The impact of remineralization agents on dental bleaching efficacy and mineral loss in bleached enamel

This study evaluated the effect of remineralization agents on bleaching efficiency, enamel mineral changes, and post-bleaching color stability. A total of 112 enamel-dentin blocks were prepared from bovine teeth. Following initial color measurements, separate treatment regimens were carried out as follows: negative control (no treatment); positive control (bleaching only); bleaching, then NaF; bleaching + NaF (mix); bleaching, then CPP-ACPF; bleaching + CPP-ACPF (mix); bleaching, then nHAP+F; bleaching + nHAP+F (mix). Color measurements were repeated after immersion in distilled water for 7 days, and again after staining with coffee solution for 14 days. The CIELAB-based whiteness index was used to evaluate bleaching efficiency, and the CIEDE2000 color difference formula for color stability. Chemical investigation was performed using scanning electron microscopy with energy dispersive spectroscopy and X-ray diffraction analyses. The experimental groups showed significant increases in whiteness compared to the negative control, and the staining after bleaching did not result in statistically significant differences between the groups. Energy dispersive spectroscopic analysis revealed that bleaching protocols had no impact on elemental levels as well as the ratio of Ca/P. The combined use of bleaching agents with remineralization agents did not affect bleaching effectiveness but also did not provide an additional contribution.

Dental age estimation with fewer than mandibular seven teeth: An accuracy study of Bedek models in Turkish children

OBJECTIVES

One or more missing teeth, such as hypodontia, make it difficult to obtain accurate results in age estimation methods. This paper aims to test the accuracy of the models developed by Bedek et al. that can estimate age with fewer than seven teeth for Turkish children.

MATERIALS AND METHODS

Panoramic radiographs of 1118 children (540 girls and 578 boys) aged between 6 and 16 years were evaluated using the Willems method and Bedek models for the entire sample and for different ages and sexes. Differences between dental age (DA) and chronological age (CA) calculated for all methods for each sex and all age groups were analyzed the paired sample t-test and Wilcoxon signed rank test. The accuracy of the DA estimation methods was determined by the proximity of DA to CA by calculating mean absolute error (MAE).

RESULTS

While all Bedek models underestimated CA by 0.2 to 0.1 years, the Willems method overestimated CA by 0.3 years. DA-CA difference in the total sample and girls was statistically significant in all methods. In the total sample, the seven- and four-teeth models had the lowest MAE, while the one-tooth model had the highest MAE.

CONCLUSIONS

Seven- and four-teeth models were the most suitable for age estimation, and all models except the one-tooth model were found to be more accurate than the Willems method in northwestern Turkish children.

CLINICAL RELEVANCE

Especially in children with hypodontia, it may be possible to estimate DA with the use of Bedek models.

Dental age and tooth development in children with molar-incisor hypomineralization: A case-control study

OBJECTIVE

The aim of the study was to determine the dental age for the evaluation of tooth development in children with molar-incisor hypomineralization (MIH) by using the Willems method, Cameriere-European formula, and London Atlas.

DESIGN

Panoramic radiographs of 308 children between the ages of 6-13 diagnosed with MIH and the same number of sex- and age-matched children without MIH were evaluated by two different examiners using the Willems method, Cameriere-European formula, and London Atlas. The mean difference between chronological age and dental age in both groups was calculated for each sex and age. The mean absolute error was used to determine the accuracies of the Willems method, Cameriere-European formula, and London Atlas.

RESULTS

There was a statistically significant difference found only in Willems method in dental age estimation between the groups with and without MIH (P = 0.001). In the evaluation performed with Cameriere-European formula and London Atlas, which are more accurate methods for dental age estimation in both groups, no statistically significant difference was found in dental age estimation between the two groups (P = 0.322, P = 0.290, respectively). There was a statistically significant intense linear correlation for three methods in both groups (P < 0.001).

CONCLUSIONS

MIH, which is a developmental enamel defect, does not affect dental age and tooth development since there was no significant difference between groups with and without MIH according to the evaluations made with accurate dental age estimation methods.

Accuracy of the London Atlas, Haavikko's Method and Cameriere's European Formula of dental age estimation in Turkish children

Age estimation is a mandatory procedure when the chronological age is unknown or uncertain. Dental development is the preferred characteristic for estimating a child's age. There are many methods for dental age estimation, but their reliability can differ between populations. This study compared the accuracy of three of these methods-the London Atlas (LA), Haavikko's method (HM), and Cameriere's European formula (CF)-in Turkish children living in northwestern Turkey. Panoramic radiographs of 980 children from northwestern Turkey aged between 6.00 and 14.99 years were examined for the whole study group and separately for different ages and sexes by all three methods. Statistical differences between chronological age and dental age were tested using the paired sample t-test and the Wilcoxon signed-rank test. The LA, HM, and CF accuracies were determined based on the mean absolute error. Spearman's rank correlation coefficient showed that the correlation between chronological age and dental age for both sexes was linear for all methods. The LA overestimated the chronological age by 0.09 years, while HM and CF underestimated it by 0.49 and 0.11 years, respectively. The difference between dental age and chronological age was significant in all samples, for all methods, except for the LA in boys. When boys, girls, and the total sample were evaluated, values with the lowest mean absolute error were obtained by HM and were statistically significant in all three groups. Therefore, HM is more accurate than the LA and CF for dental age estimation in Turkish children living in northwestern Turkey.

Effects of radiotherapeutic X-ray irradiation on cervical enamel

PURPOSE

Therapeutic radiation used for head and neck cancers mainly affects the cervical region of the tooth. To better understand the impact of therapeutic radiation on tooth, we aimed to examine the crystallinity, micro-morphology, and elemental composition of the cervical inner enamel located adjacent to the dento-enamel junction.

MATERIALS AND METHODS

Ninety-one specimens obtained from 16 impacted third mandibular molars were randomly divided into seven groups (0, 10, 20, 30, 40, 50, and 60 Gy irradiation groups). Energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM) were performed after the irradiation by 6 MV photon energy. The X-ray diffraction (XRD) were conducted in every group before and after irradiation. Elemental compositions, and Ca/P, P/N, Ca/N atomic ratios were subjected to the Shapiro-Wilk normality test. All of the elements except Mg showed a normal distribution and were compared by the one-way ANOVA. The non-normally distributed Mg data and Ca/P, P/N, and Ca/N ratios were compared by the Kruskal-Wallis test.

RESULTS

The results showed that widening in the interprismatic spaces were observed in the experimental groups subjected to 30 Gy and the following increased doses. In addition, there were no significant differences in C, O, Ca, P, N percentages between irradiated and non-irradiated groups (p > .05). An increase in atomic ratio of the Mg was detected after samples conducted by 60 Gy radiation dose (p < .05). The stoichiometric Ca/P, Ca/N, and P/N atomic ratios did not change by irradiation (p > .05). The XRD peaks of the inner enamel crystalline phase showed a slight decline in the 60 Gy radiation dose group.

CONCLUSION

Radiation effects begin to be seen after 30 Gy radiation dose groups. The widen interprismatic spaces seen obviously in 50 Gy and 60 Gy dose groups. Besides Mg ratio showed an increase in the 60 Gy dose group. But it should be thought that radiation caries is a multi-factorial disease that is in collaboration with various radiation-induced side effects.

Effects of high temperature on dental restorative materials for forensic purposes

This study aimed to observe the effects of high temperature on different restorative dental materials by detecting changes in their microstructural and elemental composition. Disk shaped samples (10 mm diameter, 2 mm depth) were prepared from 8 dental materials (compomer, glass carbomer, ormocer, giomer, zinc reinforced glass ionomer (GI), silver-alloy reinforced GI, zirconia reinforced GI, and conventional GI). Scanning electron microscopy/Energy dispersive X-ray spectroscopy (SEM/EDS) was used to characterize sample surface structures and elemental composition. The same samples were also analyzed using X-ray fluorescence (XRF) to determine the trace element content. Each sample was placed in a porcelain furnace and exposed to 900 °C for 30 min. Observations of macroscopic changes in samples after exposure high temperature were recorded. The microstructural changes in sample surfaces after incineration were detected by SEM. The elemental compositions obtained before and after the incineration were compared after repeating the XRF and EDS analyses. Dental materials demonstrated specific macroscopic changes and microstructural deteriorations detected by SEM images after exposure to high temperature. While several changes occurred in the elemental content of materials in terms of amount, the original elemental composition was preserved. The ability to distinguish dental materials by elemental analyses has had an important impact on the identification process.