Accuracy of Two Condensation-Type Light Body Silicones after Setting

Svrha rada bila je ustanoviti ima li dimenzijskih promjena kod dvajurazličitih kondenzacijskih silikonskih materijala za otiske male viskoznosti (Xantopren - Bayer, Njemačka i RTV - Bosnalijek, Sarajevo, BiH) s obzirom na različite načine pripreme (pasta i katalizator miješani ručno ili aparatom, s dodatkom triju kapljica vode ili bez njih), a u odnosu prema različitom vremenu odlaganja. Ukupno je napravljeno 56 uzoraka po 7 uzoraka svakoga silikona (Xantopren, RTV) u različitim uvjetima (miješani rukom ili mehanički, s dodatkom triju kapljica vode ili bez njih). Zamiješani materijal izliven je u kalup i u njem se stvrdnuo. Tada su uzorci pažljivo izvađeni iz kalupa i pohranjeni na sobnoj temperaturi. Za mjerenje je poslužio optički instrument SIP-414 s digitalnim mikroskopom. Mjerenja dimenzijskih promjena učinjena su u različitim vremenskim razmacima nakon stvrdnjavanja (2, 4, 8 24 i 48 sati). Kao referentna vrijednost poslužila je dimenzija mjerne pločice kalupa, a iznosila je 24,7 mm. Oba ispitana silikonska kondenzacijska materijala niske viskoznosti, bez obzira na način pripreme (miješane ručno ili strojno, s dodatkom triju kapljica vode ili bez njih) pokazali su kontinuiranu kontrakciju. Referentna vrijednost (dimenzija kalupa) bila je znatno veća od svih mjerenih vrijednosti nakon što se materijal stvrdnuo i bio izvađen iz kalupa (2, 4, 8, 24 i 48 sati). Što je razdoblje odlaganja materijala bilo duže, kontrakcija je bila veća. χ2 test pokazao je da su srednje vrijednosti izmjerenih uzoraka znatno manje od referentne vrijednosti, a u ovisnosti o vremenu odlaganja uzoraka. Kontrakcija je bila veća što su materijali duže bili odloženi. Već nakon 2 sata kontrakcija je kod svih uzoraka bila veća od 0,5 %. Rezultati pokazuju da otisci silikonskim materijalima kondenzacijskoga tipa nemaju dovojnu dimenzionalnu stabilnost te ih treba izliti u tvrdome gipsu što je prije moguće kako bi se zadržala željena preciznost.The aim of the study was to determine which dimensional changes occur in two types of low viscosity condensation-type silicone materials (Xantopren - Bayer, Germany and RTV - Bosnalijek, Sarajevo, BiH), when prepared in different conditions (mixed by hand or mechanically, with and without the addition of 3 drops of water) a different time period after setting. A total of 56 samples were prepared, 7 samples of each silicone (Xsantopren, RTV) in each examined condition (mixed by hand or mechanically, with or without the addition of 3 drops of water). Specimens were poured into a mould until set. The samples were then removed from the mould and stored at room temperature. Using an optical instrument SIP-414 with a digital microscope, dimensional measurements at different time intervals after setting (2, 4, 8 24 and 48 hours) were made. The referent value was the measure of the mould, which was 24.7 mm. The examined silicone condensation-type impression materials, mixed by hand or mechanically with or without addition of 3 drops of water, showed continuous contraction. The referent value (mould dimension) was greater than all other values measured 2, 4, 8, 24 and 48 hours after setting. The longer the period of sample storage, the greater the silicone contraction. χ2 test revealed that mean values measured in this study are significantly smaller than the referent value, depending on the period of the material storage. Contraction was greater than 0.5% after 2 hours of storage, regardless of mixing condition. The examined silicone condensation-type impression materials showed significant contraction, which increased during the period of storage, no matter how the material was prepared (mechanically mixed, or by hand; with or without addition of water). The results indicate that silicone condensation-type impressions should be poured into hard stone as soon as possible, to preserve the desired accuracy

Aesthetic rehabilitation of the upper frontal teeth with lithium disilicate glass ceramics – Case report

Cilj: Nezadovoljstvo izgledom prednjih zuba jedan je od čestih razloga posjeta pacijenata ordinaciji dentalne medicine. Izradom ljuski od litijeve disilikatne staklokeramike omogućava se zbrinjavanje prednjeg segmenta koje uz maksimalno očuvanje zubnog tkiva osigurava visokoestetske zahtjeve. Prikaz slučaja: 28-godišnji pacijent došao je u specijalističku ordinaciju stomatološke protetike nezadovoljan izgledom gornjih prednjih zuba. Pacijentu su planirane i izrađene ljuske iz litijeve disilikatne IPS e.max press staklokeramike metodom tlačenja. Zaključak: Odabirom litijeve disilikatne IPS e.max press keramike omogućena je izrada izuzetno otpornih protetskih nadomjestaka minimalnih debljina te visoke estetike uz maksimalno očuvanje zubnog tkiva.Aim: In many cases, patients visit dental offices unsatisfied with the aesthetic appearance of the upper anterior teeth. Lithium disilicate glass ceramic veneers used in the anterior region provide high aesthetics with maximum conservation of the tooth structure. Case report: A 28 years old patient was unhappy with his upper frontal teeth. The lithium disilicate IPS e.max Press ceramic veneers using a hot pressing technique was planned and fabricated for the patient. Conclusion: Lithium disilicate IPS e.max Press ceramics provide the production of extremely resistant and highly aesthetic prosthetic appliances allowing minimal thickness of the bonded porcelain restorations in the anterior dentition and maximum conservation of the tooth structure

Implant Prosthetic Rehabilitation of the Patients with Mandibular Resection Following Oral Malignoma Surgery

Patient underwent mandibular resection due to surgical therapy of oropharingeal malignoma. Facial asymmetry and cosmetic distortion are frequent consequences of such interventions, which may also include deviation and intrusion of the mandible, motor and sensory disorders, abnormal intermaxillary relations and malocclusion. Implant-supported prosthesis could be an optimal solution to prosthodontic treatment of such patients. However, there is a problem in determination of stable (interocclusal) intermaxillary relations. This article describes the choice of therapy and procedures undertaken in prosthetic rehabilitation of a patient who underwent mandibular resection and radiotherapy with supported prosthesis retained with four implants

Implant Prosthetic Rehabilitation of the Patients with Mandibular Resection Following Oral Malignoma Surgery

Patient underwent mandibular resection due to surgical therapy of oropharingeal malignoma. Facial asymmetry and cosmetic distortion are frequent consequences of such interventions, which may also include deviation and intrusion of the mandible, motor and sensory disorders, abnormal intermaxillary relations and malocclusion. Implant-supported prosthesis could be an optimal solution to prosthodontic treatment of such patients. However, there is a problem in determination of stable (interocclusal) intermaxillary relations. This article describes the choice of therapy and procedures undertaken in prosthetic rehabilitation of a patient who underwent mandibular resection and radiotherapy with supported prosthesis retained with four implants

Fixed prosthodontic restorations and periodontal health

Ispravan odnos fiksnog protetskog nadomjestka i parodontnih tkiva temelj je uspješne protetske terapije. U planiranju se uzimaju u obzir biološki i tehnološki čimbenici. S aspekta zdravlja parodontnih tkiva inicijalna terapija i oralna higijena uvjet su dugotrajno stabilne protetske rehabilitacije. S protetskog aspekta najvažniju ulogu imaju nivo i oblik preparacije na vratu zuba, njena reprodukcija u otisku i na modelu, izbor materijala, precizna izrada nadomjestaka, pričvršćenje i optimalno rubno brtvljenje. Nužno je da se, u planiranju protetske terapije, zdravlje parodontnih tkiva i uspješna protetska opskrba smatraju jednom cjelinom. Poznavanjem i poštovanjem obiju disciplina možemo računati na dugotrajnost radova i zdravlje pacijenta.The relationship between fixed prosthodontic restorations and periodontal health is the key to successful therapy. In the planning process, biological and technological factors must be taken into consideration. Initial periodontal therapy and oral hygiene are essential for long term stability of rehabilitation. Prosthodontic aspect includes: level and form of cer- vical finish line preparation, its reproduction and impression, materials, accurate fabrication, cementation and optimal sealing. Periodontal health and successful prosthetic therapy should be considered as one in the process of prosthodontic rehabilitation. Durability of res- torations and patient’s long term health can only be achieved by implementing knowledge from both professions