Trends in Dental Caries in 12-Year Old Children in Croatia

In this epidemiological study the caries status of 12-year-old children was compared over time for the years 1968, 1973, 1980, 1985, 1990, 1991 and 1999. The mean number of decayed, missing and filled teeth (DMFT) decreased from 7.0 in 1968 to 2.6 in 1991. From 1991 to 1999 and increase of DMFT 2.6 in 1991, to 3.5 in 1999) has been seen which is result of war in Croatia and reorganisation of health care delivery system. With the expected continuing decline in the prevalence and severity of oral diseases, one of the main problems in the future seems to be the transition of the oral health care delivery system from a disease-oriented system to a health-oriented one

Interferometry in the Assessment of Biomechanical Features of the Masticatory System Hard Segments

Biomechanical studies have found wide application and solved many problems in dental medicine. An interdisciplinary approach has allowed an ever-faster progress in the field. The aim of this study was to point out the advantages of holographic interferometry. With the use of this method, the study object is observed as a whole rather than as a substrate, thus providing a three-dimensional holographic image visualizing the load transmission from one jaw to another, tooth pressure against the alveolus, and strain of Sharpey\u27s fibers, and yielding precise data on deformities, dislocations and force distribution

Interferometry in the Assessment of Biomechanical Features of the Masticatory System Hard Segments

Biomechanical studies have found wide application and solved many problems in dental medicine. An interdisciplinary approach has allowed an ever-faster progress in the field. The aim of this study was to point out the advantages of holographic interferometry. With the use of this method, the study object is observed as a whole rather than as a substrate, thus providing a three-dimensional holographic image visualizing the load transmission from one jaw to another, tooth pressure against the alveolus, and strain of Sharpey\u27s fibers, and yielding precise data on deformities, dislocations and force distribution

Preventive Sealing of Dental Fissures with Heliosil: A Two-year Follow-up

Due to their shape and configuration of dental crown, especially its biting surface with numerous pits and fissures permanent molars are suitable sites for retaining food remnants and bacteria. For this reason, preventive efforts and early prophylactic procedures should prevent the development of caries at these critical sites. Deciduous and permanent teeth of 300 children aged 6–7 years with healthy parallel teeth were included in the study. Fissure sealing was performed on one side, whereas contralateral teeth served as controls. During a two-year period, control examinations with finding recordings were performed every six months. During the two-year follow-up period, the sealed teeth remained free of caries as long as the coating persisted. In deciduous teeth, the sealant was first observed to be missing at 18 months in 5%, and at 24 months in 8% of the teeth. None of these teeth was affected by caries, suggesting that a part of the sealant was retained in the fissures. In permanent teeth, caries developed in 18% of the sealed teeth at 24 months

Modeling-based Development of an Enantioselective Hydrogenation Reaction of a Sitagliptine Intermediate

This work presents a quality by design (QbD) driven approach to the plan of experiments and reaction modeling that was effective in obtaining enhanced process knowledge and defining a design space for an active pharmaceutical ingredient (API) manufacturing process. Engineering aspects of the process were explored by process modeling using computer predictive process simulators. QbD approach is presented on a case study of the process development of the sitagliptine synthesis step. The process involves an enantioselective hydrogenation step. Based on the proposed reaction mechanism and by combining the heat and mass transfer, thermodynamics, and the kinetics of the reactions, the API quality specifications (enantiomeric purity, impurity levels) are described across the modeling of process space. This process space was defined through target specifications, practical operating conditions for scale-up, and plant control capabilities. Model predictions were verified with results obtained in the laboratory, and at pilot plant scale

Chronology, Dynamics and Period of Permanent Tooth Eruption in Zagreb Children (Part II)

The aim of the present paper is to determine the beginning, order, median time, termination, dynamics, continuity and intensity of the permanent tooth eruption, as well as its calendar, in a sample of Zagreb children. The study included 2768 children (1398 boys and 1370 girls). All subjects were classified in one-year age groups. The continuity of tooth eruption occurs from 5.1 years to 14.97 years, i.e., for a period of 9.87 years. Each particular tooth has its own dynamics of eruption (V5–V95) which on the average amounts to 4.25 years. The continuity of eruption is 10.1 years in boys and 9.8 years in girls. The dynamics of eruption is 4.15 years in boys and 4.35 years in girls. A certain asymmetry in eruption has been described

Investigation of Ion Release from Ni-Cr Alloy in Various Acidity Conditions

Cytotoxicity is in direct correlation to the level of ion release, with non-precious alloys having higher ion release than that of precious alloys. The most often used non-precious dental alloy is Ni-Cr alloy. The aim of the investigation was to determine the type and quantity of ions released from Ni-Cr alloy (Wiron 99(r), Bego, Germany), in acid solutions with different pH values, and to determine the influence of the type of acid solution, its pH value, and duration of interaction on ion release. The overall sample consisted of 180 pieces of Ni-Cr alloy, 60 samples submerged in each of three different solutions (buffered phosphate solutions pH 3.5 and pH6, and lactic acid solution pH 3.5). Quantity of ion release was measured on solution samples taken at 10 different time intervals by means of the ICP-AES method. Average release of Ni ions in lactic acid solution was 432.42 μg/L, while the highest average Ni+ ions release of 541.67μg/L was measured in buffered phosphate solution pH 6.0. MANOVA demonstrated significant influence of the type of solution on Ni ion release (p<0.01), while the time of exposure was not a significant factor (p=0.23). Zn ions demonstrated the lowest average ion release (88.95 μg/L, phosphate solution pH 3.5). Statistically significant influence of the type of solution and pH value on ion release was determined, except for chromium ions (p<0.05). Dentobacterial plaque acidity is sufficient to start corrosion of Ni-Cr dental alloys