Atlas Edson Moleros Nakamae

A Multispecies Probiotic Reduces Oral Candida Colonization in Denture Wearers

PURPOSE The prevalence of Candida infections has been rising with an increasingly aging population and a larger population of immunocompromised individuals. The use of probiotics may be an alternative approach to antifungal agents in the prevention and treatment of oral candidiasis. This study aimed to evaluate the short-term effect of probiotics in reducing the infection level of oral Candida in candidiasis-asymptomatic elderly denture wearers. MATERIALS AND METHODS In a double-blind randomized study, 59 denture wearers harboring Candida spp. in the oral cavity with no clinical symptoms were allocated into two groups: probiotic and placebo. All patients were instructed to clean the denture daily. The probiotic group poured a capsule containing lyophilized Lactobacillus rhamnosus HS111, Lactobacillus acidophillus HS101, and Bifidobacterium bifidum daily on the palatal surface of the maxillary denture, whereas the placebo group was submitted to the same regimen using placebo capsules. Candida spp. infection levels were evaluated in palate mucosa samples obtained before and after a 5-week experimental period. RESULTS All patients harbored Candida in the palate mucosa at baseline. Fifty-five individuals completed the experimental period. The detection rate of Candida spp. was 92.0% in the placebo group after the experimental period, whereas it was reduced to 16.7% in the probiotic group. The reduction promoted by the probiotic regimen was independent of baseline characteristics such as Candida infection level and colonizing species, age of denture, and other variables. CONCLUSION The probiotic product was effective in reducing the colonization of the oral cavity with Candida in candidiasis-asymptomatic elderly denture wearers, suggesting that this multispecies probiotic could be used to prevent oral candidiasis. CLINICAL IMPLICATIONS Colonization of oral surfaces by Candida is considered a risk factor for invasive fungal infections. The use of a product with L. rhamnosus, L. acidophilus, and B. bifidum may represent an alternative treatment for reduction of Candida infections in elderly denture wearers.

Use of Silver Nanoparticles Reduces Internal Contamination of External Hexagon Implants by Candida albicans

Since the dental implant/abutment interface cannot totally seal the passage of microorganisms, the interior of implant becomes a reservoir of pathogenic microorganisms that produce and maintain chronic inflammation in the tissues around implants. Silver nanoparticles (nano-Ag) are potent and broad-spectrum antimicrobial agents. The aim of this study was to evaluate the capacity of the nano-Ag to prevent the contamination of the implant internal surface by Candida albicans, caused by the implant/abutment microgap infiltration. Thirty-six implants were used in this experiment. Three study groups were performed: experimental group (implants receiving an application of nano-Ag in their inner cavity before installation of the abutment); positive-control group (implants receiving sterile phosphate buffer saline application instead of nano-Ag) and negative-control group (implants receiving the application of nano-Ag in the inner cavity and immersed in a sterile medium). In the positive-control and experimental groups, the implants were immersed in a Candida albicans suspension. The abutments of all three groups were screwed with a 10 N torque. After 72 h of immersion inC. albicans suspension or sterile medium, the abutments were removed and the inner surface of the implants was sampled with absorbent paper cone for fungal detection. No C. albicans contamination was observed in the negative-control group. The positive-control group showed statistically higher values of colony forming units (CFUs) of C. albicans compared with the experimental group. In conclusion, silver nanoparticles reduced C. albicans colonization inside the implants, even with low torque screw abutment.

Study of the surface hardness and modulus of elasticity of conventional and microwave-cured acrylic resins

The aim of this study was to evaluate the following acrylic resins: Clássico, QC-20 and Lucitone, recommended specifically for thermal polymerization, and Acron MC and VIPI-WAVE, made for polymerization by microwave energy. The resins were evaluated regarding their surface nanohardness and modulus of elasticity, while varying the polymerization time recommended by the manufacturer. They were also compared as to the presence of water absorbed by the samples. The technique used was nanoindentation, using the Nano Indenter XP, MTS. According to an intra-group analysis, when using the polymerization time recommended by the manufacturer, a variation of 0.14 to 0.23 GPa for nanohardness and 2.61 to 3.73 GPa for modulus of elasticity was observed for the thermally polymerized resins. The variation for the resins made for polymerization by microwave energy was 0.15 to 0.22 GPa for nanohardness and 2.94 to 3.73 GPa for modulus of elasticity. The conclusion was that the Classico resin presented higher nanohardness and higher modulus of elasticity values when compared to those of the same group, while Acron MC presented the highest values for the same characteristics when compared to those of the same group. The water absorption evaluation showed that all the thermal polymerization resins, except for Lucitone, presented significant nanohardness differences when submitted to dehydration or rehydration, while only Acron MC presented no significant differences when submitted to a double polymerization time. Regarding the modulus of elasticity, it was observed that all the tested materials and products, except for Lucitone, showed a significant increase in modulus of elasticity when submitted to a lack of hydration.

Avaliação das disfunções craniomandibulares em pacientes parcialmente edentados unilaterais: um estudo longitudinal sobre o efeito da utilização de Prótese Parcial Removível (PPR)

This study was performed to compare the severity of Craniomandibular Disorders (CMD), signs and symptoms in 29 subjects with shortened dental arches (SDA), who required prosthodontic treatment and were followed and longitudinally evaluated for two years after the removable partial denture (RPDs) treatment. In each case, to measure and compare differences before and after reconstruction procedures, the degree of severity of CMD was checked on a score basis methodology, following clinical history, muscular and temporomandibular joint (TMJ) sensibility examination, clicking and mandibular movements (MM) registration. Twenty-nine other subjects acted as a control group. After non parametric statistical analysis it was concluded that subjects had a significant higher CMD severity prevalence before RPD treatment and that an adequate indication and treatment with RPD acts positively, resulting in a decline in the prevalence of these disorders.

Probiotic Bacteria Alter Pattern-Recognition Receptor Expression and Cytokine Profile in a Human Macrophage Model Challenged with Candida albicans and Lipopolysaccharide

Probiotics are live microorganisms that confer benefits to the host health. The infection rate of potentially pathogenic organisms such as Candida albicans, the most common agent associated with mucosal candidiasis, can be reduced by probiotics. However, the mechanisms by which the probiotics interfere with the immune system are largely unknown. We evaluated the effect of probiotic bacteria on C. albicans challenged human macrophages. Macrophages were pretreated with lactobacilli alone (Lactobacillus rhamnosus LR32, Lactobacillus casei L324m, or Lactobacillus acidophilus NCFM) or associated with Escherichia coli lipopolysaccharide (LPS), followed by the challenge with C. albicans or LPS in a co-culture assay. The expression of pattern-recognition receptors genes (CLE7A, TLR2, and TLR4) was determined by RT-qPCR, and dectin-1 reduced levels were confirmed by flow cytometry. The cytokine profile was determined by ELISA using the macrophage cell supernatant. Overall probiotic lactobacilli down-regulated the transcription of CLEC7A (p < 0.05), resulting in the decreased expression of dectin-1 on probiotic pretreated macrophages. The tested Lactobacillus species down-regulated TLR4, and increased TLR2 mRNA levels in macrophages challenged with C. albicans. The cytokines profile of macrophages challenged with C. albicans or LPS were altered by the probiotics, which generally led to increased levels of IL-10 and IL-1β, and reduction of IL-12 production by macrophages (p < 0.05). Our data suggest that probiotic lactobacilli impair the recognition of PAMPs by macrophages, and alter the production of pro/anti-inflammatory cytokines, thus modulating inflammation.

Análise crítica das construções protéticas, fixas e removíveis,sobre implantes em pacientes edentados: [revisão]

A osseointegracao e, sem sombra de duvida, a responsavel pelo notavel avanco tecnologico, mudanca deconceitos filosoficos e conducao de planejamentos voltados a reabilitacao oral, como tambem, pela disseminacaoe propagacao dos conhecimentos, interferindo sobremaneira nas demais areas da Odontologia contemporânea.Os implantes osseointegrados sao cada vez mais utilizados para substituir dentes perdidos em varias situacoes, desde a perda de um unico dente ate em casos de completo edentulismo. A reabilitacao de pacientes desdentados com proteses fixas ou overdentures removiveis e um processo complexo e desafiador. Existem fatores cruciais para a decisao de uma protese fixa ou removivel para se obter estetica, fonetica, promover conforto e funcao. Alem disso, o resultado do tratamento esta relacionado a taxa de sobrevivencia dos implantes, a manutencao do osso marginal, a saude do tecido periimplantar, a longevidade dos componentes proteticos e da protese em si. Esse estudo buscou analisar as vantagens e desvantagens das reabilitacoes proteticas sobre implantes, fixas e removiveis, para pacientes totalmente desdentados. (AU) Doubtless, osseointegration is the major responsible for the remarkable technological advance, changing philosophical concepts and guiding treatment plans related to oral rehabilitation. It also contributes to knowledge spread and diffusion, interfering in other areas of contemporary dentistry. Osseointegrated implants are widelyused to replace lost teeth in many situations, since the loss of a single tooth to completely edentulous archcases. Rehabilitation of edentulous patients by using fixed or removable implant-supported prostheses is a complex and challenging procedure. There are crucial factors involved at the decision of whether fixed or removable implant prosthesis should be planned to acquire optimal esthetics, phonetics, comfort, and function. In addition, the treatment result is related to implant survival, crest bone loss, soft tissue health, prosthesiss components longevity and prosthesis longevity itself. The aim of the present study is analyze the advantages and disadvantages of prosthetic rehabilitation of completely edentulous patients with fixed or removable implants. (AU)

Different Occlusal Schemes in a Persistent Protruding Complete Denture Wearer

Different types of artificial teeth and occlusal designs can be used in complete dentures. Bilateral balanced occlusion, lingualized occlusion, canine guidance, and monoplane are the main occlusal designs; however there is no agreement on which tooth arrangement is ideal for achieving success in complete dentures. This report presents an alternative for persistent involuntary protruding complete denture wearers through the use of artificial teeth with higher cusps. Due to an old and worn pair of complete dentures, the patient had the habit of protruding. New dentures were made with Biotone artificial teeth and in the trial session, the patient would still protrude. A new set was made with Premium artificial teeth, which present higher cusps. With these dentures, the involuntary protrusion did not occur. From the delivery to the follow-up sessions, the patient stopped protruding.