Secondary dentin formation mechanism: The effect of attrition

Human dentin consists of a primary layer produced during tooth formation in early child-hood and a second layer which first forms upon tooth eruption and continues throughout life, termed secondary dentin (SD). The effect of attrition on SD formation was considered to be confined to the area subjacent to attrition facets. However, due to a lack of three‐dimensional methodologies to demonstrate the structure of the SD, this association could not be determined. Therefore, in the current study, we aimed to explore the thickening pattern of the SD in relation to the amount of occlusal and interproximal attrition. A total of 30 premolars (50–60 years of age) with varying attrition rates were evaluated using micro‐computerized tomography. The results revealed thickening of the SD below the cementoenamel junction (CEJ), mostly in the mesial and distal aspects of the root (p < 0.05). The pattern of thickening under the tooth cervix, rather than in proximity to attrition facets, was consistent regardless of the attrition level. The amount of SD thickening mildly corre-lated with occlusal attrition (r = 0.577, p < 0.05) and not with interproximal attrition. The thickening of the SD below the CEJ coincided with previous finite element models, suggesting that this area is mostly subjected to stress due to occlusal loadings. Therefore, we suggest that the SD formation might serve as a compensatory mechanism aimed to strengthen tooth structure against deflection caused by mechanical loading. Our study suggests that occlusal forces may play a significant role in SD formation

Health Care Service of Dental Specialists in Lithuania

Darbo tikslas – įvertinti, kokia dalis odontologų specialistų teikia nespecializuotas odontologinės sveikatos priežiūros paslaugas, nustatyti teikiamų paslaugų ir demografinių bei profesinių požymių ryšį. Visiems Lietuvoje praktikuojantiems gydytojams odontologams specialistams (N = 551) išsiųsta anketa. Gauti 345 atsakymai, kas sudarė 62,6% tyrimo atsako dažnį. 41,8% visų odontologų specialistų Lietuvoje teikia ne tik specializuotas odontologinės sveikatos priežiūros paslaugas, bet dirba ir kaip odontologai. Tikimybė, kad odontologinės sveikatos priežiūros klinikų vadovai ar patalpų nuomininkai dirbs ir kaip odontologai specialistai ir odontologai 2,49 karto didesnė lyginant su samdomais odontologais specialistais. Ryšys tarp odontologų specialistų teikiamų paslaugų ir amžiaus, specializacijos įgijimo būdo bei jaučiamo pacientų trūkumo nenustatytas. Dalis odontologų specialistų baigė studijas valstybės lėšomis, todėl situacija parodo neracionalų podiplominėms studijoms (rezidentų ruošimui) skiriamų valstybės lėšų panaudojimą.The aim of the present study was to explore the health care service of dental specialists in Lithuania, to investigate the relation between the service and dental specialists‘ demographic and professional factors. Census sampling was employed (n=551) and the data collected by means of a structured questionnaire. Response rate was 62.6%. 58.2% of all dental specialists provided only specialized care, while the rest 41.8% worked as a specialist and also as a general dentist. Possibility of providing only specialized care was 2.49 times higher for private practice owners or those who rented dental chair for dental practice when compared to associate dentists. No significant difference between the dentist’ age, organizational type of residency studies, perceived lack of patients and provided service was found. As part of dental specialists‘ postgraduate (residency) studies was government funded, the situation leads to an inefficient use of state finance and need to be addressed by policy makers and health care planners in Lithuania