The prevalence of crown injuries to frontal teeth at schoolchildren aged 6 to 14 and their effects on the periodontal tissue.

The research aims at emphasizing the interrelation between the social impact and the self-esteem of schoolchildren with dental crown fractures in the frontal group. Dental traumatic injuries are frequently met to schoolchildren, therefore, the prevention and interception of traumatic pathology within parents, teachers and children is more than necessary. Our statistical study intends to determine the prevalence of dental trauma to southwestern Romanian schoolchildren aged 6 to 14. The survey included a number of 1684 schoolchildren attending public schools, randomly chosen. Data were collected from October 2012 to December 2013. Clinical examination was conducted to assess the dental traumatic injuries. Age and gender distribution, etiological factors, risk factors and the cause of injuries were the parameters taken into consideration. The data collected was processed and analyzed using the SPSS (Statistical Package for the Social Sciences) statistical software. The overall prevalence of dental trauma was 4.63% amongst the subjects examined. The maxillary central incisor was the most commonly affected tooth (85.19% in boys and 97.87% in girls). We observed a significant statistical difference in the number of children with one, two or three fractured teeth from the urban and rural areas. The percentage of schoolchildren with crown fractures that we examined was of 3.09% in the urban area and 1.54% in the rural area. The traumatic injuries of the maxillary upper teeth were most prevalent. Since the dental trauma of incisors has a strong impact on the quality of life of children and their families, health preventive policies are needed in order to avoid psychological implications on the lifelong existence of children affected.

The histopathological study of radicular dentinal changes in patients with chronic marginal periodontopathies.

Periodontal disease is one of the most frequent conditions in individuals, having major health and social implications. Progressing as a chronic inflammation at the level of tooth support tissues, untreated chronic periodontitis may lead to a premature loss of the dental organ. Even though the main lesions caused by the periodontal disease affect the alveolo-dental ligaments, we tried to highlight the presence of certain lesions of radicular dentine in patients with chronic marginal periodontopathy. In our study, in the patients with chronic marginal periodontopathy, at periodontium level, there was highlighted the presence of a chronic inflammatory process with numerous lymphocytes and macrophages, microhemorrhages, and also areas with tissular necrosis. At radicular dentine level, in the cases of old, untreated periodontal disease, there were observed areas of more or less extended demineralization, erosion and necrosis. Our study showed that chronic periodontal disease may affect the tooth, as well, not only its support tissues.

Considerations regarding the optical properties of the composite resin restorative materials.

The purpose of this study has been to investigate the effects of certain substances frequently used in alimentation on the color stability of the composite resin restorative materials. The research hypothesis was that color stability of the composite resin is affected by the type of composite material used and by the polishing procedure. 14 samples of 5X15X2mm have been prepared from seven universal light curing restorative composite resins. The materials have manipulated and cured using LA 500 Blue Light lamp. A first color determination was done before the introduction of the samples in the dyeing agent with the help of an Easy Shade device. The samples have been splited into two lots each with seven samples. The samples from the first lot have been sectioned into three equal segments. The samples from the second lot have also been sectioned into three equal segments, and in addition to the previous group, their exterior surfaces were processed with a diamond burr. For each type of composite we have introduced a sample in one of the three chosen dyes: red alimentary colorant, coffee and red wine. The color of the samples has been determined again using the Vita Easy Shade device. From clinical point of view the results of this study shows that there are three important factors that matter when we talk about durable aesthetic results: the type of composite resin used for the restoration, the finishing and polishing procedures and the pacients' alimentation habits. The composite resins with a good representation of the anorganic structure are easier to be polished, therefore they have only slight color modifications. Using plastic matrixes for shaping the exterior surface of the restoration is the best solution for obtaining a very smooth surface. The most significant color modifications have been done by the red wine. Coffee and to a smaller extent the red alimentary colorant have modified the color of the restoration material in a smaller degree.

Contributions on the study of the compressive strength of the light-cured composite resins.

The mechanical properties of the light-cured composite resins are related to the material composition, but also vary according to the light-source characteristics used for polymerization. In this study we followed the compressive strength variation for a light-cured composite resin according to the time of exposure to the curing light. With that end in view,18 test pieces were made from a light-cured hybrid composite material (Filtek Z250). The test pieces where then submitted to a compressive force by a mechanical properties universal testing machine. Our results didn't show an increase of the compressive strength according to the light-curing time increasing, than only in the light-curing time limit indicated by the manufacturer. A longer light-curing time may induce a shrinkage polymerization growth with the formation of internal tensions inside the material. The composite materials light-curing in short layers as long as there is indicated by the manufacturer seems to be a safer method to make the best from a resin qualities, then an exaggerated increase of the light-curing time. The light-curing is indicated to be done in the direction of the compressive forces. To confirm this supposition other mechanical tests are also necessary.