Subjective assessment of mastication as parameter for successful prosthetic therapy

Introduction. Success in functional rehabilitation of the craniomandibular system in patients without teeth, which have total prosthesis, can be assessed using different clinical and functional methods. Subjective assessment, motivation, comfort level and functional efficacy are important elements for adaptation to dental prosthesis as well as base for success in prosthetic therapy. The aim of this study was to evaluate the importance of subjective assessment of the mastication in people with new dental prosthesis as well as to assess the value of that parameter in determining the successful prosthetic therapy. Material and Methods. Study was conducted at the Dental Clinic in Novi Sad. Thirty patients (16 males and 14 females) with average age of 62.5 years who received total prosthesis were included. Analysis was done according to the data from the medical records and conducted survey in the form of questionnaire which was adjusted to our clinical examinations. Results. Results showed that 96.6% of the patients were satisfied with new prosthesis. Subjective assessment of the quality of their mastication before therapy showed that 63.4% consider their mastication as unsatisfied, 26.6% satisfied while 10% of toothless patients thought their mastication was good. Statistic analysis showed there was significant difference in subjective assessment before and after the therapy (p<0.01). In fact, there was significant connection between subjective assessment of the mastication and satisfaction with new prosthesis and therapy at all (p<0.01). Conclusion. Patients satisfaction with total prosthesis and subjective assessment of mastication are in direct correlation with successful prosthetic treatment. Results of subjective assessment of the mastication are important and can be used as a parameter for success along with precise survey

Influence of different types of partial dentures on dental plaque accumulation

The aim of the paper was to assess influence of different types of partial dentures on dental plaque accumulation. The study was conducted in three experimental and one control group with 30 examinees each. In the first experimental group were patients with partial acrylic dentures, in the second were patients with overdentures and in the third group were the patients with metal skeletal dentures. Dental plaque on the remaining teeth was measured by Silness-Loe modified method. Dental plaque scores were obtained at a time when dentures were given to patients and after 6 and 12 months of wearing, respectively. The plaque index of all teeth after 12 months of wearing dentures was relatively low in all three examined groups which resulted from previous education and motivation of examinees for oral hygiene maintenance. However, the highest risk of oral diseases caused by dental plaque is in patients with partial acrylic dentures, then in patients with overdentures, and best preventive effect was achieved in patients with metal skeletal dentures

Prevalence and risk factors for musculoskeletal disorders in dentists

Introduction. Working in dental practice requires clear working field and easy access to all parts of oral cavity. For this reason, dentists often take non-physiological positions during treatment increasing the risk for musculoskeletal disorders. The aim of this study was to determine the prevalence of musculoskeletal disorders in dentists with different work experience in Novi Sad. Material and Methods. The study included 89 dentists. Data related to musculoskeletal disorders was collected using a questionnaire. Potential risk factors for musculoskeletal disorders were detected and analyzed. Results. Out of 89 dentists, 32 (36%) were male and 57 (64%) were female. Musculoskeletal disorders were detected in 62 dentists (69.7%). 50% of dentists reported pain during first three years of work in the office, while others noted these problems later. 49 dentists (77.8%) reported increasing pain during the day. Of the total respondents, 76.2% had pain in neck, 71.4% reported discomfort in the upper part of their back, 68.3% in the region of shoulder, and 65.1% complained for pain in lower back. Lower prevalence of pain was found in the region of wrists and hands, hips, knees, ankles and elbows. Statistical analysis did not show significant difference between observed risk factors. Conclusion. The prevalence of musculoskeletal disorders in examined dentists in Novi Sad was 69.7%. It was higher in male compared to female respondents. Most dentists had musculoskeletal disturbances in the region of neck, shoulders and upper back

Ispitivanje preciznosti radnih modela pomoću koordinatne merne mašine u stomatologiji

Background/Aim. Dental impressions present a negative imprint of intraoral tissues of a patient which is, by pouring in gypsum, transferred extraorally on the working cast. Casting an accurate and precise working cast presents the first and very important step, since each of the following stages contributes to the overall error of the production process, which can lead to inadequately fitting dental restorations. The aim of this study was to promote and test a new model and technique for in vitro evaluation of the dental impression accuracy, as well as to asses the dimensional stability of impression material depending on the material bulk, and its effect on the accuracy of working casts. Methods. Impressions were made by the monophasic technique using the experimental master model. Custom trays with spacing of 1, 2 and 3 mm were constructed by rapid prototyping. The overall of 10 impressions were made with each custom tray. Working casts were made with gypsum type IV. Measurement of working casts was done 24 h later using a coordinate measuring machine. Results. The obtained results show that the working casts of all the three custom trays were in most cases significantly different in the transversal and sagittal planes in relation to the master model. The height of abutments was mainly unaffected. The degree of convergence showed certain significance in all the three custom trays, most pronounced in the tray with 3 mm spacing. Conclusion. The impression material bulk of 1-3 mm could provide accurate working casts when using the monophasic impression technique. The increase of the distance between abutment teeth influences the accuracy of working casts depending on the material bulk.Uvod/Cilj. Otisak predstavlja negativ intraoralnih tkiva, čijim se izlivanjem u gipsu njihova morfologija prenosi ekstraoralno na budući radni model. Sa laboratorijskog aspekta izrade zubnih nadoknada, izlivanje tačnog i preciznog radnog modela predstavlja prvi i veoma bitan korak, pošto svaka sledeća faza doprinosi daljem povećanju greške tokom izrade, što za krajnji ishod može imati neodgovarajuću zubnu nadoknadu. Cilj istraživanja bio je da se ispitaju novi model i tehnika za in vitro procenu preciznosti zubnih otisaka, kao i da se odredi uticaj količine otisnog materijala na dimenzionu stabilnost otisaka i preciznost izrade radnih modela. Metode. Za uzimanje otisaka korišćena je monofazna tehnika otiskivanja. Individualne kašike sa međuprostorom od 1, 2 i 3 mm napravljene su aditivnom tehnologijom za brzu izradu prototipova. Sa svakom kašikom napravljeno je po 10 otisaka. Radni modeli izlivani su u gipsu tipa IV. Merenje radnih modela vršeno je nakon 24 sata na koordinatnoj mernoj mašini. Rezultati. Rezultati pokazuju da radni modeli napravljeni pomoću sve tri individulane kašike u transverzalnoj i sagitalnoj ravni značajno odstupaju od glavnog dela modela. Visina patrljaka je u većini slučajeva bila kao na glavnom modelu. Stepen konvergencije pokazao je određena odstupanja samo kod kašike sa međuprostorom od 3 mm. Zaključak. Monofazna tehnika otiskivanja i otisni materijal debljine od 1 do 3 mm obezbeđuju izradu preciznih radnih modela. Rastojanje između zubnih patrljaka utiče na preciznost izrade radnih modela u zavisnosti od količine otisnog materijala

Utvrđivanje korozionih karakteristika stomatološke legure sa induktivno spregnutim plazma masenim spektrometrom

Corrosion resistance is one of the characteristics that dental alloy should possess as it should be placed in the oral cavity. Adverse tissue reactions of the gingiva and the periodontium close to dental cast alloys may be caused by the effects of released metal elements. Corrosion effect of dental Co-Cr-Mo alloy was investigated by ICP MS according to the EN ISO 10271 and EN ISO 22674. Co- Cr dental alloy Remanium GM 800+ (Dentaurum Ispringen, Germany was tested in artificial saliva for 7 days at 37ºC. The released metals were detected by Nexion 300X ICP MS (Perkin Elmer, USA). The results showed that the metal release was very low for Co, Cr and Mo, far below the permitted levels. ICP-MS can be considered as very reliable method for such a research.Otpornost na koroziju je jedna od karakteristika koju poseduju stomatološke legure koje trebaju biti postavljene u usnoj duplji. Neželjene reakcije tkiva gingive i parodoncijuma sa stomatološkim legurama može biti uzrokovano efektima oslobođenih metalnih elemenata. Efekat korozije stomatološke Co- Cr -Mo legure ispitana je ICP MS prema EN ISO 10271 i EN ISO 22674 . Co- Cr stomatološke legure Remanium GM 800 + ( Dentaurum Ispringen , testirano u Nemačkoj u veštačkoj pljuvački tokom 7 dana na 37º C. Otkriveni su oslobođeni metali Nekion 300Ks ICP MS ( Perkin Elmer , SAD ). Rezultati su pokazali veoma slabo oslobađanje metala, Cr i Mo , daleko ispod dozvoljenih nivoa. ICP -MS može smatrati veoma pouzdan metod za ovakvo istraživanje

Application of Replica Technique and SEM in Accuracy Measurement of Ceramic Crowns

The paper presents a comparative study of the measuring values of the marginal gap related to the ceramic crowns made by dental CAD/CAM system using the replica technique and SEM. The study was conducted using three experimental groups, which consisted of ceramic crowns manufactured by the Cerec CAD/CAM system. The scanning procedure was carried out using three specialized dental 3D digitization systems from the Cerec family - two types of extraoral optical scanning systems and an intraoral optical scanner. Measurements of the marginal gap were carried out using the replica technique and SEM. The comparison of aggregate values of the marginal gap using the replica technique showed a statistically significant difference between the systems. The measured values of marginal gaps of ceramic crowns using the replica technique were significantly lower compared to those measured by SEM. The results indicate that the choice of technique for measuring the accuracy of ceramic crowns influences the final results of investigation

Comparative analysis of 3d digitization systems in the field of dental prosthetics

Amongst the modern engineering technologies which have found broad application in the field of dentistry, one of the most widely used is the 3D digitization. This paper deals with the application of 3D digitization systems in the field of dental prosthetics, and attempt to contribute in this field through comparative analysis of this kind of systems. Special attention is focused on extra oral 3D digitization systems and among them on non specialized dental 3D digitization systems. Beside the general overview and analysis of nine different systems, this paper presents experimental results of comparative accuracy analysis of two high-end 3D digitization systems - Atos II Triple Scan and Zeiss Metrotom 1500. Investigation was based on CAD inspection technique and included 3D and 2D cross sectional analysis. Results related to 3D analysis show that the majority of deviations are in positive direction, concentrated around 0,025 mm. Results of 2D analysis implicate the conclusion that the accuracy of the analysed systems is dependent on surface shape as well as on the model position during the process of 3D digitization

Re-CAD/CAM pristup projektovanju i izradi zubnih keramičkih navlaka u kombinaciji sa ručnim individualnim prilagođavanjem

CAD/CAM technology in dentistry offers high-end ceramic restorations, known for its quality, preciseness, swiftness and repeatability. However, some features are still human-dependent. A young female patient required smile enhancement, since suffering from colour change on three devitalized frontal teeth. After fiber post placement, teeth were prepared for metal-free restoration. Consequently, abutments were scanned using extraoral scanner (Sirona, InEos Blue; Beinsheim, Germany). CAD software (version 3.8) has been used to create three crown copings, with cut-back in the incisal region. After finalization of the virtual modeling, data file has been transferred to a milling unit (Sirona, MCXL, Beinsheim, Germany) that produced crown copings out of a ceramic block (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtestein). Crowns were tried for the fit and occlusion in the so-called blue stage, after which final strength and shape has been achieved by thermal treatment in the ceramic furnace. Individualization has been done manually, creating special effect in the cut-back region. Crowns were cemented adhesively. CAD/CAM offers modern and relevant way of producing ceramic restorations, however, special effects still require manual adjustments.CAD/CAM tehnologije u stomatologiji nude visoko kvalitetne keramičke zamene, poznate po kvalitetu, preciznosti, brzini izrade i ponovljivosti. Međutim neke opcije još uvek zavise od ljudske intervencije. Mlada pacijentkinja je imala zahtev za poboljšanjem osmeha, pošto je patila od promene boje na tri prednja nezdrava zuba. Posle instalacije vlaknene podloge, zubi su bili spremni za bez-metalnu reparaciju. Otisci su bili skenirani ekstraoralnim skenerom (Sirona, InEos Blue, Beinsheim, Nemačka). CAD softver (verzija 3.8) je korišćen za generisanje tri navlake. Po završetku virtuelnog modeliranja podaci su prebačeni na glodalicu (Sirona, MCXL, Beinsheim, Nemačka) koja je izradila navlake od keramičkih blokova (IPS-a, max CAD, Ivoclar Vivadent, Schaan, Lihtenštajn). Navlake su posle isprobane zbog procene naleganja i začepljenja u tzv. plavoj etapi, posle čega je konačno očvršćavanje i oblikovanje postignuto termičkom obradom u peći za keramiku. Individualno prilagođavanje je izvršeno ručno, sa izradom posebnog efekta u zadnjem delu. Navlake su cementirane adhezijom. CAD/CAM nudi moderan i važan način u izradi keramičkih implanta ali posebni efekti još uvek zahtevaju intervenciju čoveka

In vitro procena citotoksičnosti 3D štampanog polimera na bazi epoksi smole namenjenog za upotrebu u stomatologiji

Background/Aim. There is limited published evidence on the cytotoxicity of 3D printed polymer materials for dentistry applications, despite that they are now widely used in medicine. Stereolithography (SLA) is one of the foremost 3D processes used in 3D printing, yet there are only a small number of resin materials reported to be suitable for medical applications. The aim of this study was to investigate, in vitro, the cytotoxic effect of the 3D printed resin in order to establish the suitability for its usage in dentistry and related medical applications such as surgical dental guides, occlusal splits and orthodontic devices. Methods. To examine the cytotoxicity of the 3D printed polymer-based epoxy resin, Accura® ClearVue™ (3D-Systems, USA), two cell cultures were used: mouse fibroblasts L929, and human lung fibroblasts MRC-5. The cell viability was determined by the Mosmann's colorimetric (MTT) test and the agar diffusion test (ADT). Results. Direct contact of the tested material with the ADT test showed nontoxic effects of tested material in any cell culture. The tested material showed no cytotoxic effect after 3 days of extraction of the eluate by the MTT, but mild cytotoxic effect after 5, 7 and 21 days on both cell lines. The cytotoxicity increased with increasing the time of the eluate extraction. Conclusion. The 3D printed polymer-based epoxy resin, Accura® ClearVue™ (3D-Systems, USA) is considered appropriate for making surgical dental implant guides according to the cytotoxic behavior. According to the mild level of cytotoxicity after the longer extraction periods, there is a need for further evaluation of biocompatibility for its application for the occlusal splints and orthodontic devices.Uvod/Cilj. Malo je objavljenih dokaza o citotoksičnosti 3D štampanih polimernih materijala za upotrebu u stomatologiji, bez obzira na njihovu sve širu primenu u medicini. Stereolitografija (SLA) jedan je od najvažnijih 3D procesa koji se primenjuje za 3D štampu, ali postoji samo Mali broj materijala na bazi smola za koje je dokazano da su pogodni za medicinsku primenu. Cilj ove studije je bio da se ispita, in vitro, citotoksični efekat 3D štampanog polimera kako bi se utvrdila mogućnost za njegovu upotrebu u stomatologiji i srodnim medicinskim oblastima, kao što su hirurške dentalne vođice, okluzalni splintovi i ortodontski aparati. Metode. Da bi se ispitala citotoksičnost 3D štampanog polimera na bazi epoksi smole, Accura® ClearVue ™ (3D-Sistems, USA), korišc'ene su dve c'elijske kulture: fibroblasti miša L929 i humani fibroplasti pluc'a MRC-5. Vijabilnost c'elija utvrđena je Mosmannovim kolorimetrijskim testom (MTT) i testom difuzije agara (ADT). Rezultati. Direktan kontakt testiranog materijala ispitan pomoću ADT pokazao je da materijal nije imao citotoksičan efekat ni na jednu ćelijsku kulturu. Testitrani materijal je imao blag citotoksični efekat posle 5, 7 i 21 dana ekstrakcije eluata primenom MTT na obe ćelijske linije. Citotoksičnost je rasla sa produženjem vremena ekstrakcije eluata. Zaključak. 3D štampani polimer na bazi epoksi smole, Accura® ClearVue ™ (3D-Sistems, USA) se može smatrati pogodnim za izradu hirurških dentalnih implantnih vođica sa tačke gledišta njegovog citotoksičnog uticaja. Zbog pokazanih blagih citotoksičnih efekata nakon dužih ekstrakcionih perioda eluata potrebna su dalja istraživanja u oblasti biokompatibilnosti materijala da bi se taj polimer mogao koristiti za izradu okluzalnih splintova i ortodontskih aparata

Klinička evaluacija inlej-retiniranih adhezivnih mostova tokom dvogodišnjeg opservacionog perioda

Introduction. Inlay retained adhesive restorations present a conservative approach when a single tooth is missing in the posterior region. Material and methods. Twenty five restorations were included in the clinical study. Patient selection, preparation technique as well as denture fabrication followed current principles in this area. Patients were examined every 6 months over a 2 year examination period. Results were statistically analyzed. Results. The success rate for the first year comes to 91.1%, while cumulative success probability during the second year (24 months) was 86.6%. Furthermore, colour, texture and marginal staining were satisfactory during the observation period. Conclusion. Fibre-reinforced composite adhesive dentures are a tooth preserving, minimally invasive, aesthetic and reliable treatment option for single tooth replacement in the posterior area.Uvod. Inlej retinirani adhezivni mostovi predstavljaju konzervativni modalitet tretmana nedostatka pojedinačnog zuba u bočnoj regiji. Materijal i metod. U kliničku studiju, uključeno je 25 adhezivnih nadoknada. Odabir pacijenata, principi preparacije, kao i tehnika izrade mostova urađeni su prema važećim standardima u ovoj oblasti. Pacijenti su praćeni na svakih 6 meseci tokom dvogodišnjeg perioda. Rezultati su statistički obrađeni. Rezultati. Uspešnost nadoknada u prvoj godini iznosi 91.1%, dok kumulativna uspešnost tokom druge godine (24 meseca) iznosi 86.6%. Takođe, ocena boje, teksture i marginalnog prebojavanja daje zadovoljavajuće rezulate tokom perioda praćenja. Zaključak. Kompozitne nadoknade ojačane vlaknima su minimalno invazivni, estetski i pouzdan način tretmana minimalne krezubosti bočnog segmenta denticije