scholarly journals Microcomputed Tomography Evaluation of Root Dentin Caries Prevention by Topical Fluorides and Potassium Iodide

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 874 ◽  
Author(s):  
Vernon Zander ◽  
Daniel Chan ◽  
Alireza Sadr

The mineral content of dental hard tissues has traditionally been measured by destructive tests such as transverse microradiography. Microfocus X-ray computed tomography (micro CT) has enabled non-destructive 3D assessment of tooth demineralization. This study compared the preventive effects of silver diammine fluoride (SDF) and potassium iodide (KI) in comparison with fluoride varnish. SDF has been known to arrest caries but darkens the tooth. KI creates a precipitate with SDF that reduces the discoloration, but its effects on SDF efficacy in terms of preventing demineralization of at-risk root dentin surfaces is unknown. Bovine root dentin blocks were randomly distributed into four groups and subjected to a pretreatment in each group (n = 8); Control: deionized water (DIW); F-Varnish: 5% sodium fluoride varnish: 38% Saforide; SDF+KI: SDF followed by saturated solution of KI in DIW. The treated dentin was subjected to 8 cycles of demineralization (pH 5) for 14 h and remineralization in artificial saliva (pH 7) for 10 h. Specimens were then scanned for 12 min using micro CT at 73 KV and 1012 µA with 8.3 μm resolution. The 3D images were analyzed in Amira software to calculate lesion depth (LD), surface layer mineral density (SL) and mineral loss (ΔZ) for each specimen. One-way ANOVA with Bonferroni posthoc showed that there was a statistically significant difference between Control and all three other groups for all parameters (P < 0.001), however, there was no statistical difference among F-Varnish, SDF and SDF+KI (P > 0.05). Single application of F-Varnish, SDF and SDF+KI showed comparable preventive effects against root dentin demineralization. Application of KI did not affect anti-demineralization properties of SDF in this study. Micro CT is a quick and effective method for objective and high-resolution characterization of dentin caries lesions.

2021 ◽  
Author(s):  
Yung-Chang Lu ◽  
Ting-Kuo Chang ◽  
Tzu-Chiao Lin ◽  
Shu-Ting Yeh ◽  
Hsu-Wei Fang ◽  
...  

Abstract Background: Osteolysis is one of the most prevalent clinical complications of total joint replacement (TJR). Wedelolactone (WDL) is a coumestan compound derived from the Wedelia chinensis plant and has been demonstrated to exhibit anti-inflammatory properties. This study aimed to investigate the use of WDL as a potential treatment for reducing the risk of particle-induced osteolysis using a well-established particle-induced mice calvarial disease model. Methods: Thirty-two C57BL/6J mice were randomized into four groups: sham, polystyrene particles (PS), PS particles with WDL treatment for 4 weeks (WDL 4w) and PS particles with WDL treatment for 8 weeks (WDL 8w). Micro-CT was used to quantitatively analyze the bone mass. Osteoclast numbers were also measured from histological analysis. Results: The results showed that bone mineral density was significantly higher in the WDL 8w group than in the PS group (p < 0.05), and both the WDL 4 and WDL 8w groups had lower osteoclast numbers (p < 0.05). No significant difference in osteoclast number was found between the WDL 4w and WDL 8w groups. Conclusions: These results support the use of WDL as a herbal medicine for reducing the severity of particle-induced osteolysis after TJR.


2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Zahra Khoubrouypak ◽  
Mahdi Abbasi ◽  
Elham Ahmadi ◽  
Niyousha Rafeie ◽  
Marjan Behroozibakhsh

Purpose. Considering the suggested advantages of cold atmospheric plasma (CAP) in increasing the fluoride uptake by the enamel, this study aimed to assess enamel erosion following the application of helium CAP and two types of fluoride varnishes. Methods. The microhardness of 70 bovine enamel specimens was measured using a Vickers hardness tester. The specimens were randomly divided into 7 groups (n = 10): control, CAP (P), resin-containing fluoride varnish (RF), CAP + resin-containing fluoride varnish (PRF), fluoride varnish (F), CAP + fluoride varnish (PF), and erosion (E). The specimens in the control and erosion groups did not receive CAP or fluoride varnish. All specimens underwent erosive challenge 4 times/day using hydrochloric acid and artificial saliva except for the control specimens that remained in distilled water during the course of the study. After 5 days of erosive challenge, microhardness was measured again, and the percentage of microhardness change was calculated. Surface roughness of two specimens in each group was assessed by atomic force microscopy (AFM). Data were analyzed using one-way ANOVA followed by Tamhane’s post-hoc test. Results. The percentage of microhardness change in all groups was significantly higher than that of the control group. All groups showed significantly lower percentage of microhardness change compared with the E group except for the P group; no significant difference was noted in microhardness change of P and E groups. Other experimental groups had no significant difference with each other. Surface roughness was the highest in PRF and the lowest in the F group. Conclusion. CAP application had no significant effect on increasing the enamel resistance to erosion. However, enamel resistance to erosion increased significantly after fluoride varnish application alone or fluoride varnish application combined with CAP. No significant difference was noted between the two types of varnishes in this regard. CAP increased the surface roughness while fluoride varnish application alone decreased the roughness.


2017 ◽  
Vol 87 (6) ◽  
pp. 841-846 ◽  
Author(s):  
Aslihan Zeynep Oz ◽  
Abdullah Alper Oz ◽  
Sabahat Yazıcıoglu

ABSTRACT Objectives: The aim of this in vivo study was to investigate the preventive effect of two different adhesives on enamel demineralization and compare these adhesives with a conventional one. Materials and Methods: Fifteen patients requiring the extraction of their first four premolars for orthodontic treatment were included in the study. One premolar was randomly selected, and an antibacterial monomer-containing and fluoride-releasing adhesive (Clearfil Protect Bond, Kuraray Medical, Okayama, Japan) was used for orthodontic bracket bonding. Another premolar was randomly selected, and a fluoride-releasing and recharging orthodontic adhesive (Opal Seal, Ultradent Products, South Jordan, Utah) was used. One premolar was assigned as a control, and a conventional adhesive (Transbond XT, 3M Unitek, Monrovia, Calif) was used. The teeth were extracted after 8 weeks, and the demineralization areas of the 45 extracted teeth were analyzed using microcomputed tomography with software. Results: There was no significant difference between the white spot lesion (WSL) rates of the adhesives (P &gt; .05). The volumes of the WSLs varied from 0 to 0.019349 mm3. Although Opal Seal showed the smallest lesion volumes, there was no significant difference in volumetric measurements of the lesions among the groups (P &gt; .05). Conclusions: The findings indicated no significant differences between the preventive effects of the adhesives used in this in vivo study over 8 weeks.


2021 ◽  
Author(s):  
Fan Yu ◽  
Bo Li ◽  
Guoliang Zhang ◽  
Song Zhou

Abstract ObjectiveTo investigate whether interleukin-17 receptor C (il-17rc) gene knockout leads to systemic osteoporosis in transgenic mice. MethodsThe immunohistochemistry and micro computed tomography (micro-CT) were used to analyze the condition of vertebral cancellous bone in 3-month healthy female wild-type C57BL/6 mice (control group) and il-17rc gene knockout C57BL/6 mice (experimental group). ResultsWild type C57BL/6 mice had higher bone density per unit volume (0.52 ± 0.12 vs. 0.47 ± 0.05, P = 0.028) (g/cm3), more trabecular connections (8.97 ± 1.46 vs. 5.59 ± 3.15, P = 0.017) (1/mm), thicker trabecular thickness (0.16 ± 0.08 vs. 0.10 ± 0.04, P = 0.029) (1/mm) and the number of trabeculae was more (5.01 ± 0.33 vs. 3.16 ± 0.37, P = 0.038) (1/mm) than mut-il-17rc mice. In addition, the results of micro-CT also showed that the osteoporosis of il-17rc gene knockout C57BL/6 mice was mainly manifested in T13 (P = 0.039), L1 (P = 0.035), L3 (P = 0.018), L5 (P = 0.021) and L6 (P = 0.036), but the mean bone mineral density between L2 (P = 0.317) and L4 (P = 0.242) was no significant difference between the two groups. ConclusionIL-17/il-17rs signal axis is widely distributed in the animal skeletal system and is one of the important signal pathways regulating bone metabolism. Knockout of il-17rc gene can lead to the occurrence of osteoporosis in model animals.


2016 ◽  
Vol 50 (4) ◽  
pp. 422-431 ◽  
Author(s):  
Nobuhiro Takahashi ◽  
Bente Nyvad

Recent advances regarding the caries process indicate that ecological phenomena induced by bacterial acid production tilt the de- and remineralization balance of the dental hard tissues towards demineralization through bacterial acid-induced adaptation and selection within the microbiota - from the dynamic stability stage to the aciduric stage via the acidogenic stage [Takahashi and Nyvad, 2008]. Dentin and root caries can also be partly explained by this hypothesis; however, the fact that these tissues contain a considerable amount of organic material suggests that protein degradation is involved in caries formation. In this review, we compiled relevant histological, biochemical, and microbiological information about dentin/root caries and refined the hypothesis by adding degradation of the organic matrix (the proteolytic stage) to the abovementioned stages. Bacterial acidification not only induces demineralization and exposure of the organic matrix in dentin/root surfaces but also activation of dentin-embedded and salivary matrix metalloproteinases and cathepsins. These phenomena initiate degradation of the demineralized organic matrix in dentin/root surfaces. While a bacterial involvement has never been confirmed in the initial degradation of organic material, the detection of proteolytic/amino acid-degrading bacteria and bacterial metabolites in dentin and root caries suggests a bacterial digestion and metabolism of partly degraded matrix. Moreover, bacterial metabolites might induce pulpitis as an inflammatory/immunomodulatory factor. Root and dentin surfaces are always at risk of becoming demineralized in the oral cavity, and exposed organic materials can be degraded by host-derived proteases contained in saliva and dentin itself. New approaches to the prevention and treatment of root/dentin caries are required.


Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2116
Author(s):  
Katja Bächli ◽  
Patrick R. Schmidlin ◽  
Florian Wegehaupt ◽  
Frank Paqué ◽  
Liza Ramenzoni ◽  
...  

To assess the remineralizing potential of dentin matrix proteins and enamel matrix derivatives (DMPs and EMDs) after application on artificially induced dentin lesions, given the hypothesis that these materials increase the mineral uptake, binding, and mineralization. Forty-eight caries-free human premolars were used. Teeth were cut, polished, and embedded, leaving an open window on the root surface, of which one-third was covered with a flowable composite to preserve the healthy untreated dentin. Then, samples were demineralized in Buskes solution for 33 days. A micro-CT scan prior to treatment was performed. Next, the samples were randomly allocated into four groups: (A) An untreated negative control (CON), (B) application of porcine dentin matrix proteins (DMP), (C) treatment with enamel matrix derivatives (EMD, Emdogain, Straumann), and (D) amine fluoride application (AMF, Elmex fluid, GABA). All samples were placed in artificial saliva for 21 days. A second micro-CT scan was performed, after which the change in gray scaling within a defined region of interest (0.25 mm3) was analyzed. ANCOVA was applied to discover statistical differences between the different treatments. Both, treatment with AMF; (P = 0.011 versus CON) as well as with DMP (P = 0.043 versus CON) yielded a statistically significant difference compared to the control treatment. EMD treatment was not found to differ (P > 0.05). Mainly the top layer of the defects showed clear signs of remineralization, which was also evident in CON. This study was able to visually confirm the remineralization potential of demineralized dentin especially after DMP application, which, however, did not outperform AMF. Based on this, additional studies combining proteins and fluorides are now warranted and ongoing.


2015 ◽  
Vol 26 (6) ◽  
pp. 671-677 ◽  
Author(s):  
Mariana Alencar Nemezio ◽  
Sandra Chiga Carvalho ◽  
Renata Siqueira Scatolin ◽  
Vivian Colucci ◽  
Rodrigo Galo ◽  
...  

This study evaluated the combined effect of fluoride varnish and Er:YAG laser on the permeability of eroded bovine root dentin. After initial erosive challenge followed by a remineralization period, the specimens were divided in two groups according to the treatment - fluoride varnish and non-fluoride varnish - and were subdivided according to the irradiation protocol: Er:YAG laser (100 mJ, 3 Hz, 12.8 J/cm2per pulse, non-contact and defocus mode) and non-irradiated. After a lead-in period, 7 volunteers wore a palatal device containing 4 specimens that were subjected to erosive challenges. At the first experimental phase, 4 volunteers used specimens treated with fluoride varnish and fluoride varnish+Er:YAG laser and 3 volunteers used specimens treated with non-fluoride varnish and non-fluoride varnish+Er:YAG laser. After a washout period, volunteers were crossed to treatments, characterizing a 2x2 crossover experiment. At the end of the experimental phase, the quantitative response variable was obtained by permeability analysis and the qualitative response by scanning electron microscopy (SEM). Two-way ANOVA and Tukey-Kramer's test revealed that specimens treated with fluoride varnish+Er:YAG laser showed the lowest permeability and a significant difference was found between this group and the others. When varnish (fluoride/non-fluoride) was applied in the absence of Er:YAG laser, higher permeability was found when compared to the laser-treated groups. SEM evaluations showed partially or completely obliterated dentinal tubules when specimens were treated with fluoride varnish+Er:YAG laser. It may be concluded that Er:YAG laser was able to control the permeability of eroded root dentin and the combination with fluoride varnish increased laser action.


2021 ◽  
Vol 2 ◽  
Author(s):  
Kaushik Mukherjee ◽  
Amrita Chakraborty ◽  
Garima Sandhu ◽  
Sohaib Naim ◽  
E. Bauza Nowotny ◽  
...  

We designed synthetic peptides that have demonstrated an effective remineralization potential to restore incipient enamel decay. In order to develop a clinically viable approach we incorporated the amelogenin-derived peptides P26 and P32 into chitosan hydrogel and examined their efficacy in the remineralization of enamel. Peptides in chitosan exhibited increased stability in vitro as compared to peptides in solution at room temperature and at 37°C. Tooth models for enamel erosion (sections) and white spot lesions (blocks) were subject to periods of demineralization. Treatment groups were subjected to remineralization in artificial saliva in the presence of P26 and P32 in solution and in chitosan hydrogel (P26-CS and P32-CS). Quantitative light-induced fluorescence (QLF) was employed to analyze mineral density following demineralization and remineralization across all the treatment groups. Scanning electron microscopy and nanoindentation were used to characterize the surface structure and mechanical strength of regrown enamel. Control enamel sections treated in artificial saliva demonstrated randomly distributed, tiny, needle-shaped crystals with a low packing density and porosities displaying mineralization defects. In samples treated with P26-CS or P32-CS a denser coating of organized hydroxyapatite (HAP) crystals was formed covering the entire surfaces of demineralized enamel window. The hardness and modulus of enamel surfaces were increased after treatment with P26-CS and P32-CS with no significant difference in the mechanical properties between the two peptide hydrogels. Analysis of mineral density by QLF showed that in enamel sections P26 peptide alone or P26-CS significantly enhanced the remineralization. In enamel blocks P26 in solution had a better efficacy than P26-CS.


2020 ◽  
Vol 9 (10) ◽  
pp. 675-688
Author(s):  
Li-tao Shao ◽  
Yu Gou ◽  
Jia-kang Fang ◽  
Yun-peng Hu ◽  
Qiang-qiang Lian ◽  
...  

Aims Parathyroid hormone (PTH) (1-34) exhibits potential in preventing degeneration in both cartilage and subchondral bone in osteoarthritis (OA) development. We assessed the effects of PTH (1-34) at different concentrations on bone and cartilage metabolism in a collagenase-induced mouse model of OA and examined whether PTH (1-34) affects the JAK2/STAT3 signalling pathway in this process. Methods Collagenase-induced OA was established in C57Bl/6 mice. Therapy with PTH (1-34) (10 μg/kg/day or 40 μg/kg/day) was initiated immediately after surgery and continued for six weeks. Cartilage pathology was evaluated by gross visual, histology, and immunohistochemical assessments. Cell apoptosis was analyzed by TUNEL staining. Microcomputed tomography (micro-CT) was used to evaluate the bone mass and the microarchitecture in subchondral bone. Results Enhanced matrix catabolism, increased apoptosis of chondrocytes in cartilage, and overexpressed JAK2/STAT3 and p-JAK2/p-STAT3 were observed in cartilage in this model. All of these changes were prevented by PTH (1-34) treatment, with no significant difference between the low-dose and high-dose groups. Micro-CT analysis indicated that bone mineral density (BMD), bone volume/trabecular volume (BV/TV), and trabecular thickness (Tb.Th) levels were significantly lower in the OA group than those in the Sham, PTH 10 μg, and PTH 40 μg groups, but these parameters were significantly higher in the PTH 40 μg group than in the PTH 10 μg group. Conclusion Intermittent administration of PTH (1-34) exhibits protective effects on both cartilage and subchondral bone in a dose-dependent manner on the latter in a collagenase-induced OA mouse model, which may be involved in regulating the JAK2/STAT3 signalling pathway. Cite this article: Bone Joint Res 2020;9(10):675–688.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1188.1-1188
Author(s):  
C. Daldoul ◽  
N. El Amri ◽  
K. Baccouche ◽  
H. Zeglaoui ◽  
E. Bouajina

Background:Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn’s disease (CD), is considered as a risk factor of low bone mineral density (BMD). In fact, the prevalence of osteoporosis ranges from 17% to 41% in IBD patients. The possible contributing factors may include malabsorption, glucocorticoid treatment and coexisting comorbiditiesObjectives:The purpose of our work was to determine the frequency and the determinants of osteoporosis in patients with IBD and to assess whether there is a difference in BMD status between UC and CD.Methods:This is a retrospective study, over a period of 5 years (from January 2014 to December 2018) and including patients followed for IBD who had a measurement of BMD by DEXA. Clinical, anthropometric and densitometric data (BMD at the femoral and vertebral site) were recorded. The WHO criteria for the definition of osteoporosis and osteopenia were applied.Results:One hundred and five patients were collected; among them 45 were men and 60 were women. The average age was 45.89 years old. The average body mass index (BMI) was 25.81 kg/m2 [16.44-44.15]. CD and UC were diagnosed in respectively 57.1% and 42.9%. A personal history of fragility fracture was noted in 4.8%. Hypothyroidism was associated in one case. Early menopause was recorded in 7.6%. 46.8% patients were treated with corticosteroids. The mean BMD at the vertebral site was 1.023 g/cm3 [0.569-1.489 g/cm3]. Mean BMD at the femoral site was 0.920g/cm3 [0.553-1.286g / cm3]. The mean T-score at the femoral site and the vertebral site were -1.04 SD and -1.27 SD, respectively. Osteoporosis was found in 25.7% and osteopenia in 37.1%. Osteoporosis among CD and UC patients was found in respectively 63% and 37%. The age of the osteoporotic patients was significantly higher compared to those who were not osteoporotic (52.23 vs 43.67 years, p = 0.01). We found a significantly higher percentage of osteoporosis among men compared to women (35.6% vs 18.3%, p=0.046). The BMI was significantly lower in the osteoporotic patients (23.87 vs 26.48 kg/m2, p=0.035) and we found a significant correlation between BMI and BMD at the femoral site (p=0.01). No increase in the frequency of osteoporosis was noted in patients treated with corticosteroids (27.9% vs 21.6%, p=0.479). Comparing the UC and CD patients, no difference was found in baseline characteristics, use of steroids or history of fracture. No statistically significant difference was found between UC and CD patients for osteoporosis(p=0.478), BMD at the femoral site (p=0.529) and at the vertebral site (p=0.568).Conclusion:Osteoporosis was found in 25.7% of IBD patients without any difference between CD and UC. This decline does not seem to be related to the treatment with corticosteroids but rather to the disease itself. Hence the interest of an early screening of this silent disease.Disclosure of Interests:None declared


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