Avaliação da estabilidade primária de implantes curtos e convencionais instalados em ossos de diferentes densidades / Evaluation of primary stability of short and conventional implants in bones with different densities

O objetivo deste estudo foi avaliar a estabilidade primária de implantes curtos e convencionais instalados em ossos com densidades tipo I e tipo IV de origem sintética e natural. Implantes nos tamanhos (Diamêtro x Comprimento) 3,75 x 13 mm, 3,75 x 10 mm, 4,3 x 5,5 mm e 5 x 5,5 mm foram instalados em blocos ósseos seguindo uma sequência de fresagens e avaliados o torque de inserção e o coeficiente de estabilidade primária (CE) através da análise da frequência de ressonância (AFR). Os resultados mostraram que implantes de diferentes tamanhos e ossos de diferentes densidades e origens influenciam tanto nos valores de torque de inserção quanto de AFR (p<0.05). Todos os implantes instalados nos ossos tipo IV apresentaram menores torques de inserção e menores CE (p<0.05) comparados aos instalados nos ossos tipo I, e implantes curtos apresentaram maiores torques que os convencionais intalados no osso tipo I. Assim, a utilização de implantes curtos pode ser uma alternativa viável de tratamento, principalmente em sítios ósseos com maiores densidades (AU).

The aim of this study was to assess the primary stability of short and conventional implants placed in bone with type I and type IV densities of synthetic or natural origin. Implants (D x C) of 3.75 x 13 mm, 3.75 x 10 mm, 4.3 x 5.5 mm, and 5 x 5.5 mm were placed in bone blocks following a drilling sequence and assessment of insertion torque and primary stability coefficient (SC) through resonance frequency analysis (RFA). The results showed that implants of different sizes and bones of different densities and origins influence both insertion torque and RFA values (p <0.05). All implants placed in type IV bones presented lower insertion torques and lower SC (p <0.05) compared to those placed in type I bones, and short implants presented higher torques than conventional implants in type I bone. So the use of short implants may be a viable treatment alternative, mainly in bone areas with higher densities (AU).

Mecanismos de ação das placas oclusais û revisão de literatura / Mechanism of action of occlusal appliances û literature review

O termo Desordem Temporomandibular (DTM) sugere a inclusão dos distúrbios associados ao sistema mastigatório e suas modalidades de tratamento estão relacionadas aos sinais e sintomas presentes nos pacientes, o que gera uma variedade de terapias que podem ser utilizadas individualmente ou associadas, com objetivo de reorganizar as funções deste sistema. A terapia com placas oclusais é um método eficaz no tratamento das DTMs, propondo a reorganização da atividade reflexa neuromuscular e a redução de hábitos parafuncionais, como o bruxismo. É uma modalidade de tratamento reversível e não invasivo e seu sucesso ou falha depende da sua correta indicação. Vários mecanismos de ação pelos quais essa terapia se torna eficaz são propostos, tendo em vista que nenhum desses mecanismos isoladamente explica sua eficiência. Desta forma, o objetivo deste estudo é revisar os possíveis mecanismos de ação das placas oclusais...

The term temporomandibular disorder (TMD) suggests the inclusion of disorders associated to the masticatory system and their treatment modalities are related to signs and symptoms present in patients, which generates a variety of therapies that can be used individually or in association, in order to reorganize the functions of this system. Therapy with occlusal appliances is an effective method in the treatment of TMD, proposing the reorganization of neuromuscular reflex activity and the reduction of parafunctional habits such as bruxism. It is a reversible and non-invasive modality of treatment and its success or failure depends on proper indication. Several mechanisms of action by which this therapy becomes effective are proposed, considering that none of those mechanisms explains alone their efficiency. Thus, the aim of this study is to review the possible mechanisms of action of occlusal appliances...

Efficacy of denture cleansers in reducing microbial counts from removable partial dentures: a short-term clinical evaluation.

This clinical study investigated if daily immersion in denture cleansers reduces microbial counts on removable partial denture's (RPD) biofilm. Twenty-five RPD wearer volunteers were selected and instructed to complement the hygiene of their dentures by immersing them in an enzymatic peroxide-based denture cleanser (Polident® 3 minute) once a day for 3 min for a period of 15 days. The biofilm was collected from RPD surfaces with a swab immediately before (baseline) and after the experimental period. The samples were placed in sterile saline solution, sonicated at 7 W and then plated on specific culture media to quantify total microorganisms, total streptococci and Candida spp. counts. Data from both collections were compared by paired t-test (α=0.05). It was observed a significant reduction on total microorganisms' counts in RPD biofilm after denture cleanser use (p=0.007). This reduction was also observed for total streptococci (p=0.0428), but no difference was observed on Candida spp. counts. It was concluded that daily use of denture cleanser improved denture hygiene by reducing total microorganisms and total streptococci from RPD surface but had no effect on Candida spp. population.

Efficacy of Denture Cleansers in Reducing Microbial Counts from Removable Partial Dentures: A Short-Term Clinical Evaluation

This clinical study investigated if daily immersion in denture cleansers reduces microbial counts on removable partial denture's (RPD) biofilm. Twenty-five RPD wearer volunteers were selected and instructed to complement the hygiene of their dentures by immersing them in an enzymatic peroxide-based denture cleanser (Polident® 3 minute) once a day for 3 min for a period of 15 days. The biofilm was collected from RPD surfaces with a swab immediately before (baseline) and after the experimental period. The samples were placed in sterile saline solution, sonicated at 7 W and then plated on specific culture media to quantify total microorganisms, total streptococci and Candida spp. counts. Data from both collections were compared by paired t-test (α=0.05). It was observed a significant reduction on total microorganisms' counts in RPD biofilm after denture cleanser use (p=0.007). This reduction was also observed for total streptococci (p=0.0428), but no difference was observed on Candida spp. counts. It was concluded that daily use of denture cleanser improved denture hygiene by reducing total microorganisms and total streptococci from RPD surface but had no effect on Candida spp. population.

Este estudo clínico investigou se a imersão diária de próteses parciais removíveis (PPR) em limpador químico reduz as contagens de micro-organismos no biofilme. Vinte e cinco voluntários que utilizavam PPR foram selecionados e instruídos a complementar a higiene das PPRs imergindo suas próteses em um limpador químico enzimático (Polident® 3 minute) uma vez por dia, por 3 min, durante 15 dias. O biofilme foi coletado da superfície das próteses com auxílio de um swab imediatamente antes (baseline) e após o período experimental. A amostra foi imersa em solução salina estéril, submetida a sonicação a 7 W, e semeada em meios de cultura específicos para quantificar micro-organismos totais, estreptococos totais e Candida spp. Os dados de ambas as coletas foram comparados pelo teste t pareado (α=0,05). Foi observada uma redução significativa nas contagens de micro-organismos totais no biofilme da PPR após o uso do limpador químico (p=0,007). Essa redução também foi observada para estreptococos totais (p=0,0428), mas não foi observada diferença nas contagens de Candida spp. Concluiu-se que o uso diário do limpador químico melhorou a higienização das próteses por reduzir o número de micro-organismos totais e estreptococos totais na superfície da PPR, mas não teve efeito sobre a população de Candida spp.

Influence of substratum position and acquired pellicle on Candida albicans biofilm

The purpose of this study was to evaluate the influence of the substratum position and the saliva acquired pellicle (AP) on Candida albicans biofilm development. Poly(methylmethacrylate) (PMMA) disks were fabricated and randomly allocated to experimental groups: HNP (disks placed in a horizontal position and uncoated by pellicle), VNP (disks placed in a vertical position and uncoated by pellicle), HCP (disks placed in a horizontal position and coated by pellicle), and VCP (disks placed in a vertical position and coated by pellicle). Disks were placed in a 24-well plate and a suspension of 107 cells/mL of Candida albicans was added to each well for biofilm development. The plates were aerobically incubated at 35°C. The biofilms were evaluated at 1.5 (adhesion time point), 24, 48, 72, and 96 hours. The number of viable cells was quantified in terms of the colony-forming units per milliliter (CFU/mL). Metabolic activity was measured by the XTT assay. The biofilm structure was analyzed by scanning electron microscopy. The data were analyzed by three-way ANOVA followed by Tukey's test, with significance set at 5%. The vertical groups showed less biofilm formation and lower metabolic activity than the horizontal groups (p< 0.05). Significant differences in cell viability and metabolic activity were observed between the adhesion and other time points (p< 0.05), but these variables were not affected by the presence of the pellicle (p > 0.05). It can be concluded that the substratum position influenced biofilm development.

Influence of substratum position and acquired pellicle on Candida albicans biofilm.

The purpose of this study was to evaluate the influence of the substratum position and the saliva acquired pellicle (AP) on Candida albicans biofilm development. Poly(methylmethacrylate) (PMMA) disks were fabricated and randomly allocated to experimental groups: HNP (disks placed in a horizontal position and uncoated by pellicle), VNP (disks placed in a vertical position and uncoated by pellicle), HCP (disks placed in a horizontal position and coated by pellicle), and VCP (disks placed in a vertical position and coated by pellicle). Disks were placed in a 24-well plate and a suspension of 107 cells/mL of Candida albicans was added to each well for biofilm development. The plates were aerobically incubated at 35°C. The biofilms were evaluated at 1.5 (adhesion time point), 24, 48, 72, and 96 hours. The number of viable cells was quantified in terms of the colony-forming units per milliliter (CFU/mL). Metabolic activity was measured by the XTT assay. The biofilm structure was analyzed by scanning electron microscopy. The data were analyzed by three-way ANOVA followed by Tukey's test, with significance set at 5%. The vertical groups showed less biofilm formation and lower metabolic activity than the horizontal groups (p<0.05). Significant differences in cell viability and metabolic activity were observed between the adhesion and other time points (p<0.05), but these variables were not affected by the presence of the pellicle (p>0.05). It can be concluded that the substratum position influenced biofilm development.