Adnan Ćatović

Qualitative evaluation of elderly home residents' fixed and removable prostheses in relation to the ADL index

UNLABELLED Functional diversity and biopsychosocial state is a significant issue, which greatly influences elderly oral health and state of fixed and removable prostheses. OBJECTIVES The goal of the investigation was to evaluate the quality of fixed and removable prostheses in a group of elderly home residents in relation to the ADL index. METHODS The group consisted of 175 institutionalised elderly, mean age 76.8 years. Special care need was assessed on ADL scale. To evaluate the quality and need for replacement of fixed and removable prostheses Karlssons and modified Nevalainen et al. indices were used. RESULTS Spearmans correlation analysis showed significant correlation of ADL index scores and both Karlssons index values (rho=-0.468, p<0.01) as well as for modified Nevalainens indices (rho=-0.572, p<0.01). Lower ADL score was correlated with poorer oral hygiene and condition of fixed or removable dentures. It was determined that 87% of the examined patients were in objective need of fixed, removable or combined prosthodontic treatment. CONCLUSIONS The study showed that lower ADL index scores of functionally dependent elderly patients correlate with poorer condition of fixed and removable prostheses and greater need of fixed, removable or combined prosthodontic treatment.

The fatigue strength of the interface between Ag-Pd alloy and hydrothermal ceramic.

OBJECTIVE The purpose of this paper was to investigate the fatigue strength of a hydrothermal ceramic fused to Ag-Pd alloy. This study compared the values with those of other metal-ceramic systems previously reported by other authors. METHODS This investigation was performed on 48 specimens made of Ag-Pd alloy frames (45 x 12 x 4 mm) on which the hydrothermal ceramic was fused (25 x 12 x 2 gmm). The specimens were divided into two groups. The first group of specimens was dynamically loaded immediately after casting and fusing, while the other group of specimens was thermocycled (1000 times at 0 degree C and 55 degrees C) before dynamic loading. The dynamic loading tests were carried out by using a modified three-point load method in a universal testing machine. RESULTS The determined dynamic loading limit was up to 550 N for thermocycled, and up to 850 N for non-thermocycled specimens. These results are very respectable in comparison with other metal-ceramics. A statistically significant difference between maximal dynamic forces and number of loading cycles for thermocycled and non-thermocycled samples was determined. SIGNIFICANCE From the data obtained in this study and current literature profiles, it is concluded that the tested metal-ceramic system is more durable than other metal-ceramic systems.

Amorphous alloys resistant to corrosion in artificial saliva solution

The tailoring of new corrosion-resistant alloys with specific properties has recently been performed mostly by the sputter deposition technique. The aim of this work was to investigate corrosion resistance of aluminum–tungsten (Al–W) amorphous alloys in artificial saliva solution, pH=5.5, based on the electrochemical methods of cyclic voltammetry and linear polarization. Thin alloy films were prepared on a sapphire substrate by magnetron codeposition. Completely amorphous films were obtained in the Al80W20–Al67W33 composition range. Amorphous Al–W alloys exhibit very high corrosion resistance due to their homogeneous single-phase nature. The passive films spontaneously formed at their surface are uniform with characteristics of an insulator film and prevent corrosion progression in the bulk in a very demanding oral environment. The mechanism of increasing resistivity of Al–W alloys to pitting corrosion and generalized corrosion has been discussed in the view of increasing tungsten content in the alloy. Considering these exceptional corrosion properties and microhardness which falls in the range 7.5±1.6 Pa, Al–W alloys represent promising materials for dental applications.

Prevalence and significance of minor anomalies in children with impaired development

Aim: To compare the prevalence of Waldrops minor physical anomalies in children with developmental disorders (mental retardation, hearing and visual impairment) and healthy schoolchildren. Methods: The study was carried out on a sample of 469 children (223 children with developmental disorders and 246 healthy schoolchildren). Results: Significant differences were found between the children with developmental disorders and the healthy children with regard to the number of minor anomalies and their weighted scores according to Waldrop. Multivariate discriminant analysis with two discriminative functions explained as much as 96.51% of the total variability and significantly distinguished the healthy children from the children with developmental disorders. However, no clear distinction was found between the mentally retarded children and those with visual impairment. Interrelation of the number and sum of the weighted scores of minor anomalies showed similar minor anomalies in the mentally retarded children (mean per person 3.65 and 3.82, respectively), the children with visual impairment (3.24 and 3.50), the children with hearing impairment (3.84 and 3.67) and the control group (1.70 and 1.46), although at different levels.