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Introduction: Various techniques have been developed for 3D reconstruction of the lost bone tissue, with currently the most widely used being titanium mesh replacement, the Khoury technique, and the distraction osteogenesis. All three techniques have significant disadvantages, narrow indication, and require exceptional operator skill. IBAM scaffold is made of biodegradable material, provide space for the formation of new bone tissue, and have the ability to be built into 3D complex individualized shapes. Simple individualized fabrication, biocompatibility, and planned biodegradability are the properties due to which PLA has found its application in tissue engineering. Materials and methods: In order to optimize the shape and mechanical characteristics of the biodegradable scaffold, the mechanical properties of 3D printed specimens were tested by finite element analysis (FEA) with different print orientations - horizontal, lateral and vertical. Also, the flexural strength and impact strength of extruded PLA were tested on an Inspekt table 50 kN (Hegewald & Peschke Meß - und Prüftechnik GmbH). Results: The results of the FEA examination demonstrated higher values of tensile strength in the horizontal (32.98- 35.53 MPa) and the lateral positions (26.97-29.69 MPa) compared to the vertical position (4.43-14.20 MPa). The horizontal position of the specimens also demonstrated the highest values when testing flexural strength, while during the impact strength testing the horizontal (0.40 J) and lateral positions (0.41 J) demonstrated double the values of the vertical position (0.2 J). Specimens of all tested orientations showed similar hardness values after 60s. Conclusions: Based on the defined marginal loads of the model and the FEA, the results demonstrate that the planned arc geometry satisfies the criteria of the loads to which the scaffold will be exposed in the oral cavity. Mechanical properties of PLA meet the planned utilization of IBAM in computer-guided individualized bone augmentation.

Short implants

Background: Various techniques have been developed for 3D reconstruction of the lost bone tissue, with currently the most widely used being titanium mesh replacement, the Khoury technique, and the distraction osteogenesis. All three techniques have significant disadvantages, narrow indication, and require exceptional operator skill. IBAM scaffold is made of biodegradable material, provide space for the formation of new bone tissue, and have the ability to be built into 3D complex individualized shapes. Aim / Hypothesis: The aim of the present study was to define the mechanical properties of 3D printed PLA material, to determine the stress distribution within the virtual test form–finite element method (FEA), and to compare the obtained stress values with the reference values. Material and Methods: In order to optimize the shape and mechanical characteristics of the biodegradable scaffold, the mechanical properties of 3D printed specimens were tested by finite element analysis (FEA) with different print orientations–horizontal, lateral and vertical. Also, the flexural strength and tensile strength of extruded PLA were tested on an Inspekt table 50 kN (Hegewald & Peschke Meß–und Prüftechnik GmbH). Results: The results of the FEA examination demonstrated higher values of tensile strength in the horizontal (32.98-35.53 MPa) and the lateral positions (26.97-29.69 MPa) compared to the vertical position (4.43-14.20 MPa). The horizontal position of the specimens also demonstrated the highest values when testing flexural strength, while during the impact strength testing the horizontal (0.40 J) and lateral positions (0.41 J) demonstrated double the values of the vertical position (0.2 J). Specimens of all tested orientations showed similar hardness values after 60s. Conclusion and Clinical implications: Based on the defined marginal loads of the model and the FEA, the results demonstrate that the planned arc geometry satisfies the criteria of the loads to which the scaffold will be exposed in the oral cavity. Mechanical properties of PLA meet the planned utilization of IBAM in computer-guided individualized bone augmentation. Biodegradable scaffolds will play a significant role in personalized patient care to provide predictable treatment options to enhance clinical outcomes.

Background and Aim: Implant-abutment connection (IAC) is a key fac-tor for long-term success and stability of implant–borne prostheticrestoration and its surrounding tissues. Misfit between prosthodonticabutment and implant at the IAC leads to mechanical and biologicalcomplications. Two kinds of custom-made abutments are currentlyavailable on the market: original and third-party abutments. The aimof this pilot study is to indirectly check the internal fit (gap) at theimplant–abutment interface depending on the abutment fabricationmethod based on microbial leakage in static conditions and the needfor the use of the gap sealing material.Methods: 80 dental implants and respective abutments were used inthis study. Two groups of 40 implants were formed relative to thetype of abutment (original and third party). Group A consisted of20 GC Aadva Standard implants (GCTech.Europe GmbH, Breckerfeld, Germany) and 20 Zimmer Tapered Screw - Vent implants (ZimmerBiomet Dental, Palm Beach Gardens, Florida, USA) connected torespective original factory–made prosthodontic abutments. Group Bconsisted of same number and type of implants, but connected torespective third party custom–made abutments. In each of thegroups, two test subgroups of 10 implants in each were formed. TheGapSeal (Hager and Werken, Duisburg, Germany) was applied in testsubgroups. The implant–abutment assemblies were contaminatedwith a solution containingStaphylococcus aureusandCandida albicansfor 14 days under an aerobic conditions.Results: This study showed that there was no statistically significantdifference (p> 0.05) regarding microleakage between original andthird-party custom–made abutments regardless of the use of sealingmaterial.Conclusions: The abutment fabrication method has no significantinfluence on sealing efficacy regarding the bacterial and fungal leak-age in static conditions

Objectives of Investigation: The data about shear bond strength between digitally produced denture base materials and artificial teeth are scarce. Several studies investigated shear bond strength values between milled denture base material and different types of artificial teeth. The aim of the present study was to compare and evaluate the available evidence through a systematic review, and to enable the selection of optimal material for a given clinical situation. Methods Used: A bibliographic search was conducted in Pubmed, Scopus, and Web of Science to assess adequate studies published up to June 1st 2022. This review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta- Analyses) guidelines. The studies that determined the shear bond strength values between milled denture base materials and artificial teeth were selected. The search identified 15 studies which were included in PRISMA 2020 flow diagram for new systematic reviews. Studies that scored between 0 and 3 were categorized as being at low risk of bias, studies with score between 4 and 7 as moderate risk, and scores between 8 and 10 as high risk. Results: Only 3 studies met inclusion criteria and according to PRISMA 2020 present moderate risk of bias (score 6). The risk of bias is as follows: single operator of the machine, depiction of the sample size calculation, and blinding of the testing machine operator. The scores for these parameters were basically low (score 2) when compared to other risk of bias parameters (score 0). Conclusion: Bonding agents ensure bonding strength at least similar to the conventional methods. In order to upgrade the quality of future studies, it would be advantageous to use larger number of specimens with standardized dimensions, and blinded testing machine operator to decrease the risk of bias.

Svrha rada: Spoj abutmenta i implantata ključan je faktor za dugotrajan uspjeh protetskog rada nošenog implantatima i stabilnost okolnih tkiva. Neadekvatno prianjanje na spoju između abutmenta i implantata vodi do mehaničkih i bioloških komplikacija. Dvije vrste abutmenta su trenutno dostupne na tržištu: tvornički i individualni. Cilj ove pilot studije bio je indirektno istražiti brtvljenje na spoju implantata i abutmenta testirajući mikropropuštanje u statičkim uvjetima te potrebu za korištenjem materijala za brtvljenje. Materijali i metode: 80 dentalnih implantata i abutmenta korišteno je u ovoj studiji. Dvije skupine od 40 implantata formirane su ovisno o vrsti abutmenta (tvornički i individualni). Skupina A sastojala se od 20 GC Aadva Standard implantata (GCTech.Europe GmbH, Breckerfeld, Germany) i 20 Zimmer Tapered Screw - Vent implantata (Zimmer Biomet Dental, Palm Beach Gardens, Florida, USA) spojenih s originalnim tvorničkim abutmentima. Skupina B sastojala se od istog broja i vrste implantata, ali su bili povezani s individualnim abutmentima. U svakoj od skupina, formirane su po dvije podskupine od 10 implantata. GapSeal (Hager and Werken, Duisburg, Germany) korišten je u testnim podskupinama. Sklopovi implantat/abutment uronjeni su u suspenziju kontaminiranu sa Staphylococcus aureus i Candida albicans na 14 dana u aerobnim uvjetima. Rezultati: Ova studija pokazala je da nema statistički značajne razlike (p > 0.05) u mikropropuštanju između tvorničkih i individualnih abutmenta neovisno o korištenju materijala za brtvljenje. Zaključak: Način proizvodnje abutmenta nema značajan utjecaj na učinkovitost brtvljenja u pogledu propuštanja bakterija i gljivica u statičkim uvjetima.

Usprkos značajnoj uspješnosti, predvidljivosti i dugotrajnosti implanto-protetske terapije, biološke i tehničke komplikacije su klinička realnost. Prisutnost odgovarajuće širine pričvrsne sluznice oko dentalnih implantata osigurava stabilnost periimplantatnih mekih tkiva, smanjeno nakupljanje plaka, manji postotak recesija mekog tkiva i manje incidencije upalnih promjena periimplantatnih tkiva. Prisutnost minimalno 2 mm pričvrsne sluznice pokazalo se kao preventivni faktor nastanka periimplantatnih bolesti. Etiologija nastanka recesija sluznice oko implantata povezana je s različitim čimbenicima kao što su fenotip gingive (debeli ili tanki), nedovoljna širina pričvrsne sluznice, nepravilno postavljen implantat u vestibulo-oralnom smjeru, kut postave implantata te spoj implantata i protetskog nadomjestka. Kako bi se povećala širina pričvrsne sluznice, predložene su različite augmentacije mekih tkiva. Slobodni gingivni transplantat i vezivno tkivni transplantat predstavljaju terapijske postupke za povećanje širine pričvrsne sluznice oko implantata. Protetski vođena ugradnja implantata može unaprijediti estetiku i funkciju implanto- protetskog nadomjestka, optimalnu biomehaniku sustava kost-implantat-protetski nadomjestak, ali i primjerenu zonu pričvrsne sluznice. U ovom će se izlaganju prikazati pregled novije znanstvene literature i prikaz implanto-protetskih kliničkih slučajeva kod kojih je prisutna optimalna širina pričvrsne sluznice ( ≥ 2 mm) i kliničkih slučajeva bez dovoljne širine pričvrsne sluznice.

Uvod: Potpune proteze koriste se dugi niz godina i predstavljaju zlatni standard u liječenju potpune bezubosti. Nedavni napredak znanosti i tehnologije omogućio je korištenje digitalnih metoda pri izradi baze proteze, uključujući oblikovanje pomoću računala/ proizvodnju pomoću računala (CAD/CAM) i trodimenzionalno (3D) printanje. Ispitivanje žilavosti nastavak je istraživanja “Comparison of Mechanical Properties of 3D- Printed, CAD/CAM, and Conventional Denture Base Materials” (1) koje je odredilo vrijednosti savojne čvrstoće i tvrdoće. Materijali i metode: Ukupno 160 pravokutnih uzoraka dobiveno je od tri konvencionalna toplopolimerizirajuća akrilata, tri CAD/CAM, jednog 3D-printanog, i jednog poliamidnog materijala za izradu baze proteze. Za testiranje savojne čvrstoće korišten je test trotočkastog opterećenja, dok je za testiranje tvrdoće korištena Brinellova metoda. Žilavost je testirana na Charpyjevom batu. Podaci su analizirani deskriptivnom i analitičkom statistikom (α = 0.05). Rezultati: Vrijednosti savojne čvrstoće bile su u rasponu od 71.7 ± 7.4 MPa do 111.9 ± 4.3 MPa (1). Vrijednosti tvrdoće bile su u rasponu od 67.13 ± 10.64 MPa do 145.66 ± 2.22 MPa (1), dok su se vrijednosti žilavosti kretale od 8.01 ± 3.52 MPa do 44.68 ± 39.37 MPa. Tijekom testiranja savojne čvrstoće, uzorci IvoBase CAD i Vertex ThermoSens materijala nisu slomljeni. CAD/CAM materijal i poliamid imali su najveće vrijednosti savojne čvrstoće. 3D-printani materijal imao je najniže vrijednosti savojne čvrstoće. Dvije skupine CAD/CAM materijala imale su najveće vrijednosti tvrdoće. Poliamid i CAD/CAM materijali pokazali su najveće vrijednosti žilavosti. Zaključci: CAD/CAM materijali pokazuju bolja mehanička svojstva od toplopolimerizirajućih i 3D- printanih akrilata. Ipak, tip polimerizacije materijala nije garancija njegovih optimalnih mehaničkih svojstava.

The paper investigates the influence of the 3D printing process, specifically the orientation of the samples on the basic mechanical properties of PLA polymers. The test specimens were printed from MAKERBOT PLA polymers under the same parameters but in three different build orientations. Analysis of the macrostructure of the samples revealed the appearance of "elephant's foot" phenomenon due of the printing process. The tests included static tensile testing, three-point bending, impact toughness and hardness measurement. The obtained results showed significant deviations depending on the build orientation. The analysis of fracture surfaces demonstrated a large alotment of porosity in the structure, which was most likely one of the causes of such dispersion of the obtained results.

Selective laser melting (SLM) technique is used to produce Co-Cr dental prosthodontic appliances with generally insufficient relevant material properties information. Experimental work was conducted on specimens made from the commercial Co-Cr dental alloy powder for SLM production on machines from three different manufacturers. Recommended production parameters which fulfill the requirements for Co-Cr dental materials, according to EN ISO 22674, were used. Specimens were used for tensile, three-point bending, and toughness tests. Optical and SEM analyses of microstructure were performed on the same specimens. Although specimens were made according to EN ISO 22674, with the same process and under the recommended production parameters, significant differences in microstructures and mechanical properties were determined. The paper will consider the impact of three different types of SLM machines on the structure and mechanical properties of 3D printed Co-Cr dental alloy.

3D printed CoCr for metal-ceramic crowns and bridges have become a standard in prosthetic dentistry. Still, aesthetic and functional durability of metal-ceramic crowns and bridges with 3D printed metal-base in correlation to the production methods has not been extensively investigated, so it has been used without relevant data on material characteristics, nor evidence- based conclusions and clinical recommendations regarding the material. Production phases have significant influence on the final products’ characteristics. However, there is no standard for 3D printed metal production workflow, no input atomized powder control, and SLS machine settings are often left to the laboratory technician to master and optimize for their own benefit. This results in unstandardized final product with questionable mechanical characteristics and ceramic bonding strength. 3D printed CoCr metal- base for metal- ceramic crowns and bridges in form of test tubes and actual crowns and bridges will be analyzed for its precision, volume definition, build-up parameters, surface chemistry characteristics and mechanical characteristics.

Kobalt – krom legure koriste se za široku primjenu u dentalnoj medicini, od mobilnih djelomičnih proteza do fiksnih nosača sinterirane estetske keramike, radi svojih odličnih mehaničkih svojstava i otpornosti na koroziju. Uz klasične postupke proizvodnje i oblikovanja aditivni tehnološki postupak selektivnog laserskog taljenja – SLM posljednjih godina bilježi sve veću upotrebu u izradi CoCr dentalnih fiksno-protetskih konstrukcija. U ovom radu prikazani su najvažniji postupci aditivne proizvodnje te utjecaj parametara selektivnog laserskog taljenja na mikrostrukturu i mehanička svojstva CoCr legura u usporedbi sa lijevanim legurama za istu namjenu u dentalnoj medicini.

U suvremenoj stomatologiji je sve češća primjena 3D printera, pogotovo za izradu individualiziranih protetskih nadomjestaka. Osim polimera, sve je učestalije i printanje metalnih legura kao što su Co-Cr legure. To je relativno novo područje u stomatologiji i postoje razne nepoznanice vezane uz povezanost parametara printanja sa strukturom i svojstvima izrađenih dijelova. U istraživanju su provedena laboratorijska ispitivanja strukture i osnovnih mehaničkh svojstva 3D isprintane Co-Cr legure. Dobiveni rezultati su uspoređeni s vrijednostima za Co-Cr legure dobivene tradicionalnim postupcima lijevanja. Rezultati su pokazali značajnu razliku i u strukturi i u svojstvima analiziranih materijala.

Uvod: Svrha ovoga istraživanja bila je procijeniti ponovljivost položaja centrične relacije kod pacijenata s dislokacijom diska s redukcijom. Materijali i metode: U ispitnoj skupini bilo je 30 ispitanika s utvrđenom dislokacijom diska s redukcijom u desnom i lijevom zglobu ili u oba. Kontrolna skupina sastojala se od 12 sudionika bez znakova i simptoma temporomandibularnih poremećaja. Koristeći se metodom vođenja brade s prednjim deprogramatorom, učinjena su tri registrata centrične relacije za svakog ispitanika i to tijekom jednog posjeta. Elektroničkim ultrazvučnim mjernim uređajem snimljen je položaj lijevoga i desnoga kondila kod svakog dobivenog registrata centrične relacije. Podatci su analizirani računalom. Izmjerena je udaljenost kondila dobivena kod različitih registrata centrične relacije (anteroposteriorne, vertikalne, transverzalne i linearne vrijednosti) te su podatci statistički analizirani t i F testom. Rezultati: Nije utvrđena statistički značajna razlika između ispitne i kontrolne skupine. Kod dvije trećine ispitanika kondilni je položaj tijekom ponavljanja određivanja centrične relacije bio unutar promjera od 0,3 milimetra. Za više od 90 posto ispitanika to je područje bilo unutar 0,4 milimetra. Zaključak: Ne postoji razlika u ponovljivosti centrične relacije između pacijenata s dislokacijom diska s redukcijom i onih sa zdravim temporomandibularnim zglobom (p > 0,05). Kada se radi registrat centrične relacije na pacijentu s dislokacijom diska s redukcijom, prije toga nije potrebna terapija udlagom, dovoljne su standardne mjere opreza. Dobiveni rezultati moraju se interpretirati unutar ispitne skupine, bez povezivanja s drugim skupinama temporomandibularnih poremećaja., Objective: The aim of this study was to investigate reproducibility of the position of centric relation in patients with disc displacement with reduction. Materials and methods: The test group included 30 subjects, diagnosed with disc displacement with reduction in right, left or both joints. The control group included 12 individuals with no signs and symptoms of temporomandibular disorders. Using chin point guidance with a jig, centric relation record was made three times by every participant, in a single session. Left and right condylar position for each centric relation record was determined and recorded using the electronic ultrasonic measuring device. The data were transferred to the computer, processed and analyzed. Condylar distances between centric relation records were measured (anteroposterior, vertical, transversal and linear values), and the data were statistically analyzed using the t and the F tests. Results: No statically significant difference was found between the test and the control groups. Two thirds of study participants demonstrated condylar position of the repeated centric relation recording within the area of 0.3 mm in diameter. For more than 90% of participants that area was within 0.4 mm. Conclusions: There is no difference in reproducibility of the centric relation between patients with disc displacement with reduction and healthy temporomandibular joint individuals (p>0.05). When doing centric relation record on a patient with disc displacement with reduction there is no need for previous splint therapy and standard precautions are acceptable. The obtained results must be interpreted within the experimental group, and not projected on the other groups of temporomandibular disorders.

Svrha rada: Udlage su okluzijske ortopedske naprave koje se koriste kao terapijsko sredstvo u liječenju temporomandibularnih poremećaja. Najčešće se izrađuju iz polimetilmetakrilata (PMMA) koji predstavlja zlatni standard. Daljnjim razvojem tehnologije omogućena je i izrada udlaga putem CAD/CAM te aditivnim tehnologijama. Svrha ovog rada bila je istražiti mehanička svojstva različitih vrsta materijala za izradu nagriznih udlaga izrađenih različitim tehnologijama s naglaskom na digitalne tehnologije (CAD/CAM i 3D printanje) Materijali i metode: Istraživanje je obuhvatilo 7 različitih materijala za izradu nagriznih udlaga na kojima su testirana mehanička svojstva: 3 vrste hladnopolimerizirajućeg akrilata (Ortocryl, Resilit S, Probase Cold), 2 vrste akrilata za 3D printanje (VarseoWax Splint, Orthorigid) i dvije vrste CAD/CAM materijala (Ceramill Splintec, Copradur). Uzorci dimenzija 64x10x3, 3mm korišteni su pri ispitivanju savojne čvrstoće i tvrdoće dok su uzorci dimenzija 39x8x4mm korišteni pri ispitivanju žilavosti (10 uzoraka za svaku ispitnu skupinu, sveukupno 140 uzoraka). Ispitivanje savojne čvrstoće provedeno je „three-point bend“ testom, ispitivanje tvrdoće provedeno je Brinellovom metodom dok je žilavost ispitana na Charpy-evom batu. Rezultati: Statistička analiza potvrdila je da između dobivenih rezultata mjerenja postoje statistički značajne razlike. Hladnopolimerizirajući akrilati imaju najviše vrijednosti tvrdoće te najniže vrijednosti žilavosti. Copradur i Varseo su imali najniže vrijednosti tvrdoće i jedini se nisu slomili pri ispitivanju savojne čvrstoće. Copradur i Probase Cold su imali veće prosječne vrijednosti udarnog rada loma. Zaključak: Svi ispitani materijali su postigli zadovoljavajuće rezultate mehaničkih ispitivanja te se smatraju prikladnima za izradu okluzijskih udlaga. Utvrđene razlike sugeriraju moguće razlike u djelovanju nagriznih udlaga proizvedenih različitim materijalima.

Paper presents result of development of new metallic material for dental implant.

One of the main issues concerning dental, but also all other implants, arises from their Young’s modulus being considerably higher than that of bone. This can lead to stress shielding, bone resorption, and poor osseointegration of dental implants. Therefore, intensive activities are directed to lowering Ti implants Young’s modulus while preserving sufficient values of other mechanical properties. Most of them are oriented at β-type Ti alloys, but recently some other metal matrix composites appear as a possible solution. This presentation report on the development of the titanium-magnesium (Ti–Mg) bioactive metal- metal composite designed concretely for a fabrication of dental implants. The biomedical Ti-12vol. %Mg composite is manufactured using a cost effective approach, where a mixture of elemental Ti and Mg powders is extruded at low temperature to sound profiles. Microstructure of composite comprises filaments of biodegradable Mg component, which are arrayed along extrusion direction and are homogenously distributed within permanent, bioinert Ti matrix. Compared to Ti Grade 4, the reference material used for dental implants, the properties of as-extruded composite include significantly reduced Young’s elastic modulus (92.1 GPa) and low density (4.12 g/cm3), while the mechanical strength of Ti Grade 4 is maintained (at values required for dental implants). Dynamic testing of dental implants fabricated from as- extruded composite, realized to follow the ISO 14801 standard for endosseous dental implants, confirms fatigue performance of Ti-Mg implants equal to the one of the reference material. Exposure of as- extruded composite samples to Hank’s solution, realized to simulate behavior in human body over the time after implantation, yields gradual dilution of Mg from composites surface and volume. Corroded Mg leaves at prior Mg filament sites pores within Ti matrix, which remains intact. This provides further decrease of Young’s modulus and enhances macro and micro roughness at implants surface. As a result, newly developed Ti-Mg composite shows improved mechanical compatibility (i.e., reduction of stress-shielding) and better osseointegration potential.

Objectives: There are still controversies in the literature and various clinical recommendations regarding fixed partial dentures (FPDs) splinting natural teeth and implant abutments. This type of FPD has been reported prone to several types of complications. The authors decided to perform a retrospective study on a large sample and suggest recommendations based on those results. Subjects and methods: In 197 patients residual teeth served as abutments in 217 combined tooth (754) and implant (781) supported cement retained FPDs and were retrospectivelly evaluated after a period 12 to 72 months. Inclusion criteria were normal periodontal support and adequate oral hygiene. The FPDs were constructed in both jaws, and were devided into 3 topographic categories (lateral- linear bridge, arch-linear bridge, and full arch bridge) and relative to the type of distal abutment (tooth-ending and implant-ending). Complications were organized into technical and biological. Descriptive statistics, ANOVA (p

Aim: The aim of this study was to clarify the relationship between tooth loss, quality and types of prosthodontic appliances and their impact on chewing performance and food choice in elderly. Material and methods: In this study 110 geriatric care home residents from northern Croatia participated between the age of 64 and 98. Informed consent was taken for all the subjects and privacy and confidentiality of the information were maintained. Each examinee completed a questionnaire after which an oral examination was performed. Obtained data included dental and medical history, tooth loos, assessment of prosthodontic appliances by CDA Quality Index, Chewing Ability Index according to Yoshida et al., and oral hygiene assessment. Results: From total number of participants 78 % were female and 22 % male participants. Edentulous or subtotal edentulous with 25 or more extracted teeth were 54 % of the examinees. Some type of prosthodontic appliances had 84% of subjects , most commonly complete and /or partial dentures (68%). According to CDA Index of Quality , 46 % of all examined prosthodontic appliances were in need for replacement, among them 16 % for immediate replacement. Up to 10 years old were 63% of the appliances, and the oldest was 50 years old. Chewing ability assessed according to Yoshida et al. demonstrated that only 32 % of examinees were able to chew all types of food, but mostly slow, while 20 % of them were able to eat liquid food only. Conclusion:. Extensive tooth loss, inadequate quality status of prosthodontic appliances, or lack of them at all, influenced the chewing ability of the tested examinees.This is one of the reasons for inadequate nutritional status in elderly, which can affect maintenance of good health, physical power and activity. Population of the elderly is rapidly increasing and it is important to emphasize the importance of maintaining good oral health to achieve good quality of life.

Background: Magnesium enhances osteoinduction, osteoconduction and osseointegration of implanted material by interacting in important intra- and intercellular osteogenic processes in the alveolar bone during a new, perimplant bone formation. However, because of its poor corrosion resistance and high chemical reactivity, it can not be used as a pure magnesium. Powder metallurgy technique is one of possible production strategy how to incorporate magnesium in titanium matrix. In that way produced, innovative titanium- magnesium composite material can develop a biologically inspired titanium- based surface by releasing magnesium, increasing porosity and developing a favorable surface chemistry in order to improve the process of osseointegration. Aim: The aim of the present study is to quantify the amount of in vitro released magnesium from the surface of an innovative titanium- magnesium composite material and to determine physical properties and the chemistry of the surface after 42 days of immersion in simulated body fluid. Material and methods: Two groups of experimental innovative titanium-magnesium composite were produced by means of powder metallurgy technique: 1 mass% of magnesium in titanium matrix and 2 mass% of magnesium in titanium matrix. Specimens were prepared using standard metallographic methods, ground and polished. In vitro static immersion test was performed for 42 days using Hank’s balanced salt solution as a simulated body fluid at 37 ºC in thermostat. The test was carried out in triplicates. The blank test solutions were set and treated in identical manner. The mass concentration of released magnesium ions in the simulated body fluid was measured using inductively coupled plasma mass spectrometry and the amount of released magnesium per cm2 of tested surface was calculated from obtained data. The surface topography was observed by means of scanning electron microscopy using back- scattered electron and secondary electron detectors at the magnification of 50 and 200 times and the electron beam acceleration voltage of 20 kV. Energy dispersive spectroscopy was used in order to determine the chemical microanalysis of the surface. X-ray diffraction analysis was performed for identification of crystal phases formed on the surface after immersion time. Basic statistic method was used to find mean value and standard deviations of the amount of released magnesium. The difference between the tested groups was evaluated by means of Student-t statistical test. Results: Mean value for the amount of the released magnesium after 42 days of immersion in Hank’s balanced salt solution from the material with 1 mass% of magnesium was 448.66 ± 23.42 μg/cm2 and from the material with 2 mass% magnesium was 503.11 ± 18.92 μg/cm2. Student t statistical test showed that there wasn’t statistical significant difference (p

U radu je prikazan slučaj interdisciplinarne suradnje ortodonta i protetičara u oralnoj rehabilitaciji pacijenta s bruksizmom.

Svrha ovog istraživanja bila je procijeniti utjecaj umjetne okluzijske interference na položaj kondila. Materijali i postupci: U istraživanje je bilo uključeno deset ispitanika. Sva mjerenja položaja kondila obavljena su ultrazvučnim mjernim uređajem za snimanje kretnji donje čeljusti na temelju šest stupnjeva slobode. Paraokluzijska žlica bila je pričvršćena na donji zubni niz, a od kompozita napravljena je umjetna okluzijska interferenca na drugom donjem lijevom pretkutnjaku debljine 1 mm. Mjernim uređajem izmjerena su kondilarna odstupanja položaja okluzije s umjetnom okluzijskom interferencom. Kondilarni položaji utvrđeni su prema Kartezijevu koordinatnom sustavu. Sva odstupanja mjerena su prema referentnom položaju maksimalne interkuspidacije. Iz vrijednosti Kartezijeva koordinatnog sustava dobivene su vrijednosti linearnog odstupanja kondila između referentnog položaja i položaja okluzije s umjetnom okluzijskom interferencom. Rezultati: Prosječni superiorni pomak kondila iznosio je 0, 17 mm (SD 0, 39). Prosječno linearno odstupanje između položaja maksimalne interkuspidacije i položaja okluzije s umjetnom okluzijskom interferencom iznosilo je 0, 48 mm (SD 0, 29, min. 0, 17 mm, maks. 1, 19 mm). Zaključak: Okluzijske interference rezultiraju neposrednim promjenama u položaju kondila u temporomandibularnom zglobu. Utvrđeni prosječni superiorni položaj kondila govori u prilog stvaranju poluge unutar stomatognatog sustava. Rezultati se moraju interpretirati u sklopu ograničenja ove studije (neposredno mjerenje položaja kondila). Za spoznaje o progresiji položaja kondila pri okluzijskoj interferenci preporučuju se nove studije.

U radu su objašnjene indikacije i kontraindikacije za izradu nadogradnji, prikazani trenutno dostupni sustavi na tržištu i objašnjenje prednosti i nedostaci svakog sustava.

Commercially pure titanium (CP Ti) manufactured by cold isostatic and hot vacuum pressing (CIP/HVP) processes of powder metallurgy (PM) has not yet been used in dental prosthodontics. The aim of this study was to evaluate the effects of surface modifications of CP Ti substructures manufactured by powder metallurgy processes on bond strength with three veneering ceramics. 120 samples of CP Ti manufactured by PM shaped on WEDM were divided into 5 groups according to surface modifications: 1. untreated ; 2. sandblasted (Al2O3) ; 3. applied bonding agent ; 4. sandblasted (Al2O3) and applied bonding agent ; 5. etched with hydrochloric acid. All samples were veneered with low fusing dental ceramics. Each group was divided into 3 subgroups of 8 samples according to veneering ceramics. Bond strength evaluation was done according to ISO 9693. The surface of the samples was evaluated by SEM and EDS analysis before and after modifications, after applying veneering ceramics, and after debonding. Bond strength values were measured and results were compared to ISO 9693 requirements (>25 MPa). The results of bond strength testing showed the following values: Duceratin Kiss veneering ceramics values range from 25, 6 MPa to 41, 2 MPa ; Initial Ti from 12, 7 MPa to 38, 5 MPa ; Titankeramik from 17, 3 MPa to 38, 5 MPa. ANOVA showed statistically significant differences in bond strength values within a group of veneering ceramics relative to surface treatment for the Duceratin Kiss group 4, the Initial Ti group 2 and the Titankeramik group 2. No statistically significant differences in bond strength values were determined between the veneering ceramics. The SEM and EDS analyses showed predominantly adhesive fractures between veneering ceramics and metal samples. CP Ti manufactured by PM and veneered with low fusing ceramics meets requirements from ISO 9693 and could be used in prosthodontics as a metal base material in metal–ceramic systems.

U radu su prikazani osnovna metodologija i tehnike rada s CAD/CAM uređajima. Također, definirane su indikacije za korištenje tehnologije, te praktične napomene vezane uz principe preparacije zuba za protetske nadomjeske izrađene CAD/CAM tehnologijom, i tehnike i materijali za fiksaciju takvih nadomjestaka.

There have been studies that investigated mandibular movements during swallowing, but the results were inconsistent, and still the exact position of the condyles during swallowing is unknown. The purpose of this investigation was to determine the actual position of the mandible and the condyles during the process of swallowing.The results of the study suggest that retrusion during swallowing is not the rule, although on average there is a slight tendency of condylar movement toward posterior.

Purpose: The Bennett angle is an important parameter during prosthodontic rehabilitation. Existing data about impact of different occlusion types on the values of the Bennett angle are scarce. The purpose of this study was to investigate effect of different occlusion types on the Bennett angle values. Materials and Methods: Study included 98 participants (26.0 ± 5.2 years) divided into four study groups: Angle’s class I, Angle’s class II, subdivision 1, Angle’s class II, subdivision 2 and Angle’s class III. All recordings were obtained using ultrasound jaw tracking device with six degrees of freedom. After paraocclusal tray was fixed on the lower jaw, every subject had to make three protrusive, three left and right laterotrusive movements. From the laterotrusive movements, device’s software automatically calculated Bennett angle values for left and right joints, and data were statistically analyzed. Results: One-way ANOVA did not show differences between different Angle’s classes of occlusion for the Bennett angle values. Average Bennett angle value for all participants was 7.7°. Conclusions: Our results suggest that different Angle’s classes of occlusion do not have impact on the Bennett angle values. Average value of the Bennett angle is 8°, and should be used for average articulator settings.

Purpose Bonding of dental ceramics to commercially pure titanium (CP Ti) has always been a challenge. Thick oxide layer formation on the surface of titanium weakens the bond and leads to predominantly adhesive fractures between CP Ti and veneering ceramics. CP Ti manufactured by powder metallurgy (PM) processes has not yet been used in prosthodontics as a method for metal substructure manufacturing. The aim of this study is to evaluate the fracture mode between CP Ti manufactured by PM and veneering ceramics. Materials and Methods 120 samples of CP Ti manufactured by PM were divided into 5 groups according to surface modifications: 1.untreated ; 2.sandblasted (Al2O3) ; 3.applied bonding agent ; 4.sandblasted (Al2O3) and applied bonding agent ; 5.etched with hydrochloric acid. All samples were veneered with low fusing dental ceramics. Each group was divided into 3 subgroups of 8 samples according to veneering ceramics. Surface of the samples was evaluated for fracture mode by XRD analysis before veneering and after debonding. Results XRD analysis of samples analysed before veneering showed pure α-Ti. After debonding only two of the fifteen groups showed traces of ceramics on the surface (cohesive fracture) and the rest showed only presence of α-Ti, β-Ti and different types of titanium oxides (adhesive fracture). Conclusions Fracture mode analysis of veneered CP Ti manufactured by PM shows similar results as conventionally manufactured CP Ti, suggesting the PM Ti material can potentially be used in crown manufacturing. However, further studies involving other methods of fracture mode analysis are necessary to draw definite conclusions.

Objectives: Aim is to investigate properties of polylactic acid material as a potential resorptive membrane material in GBR techniques. Methods: Purasorb PDLG 5010 (50/50 DL-lactide/glycolide copolymer ; Purac Biomaterials, The Netherlands) was used. Granules of PLDG 5010 were heated (210°C) in aluminum mold to simulate 3D printing conditions and than gradually cooled during 30 minutes. The plate was cut into 2x5x20mm samples and inserted in three different solutions (saline, Ringer's solution and artificial saliva). The solutions were changed every seven days and samples masses measured. The samples were kept at constant temperature of 37°C. Results: After seven days, on first measurement, slight mass increase was noticed (average 0, 002g). After fourteen days there also came to mass increase (average 0, 003g). After 21 days samples lost their shape (they took the shape of test tube) and mechanical properties so further measurements were no longer possible. Conclusions: PDLG 5010 looses its shape and mechanical properties (strength) after 21 days. Therefore it is not adequate for time needed for bone augmentation. Further investigations with different sizes and shapes are necessary.

Most of the literature states that slide from centric relation occlusion (OCR) to intercuspal position (ICP) occur at approximately 90% of people, and on average is 1 mm long. The purpose of this study was to test the possible differences in OCR-ICP slide between different Angle classes of occlusion. Study included 98 participants (58 class I, 10 class II/1, 14 class II/2, 16 class III). Each participant gave written informed consent, which was approved by the Ethical Committee of the School of Dentistry, University of Zagreb. Recordings were obtained by the electronic ultrasound measuring device (Arcus Digma II, Kavo, Germany), using module “EPA- Electronic Position Analysis”. Reference position was ICP, while OCR was achieved with training participants to move mandible posteriorly (no guidance). Data were transferred to the computer, and processed and analyzed with device's software. For every participant, distance between ICP and OCR was measured (x-anteroposterior, y-vertical, z-transversal values). Analysis of variance, followed by Newman-Keuls test was applied. Analysis of variance showed significant differences in vertical values of OCR-ICP slide (p=0.045). Newman-Keuls test for vertical distances between tested groups showed significant difference between II/2 and II/1 (p=0.049), and between II/2 and I (p=0.043). Out of 98 participants, none showed coincidence of OCR and ICP position. Unlike other studies, Angle class II/2 showed smaller movements in vertical direction, in comparison with Angle class I and II/1. Since function and morphology of the TMJ are closely related, it is possible that smaller OCR- ICP slide in vertical direction, as expression of anatomy/function, happens at Angle class II/2. This could be explained by „locked occlusion“, and posterior condylar position in Angle class II/2 advocated by some authors. In concordance with novel studies, coincidence of OCR and ICP position is less than 10 %.

Objective: Conventional manufacturing processes of commercially pure titanium (CP Ti) for metal- ceramic systems involve complicated and costly casting methods. Powder metallurgy (P/M) is a series of novel, simple and efficient manufacturing processes used in metal production. The objective of this study is to evaluate the mechanical and structural properties of hot vacuum pressed (HVP)/hot extruded (HE) CP Ti and compare them to conventional manufacturing processes for metal-ceramic systems. Method: Six HVP/HE CP Ti 99.4%, grain size

Komercijalno čisti titan (CP Ti) prepoznat je u dentalnoj medicini zbog svoje biokompatibilnosti, dobrih mehaničkih svojstava i otpornosti na koroziju. Konvencionalni proizvodni procesi CP Ti mogu utjecati na kvalitetu površine uzoraka i rezultirati slabom vezom s dentalnom keramikom. Stoga se uvode nove proizvodne tehnologije ; metalurgija praha i WEDM. Cilj ovog istraživanja odrediti utjecaj WEDM na površinu P/M CP Ti uzoraka proizvedenih za ispitivanje vezne čvrstoće prema ISO 9693. Materijali i metode Osam uzoraka P/M CP Ti dimenzija prema ISO 9693 proizvedeni su korištenjem WEDM i podijeljeni u dvije grupe (neobrađeni i brušeni). Analiza površine obje grupe uzoraka učinjena je korištenjem SEM, EDS i XDR metode. Rezultati SEM i EDS analiza neobrađenih uzoraka pokazuje takni sloj različitog sastava uz prisutnost fraktura. Brušeni uzorci pokazuju homogenu strukturu bez fraktura. XDR analiza pokazuje visoku koncentraciju titanovih oksida na površini neobrađenih uzoraka, dok je nakon brušenja prisutna samo čista α-faza. Zaključak WEDM je prikladna metoda proizvodnje uzoraka za ISO 9693 ukoliko se uzorci naknadno bruse.

Objective: The purpose of this study was to determine the effect of occlusal splint on mandibular range of movements in individuals with bruxism. Method: Nine individuals with diagnosed bruxism and no signs and symptoms of TMD were included in this pilot study. An occlusal relaxation splint was made by a standardized procedure in a fully adjustable articulator (Protar Evo 7, Kavo, Germany) for each subject. Recordings for fabrication of splints and for mandibular range of movements were obtained by an electronic ultrasound measuring device (Arcus Digma II, Kavo, Germany), by using the kinematic axis as the posterior reference point. Measurements were made initially and after 2, 4, 8 and 12 weeks of wearing the splint. Each subject performed opening and closing, laterotrusion to the left and right and Posselt`s movement in the sagittal and horizontal axis, based on which opening incisal, opening left condyle, opening right condyle, laterotrusion left and laterotrusion right were calculated as parameters for mandibular range of movements. Result: The mean values of all tested variables increased slightly with increasing of the follow-up time. Laterotrusion left had the highest and opening right condyle the lowest increase. The results of variance analysis showed no statistically significant difference among the groups of the tested parameters at the significance level of p

Background: Although implants are widely used in everyday practice there are insufficient data on the type of suprastructure fixation (screw versus cement) of the prosthetic appliance and presence of microbial species. Aim: The aim of the study was to analyse the relationship between the type of prosthetic suprastructure fixation (screwed or cemented) and the presence of A. actinomycetemcommitans, P. gingivalis, T. forsythia, P. intermedia, T. denticola and F. nucleatum. Furthermore, the aim of this study was to evaluate possible correlation between the presence of systemic diseases and the type of the investigated bacteria. Materials and Methods: In fifty one dentate patient, 136 implants were inserted either in the upper or lower jaw in the place where molars were missing. Cemented suprastructure was put in 32 patients and screw retained suprastructure in 19 patients. Samples were taken with sterile paper points before abutment fixation and six months later (three times during ten seconds from the gingival sulcus) and analyzed with real-time polymerase chain reaction. Plaque index, Papillla bleeding index and Community Periodontal Treatment Need Index as well as the presence of systemic diseases was recorded. Shapiro – Wilks test was used when samples were smaller than 30 and Kolmogorov – Smirnov test when they were more than 30. P value under 0.05 was significant. No differences in the presence of A. actinomycetemcommitans, P. gingivalis, T. forsythia, P. intermedia, T. denticola and F. nucleatum with regard to the type of fixation (screwed versus cemented) were seen. There was a significant increase in bacterial count in persons with cardiovascular, rheumatic diseases and in those who took medications and were older. Preoperatively, there was no correlation between periodontal pocket depth with the number of the bacteria. Postoperatively, patients with more periodontal pockets of ≥4 mm harvested higher number of investigated bacteria.

Objective: The purpose of this study was to investigate reproducibility of the centric relation position (CR) in patients with disc displacement with reduction, in comparison to control group. Method: Test group included 30 participants, who had disc displacement with reduction (according to RDC-TMD) in right, left or both joints. Control group included 12 individuals with no signs and symptoms of the TMD. Each participant gave written informed consent, which was approved by Ethical Committee of the School of Dentistry, University of Zagreb. CR record (chin point guidance, front jig) was made three times by every participant, in one session, and condylar position for each CR record was determined and recorded using the electronic ultrasound measuring device (Arcus Digma II, Kavo, Biberach, Germany. Data were transferred to the computer, processed and analyzed. Distances between CR records were measured (X- anteroposterior, Y-vertical, Z- transversal values). For every participant, mean value of distances between CR records was calculated, and used for statistical evaluation. Data were analyzed statistically using the T test. Result: Mean values of the obtained distances and T test are summarized in the Table (X- anteroposterior ; Y-vertical ; Z-transversal ; L- left ; R-right ; E-experimental group ; C- control group). Conclusion: There is no difference in reproducibility of the CR record between patients with disc displacement with reduction and TMJ healthy individuals (p>0.05). When doing CR record on a patient with disc displacement with reduction, standard precautions are acceptable. Obtained results must be interpreted within the experimental group, and not projected on the other TMD groups.