Toxicity Assessment of Long-Term Exposure to Non-Thermal Plasma Activated Water in Mice.

Non-thermal plasma activated water (PAW) has recently emerged as a powerful antimicrobial agent. Despite numerous potential bio-medical applications, studies concerning toxicity in live animals, especially after long-term exposure, are scarce. Our study aimed to assess the effects of long-term watering with PAW on the health of CD1 mice. PAW was prepared from distilled water with a GlidArc reactor according to a previously published protocol. The pH was 2.78. The mice received PAW (experimental group) or tap water (control group) daily for 90 days as the sole water source. After 90 days, the following investigations were performed on the euthanatized animals: gross necropsy, teeth mineral composition, histopathology, immunohistochemistry, hematology, blood biochemistry, methemoglobin level and cytokine profile. Mice tolerated PAW very well and no adverse effects were observed during the entire period of the experiment. Histopathological examination of the organs and tissues did not reveal any structural changes. Moreover, the expression of proliferation markers PCNA and Ki67 has not been identified in the epithelium of the upper digestive tract, indicating the absence of any pre- or neoplastic transformations. The results of our study demonstrated that long-term exposure to PAW caused no toxic effects and could be used as oral antiseptic solution in dental medicine.

Fluoride Rinses, Gels and Foams: An Update of Controlled Clinical Trials.

AIM: The aim of this conference paper was to systematically review the quality of evidence and summarize the findings of clinical trials published after 2002 using fluoride mouth rinses, fluoride gels or foams for the prevention of dental caries. METHODS: Relevant papers were selected after an electronic search for literature published in English between 2003 and 2014. The included papers were assessed for their risk of bias and the results were narratively synthesized due to study heterogeneity. The quality of evidence was expressed according to GRADE. RESULTS: A total of 19 papers were included (6 on fluoride mouth rinse, 10 on fluoride gel and 3 on fluoride foam); 6 had a low risk of bias while 2 had a moderate risk. All fluoride measures appeared to be beneficial in preventing crown caries and reversing root caries, but the quality of evidence was graded as low for fluoride mouth rinse, moderate for fluoride gel and very low for acidulated fluoride foam. No conclusions could be drawn on the cost-effectiveness. CONCLUSIONS: This review, covering the recent decade, has further substantiated the evidence for a caries-preventive effect of fluoride mouth rinse, fluoride gel and foam, previously established in systematic reviews. The lack of clinical trials free from bias is, however, still a concern, especially for fluoride mouth rinses and fluoride foam. There is also a scientific knowledge gap on the benefit and optimal use of these fluoride supplements in combination with daily tooth brushing with fluoride toothpaste.

Fluoride Varnish for Caries Prevention: Efficacy and Implementation.

Many reviews support fluoride varnish (FV) as a caries-inhibitory agent. Evidence from 6 Cochrane systematic reviews involving 200 trials and more than 80,000 participants further confirms the effectiveness of FV, applied professionally 2-4 times a year, for preventing dental caries in both primary and permanent teeth. The relative benefit of FV application seems to occur irrespective of baseline caries risk, baseline caries severity, background exposure to fluorides, use of fluoride toothpaste and application features such as prior prophylaxis, concentration of fluoride or frequency of application. While the efficacy of FV is acknowledged in clinical practice guidelines globally, the implementation of this recommendation may still be an issue. Factors that may facilitate FV application in the USA include Medicaid eligibility, relationships with dentists/community centers and strong cooperation and communication between physicians and support staff. Barriers include insufficient time to integrate oral health services into well-child visits, difficulty in applying FV (lack of skills/training) and resistance among colleagues and staff. Research in the UK/Scotland also suggests encouraging clinicians in their motivation to perform this treatment and addressing professional and parental concerns relating to possible negative consequences may be influential. Further research targeting cost-effectiveness and how FV in routine care may fit in with political agendas relating to, for example, inequalities in health care provision and access will also play a key part in stakeholder decisions to put resources into this issue.

Cytotoxicity assessment of graphene-based nanomaterials on human dental follicle stem cells.

Graphene-oxide (GO) and its most encountered derivatives, thermally reduced graphene oxide (TRGO) and nitrogen-doped graphene (N-Gr), were synthesized and structurally characterized by spectroscopic techniques, like Raman and (13)C MAS solid state NMR. Several biological effects (cytotoxicity, oxidative stress induction, and cellular and mithocondrial membrane alterations) induced by such graphene-based materials on human dental follicle stem cells were investigated. Graphene oxide shows the lowest cytotoxic effect, followed by the nitrogen-doped graphene, while thermally reduced graphene oxide exhibits high cytotoxic effects. Graphene oxide induces oxidative stress without causing cell membrane damage. Nitrogen-doped graphene shows a slight antioxidant activity; however, at high doses (20 and 40 µg/ml) it causes membrane damage. Both graphene oxide and nitrogen-doped graphene seem to be valuable candidates for usage in dental nanocomposites.

Assessment of Pain Intensity in Patients with Dentin Hypersensitivity After Application of Prophylaxis Paste Based on Calcium Sodium Phosphosilicate Formula.

BACKGROUND: One of many functions of the pulp-dentin complex is sensory function. Acute, situated, receding pain after the cessation of the stimulus action is called dentin pain. Dentin hypersensitivity has been described as one of the most painful and least successfully treated chronic ailments of teeth. The aim of this research was the clinical evaluation of the effectiveness of professional polishing paste containing calcium sodium phosphosilicate formula (NovaMin) in eliminating dentin hypersensitivity after a single application. MATERIAL AND METHODS: The study comprised 92 teeth with dentin hypersensitivity diagnosed on the basis of history and clinical examination. The pain reaction of exposed dentine was induced by tactile and dehydrating stimuli, asking patients to assess the severity of pain on the VAS scale. Clinical trial and survey were carried out twice: before and 1 week after the application of the polishing paste. RESULTS: After the application of the examined paste, the percentage of teeth reacting with a severe pain to the touch of the probe decreased from 16.3% to 4.3%, and with a moderate pain from 42.4% to 12%. Examination after applying dehydrating stimulus a week after carrying out the application showed a decrease in the proportion of teeth with strong pain from 28.3% to 0% and moderate pain from 38% to 15.2%. The lack of pain increased from 12% to about 50%. CONCLUSIONS: The use of prophylactic professional paste with NovaMin formula in in-office procedure provides the reduction of dentin hypersensitivity noticeable by 1 week after application.

Employment of Reservoirs in At-Home Whitening Trays: Efficacy and Efficiency in Tooth Whitening.

AIM: This study aimed to determine the efficacy of trays made with and without reservoirs, in conjunction with time and cost evaluations, by measuring color change with home whitening procedures. MATERIALS AND METHODS: Extracted human maxillary teeth (central incisors n = 20; canines n = 20; molars n = 20) and 60 artificial teeth (lateral n = 20; premolar n = 40) were mounted into ten typodonts. Tray fabrication was completed such that a block-out resin reservoir was placed on half of the buccal surface of the tray, while the other half remained without a reservoir. Whitening with custom fabricated trays was performed based on two different whitening regimens, where each regimen was assigned to five typodonts: Night-time: Opalescence PF 10% carbamide peroxide for 8 hours daily and Day-time: Philips DayWhite 9.5% hydrogen peroxide for 30 minutes, twice daily. Both systems were applied for 1 week. To evaluate tooth shade, the VITA Easyshade® Advance 4.0 spectrophotometer was used. Color measurements were obtained at baseline (T1), 1-day post-whitening (T2), and 1 month post-whitening (T3). One-way ANOVA, followed by post-hoc Tukey's HSD test, was used to detect significant difference in the overall color change (ΔE*) among the four groups at T2 and T3. Additionally, paired-sample t-test was used to assess difference in ΔE* between T2 and T3 treatment within each of four techniques of tray fabrication. RESULTS: No significant difference in ΔE* was found among the four groups at T2 and T3 (p > 0.05 in each instance). There were significant differences in mean ΔE* between T2 and T3 treatment for the day white treatment groups without reservoir (6.96 vs 10.19 respectively; p = 0.0026) and with reservoirs (6.23 vs 9.79 respectively; p = 0.0031). CONCLUSION: The use of reservoirs does not have a significant effect on whitening efficacy, regardless of type of whitening material and regimen. CLINICAL SIGNIFICANCE: The use of custom fabricated trays with or without reservoirs were equally effective in whitening teeth.

In vitro assessment of 3 dentifrices containing fluoride in preventing demineralization of overdenture abutments and root surfaces.

STATEMENT OF PROBLEM: Caries development under overdentures has been a continuing problem and requires the daily use of fluoride to prevent demineralization. PURPOSE: The purpose of this in vitro study was to compare the effectiveness of dentifrices containing tricalcium phosphate or calcium phosphosilicate in combination with fluoride to prevent the demineralization of overdenture abutments and root surfaces. MATERIAL AND METHODS: A total of 56 caries-free extracted teeth were prepared as overdenture abutments. The teeth were painted with acid-resistant varnish, leaving one 1×4-mm window on occlusal and root surfaces. The teeth were randomly divided into 4 groups: a control group treated with distilled/deionized water only, a group treated with ClinPro 5000, a group treated with ReNew, and a group treated with Prevident 5000 gel. Each tooth was subjected to a demineralizing/remineralizing cycling protocol for 12 days with the appropriate treatment products. The teeth were sectioned longitudinally through both windows. Photomicrographs were made of 3 representative sections from each tooth. A representative section was defined as one that included both windows and was cut from the part of the tooth that had the flattest surface to reduce the edge effect. The depths of the lesions were measured on representative sections from each group. A 1-way MANOVA and a 1-way ANOVA with the post hoc Tukey-Kramer test were used to evaluate the treatment effects on the criterion variables (α=.05). RESULTS: The total lesion depths of the control teeth on the occlusal surface were not statistically significantly deeper than for the 3 dentifrices (P=.7705). However, all 3 dentifrices had narrower cavitation depths than the control (mean cavitation band depth, 43.59 [ReNew] versus 37.99 [Prevident 5000 gel] versus 36.70 [ClinPro 5000] versus 246.86 [control]) (P<.001). The mean remineralization band depth for ClinPro 5000 was significantly greater than for the other 2 treatment groups (118.03 [ClinPro 5000] versus 107.80 [ReNew] versus 102.28 [Prevident 5000 gel]) (P<.001). On root surfaces, the total lesion depth for the control group was statistically significantly deeper than for the 3 dentifrices (mean total lesion depth, 150.31 [control] versus 82.05 [ReNew] versus 68.10 [ClinPro 5000] versus 56.97 [Prevident 5000 gel]) (P<.001). The data indicated that teeth treated with Prevident 5000 gel had the shallowest total lesion depth and were statistically significantly different from those treated with ReNew and ClinPro 5000. Moreover, teeth treated with ReNew were found to have the largest remineralization band depth, which was statistically significantly different compared with ClinPro 5000 and Prevident 5000 gel (mean remineralization band depth, 49.66 [ReNew] versus 36.14 [ClinPro 5000] versus 23.27 [Prevident 5000 gel]) (P<.001), but no difference was found in cavitation depth of the root lesions between the 3 dentifrices. CONCLUSIONS: The addition of tricalcium phosphate or calcium phosphosilicate to fluoride-containing dentifrices (5000 ppm) does not significantly improve their ability to prevent demineralization of the cut dentin surface of overdenture abutments. However, on root surfaces, ReNew, which contains calcium phosphosilicate, was found to improve remineralization of the lesions compared with Prevident 5000 gel or ClinPro 5000.

In vitro assessment of tooth color alteration by two different types of endodontic irrigants.

AIM: The purpose of this study was to assess in vitro the tooth color alterations associated with two commonly used endodontic irrigants, the chlorhexidine gluconate (CHX) and the sodium hypochlorite (NaOCl) up to 15 days post-treatment. Additionally, the possible influence of endodontic access preparation on tooth color was investigated. MATERIALS AND METHODS: Thirty intact human anterior teeth were used. Black adhesive tape with a 4 mm diameter window was used to standardize the enamel surface intended for color analysis. After the access cavity, preparation and the initial root canal negotiation with stainless steel hand files, the root canal shaping was completed with rotary nickel-titanium files. The teeth were divided into three groups (n = 10). Conventional syringe irrigation was performed with one irrigant for each group. The enamel surfaces were colorimetrically evaluated before access cavity, after cavity preparation and at 1, 3, 7 and 15 days post-treatment. The CIE color parameters (L*, a*, b*) were recorded and averaged for each material and the corresponding color differences (ΔE) were calculated and statistically analyzed. RESULTS: The most significant factor in tooth color alteration, during the endodontic treatment, was the access preparation. CHX and NaOCl caused tooth color changes comparable with the saline. CHX and NaOCl did not increase the tooth color changes relative to the values induced by the access preparation. CONCLUSION: The two endodontic irrigants were not able to induce tooth color alteration to a greater extent than the access preparation. CLINICAL SIGNIFICANCE: Chlorhexidine and NaOCl cannot be considered as discoloring endodontic materials. The most contributing factor in tooth color alteration during endodontic treatment in the anterior teeth is access preparation.

Visual and digital comparative tooth colour assessment methods and atomic force microscopy surface roughness.

This study compared digital and visual colour tooth colour assessment methods in a sample of 99 teeth consisting of incisors, canines and pre-molars. The teeth were equally divided between Control, Ozicure Oxygen Activator bleach and Opalescence Quick bleach and subjected to three treatments. Colour readings were recorded at nine intervals by two assessment methods, VITA Easyshade and VITAPAN 3D MASTER TOOTH GUIDE, giving a total of 1782 colour readings. Descriptive and statistical analysis was undertaken using a GLM test for Analysis of Variance for a Fractional Design set at a significance of P < 0.05. Atomic force micros copy was used to examine treated ename surfaces and establish surface roughness. Visual tooth colour assessment showed significance for the independent variables of treatment, number of treatments, tooth type and the combination tooth type and treatment. Digital colour assessment indicated treatment and tooth type to be of significance in tooth colour change. Poor agreement was found between visual and digital colour assessment methods for Control and Ozicure Oxygen Activator treatments. Surface roughness values increased two-fold for Opalescence Quick specimens over the two other treatments, implying that increased light scattering improved digital colour reading. Both digital and visual colour matching methods should be used in tooth bleaching studies to complement each other and to compensate for deficiencies.

Spectrophotometric assessment of the effectiveness of Opalescence PF 10%: a 14-month clinical study.

OBJECTIVES: To evaluate the effectiveness of Opalescence PF 10% just after treatment, at 6-month follow-up and at a 14-month follow-up period. METHODS: Opalescence PF 10% was applied nightly for 14 days. The color of teeth 11 and 21 of 17 subjects were measured with a spectrophotometer (L*; a*; b*) before treatment, just after treatment (14 days), after 6 months and after 14 months. Subjects were instructed to take note of any tooth sensitivity. RESULTS: For all three components (L*, a* and b*) statistical significant differences (p<0.05) in the values between base-line, after treatment (14 days later), after 6 months and after 14 months were found (Wilcoxon Signed Rank Sum Test). The decrease in L* was about 20% after 6 months and about 50% after 14 months. The a* value decreased approximately 14% after 6 months but was worse after 14 months than at the beginning. The b* value decreased the least with about 9% after 6 months and about 8% after 14 months. The decrease in DeltaE(ab)(*) was approximately 20% after 14 months. Less than 20% of the subjects experienced mild tooth sensitivity just after treatment. CONCLUSION: Significantly whiter teeth were found after treatment as well as after a 6-month follow-up period. The whiteness/brightness (L*) decreased with approximately 50% after 14 months and the a* value with approximately 50% after 7 months, while the yellowness (b* value) remained even after 14 months. CLINICAL IMPLICATIONS: The product is an effective tooth whitener resulting in only low tooth sensitivity. Re-bleaching could be done at about 14 months.

Dental maturity assessment in children with acute lymphoblastic leukemia after cancer therapy.

UNLABELLED: Dental age is largely used in both forensic studies and clinical practice. All over the world, many studies have been made to determine chronological age using dental ages of individuals, but selecting individuals with no chronic or acute sickness as the study group. Cancer is the second most frequent cause of death in children, and acute lymphoblastic leukemia (ALL) is the most common type of cancer in childhood. Most of the children who survived childhood cancer experienced disturbances in dental development due to cancer therapy or to cancer itself. The aim of this study is to assess dental development in children and teenagers who had suffered from childhood leukemia and were submitted to chemotherapy isolated or associated with radiotherapy, by comparing the dental ages with those corresponding features in a healthy control group. Dental development was analyzed using panoramic radiographs of 92 children divided in two groups: 46 children between 5 and 12 years old, treated for ALL at GRAACC-IOP, UNIFESP, and as a control group, 46 healthy children treated for dental reasons at APCD, São Paulo. The dental age of the subjects was estimated using the system of Demirjian et al. [A. Demirjian, H. Goldstein, J.M. Tanner, A new system of dental age assessment, Hum. Biol. 45(2) (1973) 211-227]. A significant difference was found between the chronological and dental age of patients submitted to antineoplasic therapy for ALL, when compared to those of the control group, but there were no significant differences between patients treated with different protocols for ALL. CONCLUSIONS: although the study was within a small group of patients, we could clearly conclude that antineoplastic therapy can interfere in the dental maturity of patients treated for childhood cancer by interfering in dental formation and root development.

[Assessment of the dental status, acid-base balance in the oral cavity and Ph of the gastric medium during the use of the Dirol chewing gum]. / Otsenka stomatologicheskogo statusa, kislotno-shchelochnogo ravnovesiia polosti rta i pH zheludochnoi sredy pri ispol'zovanii zhevatel'noi rezinki Dirol.

The goal of our research was to study the short-term and long-term effects of the Dirol chewing gum on the oral cavity state and acid-forming stomach function in patients with hyperchlorhydria. It was revealed that the rational use of this chewing gum by patients with increased gastric secretion can normalize the gastric acidity. Another result of the use of this chewing gum is the improvement of the oral cavity hygienic state and reduced growth of dental caries.

Minocycline-induced pigmentation. Incidence, prevention and management.

Pigmentation is a well recognised adverse effect of minocycline therapy. Various body sites, most notably the skin, nails, bones, thyroid, mouth and eyes are affected and the pigmentation may appear at multiple sites. In general, pigmentation results from long term administration of minocycline at cumulative doses greater than 100 g, although cutaneous or oral mucosal pigmentation may appear, regardless of dose or duration of therapy. When the skin is involved, the blue-black pigmentation develops most frequently on the shins, ankles and arms. Other patterns of skin involvement include pigmentation that is either generalised and symmetrical, or that develops at sites of inflammation. The bones of the oral cavity are probably the most frequently affected sites of pigmentation affecting greater than 20% of patients taking minocycline for more than 4 years. In contrast, the oral mucous membranes and teeth are infrequently pigmented from minocycline. Ocular, thyroid and visceral pigmentation is also relatively uncommon and usually develops only with high doses and long term minocycline use. Whereas pigmentation of the skin and oral mucosa is generally reversible when the drug is discontinued, the pigmentation is often permanent when other sites are involved. Although minocycline-induced pigmentation is not harmful, the drug should be discontinued when the adverse effect is recognised. All patients receiving minocycline, especially those treated for longer than 1 year, require screening for the development of pigmentation.

Genotoxicity and carcinogenicity of fluorocarbons: assessment by short-term in vitro tests and chronic exposure in rats.

Two short-term in vitro tests for mutagenicity (Salmonella reverse mutation and BHK21 cell transformation) were conducted on a series of fluorocarbons. Some of these materials (FC22, FC31, FC142b, FC143, and FC143a) were found to be positive in one or both of the tests and could therefore be considered as being potentially carcinogenic to animals. Such activity was not anticipated for what were previously considered inert materials and in consequence several examples of these fluorocarbons, which represented different combinations of short-term test results, were tested for carcinogenicity in limited in vivo bioassays. In these studies, rats were dosed for 1 year by gavage 5 days a week with either FC22, FC31, FC133a, FC134a, or FC143a dissolved in a corn-oil at a single dosage of 300 mg/kg body weight. The animals were then observed until week 125 with detailed necropsy at termination. The study revealed that FC31 was a potent carcinogen (to the rat stomach), a result which reflected the short-term test predictions, but FC133a, which gave a negative response in both the in vitro assays, induced a high incidence of reproductive tract tumors. The weak bacterial mutagens FC22 and FC143a did not induce tumors in this study, and the nonmutagenic FC134a was without overt carcinogenic activity. It is concluded that, while recognizing the limitations of the in vivo component of this study, the short-term tests were only partially successful in identifying potential carcinogens for this series of chemicals. Fluorocarbon 31 was a potent carcinogen which was first identified by bacterial mutation and cell transformation, whereas the equally potent carcinogen FC133a was not so identified. The lack of genotoxic activity with this particular compound leads us to believe that the carcinogenic activity may be due to mechanisms other than those which involve direct DNA interactions.