Introduction: To evaluate whether the hypothesis that estrogen levels are associated with temporomandibular disorders (TMD) in humans can be confirmed or contradicted by available literature. Material and methods : A systematic review based on the content of PubMed, Scopus, and Cochrane...

A growing body of evidence suggests that bruxism exists in two separate manifestations. However, little is known about the association between specific manifestations of bruxism and temporomandibular disorder (TMD) pain. The aim of our study was to analyze the association between TMD pain and specific diagnoses of bruxism (sleep, awake, and mixed diagnosis of sleep and awake bruxism). 508 adult patients (296 women and 212 men), aged between 18 and 64 years (mean age 34±12 years), attending to a clinic for general dental treatment. Patients were asked to fill an anonymous questionnaire, consisting of three questions, verifying the presence of TMD pain and two forms of bruxism. All questions were based on the Polish version of the Research Diagnostic Criteria for Temporomandibular Disorders patient history questionnaire. Cross tabulation was done, and χ2 was used as a test of significance to find the association between the variables. Awake bruxism was associated with TMD pain only in men (χ2=7.746, p<0.05) while mixed diagnosis of bruxism was associated with TMD pain in both women (χ2=10.486, p<0.05) and men (χ2=4.314, p<0.05). There was no statistically significant association between sleep bruxism and TMD pain. Gender-related differences in the presence of all bruxism diagnoses were also statistically insignificant. Interaction between sleep and awake bruxism may increase the risk for TMD pain. We suggest considering concomitance as a confounder, when studying sleep or awake bruxism.

Currently, composite resins are used in many restorative procedures. Previous studies showed that drinking beverages may affect the mechanical properties such as microhardness or flexural strength of dental composite resins. The aim of the present study was to investigate the influence of common beverages on the mechanical properties of composite resins. Samples of the materials were prepared according to the ISO 4049:2010 standard and producer’s recommendations. The samples were next conditioned in tested fluids: distilled water, sparkling water, Coca-Cola, Red Bull and orange juice for 7 days. Vickers microhardness and flexural strength testing was performed after 7 days. Performed statistic tests confirmed the significance of microhardness changes of the tested materials in terms of both different conditioning of the samples and different composite materials. The mean flexural strength of composites was highest in distilled water and it was reduced after one week in different beverages. We conclude that all tested beverages influenced on Vickers microhardness of tested composite resins. Flexural strength only in one material was statistically significantly influenced by tested beverages. The results of this study should be taken into consideration by a dentist preparing recommendations for the patients after dental treatment with usage of composite material or after cementing composite based fixed dentures.

Composite materials are the most common materials in use in modern dentistry. Over the years, the methods of photopolymerization of composite materials have been improved with the use of various devices, such as quartz tungsten halogen lamps (QTHs), light-emitting diode units (LEDs), plasma-arc lamps and argon-ion lasers. This study aimed to compare the mechanical properties of a composite material, depending on the time and mode of photopolymerization. One hundred and forty rectangular specimens (25 × 2 × 2 mm) and forty-two disc-shaped samples (5 mm diameter and 2 mm thickness) were prepared from shade A2 Boston composite resin. Samples were cured using the following seven photopolymerization protocols: four fast-cure modes (full power for 3, 5, 10, and 20 s), two pulse-cure modes (5 and 10 shots of 1 s exposures at full power), and one step-cure mode (soft start with a progressive cycle lasting 9 s). Specimens were subjected to a flexural strength test, Vickers microhardness test, and FTIR spectroscopy test. A 2-factor ANOVA and post-hoc tests were carried out to assess the differences in the flexural strength parameter between the tested groups of samples before and after aging. A mixed-model ANOVA was carried out to assess the differences in the Vickers microhardness parameter between the tested groups of samples before and after aging. The lowest values of flexural strength (p < 0.001) and Vickers microhardness (p < 0.001) were obtained for the 3 s mode for the pre- and post-aging groups. The FTIR mapping tests showed a much more homogeneous chemical structure of the composite after 20 s of continuous irradiation, compared to the sample irradiated for 5 s in the continuous mode. The mode and cure time affects the mechanical properties of the composite resin. Appropriate selection of the cure mode and time ensures better mechanical properties of composite resin. This suggests that the survival of dental restorations within the oral cavity could be extended by using longer photopolymerization durations.

Introduction. Dental caries is considered to be a modern civilization disease;however, the state of oral health negatively influences psychological and sociological relations in children which leads to feelings of discomfort from early age. Objective. The aim of study was evaluation of the association between incidence of dental caries (d3ft index) in preschool children from urban and rural areas, and determining the relationship between dental caries intensity and hygienic habits. Materials and Method. 844 children aged 3–6 years from the city and the countryside were examined. The survey was conducted among parents/care givers regarding dental care of children. With parents’ consent, the children had a dental examination. Results. The incidence of caries was recorded at the level of 52.61%, with an average value of 4.31 on the d3ft index; however, for the children from the urban area this ratio amounted to 4.15, and in the countryside it reached the value of 4.7. A correlation was found between age and area of residence of the children and various components of hygienic behavior model. Conclusions. More than a half of the children had dental caries in combination with a high frequency of unsatisfactory hygiene needs. There is a relationship between oral hygiene habits and age of the children, depending on the place of residence

During polymerization, composite materials cause a temperature rise which may lead to irreversible changes in the dental pulp. The mechanical properties of composite materials depend on a number of factors, such as the composition of the material, the type of polymerization unit, the polymerization mode, and the duration of polymerization. The objective of this study was to assess the temperature rise values and flexural strength of composite materials, as obtained using different modes and times of polymerization. A total of six composite materials were used in the study. Samples of each of the materials were cured using seven polymerization protocols. A CMP-401 digital meter (Sonel, Świdnica, Poland), complete with a type K thermocouple (NiCr-Ni), was used to record the temperature increases during the light curing of the resin composites. Temperature rises were recorded beneath the composite disc in an acrylic matrix. The specimens were tested for flexural strength using a Cometech QC-508M2 testing machine. The lowest results for the increased mean temperature were obtained for Fast-Cure 3 s (39.0 °C), while the highest results were obtained for Fast-Cure 20 s (45.8 °C). The highest average temperature values for all tested protocols were recorded for the Z550 Filtek material. Mean flexural strengths as measured in each test group were higher than the minimum value for composite materials as per the ISO:4049 standard. In the case of deep caries with a thin layer of dentin separating the filling from pulp, a base layer or a short polymerization duration mode is recommended to protect pulp from thermal injury.