Diametral tensile strength and film thickness of an experimental dental luting agent derived from castor oil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Can the aqueous decoction of mango flowers be used as an antiulcer agent?

This study was designed to determine the effect of Mangifera indica flowers decoction, on the acute and subacute models of induced ulcer in mice and rats. A single oral administration of the aqueous decoction (AD) from M. indica up to a dose of 5 g/kg, p.o. did not produce any signs or symptom of toxicity in the treated animals. The oral pre-treatment with AD (250, 500 and 1000 mg/kg) in rats with gastric lesions induced by ethanol, decreased the gastric lesions from 89.0 +/- 6.71 (control group) to 9.25 +/- 2.75, 4.50 +/- 3.30 and 0, respectively. Pretreatment with AD (250, 500 and 1000 mg/kg) to mice with HCl/ethanol- or stress-induced gastric lesions resulted in a dose-dependent significant decrease of lesion index. In the piroxicam-induced gastric lesions, the gastroprotective effect of AD was reducing with the increase of the AD dose. In the pylorus-ligature, AD (p.o.) significantly decreased the acid output indicating the antisecretory property involved in the gastroprotective effect of M. indica. Treatment with AD during 14 consecutive days significantly accelerated the healing process in subacute gastric ulcer induced by acetic acid in rats. Pretreatment with N-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO-synthase, did not abolish the gastroprotective effects (99% with saline versus 80% With L-NAME) of AD against ethanol-induced gastric lesions. Pretreatment with N-ethylmaleimide (NEM), a blocker of endogenous sulphydryl group, significantly abolished the protective effects of AD against ethanol-induced gastric ulcers (95% with saline versus 47% with NEM). Phytochemical screening showed the presence of steroids, triterpenes, phenolic compounds and flavonoids. Estimation of the global polyphenol content in the AD was performed by Folin-Ciocalteu method and showed approximately 53% of total phenolic on this extract. These findings indicate the potential gastroprotective and ulcer-healing properties of aqueous decoction of M. indica flowers and further support its popular use in gastrointestinal disorders in Caribbean. (c) 2005 Elsevier B.V.. All rights reserved.

Vinegar as an antimicrobial agent for control of Candida spp. in complete denture wearers

The use of denture is known to increase the carriage of Candida in healthy patients, and the proliferation of Candida albicans strains can be associated with denture-induced stomatitis. The aim of this study was to evaluate the use of vinegar as an antimicrobial agent for control of Candida spp. in complete upper denture wearers. Fifty-five patients were submitted to a detailed clinical interview and oral clinical examination, and were instructed to keep their dentures immersed in a 10% vinegar solution ( pH less than 3) overnight for 45 days. Before and after the experimental period, saliva samples were collected for detection of Candida, counting of cfu/mL and identification of species by phenotypical tests ( germ tube formation, chlamidoconidia production, and carbohydrate fermentation and assimilation). The results were analyzed using Spearman's correlation and Student's t-test (p=0.05). Candida yeasts were present in 87.3% of saliva samples before the treatment. A significant reduction was verified in CFU/mL counts of Candida after treatment. A positive correlation between Candida and denture stomatitis was verified, since the decrease of cfu/mL counts was correlated with a reduction in cases of denture stomatitis. Although it was not able to eliminate C. albicans, the immersion of the complete denture in 10% vinegar solution, during the night, reduced the amounts (cfu/mL) of Candida spp. in the saliva and the presence of denture stomatitis in the studied patients.

Efficacy, safety and tolerability of terbinafine for Tinea capitis in children: Brazilian multicentric study with daily oral tablets for 1, 2 and 4 weeks

Background: Tinea capitis is a common skin disease seen predominantly in children. The standard therapies for this disease are griseofulvin and ketoconazole. Nevertheless, these drugs have drawbacks in that they are only fungistatic and require treatment for at least 6 weeks. Previous studies with oral terbinafine for the treatment of Tinea capitis have shown that this agent is effective when given for 4 weeks, comparable to an 8-week regimen with griseofulvin. To date there is no data on the use of oral terbinafine in Brazilian children. Objectives: To assess the efficacy, safety and tolerability of oral terbinafine in short-term treatments (1-, 2- and 4-week treatment) of Tinea capitis in children. Patients and methods: One hundred and thirty-two children aged 1-14 years were enrolled in this study, but only 107 were considered for the final efficacy analysis. Diagnosis included clinical assessment and examination by Wood's light. Confirmation was obtained by direct microscopy and culture for fungus. Terbinafine dosage (125 or 250 mg/day) was adjusted according to patient weight. Efficacy was evaluated both by clinical and mycological assessment. Safety and tolerability variables included data on adverse reaction and clinical laboratory evaluations. Results: Mycological evaluation in the follow-up visit at week 12 showed negative direct microscopy and culture results in 48.6, 60.5 and 69.7% patients in groups 1-, 2- and 4-week, respectively (n.s.). At week 12, 84.8% patients in group 4-week achieved clinical cure with a significant difference compared to groups 1- and 2-week, 54.3 and 60.5%, respectively (P < 0.01). Adverse reactions were present in 4.8, 6.8 and 10.9% of patients in groups 1-, 2- and 4-week, respectively. Terbinafine was not associated with clinically relevant increases in liver function tests. Conclusions: Terbinafine is an effective, well tolerated and safe antifungal agent for the treatment of Tinea capitis m children. The shorter duration of treatment resulted in lower cure rates. However, it is important to note that depending on the severity of the disease, a 1-week-only treatment can also be effective in this indication.

Influence of antimicrobial subinhibitory concentrations on hemolytic activity and bacteriocin-like substances in oral: Fusobacterium nucleatum

Fusobacterium nucleatum is considered for its role in colonization of initial and late microorganisms in dental plaque and for its coaggregation with other bacterial species. It is known that action of different antimicrobial substances may interfere with either virulence factors or with host-bacteria interaction. The goal of this study was to examine the influence of subinhibitory concentrations of chlorhexidine, triclosan , penicillin G and metronidazole on hemolytic activity and bacteriocin-like substance production of oral F. nucleatum. A high resistance to penicillin G was observed and 63% of the isolates were β-lactamase positive. All the tested isolates were susceptible to metronidazole. F. nucleatum isolates grown with or without antimicrobials were alpha-hemolytics. Bacteriocin-like substance production was increased in isolates grown with penicillin G. Impaired production of hemolytic or antagonic substances can suggest a role in the regulation of oral microbiota.

Evaluation of motivation methods used to obtain appropriate oral hygiene levels in schoolchildren.

The aim of the present study is to assess the behaviour of different motivation methods on levels of oral hygiene among schoolchildren aged from 7 to 9 years in Araraquara, SP, Brazil. The methods tested were: indirect instruction using 'The Smiling Robot' (group I), indirect instruction through class presentation (group II) and direct instruction with macromodels (group III). A control group was also constituted, which received no kind of motivation (group IV). The O'Leary Plaque Index was used as the evaluation method, applied before the instruction and 30 days after application of the different methods. It was noted that the plaque index had not decreased in group IV only. In conclusion, all the motivation methods promoted significant decrease of plaque index and among these methods, the 'The Smiling Robot' was the one that provided the best results.

Antimicrobial activity of Uncaria tomentosa against oral human pathogens

Uncaria tomentosa is considered a medicinal plant used over centuries by the peruvian population as an alternative treatment for several diseases. Many microorganisms usually inhabit the human oral cavity and under certain conditions can become etiologic agents of diseases. The aim of the present study was to evaluate the antimicrobial activity of different concentrations of Uncaria tomentosa on different strains of microorganisms isolated from the human oral cavity. Micropulverized Uncaria tomentosa was tested in vitro to determine the minimum inhibitory concentration (MIC) on selected microbial strains. The tested strains were oral clinical isolates of Streptococcus mutans, Staphylococcus spp., Candida albicans, Enterobacteriaceae and Pseudomonas aeruginosa. The tested concentrations of Uncaria tomentosa ranged from 0.25-5% in Müeller-Hinton agat. Three percent Uncaria tomentosa inhibited 8% of Enterobacteriaceae isolates, 52% of S. mutans and 96% of Staphylococcus spp. The tested concentrations did not present inhibitory effect on P. aeruginosa and C. albicans. It could be concluded that micropulverized Uncaria tomentosa presented antimicrobial activity on Enterobacteriaceae, S. mutans and Staphylococcus spp. isolates.

Evaluation of adverse effects of long-term oral administration of carprofen, etodolac, flunixin meglumine, ketoprofen, and meloxicam in dogs

Objective - To evaluate adverse effects of long-term oral administration of carprofen, etodolac, flunixin meglumine, ketoprofen, and meloxicam in dogs. Animals - 36 adult dogs. Procedures - Values for CBC, urinalysis, serum biochemical urinalyses, and occult blood in feces were investigated before and 7, 30, 60, and 90 days after daily oral administration (n = 6 dogs/group) of lactose (1 mg/kg, control treatment), etodolac (15 mg/kg), meloxicam (0.1 mg/kg), carprofen (4 mg/kg), and ketoprofen (2 mg/kg for 4 days, followed by 1 mg/kg daily thereafter) or flunixin (1 mg/kg for 3 days, with 4-day intervals). Gastroscopy was performed before and after the end of treatment. Results - For serum γ-glutamyltransferase activity, values were significantly increased at day 30 in dogs treated with lactose, etodolac, and meloxicam within groups. Bleeding time was significantly increased in dogs treated with carprofen at 30 and 90 days, compared with baseline. At 7 days, bleeding time was significantly longer in dogs treated with meloxicam, ketoprofen, and flunixin, compared with control dogs. Clotting time increased significantly in all groups except those treated with etodolac. At day 90, clotting time was significantly shorter in flunixin-treated dogs, compared with lactose-treated dogs. Gastric lesions were detected in all dogs treated with etodolac, ketoprofen, and flunixin, and 1 of 6 treated with carprofen. Conclusions and Clinical Relevance - Carprofen induced the lowest frequency of gastrointestinal adverse effects, followed by meloxicam. Monitoring for adverse effects should be considered when nonsteroidal anti-inflammatory drugs are used to treat dogs with chronic pain.

Periapical tissue healing after post space preparation with or without use of a protection plug and root canal exposure to the oral environment. Study in dogs

The purpose of this study was to evaluate the influence of coronal leakage on the healing of dogs' periapical tissues after root canal filling, post space preparation and protection or not with a temporary sealer plug. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta-percha points and Endomethasone or CRCS sealers. After post space preparation, the remaining filling material was protected or not with a plug of temporary Coltosol sealer and exposed to the oral environment for 90 days. Thereafter, the animals were sacrificed and the specimens were removed and prepared for histomorphological and histobacteriological analysis. The findings revealed 35% of microbial leakage in the groups without plugs and 15% of leakage in the groups with plugs. Statistical analysis showed that the use of a Coltosol plug improved significantly the histomorphological results regardless of the type of root canal sealer (p=0.05) and that CRCS and Endomethasone sealers showed similar results (p>0.05).

Immunohistochemical expression of PCNA, p53, bax and bcl-2 in oral lichen planus and epithelial dysplasia.

The potential for malignant transformation of oral lichen planus is still controversial. The expression of proteins related to cell proliferation and apoptosis in oral lichen planus and epithelial dysplasia was analyzed to evaluate the true potential for malignant transformation of this disease. Twenty-four cases of each lesion were subjected to the streptoavidin-biotin technique for identifying the immunohistochemical expression of PCNA, p53, bax, and bcl-2 proteins. Of the 24 cases of oral lichen planus, 14 (58.33%) were positive for PCNA, 10 (41.67%) for p53, 4 (16.67%) for bcl-2 and 12 (50%) for bax, whereas of the 24 cases of epithelial dysplasia, 20 (83.33%) were positive for PCNA, 10 (41.67%) for p53, 6 (25%) for bcl-2, and 20 (83.33%) for bax. Chi-squared test showed no statistically significant differences between the expression of p53 and bcl-2 in oral lichen planus and epithelial dysplasia, regardless of the grade (P > 0.05). However, the expression of PCNA and bax was significantly increased in epithelial dysplasia (P < 0.05). The results of this study showed that alterations in expression of these proteins are observed in oral lichen planus and epithelial dysplasia, suggesting the potential for malignant transformation in both lesions.

Clinical and microbiological evaluation of the use of toothpaste containing 1% chlorhexidine and the influence of motivation on oral hygiene in patients with motor deficiency

Patients with motor deficiency have variable difficulties with mechanical plaque control, and as a consequence, the incidence of dental caries and periodontal disease can be higher in these patients. The objective of this study was to evaluate the clinical and microbiological efficacy of a toothpaste containing 1% chlorhexidine, which was used by patients with motor deficiency for 14 days. The reduction in plaque and gingival index and the impact on salivary microorganisms was evaluated. We conclude that the motivation of caregivers to carry out oral hygiene for patients with mental and motor deficiency is of great importance and is effective in reducing the formation of plaque as long as it is continuously reinforced. The use of chlorhexidine- containing toothpaste significantly reduced the plaque index and microorganism count between days 0 and 14. A reduction was also observed in the group that used a dentifrice without the chlorhexidine, but this difference was not significant. © 2010 Special Care Dentistry Association and Wiley Periodicals, Inc.

Exfoliative cytology of the oral mucosa: Comparison of two collection methods

This study compared the sampling efficacy cia cytobrush and metal spatula for exfoliative cytology of the oral mucosa. Thirty students with no detectable oral alterations upon clinical examination were submitted to exfoliative cytology of the lateral border of the tongue, using a metal spatula on the left side and a cytobrush on the right side. The smears were stained using the Papanicoiaou technique and evaluated for cellularity, cell type, cell distribution, homogeneity, and cellular distortion, as well as the presence ol mucus, inflammatory infiltrate, and hemorrhage. A statistical test (Z-test) with a 95% confdence interval (Cl) showed a significant difference between the metal spatula and cytobrush in terms of cellularity (p = 0.02) and homogeneity (p = 0.01). No difference between the two methods was observed regarding cell type (p = 0.4, Z-test) or cell distribution for the 95% confidence interval (p = 0.2, Fisher's test). Cell distortion and the presence of mucus were observed in five cases that used the metal spatula and in two cases that used the cytobrush. No hemorrhage or inflammatory infItrate was detected in any of the slides. Based on the results of this study, the cytobrush produced qualitatively better smears in terms of cellularity and homogeneity compared to the metal spatula.

Response of human dental pulp to calcium hydroxide paste preceded by a corticosteroid/antibiotic dressing agent

Aim: To evaluate the treatment with corticosteroid/antibiotic dressing in pulpotomy with calcium hydroxide. Methods: Forty-six premolars were pulpotomized and randomly assigned into 3 groups. In Group I pulpal wound was directly capped with calcium hydroxide, and Group II and Group III received corticosteroid/antibiotic dressing for 10 min or 48 h, respectively, before pulp capping. Teeth were processed for histological analysis after 7, 30 or 60 days to determine inflammatory cell response, tissue disorganization, dentin bridge formation and presence of bacteria. Attributed scores were analyzed by Kruskal-Wallis and Mann-Whitney tests (α=0.05). Results: On the 7th day, all groups exhibited dilated and congested blood vessels in the tissue adjacent to pulpal wound. The inflammatory cell response was significantly greater in Group III (p<0.05). On the 30th day, in all groups, a thin dentin matrix layer was deposited adjacent to the pulpal wound and a continuous odontoblast-like cell layer underlying the dentin matrix was observed. On the 60th day, all groups presented a thick hard barrier characterized by an outer zone of dystrophic calcification and an inner zone of tubular dentin matrix underlined by a defined odontoblast-like cell layer. Conclusions: Within the limitations of present study, considering that the treatment was performed in healthy teeth, it may be concluded that the use of a corticosteroid/antibiotic dressing before remaining tissue protection with calcium hydroxide had no influence on pulp tissue healing.

The in vitro antimicrobial activity of natural infant fluoride-free toothpastes on oral micro-organisms

Purpose: The objective of this study was to evaluate the antimicrobial activity of six toothpastes for infants: 3 fluoride-free experimental toothpastes - cashew-based, mango-based and without plant extract and fluoride compared with 2 commercially fluoride-free toothpastes and 1 fluoridated toothpastes. Methods: Six toothpastes for infants were evaluated in this study: (1) experimental cashew-based toothpaste; (2) experimental mango-based toothpaste; (3) experimental toothpaste without plant extract and fluoride (negative control); (4) First Teeth brand toothpaste; (5) Weleda brand toothpaste; and (6) Tandy brand toothpaste (positive control). The antimicrobial activity was recorded against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus, and Candida albicans using the agar plate diffusion test. Results: First Teeth, Weleda, mango-based toothpaste, and toothpaste without plant extract presented no antimicrobial effect against any of the tested micro-organisms. Cashew toothpaste had antimicrobial activity against S mutans, S sobrinus, and L acidophilus, but it showed no antimicrobial activity against C albicans. There was no statistical difference between the inhibition halo of cashew and Tandy toothpastes against S mutans and L acidophilus. Conclusions: Cashew fluoride-free toothpaste had inhibitory activity against Streptococcus mutans and Lactobacillus acidophilus, and these results were similar to those obtained for fluoridated toothpaste.