EVALUAREA EXPERIMENTALĂ A CALITĂŢII ŢESUTURILOR DENTARE AFECTATE PRIN UZURA

A thorough knowledge of the dental structure is essential to the understanding of dental defects and pathology, as teeth composition and structure are significant factors, with an important role in hardness value increase or, on the contrary, decrease. Hardness value, mineral contents and density decrease gradually from the teeth surface towards the junction. Hardness analysis and study is important in order to understand the manner in which mastication forces are distributed on the tooth

COMPORTAMENTUL LA UZURA A MATERIALULUI CERAMIC

From practical point of view, parameters of interest are only those that can be clinically evaluated and measured both in vivo, and in vitro, using matched samples and adequate methods. For this research direction, it is important to determine the volume of worn material, because wearing is defined as a permutation of a material mass. It is well known the fact that masticatory parameters (occlusive force, number of masticatory cycles and distance of gliding/sliding) remain constant in time

The Tribological Behaviour Of Ceramic Material

The actual material wear process is influenced by a set of specific factors, such as: their filling, the used speed and lubricant, the amount of material, hardness. Aim of study: is to determine the wear coefficient of the ceramic materials. Material and method: we made disks with a radius of 2.5 cm and a 2 mm thickness, out of 2 types of ceramic restoration materials we found on the market: INLINE and HERA CERAM, on which we measured the friction coefficient and the amount of material used. The experiment was carried out using a CALOWER friction meter. The sliding speed is constant in time (about 150 r.p.m.) and acts on a variable sliding distance, between 3255 and 16277 mm, (corresponding to about 35000 mastication cycles, on a 0.5mm long occlusion). A force of 0.35N acts on the material samples. Results: the amount of material used increases with the filling increase for the whole sliding length, the number of rotations and friction length.The rate of transferred material decreases with the increase of the amount of certain constituents used, the material thus having better abrasion wear strength. Conclusions: the stress occurring on the contact surfaces is extremely interesting and enables us to understand their wear behavior

STUDY REGARDING THE INFLUENCE OF LIFESTYLE ON THE ORAL HYGIENE OF DENTAL STUDENTS

Aim of the study: determining the attitude of dental students towards their own oral hygiene. Materials and methods: in order to determine the predominance of tooth decay, the CAO-D index was used. To evaluate the sanogenous behavior of students, the Hiroshima questionnaire was used. Results and discussions: the study shows a CAO-D bigger than 8 in 72% of the students, 22% of the participant subjects have a CAO-D between 5 and 8, whereas 12.8% of them show less tooth decays than the usual range. Filling in the Hiroshima questionnaire revealed a variation between 1.01 and 3.07 of the HU-DBI score. Conclusion: Student’s behavior reflects the attendance rate at the courses of preventive dentistry, behavioral sciences and oral hygiene

The Influences of Chemical Composition Upon the Hardness and Stability of Prothetic Restoration Materials

The aim of the study was the – reducing and complex character upon the hardness of Ni-Cr alloy covered with ceramics. Matherial and method: ed into sterilized containers with artificial saliva (sterilized by autoclaving for 30 min., 1 atm) in saliva-alloy weight ratio: 15 / 1. The second solution is used electrolyte-matrix synthetic artificial saliva in the pH range 2-8, in the presence of oxalate and tartrate ions with oxidation-reduction and complex character, the ionic strength of 35-45 mmol / L. pH corrections were done with NaHCO3, CH3COONa and HCl, while the ionic strength correction was performed with buffer TISAB (Total Ionic Strength Buffer Adjudment) composed of NaCl and CH3COOH CH3COONa. Samples were collected every 15 days electrolyte and alloy elements concentration was determined by spectrometry with atomic absorption with flame (Faas type Perkin Elmer 3300) and potentiometers with SMEI (ion-selective membrane electrode-type pH-Ion-Meter OP-202-RADELKIS). Results: Micro hardness variation is visible (in cross section) depending on the layer studied. In the Plate, the average micro hardness values is quite small (285.8 GPa for a variation of micro hardness between 288-321 GPa), but as we approach the ceramic layer micro hardness gradually increases (reaching values about 987 GPa). Aluminium is currently heavily corroded due to higher electronegativity values of Cu (Cu = 1.8, Al = 1.5) and more positive standard potential of Cu (Cu 0.33 V, Al = -1.66 V). Tin is passive at pH 2-4, and at pH = 8. Nickel is turn passive at pH = 7 and dissolve at a pH = 2-6. Molybdenum is active at pH 2-4. Iron and cobalt are active at pH 2-4 and at pH = 9 passive. All these chemical reactions alter the surface quality of the alloy, with increasing surface roughness and finally compromise-to-end the resistance of restorative material. Increasing the concentration of silicon (where the ceramic material is used) increases the rate of galvanic corrosion due to the effect of Si. Conclusions: A restorative material used for the purpose of micro hardness and resistance varies depending on the type of electrolyte is introduced

THE CLINICAL METHODS TO MEASURE TOOTH WEAR

With a greater number of people living longer and tending to retain many natural teeth, the problems associated with tooth wear are likely to place greater demands upon dental professionals in the future. The aim of the study: was measuring tooth wear in the agering dentition. Material and method: was selected the subiects in order to provide approximately 80 subjects over the age of 45-50 years, whose age, sex and social characteristics reflected the socio- demographic constitution. The study design and assessment of the level of tooth surface loss using the Tooth Wear Index. Results and discussions: Several indices have been produced in recognition of the need to quantify the amount of wear at both an individual and population level. Several attempts have been made to develop an index to measure tooth wear for use at both the individual and population level. A review of these indices is undertaken

Clinical-Statistical Study On The Prevalence Of Non-Cariogenic Lesions In Adults

Biomechanical induced dental problems affect a relatively high percent of the adult population. The aim of study was to determine the prevalence of specific lesions for dental wear. Material and method The study was conducted on a group of 300 subjects, selected from the 4th Medical Clinic of CFR Clinic Hospital, for which the criteria of including- excluding was respected. For evaluating the alteration degree, the TWI indicator was used, and for statistical analysis the SPSS17 program for Windows. Results and discussions The study highlights a mean variation of patients with wear lesions quantified according to the TWI indicator (3.096 of all patients present stage 1 affection; a mean of 3.066 with stage 2 affection; 3.01 for stage 3 and 2.8 with stage 4 affection). Conclusions There are correlations between sexes, age groups, general status, wear lesion patterns, associated lesions and their predominance

STUDY REGARDING THE INFLUENCE OF THE FAMILY ENVIRONMENT ON THE ORAL HYGIENE OF CHILDREN

Aim of the study: this study aims at evaluating the dental health of schoolchildren.Materials and methods: Two study groups made up of 210 children were grouped by category of age. The CAO index was used to evaluate the oro-dental condition of the children. Results and discussions: In the year 2015, the value of the caries index was of 3.11, and in the year 2016, it has considerably increased up to 3.73. The index reaches an average of 0.09 at the time of the third evaluation. Conclusions: Even though the average value of the caries index has increased, there has been noticed a higher awareness, and behavior and attitude changes among children

Are Local Drug Delivery Systems a Challenge in Clinical Periodontology?

Placing antimicrobial treatments directly in periodontal pockets is an example of the local administration of antimicrobial drugs to treat periodontitis. This method of therapy is advantageous since the drug concentration after application far surpasses the minimum inhibitory concentration (MIC) and lasts for a number of weeks. As a result, numerous local drug delivery systems (LDDSs) utilizing various antibiotics or antiseptics have been created. There is constant effort to develop novel formulations for the localized administration of periodontitis treatments, some of which have failed to show any efficacy while others show promise. Thus, future research should focus on the way LDDSs can be personalized in order to optimize future clinical protocols in periodontal therapy

VALIDATION OF THE WHOQOL-BREF QUALITY OF LIFE QUESTIONNAIRE IN DENTAL MEDICAL STUDENTS

Oral health-related quality of life is a significant predictor of overall health and well-being. The aim was to validate the Romanian version of the WHOQOL-BREF as an instrument for measuring the quality of life of dental students. Material and method: Medical students from the fifth year of the Faculty of Dentistry, UMPh Grigore T. Popa Iasi, were invited to participate in the current study. Data were collected after completing the WHOQOL-BREF questionnaire, which consists of 26 items. Results: the average Cronbach’s alpha coefficient for the Global Quality of Life domain was 0.92 (p=0.026). Similarly, for the Global Health domain, the Cronbach’s alpha coefficient was 0.78, for the Physical Domain it was 0.84, and for the Psychological Domain it was 0.91. The Social Domain exhibited a Cronbach’s alpha coefficient of 0.71, while for the Environmental Domain it was 0.77. The intra-class correlation coefficient showed consistent values (p=0.000 – 0.035). Conclusion: WHOQOL-BREF is a reliable and valid instrument for measuring the quality of life of dental students