Effect of Activated Charcoal Toothpaste on Color Stability of Bleached Teeth Immersed in Different Drinks.

OBJECTIVE: This study aimed to evaluate the effect of activated charcoal toothpaste on the color stability of teeth subjected to tooth bleaching and pigmenting agents. METHODS: A total of 120 bovine crowns were randomly divided into 12 groups (n=10) according to two study factors: staining solutions (three levels): saliva (control), coffee, and red wine; and toothpaste (four levels): BPC, Bianco Pro Clinical (Bianco Oral Care) (Control); BIW, Black is White (Curaprox); BCA, Bianco Carbon (Bianco Oral Care); and NAT, Natural Suavetex (Suavetex). The samples were subjected to office bleaching with a 35% hydrogen peroxide-based gel (Whiteness HP Blue, FGM), followed by immersion in the solution for 45 minutes per day and daily toothbrushing for 7 days. The color (ΔE) and luminosity changes (ΔL*) were measured using reflectance spectroscopy (Vita EasyShade). The CIE values (L*, a*, b*) were measured at baseline after bleaching (T0) and immediately after immersion in solution each day (Ti1-Ti7) and after all toothbrushing cycles (Tb1-Tb7). ΔE and ΔL were analyzed using a two-way analysis of variance and Tukey's test (α=0.05). The clinically unacceptable level of ΔE > 3.3 was used to evaluate the color change. RESULTS: The color change was significantly influenced by the staining solutions and toothpastes (p<0.001). The color change (ΔE) was significantly higher when immersed in wine than in coffee, and lower ΔE values were observed for artificial saliva (control), irrespective of the toothpaste used. In artificial saliva, BPC, BIW, and BCA resulted in significantly lower ΔE values than NAT, which presented a clinically unacceptable level of dental color change (ΔE>3.3). Coffee resulted in a lower (L*) reduction than wine, irrespective of the toothpaste used. CONCLUSION: Charcoal toothpastes resulted in a color change on the surface of the tooth enamel (ΔE). The bleaching effect of the charcoal toothpastes and control evaluated in this study partially reduced the color changes on the surface of the tooth enamel caused by staining solutions but was unable to reestablish the measured values to the baseline. For teeth immersed in artificial saliva, the color change was not noticeable in BCA, BIW, and control-BPC (ΔE≥3.3), except for NAT, which showed a significant color change.

Periodontal therapy for patients before and after radiotherapy: A review of the literature and topics of interest for clinicians.

BACKGROUND: To review and discuss important topics regarding periodontal treatment pre- and post-radiotherapy for head and neck cancer in human patients; to discuss the references for adequate techniques, the appropriate moment for tooth extractions and periodontal management; and to discuss the prevention of osteoradionecrosis. MATERIAL AND METHODS: Thirty-nine studies including original studies, randomized clinical trials (RCTs) and reviews were searched in online databases MEDLINE (PubMed) and the Cochrane library. No year of publication restriction was applied. RESULTS: Language was restricted to English, and the following Medical Subject Heading terms were used: radiotherapy, radiation therapy and periodontal treatment. Studies regarding periodontal treatment and tooth extraction that involved clinical management of irradiated patients were selected. CONCLUSIONS: The treatment of periodontal diseases before radiotherapy is mainly required to avoid future dental extraction and to reduce the development of osteoradionecrosis. Periodontal treatment in irradiated patients mostly includes scaling and root planing, extraction of condemned teeth and topical and systemic antimicrobial therapy. Tooth removal should be planned at least 14 days before the first day of radiation treatment. Particular care and mouthwashes should be taken during and after radiation. CLINICAL SIGNIFICANCE: The management of irradiated patients represents a challenge for health professionals, including dentists. It is important to establish recommendations for clinicians concerning dental and periodontal management in irradiated patients before, during and after treatment.

Efficacy of a novel at-home bleaching technique with carbamide peroxides modified by CPP-ACP and its effect on the microhardness of bleached enamel.

This study was designed to evaluate in vitro the efficacy of a novel at-home bleaching technique using 10% or 16% carbamide peroxide modified by casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and its influence on the microhardness of bleached enamel. A total of 40 bovine incisors were divided into four groups (n=10) according to the bleaching agent used: 10% carbamide peroxide only; a blend of 10% carbamide peroxide and a CPP-ACP paste; 16% carbamide peroxide only; and a blend of 16% carbamide peroxide and a CPP-ACP paste. During the 14-day bleaching regimen, the samples were stored in artificial saliva. The Vickers microhardness and color of the teeth were assessed at baseline (T0) and immediately after the bleaching regimen (T14) using a microhardness tester and a spectrophotometer, respectively. The degree of color change was determined by the Commission Internationale de l'Eclariage (CIE) L*a*b* system (ΔE, ΔL*, Δa*, and Δb*) and Vita shade guide parameters. The data were analyzed by analysis of variance and the Tukey test (p<0.05). The teeth that were bleached with a blend of peroxide (10% or 16%) and the CPP-ACP paste presented increased microhardness values at T14 compared with T0, whereas the samples that were bleached with peroxide only did not show any differences in their microhardness values. All of the bleaching agents were effective at whitening the teeth and did not show a statistically significant difference using the CIEL*a*b* system (ΔE, ΔL*, Δa*, and Δb*) or the Vita shade guide parameters. The use of a CPP-ACP paste with carbamide peroxide bleaching agents increased the bleached enamel's microhardness and did not have an influence on whitening efficacy.

Relative efficacy of clindamycin, erythromycin, and penicillin in treatment of Treponema pallidum in skin syphilomas of rabbits.

The currently recommended antibiotic for treatment of fetal syphilis in pregnant women who are allergic to penicillin is erythromycin. However, clindamycin crosses the placenta more effectively than erythromycin. Therefore, an in vivo rabbit model of intradermal syphilomas was used to determine the effect of clindamycin compared with the effects of erythromycin and penicillin on the growth of virulent Treponema pallidum. The average number of motile treponemes in two, paired, mature lesions was determined before and after therapy in groups of four rabbits per dosage. Single intramuscular doses of clindamycin (15 and 40 mg/kg) and erythromycin (12 and 40 mg/kg) did not decrease treponeme counts significantly. Single injections of penicillin (10,000 units/kg) reduced treponemal counts by more than 250-fold. Multiple intramuscular injections of clindamycin reduced counts by five- to sevenfold, whereas multiple doses of erythromycin and penicillin decreased treponeme counts by greater than 300-fold. These studies indicate that clindamycin is far less active than erythromycin or penicillin in treatment of established syphilitic lesions in rabbits.

Inhibition of multiplication of Toxoplasma gondii by human monocytes exposed to T-lymphocyte products.

The multiplication of Toxoplasma gondii was quantitated in human monocytes in vitro by phase-contrast microscopy. Toxoplasma multiplication was identical in monocytes from subjects byt was significantly inhibited in cells from both sources if the monocytes were preincubated with immune lymphocytes and toxoplasma monocytes were preincubated with immune lymphocytes and toxoplasma antigen. Supernates prepared from toxoplasma-immune lymphocytes incubated with toxoplasma antigen were also effective in inducing in monocytes the capacity to inhibit toxoplasma multiplication. Supernative acitivty was evident after lymphocytes and antigen were incubated for as little as 15 min. The instruction of monocytes was also repid and reversible. Monocytes were fully induced to inhibit toxoplasma multiplication after a 2 h exposure to an active supernate, but they lost their inhibitory capacity on culture in vitro for 48 h in the absece of immune cells or their products. The lymphocytes particupating in the monocyte induction were identified as t cells. The in vitro stimulation of monocytes appeared to exhibit some specificity, since no inhibition of toxopreotein derivative and lymphocytes from tuberculin-positive subjects, concanavalin a-stimulated lymphocytes, or their supermates. Supernates which induced monocytes to inhibit toxoplasma multiplication did not influence parasite growth in HeLa cells.