Effect of 8% arginine toothpaste on Streptococcus mutans in patients undergoing fixed orthodontic treatment: randomized controlled trial

ABSTRACT Objective: To assess the effect of toothpaste containing 8% arginine on Streptococcus mutans (S. mutans) in dental plaque around orthodontic brackets, and to draw a comparison with a regular fluoride toothpaste. Trial design: A single-center, parallel-arm, triple-blind, randomized controlled trial was conducted. Methods: The clinical trial was conducted at the Orthodontic Clinic, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran. Seventy-two patients (age range: 15-30 years) who required fixed orthodontic treatment were recruited and randomly assigned to arginine and fluoride groups. Randomization was performed using RANDOM.ORG online software, and the participants were divided into two parallel groups, with a 1:1 allocation ratio. Patients were requested to brush their teeth twice daily for 30 days with an experimental toothpaste. Plaque sampling was performed at two intervals, namely at the beginning of the study (T0) and 30 days later (T1). Real-time PCR was used to assess plaque samples in terms of the number of S. mutans surrounding stainless steel brackets in orthodontic patients. A triple-blind design was employed. Results: The baseline characteristics (age, sex, and the relative number of S. mutans) between the groups were similar (p>0.05). Only the arginine group showed a significant decrease in the relative number of bacteria between T0 and T1 (p=0.02). Conclusion: Arginine is an important prebiotic agent in maintaining healthy oral biofilms, and prevent dental caries during fixed orthodontic treatments. Trial registration: The trial was registered at the Iranian Registry of Clinical Trials (IRCT20181121041713N2), https://en.irct.ir/user/trial/42409/view.

RESUMO Objetivo: Avaliar o efeito de um dentifrício contendo arginina a 8% no Streptococcus mutans (S. mutans) da placa bacteriana ao redor de braquetes ortodônticos, e compará-lo a um dentifrício fluoretado convencional. Desenho do estudo: Foi conduzido um estudo unicêntrico, com braços paralelos, triplo-cego, controlado e randomizado. Métodos: O ensaio clínico foi conduzido na Clínica de Ortodontia da Faculdade de Odontologia da Universidade de Ciências Médicas de Shiraz, no Irã. Setenta e dois pacientes (com idades variando de 15 a 30 anos) que necessitavam de tratamento ortodôntico com aparelho fixo foram recrutados e alocados aleatoriamente nos grupos arginina ou flúor. A randomização foi feita usando o programa on-line RANDOM.ORG, e os participantes foram divididos em dois grupos paralelos, com proporção de alocação de 1:1. Solicitou-se aos pacientes que escovassem os dentes duas vezes ao dia com a pasta experimental, durante 30 dias. Amostras da placa bacteriana foram coletadas em dois intervalos: ao começo do estudo (T0) e após 30 dias (T1). Um PCR em tempo real foi usado para avaliar as amostras de placa, em termos de números de S. mutans ao redor dos braquetes de aço inoxidável nos pacientes ortodônticos. Um desenho de estudo triplo-cego foi usado. Resultados: As características iniciais (idade, sexo e quantidade relativa de S. mutans) foram semelhantes entre os grupos (p>0,05). Apenas o grupo arginina mostrou uma redução significativa na quantidade de bactérias entre T0 e T1 (p=0,02). Conclusão: A arginina é um agente prebiótico importante na manutenção de biofilmes bucais saudáveis, e previne as cáries dentárias durante o tratamento ortodôntico com aparelho fixo. Registro do ensaio: O ensaio foi registrado no Iranian Registry of Clinical Trials (IRCT20181121041713N2), https://en.irct.ir/user/trial/42409/view.

Effects of menthone and piperitone on growth, chlorophyll a and β-carotene production in Dunaliella salina.

Recently, studying essential oils and secondary metabolites of plants and microalgae have received much attention. The biosynthesis of the secondary metabolites is strongly influenced by different environmental factors. Monoterpenes as a main fraction of essential oils of fruits and vegetables have many clinical applications. They could inhibit the carcinogenesis processes and therefore might be effective in treatment of cancers. Dunaliella salina, a photosynthetic green microalga is known as a rich source for β-carotene production. In this study, the effects of some monoterpenes including menthone and piperitone was investigated on yield of production of β-carotene were studied. Menthone and piperitone as parameters of stress can make tensions to the medium of D. salina increasing its β-carotene and chlorophyll a content in every single cell but on the other hand these two monoterpenes cause a decrease in the concentration of β-carotene and chlorophyll a.

Investigating the effects of phytohormones on growth and β-carotene production in a naturally isolates stain of Dunaliella salina.

The algae of the genus Dunaliella especially D. salina is among the microalgae most studied for mass culture. This alga is the richest algal source of glycerol and β-carotene, which is grown as a food source in aquaculture. In this study the effect of growth regulators (kinetin, gibberellic acid, indole-3-acetic acid, 6γ, γ-dimethylallyl aminopurine, salicylic acid and benzyl aminopurine) on the growth and β-carotene production in D. salina (MCCS 001) was investigated. Results pointed out that the β-carotene content and cell growth of D. salina could achieve the highest rates when kinetin and indole-3-acetic acid were used at 1 µM. Besides, it was shown that almost all of plant hormones has a positive effect on cell growth and β-carotene production in the microalga D. salina.