Effect of daily use of an enzymatic denture cleanser on Candida albicans biofilms formed on polyamide and poly(methyl methacrylate) resins: an in vitro study.

STATEMENT OF PROBLEM: Candida biofilms on denture surfaces are substantially reduced after a single immersion in denture cleanser. However, whether this effect is maintained when dentures are immersed in cleanser daily is unclear. PURPOSE: The purpose of this study was to evaluate the effect of the daily use of enzymatic cleanser on Candida albicans biofilms on denture base materials. MATERIAL AND METHODS: The surfaces of polyamide and poly(methyl methacrylate) resin specimens (n=54) were standardized and divided into 12 groups (n=9 per group), according to study factors (material type, treatment type, and periods of treatment). Candida albicans biofilms were allowed to form over 72 hours, after which the specimens were treated with enzymatic cleanser once daily for 1, 4, or 7 days. Thereafter, residual biofilm was ultrasonically removed and analyzed for viable cells (colony forming units/mm(2)) and enzymatic activity (phospholipase, aspartyl-protease, and hemolysin). Factors that interfered with the response variables were analyzed by 3-way ANOVA with the Holm-Sidak multiple comparison method (α=.05). RESULTS: Polyamide resin presented more viable cells of Candida albicans (P<.001) for both the evaluated treatment types and periods. Although enzymatic cleansing significantly (P<.001) reduced viable cells, daily use did not maintain this reduction (P<.001). Phospholipase activity significantly increased with time (P<.001) for both materials and treatments. However, poly(methyl methacrylate) based resin (P<.001) and enzymatic cleansing treatment (P<.001) contributed to lower phospholipase activity. Aspartyl-protease and hemolysin activities were not influenced by study factors (P>.05). CONCLUSIONS: Although daily use of an enzymatic cleanser reduced the number of viable cells and phospholipase activity, this treatment was not effective against residual biofilm over time.

Fracture resistance of teeth submitted to several internal bleaching protocols.

AIM: The aim of this study was to evaluate the fracture resistance of teeth submitted to several internal bleaching protocols using 35% hydrogen peroxide (35HP), 37% carbamide peroxide (37CP), 15% hydrogen peroxide with titanium dioxide nanoparticles (15HPTiO2) photoactivated by LED-laser or sodium perborate (SP). MATERIALS AND METHODS: After endodontic treatment, fifty bovine extracted teeth were divided into five groups (n = 10): G1-unbleached; G2-35HP; G3-37CP; G4-15HPTiO2 photoactivated by LED-laser and G5-SP. In the G2 and G4, the bleaching protocol was applied in 4 sessions, with 7 days intervals between each session. In the G3 and G5, the materials were kept in the pulp teeth for 21 days, but replaced every 7 days. After 21 days, the teeth were subjected to compressive load at a cross head speed of 0.5 mm/min, applied at 135° to the long axis of the root using an eletromechanical testing machine, until teeth fracture. The data were submitted to ANOVA and Tukey tests (α = 5%). RESULTS: The 35HP, 37CP, 15HPTiO2 and SP showed similar fracture resistance teeth reduction (p > 0.05). All bleaching treatments reduced the fracture resistance compared to unbleached teeth (p < 0.05). CONCLUSION: All bleaching protocols reduced the fracture resistance of endodontically-treated teeth, but there were no differences between each other. CLINICAL SIGNIFICANCE: There are several internal bleaching protocols using hydrogen peroxide in different concentrations and activation methods. This study evaluated its effects on fracture resistance in endodontically-treated teeth.

Ultrasonic activation of internal bleaching agents.

AIM: To evaluate the effectiveness of ultrasonic activation of bleaching agents during ex vivo internal bleaching. METHODOLOGY: Fifty canine human teeth were artificially stained, root filled and divided into five groups (n = 10) that received SP - sodium perborate plus deionized water (control group), CP - 37% carbamide peroxide gel, CPUS - 37% carbamide peroxide gel plus ultrasonic application, HP - 35% hydrogen peroxide gel or HPUS - 35% hydrogen peroxide gel plus ultrasonic application. In groups CP and HP, the bleaching agent was left inside the pulp chamber for three applications of 10 min. In groups CPUS and HPUS, the same process was performed, but ultrasonic vibration was applied to the bleaching agent by an alloy tip for 30 s, with 30 s intervals. Two sessions were performed. The colour was measured initially and after each session by an intraoral dental spectrophotometer. The variation (Δ) of the colour parameters based on the CIELab system L*, a* and b*, and the colour alteration ΔE* were calculated after first and second section. Data were analysed by one-way anova and Tukey's test. RESULTS: There was no significant difference amongst groups for ΔL*, Δa* and ΔE*, but there was a significant difference for Δb* in the first and second sessions (P = 0.0006 and 0.0016, respectively). After the first session, Δb* was significantly greater for groups HP and HPUS, without a significant difference between them. For the second session, group HPUS had the greatest Δb* values, but they were similar to groups HP and SP; group CP had the lowest values, which were similar to groups CPUS and SP. CONCLUSION: Ultrasonic activation of bleaching agents during ex vivo internal bleaching was no more effective than conventional internal bleaching procedures, without activation.

Apical limit of root canal filling and its relationship with success on endodontic treatment of a mandibular molar: 11-year follow-up.

OBJECTIVE: This article discusses the relationship between apical limit of root canal filling and success on endodontic treatment of a mandibular molar. STUDY DESIGN: A mandibular right first molar with vital pulp was endodontically treated, and 3 years later periapical lesions on mesial and distal roots were detected. The canals were retreated and obturated to the same levels as in the previous treatment. RESULTS: An 8-year radiographic follow-up showed repair of the periapical lesions on both roots. CONCLUSIONS: Results suggest that the apical limit of obturation seems to have no influence in the repair of periapical tissues in mandibular molars.

Effect of a denture cleanser on the concentration of volatile sulphur compounds and denture biofilm in institutionalised elderly.

OBJECTIVE: To determine the effectiveness of a denture cleanser in reducing the concentration of volatile sulphur compounds (VSC) and its antimicrobial action. BACKGROUND: Micro-organisms from the denture biofilm can cause local and systemic disease and halitosis. Denture cleansers are important adjuncts in oral care, but there is limited investigation on their effect in malodour compounds. MATERIAL AND METHODS: Nineteen institutionalised elderly who wore at least an upper denture were selected; their VSC concentrations were measured and the denture biofilm was collected. In phase 1, the subjects wore their old denture and data were collected before (B0) and after 7(A1), 14(A2), 28(A3) days of continuous daily use of the denture cleanser. In phase 2, new dentures were inserted and measurements were made at 30(A1.1), 60(A2.2), 90(A3.3) days of treatment. RESULTS: The VSC concentration increased from B0 to A1 (p<0.05), but no differences were found for the others intervals of times. Total micro-organism data did not show a statistical difference between times in Phase I, but in Phase II, there was a statistical difference (p<0.05) and a progressive re-colonisation was observed. CONCLUSION: Within the limits of this study, it was concluded that the denture cleanser had no antimicrobial effect and VSC levels were not reduced.

In vivo efficacy of alkaline peroxide tablets and mouthwashes on Candida albicans in patients with denture stomatitis.

OBJECTIVE: Effective cleaning of dentures is important for the maintenance of good oral hygiene for denture stomatitis patients. The in vivo efficacy of three different brands of alkaline peroxide tablets (Polident, Efferdent, and Fittydent) and two mouthwashes (CloSYS II and Corsodyl) to eliminate Candida albicans on dentures was evaluated in this in vivo study. MATERIAL AND METHODS: Ninety denture wearers with clinical evidence of denture stomatitis were randomly divided into 5 test groups and 1 control group. Each group was further divided into three subgroups in which the dentures were subjected to 15-, 30-, and 60-min disinfection procedures. The dentures of each test group were treated with one of the cleaners, while those of the control group were treated with distilled water. Swab samples from the palatal surfaces (2 cm x 2 cm template delimited area) of the upper dentures were obtained before and after 15, 30, and 60 min periods of cleaner use and examined mycologically. RESULTS: The reduction in the number of colony-forming units (CFU) of C. albicans before, and after 15, 30, and 60 min of use of CloSYS II and Corsodyl was significantly greater than that of the control group (p<0.05). Moreover, there was no statistically significant difference (p>0.05) among Polident, Efferdent and the control group in any of the treatment periods. Dentures treated with Fittydent appeared to have a significantly greater reduction in the number of Candida spp. only after 60 min of treatment. CONCLUSIONS: The results of this study showed that the use of mouthwashes significantly reduced the number of microorganisms on dentures.

In vivo efficacy of alkaline peroxide tablets and mouthwashes on Candida albicans in patients with denture stomatitis

OBJECTIVE: Effective cleaning of dentures is important for the maintenance of good oral hygiene for denture stomatitis patients. The in vivo efficacy of three different brands of alkaline peroxide tablets (Polident, Efferdent, and Fittydent) and two mouthwashes (CloSYS II and Corsodyl) to eliminate Candida albicans on dentures was evaluated in this in vivo study. MATERIAL AND METHODS: Ninety denture wearers with clinical evidence of denture stomatitis were randomly divided into 5 test groups and 1 control group. Each group was further divided into three subgroups in which the dentures were subjected to 15-, 30-, and 60-min disinfection procedures. The dentures of each test group were treated with one of the cleaners, while those of the control group were treated with distilled water. Swab samples from the palatal surfaces (2 cm x 2 cm template delimited area) of the upper dentures were obtained before and after 15, 30, and 60 min periods of cleaner use and examined mycologically. RESULTS: The reduction in the number of colony-forming units (CFU) of C. albicans before, and after 15, 30, and 60 min of use of CloSYS II and Corsodyl was significantly greater than that of the control group (p<0.05). Moreover, there was no statistically significant difference (p>0.05) among Polident, Efferdent and the control group in any of the treatment periods. Dentures treated with Fittydent appeared to have a significantly greater reduction in the number of Candida spp. only after 60 min of treatment. CONCLUSIONS: The results of this study showed that the use of mouthwashes significantly reduced the number of microorganisms on dentures.

Clinical comparison between the bleaching efficacy of 37% peroxide carbamide gel mixed with sodium perborate with established intracoronal bleaching agent.

OBJECTIVE: The aim was to evaluate the bleaching efficacy of sodium perborate/37% carbamide peroxide paste and traditional sodium perborate/distilled water for intracoronal bleaching. STUDY DESIGN: Thirty patients with dark anterior teeth were divided into 2 groups (n = 15): group A: sodium perborate/distilled water; and group B: sodium perborate/37% carbamide peroxide paste. The bleaching treatment limited each patient to the maximum of 4 changes of the bleaching agent. Initial and final color shades were measured using the Vita Lumin shade guide. RESULTS: Data was analyzed with Wilcoxon test for initial and final comparison according to the bleaching agent, demonstrating efficacy of the bleaching treatment with both agents. Mann-Whitney test was used for comparison of the efficacy of the bleaching agents, showing that there was no significant difference between them. CONCLUSION: The sodium perborate/37% carbamide peroxide association for intracoronal bleaching has proven to be as effective as sodium perborate/distilled water.

Ex vivo evaluation of the effectiveness of bleaching agents on the shade alteration of blood-stained teeth.

AIM: To evaluate ex vivo effectiveness of the three formulations of bleaching materials for intracoronal bleaching of root filled teeth using the walking bleach technique. METHODOLOGY: Extracted premolar teeth were stained artificially with human blood. After biomechanical preparation, the root canals were filled and a 3-mm thick intermediate base of zinc phosphate cement was placed at the level of the cementoenamel junction. The teeth were divided into four groups (n = 12): C (control, without bleaching material), A1 (sodium perborate + distilled water), A2 (sodium perborate + 10% carbamide peroxide) and A3 (sodium perborate + 35% carbamide peroxide). The bleaching materials were changed at 7 and 14 days. Evaluation of shade was undertaken with aid of the VITA Easyshadetrade mark (DeltaE*ab) and was performed after tooth staining and at 7, 14 and 21 days after bleaching, based on the CIELAB system. Data were analysed by anova for repeated measurements, Tukey and Dunnett tests (alpha = 0.05). RESULTS: The Tukey test revealed that group A1 (10.58 +/- 4.83 DeltaE*ab) was statistically different from the others (A2, 19.57 +/- 4.72 DeltaE*ab and A3, 17.58 +/- 3.33 DeltaE*ab), which were not different from each other. At 7 days: A1 was significantly different from A2; at 14 and 21 days: A2 and A3 were significantly better than A1; the Dunnett test revealed that the control group was different from A1, A2 and A3 at all periods (P < 0.05). CONCLUSION: Sodium perborate associated with both 10% and 35% carbamide peroxide was more effective than when associated with distilled water.

Analysis of photoreflectance and microhardness of the enamel in primary teeth submitted to different bleaching agents.

Treatment of darkened teeth in children is of great importance from an esthetic-functional point of view and for the psychoemotional development of the child. The objective of the present study was to determine the in vitro efficacy of three bleaching agents for whitening of artificially stained primary teeth. Fifty anterior primary teeth were artificially stained and then divided into three experimental groups (n = 15) submitted to bleaching treatment with 35% hydrogen peroxide gel, 35% carbamide peroxide gel, and 35% carbamide peroxide gel mixed with sodium perborate powder. The control group (n = 5) was not submitted to any bleaching treatment. Color changes were evaluated with a reflectance spectrophotometer and possible alterations in the enamel surface after bleaching were measured by Vickers microhardness testing. The data were assessed using the Student's t test. The results confirmed the bleaching action of the three agents tested. No significant difference in mean microhardness was observed between the three bleaching agents when compared to the control group.

Sealing evaluation of the cervical base in intracoronal bleaching.

Discoloration of non-vital teeth is an esthetic deficiency frequently requiring bleaching treatment. The purpose of this study was to evaluate in vitro the cervical base efficacy in order to prevent or to minimize the leakage along the root canal filling and into the dentinal tubules. Thirty-eight extracted single-root human teeth were used, which were biomechanically prepared, filled, and divided into three experimental groups: G1, a cervical base was applied (3 mm of thickness) below the cemento-enamel junction, with resin-modified glass-ionomer cement (Vitremer); G2, the base was done with glass-ionomer cement (Vidrion R); and G3 (Control), did not receive any material as base. A mixture of sodium perborate and hydrogen peroxide 30% was placed inside the pulp chamber for 3 days, and the access opening was sealed with Cimpat. This procedure was repeated thrice. Soon after this, a paste of calcium hydroxide was inserted into the pulp chamber for 14 days. All teeth were covered with two layers of sticky wax, except the access opening, and immersed in blue India Ink for 5 days. The results did not show statistically significant differences between the three groups concerning the leakage inside the dentinal tubules. Regarding the apical direction, a statistical difference (ANOVA P < 0.05) was observed among the experimental group G1 and control group G3. No statistically significant difference was observed between G2 and G3 groups. Therefore, the placement of a cervical base before internal bleaching procedures is still recommended.

Microleakage in endodontically treated teeth: influence of calcium hydroxide dressing following bleaching.

AIM: The purpose of the present study was to evaluate microleakage of a fourth generation dentine-bonding agent and composite restoration during a walking bleach treatment. METHODOLOGY: Thirty extracted non-carious incisors were selected and conventional root canal treatment was performed. Teeth were randomly divided into 3 groups (n = 10): group A (control), access cavities were restored with a fourth generation dentine-bonding agent, and incrementally restored with composite resin; group B, a paste composed of sodium perborate and hydrogen peroxide was placed into the pulp chamber and sealed with glass ionomer cement for 7 days, teeth were then restored in the same manner as group A; group C, a paste of sodium perborate and hydrogen peroxide was placed in the pulp chamber for 7 days and then after removal of the bleaching mixture, pulp chambers were filled with a calcium hydroxide paste and cavities sealed with glass ionomer for 1 week. The cavities were then restored with bonded restorations as in groups A and B. Teeth were subjected to thermal cycling and immersed in methylene blue for 8 h. Teeth were sectioned from buccal to lingual, through the centre of the restoration, using a diamond disk. Leakage was assessed using a standard scheme, under magnification (x20). Data were submitted to statistical analysis using nonparametric Kruskal-Wallis test. RESULTS: Groups A and C exhibited similar leakage patterns, and both demonstrated less leakage values than group B (P < 0.05). CONCLUSIONS: It was concluded that bleaching with sodium perborate and hydrogen peroxide increases microleakage; short-term use of a calcium hydroxide medicament did not increase microleakage.

Effect of different root canal sealers on periapical repair of teeth with chronic periradicular periodontitis.

Teeth with induced chronic periradicular periodontitis in dogs were root canal treated. After the biomechanical preparation, using K files and 5.25% sodium hypochlorite as the irrigant solution, all root canals were dressed with an antibacterial dressing based on calcium hydroxide, which was left in place for 7 days. After this time, the root canals were obturated with lateral condensation of cold gutta-percha with either a calcium hydroxide root canal filling material (Sealapex) or a zinc oxide-eugenol sealer (Fill Canal). After 270 days, histopathological analysis showed better apical and periapical repair in the teeth obturated with Sealapex (P < 0.05).

Actividad inhibitoria "in vitro" de algunos antisépticos frente a cultivos de Prototheca wickerhamii / \"In vitro\" inhibitory activity of some antiseptic drugs against Prototheca wickerhamii strains

Se estudió la acción inhibidora "in vitro" de los siguientes antisépticos: etil mercurio tiosalicilato de sodio, azida sódica, borato de sodio, yoduro de potasio, fenol y cloro, frente a cultivos de 5 cepas de Prototheca wickerhamii. La acción "in vitro" de estas drogas fue medida mediante el halo de inhibición que produjeron en los cultivos de Prototheca en medio de agar-miel de Sabouraud incubados a 28ºC. Los resultados obtenidos permitieron establecer que todas las cepas eran uniformemente susceptibles al etilmercurio tiosalicilato de sodio y a la azida sódica, la mayor parte fue inhibida por el yoduro de potasio, en tanto que, el borato de sodio, el fenol y el cloro resultaron inactivos en las diluciones utilizadas

Actividad inhibitoria "in vitro" de algunos antisépticos frente a cultivos de Prototheca wickerhamii / "In vitro" inhibitory activity of some antiseptic drugs against Prototheca wickerhamii strains

Se estudió la acción inhibidora "in vitro" de los siguientes antisépticos: etil mercurio tiosalicilato de sodio, azida sódica, borato de sodio, yoduro de potasio, fenol y cloro, frente a cultivos de 5 cepas de Prototheca wickerhamii. La acción "in vitro" de estas drogas fue medida mediante el halo de inhibición que produjeron en los cultivos de Prototheca en medio de agar-miel de Sabouraud incubados a 28ºC. Los resultados obtenidos permitieron establecer que todas las cepas eran uniformemente susceptibles al etilmercurio tiosalicilato de sodio y a la azida sódica, la mayor parte fue inhibida por el yoduro de potasio, en tanto que, el borato de sodio, el f

A randomized controlled trial of solcoseryl and duoderm in chronic sickle-cell ulcers.

A randomized controlled trial of Solcoseryl, DuoDerm and conventional conservative therapy with Eusol has been performed in 32 patients with homozygous sickle-cell (SS) disease. After 12 weeks' baseline observation, patients were randomized to one of three therapies and monitored for a further 12 weeks. Of 44 ulcerated legs, 20 received control treatment, 12 Solcoseryl and 12 DuoDerm. DuoDerm was generally unacceptable, and two-thirds of the patients defaulted from this treatment. Solcoseryl increased ulcer healing compared to the controls but the difference was not significant. Solcoseryl was well tolerated and may have a role in the treatment of chronic leg ulcers of sickle-cell disease.