Antonija Tadin

Composite-induced toxicity in human gingival and pulp fibroblast cells

Abstract Objective. The most important requirement for a material to be used in medical applications is its biocompatibility. Dental composite materials come into direct contact with oral tissues, especially gingival and pulpal cells. This study was performed to evaluate possible DNA damage in cells of human origin exposed to dental composites in vitro using a cytogenetic assay. Materials and methods. Two composite resins (Vertise Flow, Kalore) were tested on human gingival and pulp fibroblasts using the acridine orange/ethidium bromide viability staining and alkaline comet assay. Cultures were treated with polymerized composites in two different concentrations (20 mg/ml, 40 mg/ml) for 14 days. Chi-square and Kruskall-Wallis non-parametric test were used for the statistical analysis (p < 0.05). Results. Significant cytotoxicity was observed for 40 mg/ml of Vertise Flow in both cultures, while Kalore (40 mg/ml) showed cytotoxic effect only on human pulp fibroblasts. A significant level of DNA damage was detected for both materials and concentrations, in both cell cultures. Conclusion. If the two cell cultures are compared, the pulp cells were more sensitive to the cyto/genotoxic effects of dental composites. Based on the results, one can conclude that the use of tested materials may cause cellular damage in gingival and pulp fibroblasts in vitro.

Influence of Thermo-Light Curing with Dental Light-Curing Units on the Microhardness of Glass- Ionomer Cements

The purpose of this study was to verify for various glass-ionomer cement (GIC) products whether the application of thermo-light curing on the initial curing material produces an increase in microhardness, and to determine whether this hardness varies depending on the depths of the GIC samples. The efficacy of various polymerization units on this additional hardening was also examined. The GIC samples were thermo-light cured for 60 seconds with three polymerization units. The Vickers microhardness was measured at three different depths: 2 mm, 3 mm, and 4 mm. Analysis of variance and Newman-Keuls test showed statistically significant differences among tested samples for all three GIC groups (P < .001). The results of linear regression analysis showed a statistically significant relationship between the hardness of the material and the temperature for samples with depths of 2 mm (R = 0.78; P = .0028) and 3 mm (R = 0.59; P = .045). The findings of this study indicate that thermo-light curing of GIC with different polymerization units for 60 seconds during setting reaction increases the microhardness of the GICs at all depths tested and may increase resistance to mastication forces, which can be validated in future clinical studies.

Genotoxic biomonitoring of flowable and non-flowable composite resins in peripheral blood leukocytes.

Abstract Objective. Composite restorative materials represent one of the most important groups of materials in contemporary dental practice. However, their incomplete polymerization may lead to monomer-induced genotoxicity. The objective of this study was to evaluate the genotoxicity of three flowable (Filtek Supreme XT Flow, Tetric EvoFlow, Gradia Direct Flo) and three non-flowable dental composite materials (Filtek Z250, Tetric EvoCeram, Gradia Direct Posterior). Materials and methods. Genotoxicity assessment of composite materials was carried out in vitro in human peripheral blood leukocytes using the alkaline single-cell gel electrophoresis technique (comet assay). Prepared materials were eluted in saline solution for 1 h, 1 day and 5 days. Thereafter leukocyte cultures were treated with different concentrations of eluates obtained from each of the tested dental composite materials. Kruskall-Wallis non-parametric test was used for statistical analysis (p < 0.05). Results. The tested materials did not show genotoxic effects after exposure of leucocytes to 1 h eluates. Culture treated with 1 day eluates of all tested materials, only at a highest concentration (10−2), affected the measured cytogenetic parameters. Of all tested materials, only Filtek Z250 and Filtek Supreme XT Flow did not exhibit a genotoxic effect in cultures that were under the influence of 5 day eluates. Conclusion. Tested materials exhibited limited genotoxic activity in peripheral blood leukocytes. Since the effect was observed only in leukocyte cultures treated by 1-day eluates at the highest concentration (10−2) and it decreases in cultures exposed to 5 day eluates, it should not pose a significant risk to the human genome.

Micronucleus, alkaline, and human 8-oxoguanine glycosylase 1 modified comet assays evaluation of glass-ionomer cements - in vitro

Abstract The purpose of this study was to evaluate the genotoxic potential of components leached from two conventional self-curing glass-ionomer cements (Fuji IX and Ketac Molar), and light-curing, resin modified glass-ionomer cements (Vitrebond, Fuji II LC). Evaluation was performed on human lymphocytes using alkaline and hOGG1 modified comet, and micronucleus assays. Each material, polymerised and unpolymerised, was eluted in extracellular saline (1 cm2 mL-1) for 1 h, 1 day, and 5 days. Cultures were treated with eluates using final dilutions of 10-2, 10-3, and 10-4. Alkaline comet assay did not detect changes in DNA migration of treated cells regardless of the ionomer tested, polymerisation state, and elution duration. Glass ionomers failed to significantly influence micronucleus frequency. No oxidative DNA damage in treated lymphocytes was observed using hOGG1 modified comet assay. Obtained results indicate high biocompatibility of all tested materials used in the study under experimental conditions. Sažetak Svrha istraživanja bila je procijeniti genotoksični potencijal komponenata koje izlučuju dva konvencionalna samopolimerizirajuća stakleno-ionomerna cementa (Fuji IX i Ketac Molar) te svjetlosno polimerizirajući i smolom modificirani stakleno-ionomerni cementi (Vitrebond, Fuji II LC). Istraživanje je provedeno na ljudskim limfocitima primjenom alkalnog komet testa, komet testa modificiranog hOGG1 enzimom te mikronukleus testa. Svaki materijal, polimerizirani i nepolimerizirani, eluiran je u fiziološkoj otopini (1 cm2 mL-1) tijekom jednog sata, jednog dana i tijekom 5 dana. Kulture limfocita tretirane su eluatima u razrjeđenjima 10-2, 10-3 i 10-4. Alkalnim komet testom nisu zabilježene promjene u migraciji DNA iz tretiranih stanica bez obzira na ispitani ionomer, vrstu polimerizacije i trajanje elucije. Izloženost staklenim ionomerima nije značajno utjecala na učestalost mikronukleusa. Primjenom hOGG1 modificiranog komet testa nije zamijećeno oksidativno oštećenje DNA u tretiranim limfocitima. Dobiveni rezultati upućuju na visoki stupanj biokompatibilnosti svih testiranih materijala koji su se koristili u eksperimentalnim uvjetima.

The role of parental anxiety, depression and psychological stress level on the development of early-childhood caries in children

BACKGROUND It is important to understand how the psychological status of parents affects oral health in children. AIM This study aimed to assess the level of depression, anxiety, and stress of parents whose children have early-childhood caries. DESIGN The study included 235 children and their parents who visited the Dental clinic at the School of Medicine of the University of Split between October 2016 and July 2017. The dental status of each child was recorded, while parents filled out the Depression Anxiety Stress Scale questionnaire and the questionnaire related to the demographic characteristics, questions related to childs habits of the tooth brushing, eating sweets. RESULTS Multiple regression analysis showed that the incidence of active caries in the children was statistically significantly related not only to the level of parent depression (β = -0.289; P = 0.040) but also the level of anxiety (β = 0.186; P = 0.038) and stress (β = -0.120; P = 0.036). The dmft index in the examined children was negatively significant associated with the parental level of depression (β = -0.305; P = 0.032). CONCLUSION Considering the results of our research it is essential to emphasize the need for better health education of parents.

Assessment of cytotoxic and genotoxic effects of conventional and whitening kinds of toothpaste on oral mucosa cells

Abstract Objective: This study aimed to evaluate possible DNA damages to oral epithelial cells exposed to whitening kinds of toothpaste considering the effect of conventional non-whitening toothpaste. Materials and methods: Sixty volunteers were assigned into three experimental groups, each of them using a different regular toothpaste for the initial 2 months, followed by the use of whitening kind of toothpaste of the same brand for next 2 months. The oral epithelial cells were sampled prior and 30, 60, 90 and 120 days after the beginning of the use of tested kinds of toothpaste. Chromosomal damages were analyzed by micronucleus assay. Results: For just one kind of tested whitening toothpaste was observed the significant increase in the number of micronucleated cells after 60 days of use compared values obtained 60 days of usage of conventional non-whitening toothpaste (6.35 ± 3.67 and 2.8 ± 1.91; p < .05). There was no statistically significant difference in other micronucleus assay endpoints between tested types of toothpaste at either of the sampling times during the period of toothpaste application. Conclusions: Based on the results, it can be concluded that the use of certain whitening kinds of toothpaste may cause a limited biologically insignificant genotoxic effect on buccal epithelial cells.

Prevalence and Characteristics of Congenitally Missing Permanent Teeth among Orthodontic Patients in Southern Croatia

Background Congenitally missing permanent teeth (CMPT) was recognized as a clinical and public health problem in pediatric dentistry. Aim To determine the prevalence of CMPT among orthodontic patients in Southern Croatia. Materials and Methods In a retrospective study, we analyzed CMPT in patients from three different regions in Southern Croatia (SC). Two orthodontic practices from each region were selected and a total of 4649 records of patients aged 6 - 15 years, who were clinically examined for orthodontic treatment between 2008 and 2015, were evaluated. We excluded 219 patients and 4430 patients remained for further analysis. Results There was no difference in prevalence of CMPT among regions in Southern Croatia, and the whole sample was evaluated. CMPT was found in 345(7.8%) patients. The highest proportion of CMPT was with one or two missing teeth 122 (81.9%) and 158 (80.6%), followed by those with three to five missing teeth or moderate hypodontia, 25(16.8%) and 35(17.9%), in males, and females respectively. Bilateral hypodontia of the lower second premolars and upper second incisors was more common than unilateral hypodontia. Conclusions The obtained results of high prevalence of CMPT in Southern Croatia reinforce the need for a timely diagnostics and treatment of moderate and severe cases.

Biocompatibility of Dental Adhesives

The accomplishment of developing a truly adhesive bond between a restorative material and the natural tooth structures is the goal of adhesive dentistry. Dentine adhesive systems come into close contact with dental and oral tissue, especially the pulp and gingival cells. Due to this close and long-term contact, adhesives should exhibit a high degree of biocompatibility. Biocompatibility is one of the most important properties of dental materials, and adhesives are no exception. It has been long demonstrated that different components of adhesives can be released. Numerous in vitro investigations have shown that released monomers and other components can cause damage to cultured cells. In addition, many in vivo studies have shown that uncured components which reach the pulpal space cause inflammatory response and tissue disorganization. Only a combination of various in vitro and in vivo tests can provide an overview of the interaction of biomaterials with the host. Therefore, it is necessary on a regular basis to carry out and re-verify the biological compatibility of the increasing number of new dental materials. Adhesives should be biofunctional, protective, and preventive, with health-promoting effects that contribute to a better prognosis for restorative treatments and its biocompatibility.