Effect of Neodymium-Doped Yttrium Aluminum Garnet Laser Combined With Desensitizing Toothpaste on Dentinal Tubule Occlusion Against Acid Challenge / 中国医学科学院学报

Objective To assess the effects of different application sequences of neodymium-doped yttrium aluminum garnet(Nd∶YAG)laser and the desensitizing toothpaste containing stannous fluoride on dentinal tubule occlusion.Methods Twelve intact third molars freshly extracted from human were selected and prepared into dentin slices with a thickness of 0.8 mm.Each dentin slice was subdivided into four small slices,three of which were etched with 6% citric acid and randomly assigned to the following three groups(n=12):(1)control group:no treatment;(2)Nd∶YAG+toothbrushing(TB)group:first irradiated with Nd∶YAG laser and then brushed with desensitizing toothpaste;(3)TB+Nd∶YAG group:first brushed with desensitizing toothpaste and then irradiated with Nd∶YAG laser.The Nd∶YAG laser irradiation were carried out at 1 W,15 pulses/s,and the pulse width of 150 μs for 10 s(for a total of 6 cycles).After the above treatment,the 12 dentin slices from the Nd∶YAG+TB and TB+Nd∶YAG groups were randomly assigned to four subgroups(n=3)and subjected to acid etching in the Coca-Cola solution for 0,5,10,and 15 min.A scanning electron microscope was used to observe and photograph the dentin slices in each group,and eight single-blinded examiners scored the slices according to uniform criteria.The analysis of variance was carried out to compared the scores between groups.Results Before acid etching,the dentin tubule occlusion scores of the Nd∶YAG+TB and TB+Nd∶YAG groups were(4.83±0.09) scores and(3.85±0.66) scores,respectively,which had no significant difference between each other(P=0.0590)and were higher than that[(0.10±0.07)scores]of the control group(both P<0.0001).The dentin tubule occlusion scores of the Nd∶YAG+TB group after acid etching for 5,10,and 15 min were(4.33±0.60)scores,(4.27±0.24)scores,and(3.63±0.07)scores,respectively,which were not significantly different from those[(4.04±0.10)scores,(3.76±0.59)scores,and(3.17±0.29)scores,respectively]of the TB+Nd∶YAG group(all P>0.05).In the Nd∶YAG+TB subgroup,the dentin tubule occlusion score after acid etching for 15 min was significantly lower than that before acid etching(P=0.0011).In the TB+Nd∶YAG group,there was no statistically significant difference in the score between before and after acid etching(P>0.05).Conclusions Nd∶YAG laser irradiation with appropriate parameters combined with the use of desensitizing toothpaste could produce an excellent occluding effect on dentinal tubules regardless of the sequence.However,brushing with desensitizing toothpaste followed by Nd∶YAG laser irradiation produced more consistent dentin sealing after acid etching.

Eficácia de um dentifrício sem flúor no controle de Streptococcus mutans in vitro / Effectiveness of a non-fluoridated dentifrice in control of Streptococcus mutans in vitro

Objetivo: avaliar a eficácia de um dentifrício, que contém em sua composição extratos vegetais e xilitol para inibição de Streptococcus mutans (UA159). Materiais e método: para verificação da atividade antimicrobiana, foram realizados ensaios in vitro de difusão de ágar, baseados na metodologia da norma M2A8 Anvisa. O estudo foi feito utilizando inóculo de 108 UFC/mL da cepa de S. mutans. O princípio básico foi a difusão de uma solução de dentifrício na superfície do ágar a partir de um disco impregnado. O ensaio foi realizado utilizando como controle negativo água deionizada estéril e como controle positivo clorexidina 0,12%, e foram comparados aos dentifrícios Orgânico Natural® e Colgate Total 12®. O resultado foi analisado a partir da medição dos halos de inibição (mm). Resultados: a clorexidina 0,12% teve maior halo de inibição (21,08 ± 1,02), seguida do dentifrício Orgânico Natural® (11,33 ± 4,35) e do dentifrício Colgate Total 12 (3,93 ± 4,67) P<0,05. Conclusão: a inibição da cepa de S. mutans evidenciada neste ensaio in vitro demonstra o potencial antimicrobiano do dentifrício Orgânico Natural®, mesmo como um possível auxiliar no controle do biofilme dental cariogênico. (AU)

Objective: the goal was to evaluate the effectiveness of a dentifrice that has a chemical composition of plant extracts and xylitol to inhibit the Streptococcus mutans (UA159). Materials and methods: based on the methodology of the M2A8 Anvisa standard, in vitro agar diffusion assays were performed to verify antimicrobial activity. The study was carried out using inoculum of 108 CFU / mL of S. mutans strain. The principle was the diffusion of a dentifrice solution on the agar surface, from a disc impregnated therewith. The assay was performed using as a negative control the sterile deionized water, 0.12% chlorhexidine as a positive control compared to Orgânico Natural® and Colgate Total 12® toothpastes. The result was analyzed from the inhibition halos measurement (mm). Results: the chlorhexidine 0.12% had the biggest inhibition halo (21,08 ± 1,02) followed by the Orgânico Natural® dentifrice (11,33 ± 4,35) and the Colgate Total 12® dentifrice (3,93 ± 4,67) P<0,05. Conclusion: the inhibition of the S. mutans strain realized in these in vitro assay by the Orgânico Natural® dentifrice demonstrate the antimicrobial potential of the same as a possible aid in the control of the cariogenic dental biofilm. (AU)

Influence of time, toothpaste and saliva in the retention of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes

Objectives: The intraoral transmission of cariogenic and periodontopathogenic species seems to be facilitated by contaminated toothbrushes and other oral hygiene devices. The aim of this investigation was to analyze the in vitro retention and survival rate of Streptococcus mutans and Streptococcus sanguinis on different toothbrushes. The impacts of human saliva and antimicrobial toothpaste on these parameters were further evaluated. Material and Methods: Part I: Four toothbrushes (Colgate 360°, Curaprox CS5460 ultra soft, elmex InterX, Trisa Flexible Head3) were contaminated by S. mutans DSM 20523 or S. sanguinis DSM 20068 suspensions for three minutes. Bacteria were removed from the toothbrushes after either three minutes (T0) or 24 hours (T24) of dry storage and grown on Columbia blood agar plates for the quantification of colony-forming units (CFUs). Part II: The effects of saliva from a caries-active or a caries-inactive person and of toothpaste containing 0.12% chlorhexidine digluconate were also tested. Results: Part I: After three minutes of dry storage, approximately one percent of the bacteria were still detectable on the toothbrushes. After 24 hours, S. sanguinis exhibited a more pronounced decrease in viable cell numbers compared with S. mutans but the differences were not significant (Kruskal-Wallis test, p>0.05). Part II: The addition of human saliva from a caries-active or caries-inactive person slightly increased the retention of both streptococcal species at T0. The use of toothpaste had no influence on the amount of viable streptococci at T0, but it reduced the microbial load after 24 hours of storage. There were only slight nonsignificant differences (p>0.05) between the four toothbrushes. Conclusions: In vitro bacterial retention and survival of S. sanguinis and S. mutans on different toothbrushes occurred. Within the limitations of this study, the use of human saliva or an antimicrobial toothpaste ...

Effect of desensitizing toothpastes on dentin

The objective of this study was to analyze the effects of toothbrushing with desensitizing toothpastes on dentin permeability and dentinal tubule occlusion. Fifty rats provided two hundred incisor teeth divided into five groups: DW, brushed with distilled water (control); FT, brushed with fluoride toothpaste; SCT, brushed with strontium chloride toothpaste; PCT, brushed with potassium citrate toothpaste; and PNT, brushed with potassium nitrate toothpaste. Cavities were prepared to expose the dentinal tubules, and the incisor teeth were brushed using the experimental agents. After each treatment, Evans blue dye solution was applied to the teeth. Dentin permeability was analyzed using scanning electron microscopy and energy-dispersive X-rays (EDX). There were significant differences (p < 0.0001, ANOVA) among the groups regarding dentin permeability, number of dentinal tubules, diameter of dentinal tubules, and opened tubular area. In the SCT, PCT and PNT groups, opened and partially occluded tubules, deposits, and a few smear layers were observed. In the DW and FT groups, most of the dentinal tubules were open, with no deposits or smear layers on the dentin. EDX revealed peaks of calcium and phosphorus in all of the groups, as well as traces of strontium in the SCT group and of potassium in the PCT and PNT groups. Desensitizing toothpaste decreased dentin permeability, although it produced only partial dentin tubule occlusion.

In vitro study on tooth enamel lesions related to whitening dentifrice.

Background: The tooth whitening substances for extrinsic use that are available in Brazil contain hydrogen peroxide or carbamide peroxide. Several studies have attributed the appearance of lesions in the enamel morphology, including hypersensitivity, to these substances. Such lesions justify fluoride therapy and application of infrared lasers, among other procedures. However, there is no consensus among researchers regarding the relevance of the severity of lesions detected on the tooth surface. Objectives: The present study was carried out with an aim of evaluating in vitro the effects of the hydrogen peroxide, carbamide peroxide and sodium bicarbonate contained in dentifrice formulations, on human tooth enamel. Materials and Methods: After darkening process in laboratory, human premolars were brushed using dentifrice containing the two whitening substances (Rembrandt - carbamide peroxide and Mentadent - hydrogen peroxide) and the abrasive product (Colgate - sodium bicarbonate). The degree of specimen staining before and after this procedure was determined using spectrophotometry. Scanning electron microscopy (SEM) was used to obtain images, which were analyzed to show the nature of the lesions that appeared on the enamel surface. Results: The effectiveness of the whitening caused by hydrogen peroxide and carbamide peroxide and the abrasion caused by bicarbonate were confirmed, given that the treated test pieces returned to their original coloration. Based on SEM, evaluation of the enamel surfaces subjected to the test products showed that different types of morphologic lesions of varying severity appeared. Conclusions: Whitening dentifrice containing hydrogen peroxide and carbamide peroxide produced lesions on the enamel surface such that the greatest sequelae were associated with exposure to hydrogen peroxide.

Physical-chemical characteristics of whitening toothpaste and evaluation of its effects on enamel roughness

This in vitro study evaluated the physical-chemical characteristics of whitening toothpastes and their effect on bovine enamel after application of a bleaching agent (16 percent carbamide peroxide). Physical-chemical analysis was made considering mass loss by desiccation, ash content and pH of the toothpastes. Thirty bovine dental enamel fragments were prepared for roughness measurements. The samples were subjected to bleaching treatments and simulated brushing: G1. Sorriso Dentes Brancos (Conventional toothpaste), G2. Close-UP Whitening (Whitening toothpaste), and G3. Sensodyne Branqueador (Whitening toothpaste). The average roughness (Ra) was evaluated prior to the bleaching treatment and after brushing. The results revealed differences in the physical-chemical characteristics of the toothpastes (p < 0.0001). The final Ra had higher values (p < 0.05) following the procedures. The mean of the Ra did not show significant differences, considering toothpaste groups and bleaching treatment. Interaction (toothpaste and bleaching treatment) showed significant difference (p < 0.0001). The whitening toothpastes showed differences in their physical-chemical properties. All toothpastes promoted changes to the enamel surface, probably by the use of a bleaching agent.

Estudo preliminar da atividade antibacteriana do óleo essencial e da resina da Copaifera multijuga (óleo de copaíba), associados ao óxido de zinco e ao hidróxido de cálcio / Preliminary study of the activity antibacterial of the essential oil and of the resin of the Copaifera multijuaga (copaiba oil), associated to the zinc oxide and to calcium hydroxide

Atividade antibacteriana do óleo essencial e da resina da Copaire multijuga associados ao hidróxido de cálcio e ao óxido de zinco foi avaliada, visando sua introdução na Odontologia, tendo em vista as propriedades medicinais deste óleo. O óleo bruto foi submetido à análise por cromatografia gasosa e destilação para obtenção de suas frações (óleo essencial e a resina). Foram confeccionadas pastas experimentais de hidróxido de cálcio ou óxido de zinco associadas ao óleo essencial ou a resina de copaíba na proporção 1:1 ou 2:1. A avaliação da atividade antibacteriana foi realizada pelo Método de Difusão e pela determinação da Concentração Inibitória Mínima e da Concentração Bacteriana Mínima à frente à Pseudomonas aeruginosa e Streptococcus mutans. As pastas experimentais apresentaram atividade antibacteriana frente ao Streptococcus mutans; o óleo essencial apresentou melhor atividade antibacteriana do que a resina quando avaliadi isoladamente; o óleo bruto foi bacteriostático e bactericida frente ao Streptococcus mutans

Effect of fluoride dentifrices on salivary fluoride levels in children.

Fluoride dentifrices are well accepted for their caries preventive effects. The fluoride concentration in the oral fluids after tooth brushing with fluoride dentifrices may have an important relationship to the caries reducing capacity. The present study was aimed to clinically evaluate the salivary fluoride retention of dentifrices containing low fluoride concentration in 50 children, aged 7-9 years before, during and after the use of fluoride toothpaste. Estimation of fluoride in saliva was done using a Orion microprocessor ion analyser with a fluoride specific ion electrode. The results of the present study suggest that there is considerable salivary fluoride retention after brushing with fluoride dentifrices. The retention of fluoride in the saliva at a higher level even with the low fluoride concentration, proves the similar cariostatic effect as of higher concentration.

Estudio del efecto de la maltosa adicionada a un gel dental sobre el grado de infección por el streptococcus mutans en la saliva y sobre la higiene bucal: ensayo preliminar / Study of the effect of maltose added to a dental gel on degree of infection by streptococcus mutans in the saliva and oral hygiene: preliminary assay

Algunos autores han demostrado que la maltosa inhibe la formación de glucanos insolubles por el S. mutans, al interferir su mecanismo de adhesión. Esta investigación preliminar se realizó para conocer el efecto de la maltosa incorporada a un gel para el cepillado de los dientes, sobre el grado de infección por el S. mutans en la saliva y sobre la higiene bucal. En 8 participantes (personal estomatológico) se aplicó la técnica de Matsukubo (modificada) y se determinó la higiene bucal mediante los índices de Love y el IHB-S; se formaron 2 grupos y se utilizó una prueba cruzada en 2 etapas. Se halló que el cepillado con el gel-maltosa redujo el grado de infección por el S. mutans en el 50,5 % al compararse con el control, mientras que el efecto sobre los índices de higiene bucal no presentaron diferencias significativas. Se discuten los resultados y se concluye que se precisa valorar su efecto en la prevención de caries mediante un ensayo clínico de un año de duración