Effect of two whitening agents on the color of composite dental restorations

To evaluate color changes to composite resins used to restore extracted teeth compared with composite discs after whitening with two agents: hydrogen peroxide (HP) and carbamide peroxide (CP). Ten human molars with class V vestibular and palatine cavity preparation obturated with Vita hybrid nanocomposite were hemisected to obtain 20 specimens assigned randomly to two groups: O1 and O2. Twenty composite discs were divided into two groups: D1 and D2. The groups O1 and D1 were treated with 16% CP, while groups =2 and D2 were treated with 37.5 % HP. Chromaticity coordinates L*, a* and b* were registered using a spectrophotometer. Statistically significant differences were found in O1 for L* and a*, in O2 for all three coordinates, and in D1 and D2 only for L*. Comparisons between groups found significant differences in ?Ee (end of treatment) between O1 and O2, between O2 and D2, and between D1 and O1. Both whitening agents produced significant decreases in the three-color components of composites used for dental restorations, while color changes to composite discs were limited to changes in luminosity. HP produced a greater color change to composite dental restorations than to composite discs

In vitro evaluation of the efficacy of two bleaching procedures

Objective: In vitro comparison of the efficacy of two bleaching procedures, one based on carbamide peroxide (CP) and the other on hydrogen peroxide (HP), simulating clinical conditions. Study Design: Two groups of 20 teeth in each group were selected. Group A: 22% CP, one hour a day for 21 consecutive days. Group B: 37.5% HP, in 2 treatment sessions with an one week interval between each session. At each session the product was applied three successive times for eight minutes. Colour was recorded before treatment, when it was finished and one week after finishing it, with the Vita EasyShade spectrophotometer. CIEL*a*b* and ?E were established at each moment in the study. Intra-group data was compared using the paired t-test and inter-group data with the independent groups t-test. Scores from the Vita Classical guide provided with the device were recorded and the colour improvement percentage was calculated. Results: In both groups significant whitening was achieved by the end of treatment. Lightness remained significantly high when treatment was finished and one week after in both groups. The percentage of bleaching was significantly higher in group A. Conclusions: Both 22% CP and 37.5% HP were effective for bleaching teeth. Bleaching effect was greater in CP group. © Medicina Oral S. L

Presentación

This volume is dedicated to the memory of Prof. Dr. Dr. Mariano Álvarez-Gómez.Este volumen de Studia Hegeliana está dedicado a la memoria del Profesor Dr. Dr. Mariano Álvarez Gómez

Gingival bleeding reduction using a carbamide peroxide based tooth paste with lactoperoxidase

Introduction: The combination of carbamide peroxide, thiocyanate or enzymes such as amynoglucosidase or gluco-oxidase is able to reduce gingival inflammation. Objective: To evaluate antiseptic efficacy, in relation to reduced gingival bleeding, of a new dentifrice containing carbamide peroxide and lactorperoxidase. Materials and method: A sample of 32 patients, with periodontal pockets of more than 3mm in the vestibular area and 4 mm at interproximal sites, was divided into two groups of 16 and 17 patients respectively. Group A used a dentifrice containing 3% carbamide peroxide and 5% lactoperoxidase plus 0.022% sodium fluoride for three weeks followed by a control dentifrice with only 0.022% sodium fluoride for another three weeks. Group B used the same dentifrices but in reverse order. Efficacy was assessed by measuring the bleeding sites at the start of the study, and after application of the first and second dentifrices. Results: After applying the toothpaste object of this study, group A showed a significant reduction in bleeding sites (p0.05). After application of the control toothpaste, group B showed a significant reduction in the average number of bleeding sites and after application of the study toothpaste the group showed a greater reduction in the average number of bleeding sites, which was also significant in relation to the first phase (p<0.05). Conclusions: Reduction of gingival bleeding by the carbamide peroxide based dentifrice with lactoperoxidase was found to be superior to the control fluoride dentifrice

Seroprevalence of Bartonella spp. infection in HIV patients in Catalonia, Spain

<p>Abstract</p> <p>Background</p> <p>Although the first clinical descriptions of <it>Bartonella </it>infection were associated with immunocompromised patient with bacillary angiomatosis, we currently know that this organism is directly involved in diseases affecting a large number of patients, regardless of their immune status. Cat scratch disease, hepatic peliosis, and some cases of bacteraemia and endocarditis, are directly caused by some species of the genus <it>Bartonella</it>. The purpose of this study was to determinate the prevalence of IgG antibodies against <it>Bartonella henselae </it>and <it>B. quintana </it>in HIV patients and to identify the epidemiological factors involved.</p> <p>Methods</p> <p>Serum samples were collected from HIV patients treated at Hospital de Sabadell. Antibodies to <it>B. henselae </it>and <it>B. quintana </it>from 340 patients were examined by indirect immunofluorescence assay (IFA). Significance levels for univariate statistical test were determined by the Mann-Whitney U test and χ²test.</p> <p>Results</p> <p>Of 340 patients, 82 were women and 258 men, with a median age of 42.21 ± 10.35 years (range 16–86 years). Seventy-six (22.3%) patients reacted with one or more <it>Bartonella </it>antigens. Of all the factors concerning the seroprevalence rate being studied (age, sex, intravenous drugs use, alcohol consumption, CD4 levels, AIDS, HCV, HBV, residential area), only age was statistically significant.</p> <p>Conclusion</p> <p>A high percentage of HIV patients presents antibodies to <it>Bartonella </it>and is increasing with age.</p

Drug resistance mutations in HIV-2 patients failing raltegravir and influence on dolutegravir response

Producción CientíficaBackground: A broader extent of amino acid substitutions in the integrase of HIV-2 compared with HIV-1 might enable greater cross-resistance between raltegravir and dolutegravir in HIV-2 infection. Few studies have examined the virological response to dolutegravir in HIV-2 patients that failed raltegravir. Methods: All patients recorded in the HIV-2 Spanish cohort were examined. The integrase coding region was sequenced in viraemic patients. Changes associated with resistance to raltegravir and dolutegravir in HIV-1 were recorded. Results: From 319 HIV-2-infected patients recorded in the HIV-2 Spanish cohort, 53 integrase sequences from 30 individuals were obtained (20 raltegravir naive and 10 raltegravir experienced). Only one secondary mutation (E138A) was found in one of the 20 raltegravir-naive HIV-2 patients. For raltegravir-experienced individuals, the resistance mutation profile in 9 of 10 viraemic patients was as follows: N155H + A153G/S (four); Y143G + A153S (two); Q148R + G140A/S (two); and Y143C + Q91R (one). Of note, all patients with Y143G and N155H developed a rare non-polymorphic mutation at codon 153. Rescue therapy with dolutegravir was given to 5 of these 10 patients. After >6 months on dolutegravir therapy, three patients with baseline N155H experienced viral rebound. In two of them N155H was replaced by Q148K/R and in another by G118R. Conclusions: A wide repertoire of resistance mutations in the integrase gene occur in HIV-2-infected patients failing on raltegravir. Although dolutegravir may allow successful rescue in most HIV-2 raltegravir failures, we report and characterize three cases of dolutegravir resistance in HIV-2 patients, emerging variants Q148K and Q148R and a novel change G118R.Fondo de Investigación Sanitaria-Fondos FEDER (FIS, PI13/01574; ICI14/0274, CES12/003, FI14/00264, CD14/00243

Dental Treatment of White Spots and a Description of the Technique and Digital Quantification of the Loss of Enamel Volume

The prevalence of white spots on teeth has increased in recent years. Regardless of their etiology, these lesions are characterized by a reduction in the enamel’s mineral phase, which is replaced by organic fluids. This causes an alteration of its chemical composition that affects its optical characteristics. Subsurface demineralization increases the pore volume of enamel, which in turn changes its optical refraction and results in the opaque color of white spot lesions. Here, we examined a non-invasive clinical technique used for eliminating these white spot lesions from enamel via two HCl-based products at different concentrations (6.6% and 15%). We used a digital method for evaluating the volumetric changes produced in dental enamel by the application of both products, one of which involved chemical erosion and the other, abrasive erosion. The mean volume of the enamel eliminated was −0.042 mm in 15% HCl, and −0.12 mm in 6.6% HCl. Thus, both 15% HCl and 6.6% HCl are capable of eroding the surface of the tooth enamel without reaching dentin. Moreover, 6.6% HCl produced a greater erosion of the dental enamel and left the surface a texture typical of an abrasive chemical-erosive product. The 15% HCl, however, produced an etching pattern typical of an erosive chemical with open enamel prisms prepared for subsequent adhesive procedures and restorers.Odontologí

Comparative Analysis of Peri-Implant Bone Loss in Extra-Short, Short, and Conventional Implants. A 3-Year Retrospective Study

Objective: To evaluate the influence of implant length on marginal bone loss, comparing implants of 4 mm, 6 mm, and >8 mm, supporting two splinted crowns after 36-month functional loading. Materials and Methods: this retrospective clinical trial evaluated the peri-implant behavior of splinted crowns (two per case) on pairs of implants of the same length placed in the posterior maxilla (molar area). Implants were divided into three groups according to length (Group 1: extra-short 4 mm; Group 2: short 6 mm; Group 3: conventional length >8 mm). Marginal bone loss was analyzed using standardized periapical radiographs at the time of loading and 36 months later. Results: 24 patients (19 women and 5 men) were divided into three groups, eight rehabilitations per group, in the position of the maxillary first and second molars. The 48 Straumann® Standard Plus (Regular Neck (RN)/Wide Neck (WN)) implants were examined after 36 months of functional loading. Statistical analysis found no significant differences in bone loss between the three groups (p = 0.421). No implant suffered biological complications or implant loss. Long implants were associated with less radiographic bone loss. Conclusions: extra-short (4 mm); short (6 mm); and conventional length (>8 mm) implants in the posterior maxilla present similar peri-implant bone loss and 100% survival rates in rehabilitation, by means of two splinted crowns after 36 months of functional loading. Implants placed in posterior positions present better bone loss results than implants placed in anterior positions, regardless of the interproximal area where bone loss is measured. Conventional lengthOdontologí