The paper discusses four Ag-Au-Pd-Cu dental alloys, with different chemical compositions, which are used to produce fixed dental-prosthetic structures. These dental alloys must have a low level of ...biological risk after being implanted in the oral cavity, which means minimal release of ions from their surface, or the absence of corrosion, and, recently, the absence of ferromagnetism has been introduced as an additional requirement. The latter requirement is particularly important when magnetic resonance (MR) is used in the medical diagnosis of a patient who has an implanted fixed dental-prosthetic structure. With this technique, the internal structure of the human body is imaged using a strong magnetic field, radio waves and computer technology. Therefore, the absence of ferromagnetic, embedded biomaterials is necessary in the part of the body where medical diagnostics are performed. Microstructural investigations of four Ag-Au-Pd-Cu dental alloys (Auropal S, Auropal SE, Midor S and Midor SE) and measurements of their magnetic properties were carried out as part of the research. The results showed that Ag-Au-Pd-Cu dental alloys have a stable microstructure, which allows them to be processed later into fixed prosthetic constructions. The measurements of the magnetic properties showed that the Ag-Au-Pd-Cu dental alloys are diamagnetic.
During drilling implant sites, mechanical energy is converted into thermal one resulting in transient rise in temperature of surrounding bone. The temperature of 47°C exeeding one minute impairs ...osseointegration, compromises mechanical properties of the local bone and could cause early implant failure. This in vitro study aimed to assess the effect of surgical drill guide and temperature of irrigans on thermal changes of the local bone during drilling implant sites, and to test the influence of irrigans temperature on the temperature of surgical drill guide.
A total of 48 specimens obtained from bovine ribs were randomly allocated to four experimental conditions according to the 2 x 2 factorial design: drill guide (with or without) and saline (at 25°C or 5°C). Real-time infrared thermography was used as a method for temperature measurement. The primary outcome was bone temperature change during drilling implant sites measured at 3 osteotomy depths, whereas the second one was change in the temperature of the drill guide. Data were analyzed by Brunner and Langer nonparametric analysis and Wilcoxon test.
The effect of drill guide on the changes of bone temperature was significant at the entrance of osteotomy, whereas the effect of saline temperature was significant at all osteotomy levels (p < 0.001). No significant interaction was found (p > 0.05). Guided surgery and irrigation with saline at 25°C were associated with the highest bone temperature increase. Increase in drill guide temperature was significantly higher when saline at 25°C was used (p < 0.001).
Guided implant site preparation generates higher temperature of the local bone than conventional drilling, not exceeding the threshold for thermal bone necrosis. Although saline at room temperature provides sufficient heat control during drilling, cooled saline is more effective regardless the use of surgical drill guide.
Differences between the tooth and implant response to load can lead to many biological and technical implications in the conditions of occlusal forces.
The objective of this study was to analyze load ...distribution in tooth/implant-supported fixed partial dentures with the use of resilient TSA (Titan Shock Absorber, BoneCare GmbH, Augsburg, Germany) abutment and conventional non-resilient abutment using finite element method.
This study presents two basic 3D models. For one model a standard non-resilient abutment is used, and on the implant of the second model a resilient TSA abutment is applied. The virtual model contains drawn contours of tooth, mucous membranes, implant, cortical bones and spongiosa, abutment and suprastructure. The experiment used 500 N of vertical force, applied in three different cases of axial load. Calculations of von Mises equivalent stresses of the tooth root and periodontium, implants and peri-implant tissue were made.
For the model to which a non-resilient abutment is applied, maximum stress values in all three cases are observed in the cortical part of the bone (maximum stress value of 49.7 MPa). Measurements of stress and deformation in the bone tissue in the model with application of the resilientTSA abutment demonstrated similar distribution; however, these values are many times lower than in the model with non-resilient TSA abutment (maximum stress value of 28.9 MPa).
Application of the resilient TSA abutment results in more equal distribution of stress and deformations in the bone tissue under vertical forces. These values are many times lower than in the model with the non-resilient abutment.
Good and well balanced diet provided by adequate mastication is part of therapy in patients
with type 2 diabetes mellitus (DM). The critical period presents the time immediately after teeth ...extractions;
hence, immediate denture is a rational therapeutical choice for diabetic patients. The presence
of immediate denture and its compression might compromise wound healing process, affect chewing
ability, food intake and consequently blood glucose level in type 2 DM patients.
The objective of this study was to compare socket opening diameters (SOD), chewing ability,
changes in blood glucose level and food intake in type 2 DM patients with and without maxillary immediate
complete denture (MICD) during a three-week wound healing period.
The study comprised 78 type 2 DM partially removable denture wearers (42 candidates for teeth
extractions and 36 candidates for teeth extractions and insertion of MICDs). During the three-week period
participants were followed for SOD, chewing ability and changes in blood glucose level and food intake.
Patients with MICD showed significantly lower reduction of SOD (seventh, 14th, 21st day) and
higher chewing ability (seventh, 14th, 21st day) in comparison to patients without an MICD. Significantly
lower number of patients with an MICD had changes in blood glucose level and food intake.
Maxillary immediate complete denture presents a good therapeutic choice for type 2 DM
patients, as it provides possibility of adequate mastication after teeth extractions and maintenance of
nutritional status and blood glucose level.
Fertilisation strategy can have a big impact on apple (Malus domestica Borkh) yield, with considerable environmental and economic implications. This research paper presents the yield and leaf ...nutrients content of three apple cultivars fertilised with three treatment regimes over 2 years (2020–202) in Bosnia and Herzegovina. The specific apple cultivars investigated were: Jonagold Decosta, Red Idared and Gala Schnitzer®Schniga, each fertilised with three treatments: T1 (control‒without fertilization); T2 (300 kg ha−1 NPK (6:18:36) + 150 kg/ha N (calcium ammonium nitrate‒CAN)) and T3 (foliar nutrition‒mixture organic-mineral fertilizer commercially named “FitoFert Kristal” (0.6%) (10:40:10) + “FitoFert Kristal” (0.6%) (20:20:20) + “FoliFetril Ca” (0.5%) (N:Ca)) in Bosnia and Herzegovina in the period of two years (2020–2021). Significant differences of different yield categories (yield per tree, yield per hectare and yield efficiency) were found among cultivar/treatment combinations, cultivars, treatments and years. Yield per tree, yield per hectare and yield efficiency were lowest in cultivar Jonagold DeCosta. Fertilization treatment T1 significantly influenced the lowest yield per tree and yield per hectare with the magnitudes 7.55 kg tree−1 and 27.96 t ha−1, respectively. The highest yield efficiency was found in trees fertilised with treatment T3 with 9.21 55 kg tree−1, 34.11 96 t ha−1 and yield efficiency of 0.25 kg cm−2. Six mineral elements in the apple leaf, such as boron (B), calcium (Ca), manganese (Mn), iron (Fe), potassium (K), and zinc (Zn), were presented in known magnitudes. The cultivar Jonagold DeCosta's leaves had the highest K, B, and Zn contents with 8500.8 mg kg−1 FW (i.e. fresh weight of leaves), 33.8 mg kg−1 FW, and 12.2 mg kg−1 FW, respectively, while cultivar Red Idared's leaves had the highest Ca, Fe, and Mg contents. The fertilisation treatment T3 influenced significantly the highest content of Ca (301.37 mg kg−1 FW), Fe (116.5 mg kg−1 FW), B (41.6 mg kg−1 FW), Mn (22.4 mg kg−1 FW), and Zn (14.9 mg kg−1 FW) in leaves, while the highest content of K was found in leaves from trees fertilised with treatment T2 (8130.5 mg kg−1 FW). The experimental outcomes have proven that the cultivar/treatment combinations, cultivars, treatments, and time duration (in years) are the key factors affecting the potassium, calcium, iron, boron, and manganese contents. It was concluded that the foliar application enables easier mobility of elements, which results in a greater number of fruits and larger fruits, which leads to a higher yield. This study is the first of its kind in Bosnia and Herzegovina, and the findings of this research will pave the way for future research activities involving increasing the number of cultivars and different fertilisation treatments on apple yield and leaf mineral composition.
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