza. Rezultati su pokazali da na otpuštanje svih pronađenih iona statistički značajno utječe vrijeme ekspozicije legure fosfatnom puferu pH 6, 0 (p

Jednokomadni lijevani metalni odljev sastavni je dio svake metalne djelomične proteze. Njegova izradba zahtijeva preciznost i tehničara i stomatologa - od početne faze kada se još planira taj mobilni nadomjestak, pa tijekom otiskivanja, izlijevanja sadrenoga modela, dubliranja, modeliranja voštanim strukturama, kovetiranja dublikranoga modela, zagrijavanja, žarenja i izlijevanja metalne konstrukcije, uklanjanja uljevnih kanala, pjeskarenja, pa sve do završnoga poliranja odljevka i njegova prilagođavanja na sadrenome modelu i u pacijentovim ustima. U tehnološkim postupcima izradbe važnu ulogu ima zahtjevna oprema: robustan i jak motor, paralelometar, tremostatska posuda materijala za dubliranje, pjeskara, uređaji za mehaničko poliranje i elektrololiranje, peć za žarenje i naposljetku posebno lijevalo na bazi inducirane struje.

Ion release was studied in vitro from 3 principal dental alloys: Au-Pt alloy, Co-Cr-Mo alloy and Ni- Cr alloy. Alloys were immersed in solution imitating saliva (phosphate puffer pH 6) for 1, 2, 3, 4, 5, 6, 7, 14, 21, and 30 days. Results were analysed by ICP-AES (Jobin Yvon, France). Results revealed ion released from the alloys, which were in limits of dietary needs for oligoelements, except for NiCr dental alloy, where the release of Ni ions was even higher than daily allowed intake. It was concluded that care must be taken when using this alloy to be sure to be covered fully with porcelain and not exposed to oral fluids.

Svrha ovog rada bila je istražiti otpuštaju li se ioni Ni iz tri različite dentalne legure: iz visoko plemenite zlatno-platinske legure te iz neplemenitih (baznih) Ni-Cr i Co-Cr-Mo legura. Svrha rada bila je i utvrditi kako vrsta otopine u koju je legura uronjena i njena pH vrijednost, kao i vrijeme ekspozicije utječe na količinu otpuštanja iona nikla iz tri navedene legure. Upotrebljene su 3 različite dentalne legure: dvije bazne: Ni-Cr legura (Wiron 99&reg ; ; , BEGO, Njemačka) i Co-Cr-Mo legura (WIRONITR, BEGO, Njemačka) i jedna vrlo plemenita zlatno-platinska legura (Rafinerija plemenitih kovina, Zagreb, Hrvatska). Uzorci Ni-Cr legure i Co-Cr-Mo bili su u obliku valjčića istih dimenzija, tako da je promjer svakog valjčića iznosio 8 mm, a visina 15, 8 mm. Uzorci Au-Pt legure bili su u obliku pločica, dimenzija: 8 mm x 6, 5 mm x 1 mm. Svi uzorci bili su uronjeni kroz određeno vremensko razdoblje u tri različite otopine. Kao simulacija ljudske sline korištena je fosfatna puferirana otopina pH 6, a mliječna kiselina s dodacima octene i mravlje, pH 3, 5 (0, 1 M mliječna kiselina, 0, 1 M NaCl, 1%-tna octena kiselina, 1%-tna mravlja kiselina) simulirala je uvjete koji nastaju ispod dentobakterijskog plaka. Fosfatna puferirana otopina pH 3, 5, sastavljena prema recepturi farmakopeje, korištena je radi usporedbe, budući da se tako ekstremno kiseli uvjeti ne nalaze u ustima. Za svaku ispitivanu dentalnu leguru korišteno je po 6 uzoraka (n = 6), za svaku od tri otopine i svako ispitivano vremensko razdoblje, što znači da je ukupno ispitano 180 uzoraka svake legure, tj. 540 uzoraka ukupno. Otpuštanje iona iz ispitivane legure u svaku od navedenih otopina mjereno je kroz deset vremenskih razdoblja i to nakon 1, 2, 3, 4, 5, 6, 7, 14, 21 i 30 dana. Otopine su analizirane pomoću atomskog emisijskog spektrofotometra sa induciranom združenom plazmom (ICP-AES), JY 50 P, Francuska. Temeljem analize izmjerenih podataka formirani su slijedeći zaključci: 1. Od tri legure (Ni-Cr, Au-Pt i Co-Cr-Mo) proizvođač navodi prisustvo Ni samo u Ni-Cr leguri. Rezultati istraživanja ukazuju da su i Ni-Cr legura i Co-Cr-Mo legura otpustile ione Ni, a Au-Pt legura nije, čak niti pri niskim pH vrijednostima ; 2. Iz Co-Cr-Mo legure u prvim danima ekspozicije ioni Ni otpuštali su se u malim količinama (10  g/L), a porast otpuštanja zabilježen je 6. dan u fosfatnom puferu pH 3, 5, a 21. i 30. dan u fosfatnom puferu pH 6 (slina) i u mliječnoj kiselini pH 3, 5 (dentobakterijski plak). Tada je otpuštanje iona prelazilo dnevne potrebne količine za ovim oligoelementom ; 3. Iz Ni-Cr legure otpuštale su se velike količine iona Ni u sve tri otopine te su već 1. dan mjerenja bile veće od dnevnih potrebnih doza. S vremenom se količina otpuštenih iona Ni povećavala uz veliku varijabilnost u svim otopinama, a najviše u fosfatnom puferu pH 6 (slina), gdje je čak i premašivala dozvoljene dnevne doze unosa u organizam. Stoga se indikacija ove legure treba ograničiti isključivo na metal-keramične radove.

Residual alveolar ridges show continual resunption after the loss of the natural dentition resulting in reduction of the morphologic face height and a counterclockwise rotation of the mandible. The aim of this study was to analyze the residual ridge resorption (RRR) in different regions of both jaws on teleroentgenograms of 50 complete denture wearers and to correlate such changes with age, sex, number of years edentulous, nighttime wear of the denture and the surface of denture bearing area. The height of residual ridges was measured on 5 different sites of each jaw on lateral telerontgenographs by using a callibrated grid. The results revealed that all the patients whowed significant RRR in one year period (p

Electrochemical conditions in the oral cavity lead to a release of metal ions into the patients saliva.The aim of this study was to examine and compare the types and quantities of metal ions released from two base alloys : Co-Cr-_mo alloy and Ni-Cr- alloy.

The objective of this study was to measure and assess a number of radiomorphometric indices of the mandibular removable denture wearers taking into account age and gender. In a total of 136 dental panoramic radiographs (DPR) the following parameters were evaluated: MI = thickness of the mandibular cortex below the mental foramen, AI = thickness at the antegonion and GI = thickness at gonion ; PMI = MI/distance between the low border of the mandible and the low border of the mental foramen, and MCI = mandibular cortical index, based on the assessment of the 3 categories of cortical appearance due to the resorptive changes. There were 40 male patients (mean age 72.7 ; range 56 to 84 years) and 96 female patients (mean age 69.7 ; range 48 to 86 years). Patients were grouped according to age into three age groups (1 = less than 65 years ; 2 = 65-75 years ; 3 = more than 75 years). The results revealed that MI, PMI, AI and GI showed a general downward trend with age for the both sexes until 75 years of age when the mean values of GI, AI and MI begun to fall down sharply for females compared to males. The difference was significant between age groups and gender for GI and AI. Only two categories (C2 and C3) of MCI have been recognized in our study sample, due to the relatively old age groups of patients with removable dentures. However, significantly higher incidence of C3 existed in the oldest group of females.

Svrha ovog istraæ ivanja bila je pregledati one pacijente, i njihove ortopantomograme, koji su u usnoj π upljini imali fiksnoprotetski rad stariji od 5 godina kako bi se ustanovila ËestoÊ a karijesa i ËestoÊ a parodontnih dæ epova dubljih od 3 mm. Osim toga, æ eljelo se je ustanoviti postojanje razlika u ËestoÊ i patoloπ kih nalaza ovisno o vrsti razliËitih fiksnoprotetskih konstrukcija, te postoji li razlika izme u zuba nosaËa razliËitih krunica i nenosaËa krunica (nebruπ enih zuba). Sudjelovalo je 260 pacijenata (55% æ ena i 45% muπ karaca) u dobi od 25 do 70 godina koji nikada nisu imali problema s fiksnoprotetskim radom te su njime bili potpuno zadovoljni. Na 260 ortopantomograma ukupno je analizirano 2265 zuba ; 864 zuba nosaËa krunica ukljuËenih u mostove, 407 zuba nosaËa samostalnih krunica, a preostali zubi bili su nenosaËi krunica. Rezultati su pokazali razmjerno veliku ËestoÊ u patoloπ kih nalaza (karijes, dæ epovi > 3 mm) u nosilaca fiksnoprotetskih radova koji su bili stariji od 5 godina. Parodontni problemi bili su Ëeπ Ê i od karijesa. NajveÊ a ËestoÊ a patoloπ kih nalaza bila je kod krunica s akrilatnom fasetom, a najmanja kod keramiËkih radova (p0, 05). U incidenciji karijesa nije bilo statistiËki znatne razlike (p>0, 05), a u incidenciji dæ epova nenosaËi i nosaËi keramiËkih radova imali su znatno manje dæ epova od nosaËa fasetiranih ili potpunih metalnih krunica (p

The aim of this study was to screen patients with fixed prosthodontic appliances that were in oral cavity for a period of 5 years or more. Root caries, gingival recession, pocket formation and alveolar ridge resorption were assessed to find out the differences between different materials and constructions, differences between abutments and natural teeth, and to find out the need for replacement. A total of 260 orthopantomograms were examined, whith a total of 2265 teeth, 610 being bridge abutments and 246 being crowns. The most frequent were metal+ acrylic veneer crowns or bridges. Root caries was found under the abutments in 10-20% ; however abutments whith ceramic crowns had the lowest percantage of caries (p0.05). Almost 50% of metal- ceramic abutments had no patologic findings. Almost 30% of the patients needed repalcement, or even some abutments to be extracted and therefore a new prosthodontic appliance.