Mechanical strength and inhibition of plaque biofilm activity of a novel antibacterial Hawley retainer / 口腔疾病防治

Objectives @#The purposes of this study were to evaluate the long-term mechanical property, bacteria-killing ability, protein resistance and cytotoxicity of a novel antibacterial methyl methacrylate (MMA) resin. @*Methods @#The 2-methacryloyloxyethyl phosphorylcholine (MPC) has been added into the MMA used for making Hawley orthodontic retener according to the mass percentage 0% (control group), 1.5%, 2.25%, 3%, 4.5% and 6%. Specimens from the control group and MPC group were water-aged for 1 d, 90 d and 180 d, and then the universal material testing machine was used to investigate the long-term mechanical properties of the modified MMA specimens in the oral environment. The biofilm metabolic activity, colony-forming unit (CFU) and live/dead staining assay of the biofilms in the control group and MPC group in the oral environment were tested using the dental plaque biofilm model. The micro-bicinchoninic acid (BCA) method was used to determine the amount of protein adsorbed on the specimens. The MTT method was used to evaluate the cytotoxicity of the control group and MPC group.@*Results @#In the simulated oral environment, the addition of 0% to 3% MPC had no significant effect on the mechanical properties of the MMA specimen (P > 0.05). The control group and the modified MMA specimens with 3%MPC were statistically significant in time and the interaction effects between the two groups (P < 0.05). With increasing intervention time, the mechanical strength of both groups decreased, and the effect of time varied with grouping. The protein adsorption on the surface of the modified MMA material after adding 3% MPC decreased by approximately 80%, the metabolic activity of the biofilm decreased by approximately 50%, and biofilm CFU counts decreased by approximately 70% (P < 0.05) compared with the control. There was no statistically significant difference in time or interaction effects between the two groups. The amount of live green bacteria in the 3% MPC group decreased significantly after 1, 90, and 180 d of water aging. There was no significant difference in cytotoxicity between the control group and the MPC group (P > 0.05). @*Conclusions @#The addition of MPC into the MMA resin did not compromise the mechanical properties of the resin and exhibited long-lasting antibacterial and protein-repellent effects.

Alteration of the oral environment in patients undergoing esophagectomy during the perioperative period

Objective: During the perioperative period, oral ingestion is changed considerably in esophagectomy patients. The aim of this study was to investigate oral environment modifications in patients undergoing esophageal cancer treatments due to changes in dietary intake and swallowing functions. Material and Methods: Thirty patients who underwent operation for removal of esophageal cancer in Tokushima University Hospital were enrolled in this study. Results: It was found that 1) the flow rate of resting saliva decreased significantly at postoperative period by deprived feeding for one week, although it did not recover several days after oral ingestion began, 2) the accumulation of dental plaque and the number of mutans streptococci in saliva decreased significantly after operation, while both increased relatively quick when oral ingestion began, and 3) the swallowing function decreased significantly in the postoperative period. Conclusions: These results suggest that dental professionals should emphasize the importance of oral health care and provide instructions on plaque control to patients during the perioperative period of esophageal cancer treatment.

Effects of oral environment stabilization procedures on Streptococcus mutans counts in pregnant women

The aim of this study was to determine the effect of oral environment stabilization (OES) on the counting of Streptococcus mutans in high-caries-risk pregnant women participants of a prevention program in a public teaching institution. The sample was composed of 30 pregnant women aged 18 to 43 years, who looked for treatment at the Preventive Dentistry Clinic of the Araraquara Dental School, UNESP. Saliva samples were collected before and after the OES procedures and were forwarded to the pathology for observation and quantification of S. mutans CFU. There was a decrease in the number of S. mutans CFU, which was significantly different (p<0.0001) between samples. Considering the age group, 70.0 percent were between 18 to 30 years old and 30.0 percent belonged to the 31-43-year-old age group. Data related to the pregnancy period showed that 73.4 percent were in the second trimester, 13.3 percent in the first and 13.3 percent in third trimester. OES showed to be an effective clinical procedure in diminishing the number of S. mutans CFU in the saliva of high-caries-risk pregnant women. This management is simple and effective, corresponding to the basic treatment needs of pregnant women that search dental care in this public service.

O objetivo desta pesquisa foi determinar o efeito da adequação do meio bucal sobre a contagem de Streptococcus mutans em gestantes de alto risco à cárie, participantes de um programa de prevenção em uma instituição de ensino público, antes e após adequação do meio bucal. Amostras de saliva de 30 gestantes (18 a 43 anos) que procuraram atendimento na Clínica de Odontologia Preventiva da FOAr-UNESP foram coletadas antes e após procedimentos de adequação do meio bucal, e examinadas para observação e contagem das UFCs de S. mutans. Foi demonstrado que houve diminuição na quantidade das UFCs (p<0,0001) entre as amostras. Em relação à faixa etária, 70,0 por cento das gestantes tinham entre 18 e 30 anos de idade e 30,0 por cento pertenciam à faixa etária de 31 a 43 anos. Dados relativos ao período da gestação revelaram que 73,4 por cento estavam no 2º trimestre e 13,3 por cento estavam igualitariamente no 1º e 3º trimestres. A adequação do meio bucal se mostrou eficaz na diminuição das UFCs de S. mutans presentes na saliva de gestantes de alto risco de cárie. Este procedimento é simples e extremamente efetivo, atendendo às necessidades de tratamento básico de gestantes que procuram atendimento odontológico no serviço público de saúde.