Search

BACKGROUND: The purpose of the clinical study was to examine the antibacterial and plaque-reducing properties of mouthrinses containing triclosan (TRI), amine fluoride (AmF), and the combination of both (AFT) on 4-day plaque regrowth. A placebo solution (PLA) and a 0.2% chlorhexidine solution (CHX) served as negative and positive controls, respectively. MATERIALS AND METHODS: After a professional tooth cleaning (day 0), 15 volunteers refrained from all mechanical oral hygiene measures for the next 96 h and rinsed instead twice daily for 1 min with 10 ml of one of the five randomly assigned solutions. Plaque index (PlI), which was assessed after 24 and 96 h (PlI1, PlI2), and plaque area of the front teeth (PA), which was planimetrically recorded from disclosed teeth after 96 h, served as clinical parameters. After 24 and 96 h a plaque sample was taken and analyzed microbiologically to evaluate biofilm vitality (VF1, VF2). The subsequent test cycles were conducted after a washout period of 10 days each. RESULTS: No severe adverse events or allergy were seen during the study. CHX influenced all parameters at all time points in comparison to PLA. AFT and AmF showed very similar values (in all parameters), but AmF did not reach the level of significance regarding VF1, nor did AFT with VF2 and PlI1. The TRI solution only reduced PlI2 and PA significantly, but had no influence on biofilm vitality when compared to PLA. CONCLUSION: A synergism between AmF and TRI was not observed. The results suggest that the plaque-reducing and antibacterial effects of the AFT solution are mainly based on the effects of the amine fluoride moiety. [ABSTRACT FROM AUTHOR]

The experimental gingivitis model was used to compare the anti-plaque, anti-gingivitis and anti-microbiaI efficacies of a phenolic compound (Listerine®) and an amine/stannous fluoride mouthwash (Meridol®), using a placebo preparation as negative control and a chlorhexidine solution as positive control in double-blind study. After professional toothcleaning, 36 volunteers performed optimal oral hygiene for a period of 2 weeks. They then ceased all onral hygiene procedures for 21 days during which they rinsed twice daily with 1 of the 4 mouthrinses. After 3 weeks of rinsing, plaque indices remained the lowest in the chlorhexidine group, while subjects using Listerine® or Meridol® harbored similar indices significantly lower than that of individuals rinsing with the placebo solution. Up to that time, the gingival index scores were equal in all groups except for the chlorhexidine group in which the values only amounted to half of these encountered in the other groups. The plaque vitality scores showed a bactericidal effect in vivo of chlorhexidine during the entire time of experimental gingivitis. In contrast, the data gave no evidence of an antibacterial effect in vivo of Listerine®. The efficacy of Meridol® to kill micro-organisms was similar to chlorhexidine during the early stages of plaque accumulation and, with time, became insignificant. This study has demonstrated that chlorhexidine was superior to Listerine® and Meridol® in its ability to maintain low plaque scores and gingival health during this 3-week period of no mechanical oral hygiene. Moreover, it was also shown that Meridol® was as effective as Listerine® reducing plaque accumulation and, in contrast to Listerine®, possessed a remarkable but transient antibacterial effect in vivo. [ABSTRACT FROM AUTHOR]

The oral microbiota represents an important part of the human microbiota, and includes several hundred to several thousand diverse species. It is a normal part of the oral cavity and has an important function to protect against colonization of extrinsic bacteria which could affect systemic health. On the other hand, the most common oral diseases caries, gingivitis and periodontitis are based on microorganisms. While (medical) research focused on the planktonic phase of bacteria over the last 100 years, it is nowadays generally known, that oral microorganisms are organised as biofilms. On any non-shedding surfaces of the oral cavity dental plaque starts to form, which meets all criteria for a microbial biofilm and is subject to the so-called succession. When the sensitive ecosystem turns out of balance - either by overload or weak immune system - it becomes a challenge for local or systemic health. Therefore, the most common strategy and the golden standard for the prevention of caries, gingivitis and periodontitis is the mechanical removal of this biofilms from teeth, restorations or dental prosthesis by regular toothbrushing.

Aims: The aims of this double-blind, controlled, crossover study were to assess the influence of food preservatives on in situ dental biofilm growth and vitality, and to evaluate their influence on the ability of dental biofilm to demineralize underlying enamel over a period of 14 days., Materials and Methods: Twenty volunteers wore appliances with six specimens each of bovine enamel to build up intra-oral biofilms. During four test cycles of 14 days, the subjects had to place the appliance in one of the assigned controls or active solutions twice a day for a minute: negative control 0.9 % saline, 0.1 % benzoate (BA), 0.1 % sorbate (SA) and 0.2 % chlorhexidine (CHX positive control). After 14 days, the biofilms on two of the slabs were stained to visualize vital and dead bacteria to assess biofilm thickness (BT) and bacterial vitality (BV). Further, slabs were taken to determine mineral loss (ML), by quantitative light-induced laser fluorescence (QLF) and transversal microradiography (TMR), moreover the lesion depths (LD)., Results: Nineteen subjects completed all test cycles. Use of SA, BA and CHX resulted in a significantly reduced BV compared to NaCl (p < 0.001). Only CHX exerted a statistically significant retardation in BT as compared to saline. Differences between SA and BA were not significant (p > 0.05) for both parameters. TMR analysis revealed the highest LD values in the NaCl group (43.6 ± 44.2 μm) and the lowest with CHX (11.7 ± 39.4 μm), while SA (22.9 ± 45.2 μm) and BA (21.4 ± 38.5 μm) lay in between. Similarly for ML, the highest mean values of 128.1 ± 207.3 vol% μm were assessed for NaCl, the lowest for CHX (-16.8 ± 284.2 vol% μm), while SA and BA led to values of 83.2 ± 150.9 and 98.4 ± 191.2 vol% μm, respectively. With QLF for both controls, NaCl (-33.8 ± 101.3 mm(2) %) and CHX (-16.9 ± 69.9 mm(2) %), negative values were recorded reflecting a diminution of fluorescence, while positive values were found with SA (33.9 ± 158.2 mm(2) %) and BA (24.8 ± 118.0 mm(2) %) depicting a fluorescence gain. These differences were non-significant (p > 0.05)., Conclusion: The biofilm model permited the assessment of undisturbed oral biofilm formation influenced by antibacterial components under clinical conditions for a period of 14 days. An effect of BA and SA on the demineralization of enamel could be demonstrated by TMR and QLF, but these new findings have to be seen as a trend. As part of our daily diet, these preservatives exert an impact on the metabolism of the dental biofilm, and therefore may even influence demineralization processes of the underlying dental enamel in situ.

Background: There is confusion over the definition of the term "viability state(s)" of microorganisms. "Viability staining" or "vital staining techniques" are used to distinguish live from dead bacteria. These stainings, first established on planctonic bacteria, may have serious shortcomings when applied to multispecies biofilms. Results of staining techniques should be compared with appropriate microbiological data., Discussion: Many terms describe "vitality states" of microorganisms, however, several of them are misleading. Authors define "viable" as "capable to grow". Accordingly, staining methods are substitutes, since no staining can prove viability.The reliability of a commercial "viability" staining assay (Molecular Probes) is discussed based on the corresponding product information sheet: (I) Staining principle; (II) Concentrations of bacteria; (III) Calculation of live/dead proportions in vitro. Results of the "viability" kit are dependent on the stains' concentration and on their relation to the number of bacteria in the test. Generally this staining system is not suitable for multispecies biofilms, thus incorrect statements have been published by users of this technique.To compare the results of the staining with bacterial parameters appropriate techniques should be selected. The assessment of Colony Forming Units is insufficient, rather the calculation of Plating Efficiency is necessary. Vital fluorescence staining with Fluorescein Diacetate and Ethidium Bromide seems to be the best proven and suitable method in biofilm research.Regarding the mutagenicity of staining components users should be aware that not only Ethidium Bromide might be harmful, but also a variety of other substances of which the toxicity and mutagenicity is not reported., Summary: - The nomenclature regarding "viability" and "vitality" should be used carefully.- The manual of the commercial "viability" kit itself points out that the kit is not suitable for natural multispecies biofilm research, as supported by an array of literature.- Results obtained with various stains are influenced by the relationship between bacterial counts and the amount of stain used in the test. Corresponding vitality data are prone to artificial shifting.- As microbiological parameter the Plating Efficiency should be used for comparison.- Ethidium Bromide is mutagenic. Researchers should be aware that alternative staining compounds may also be or even are mutagenic.

During host interaction against oral biofilm, matrix metalloproteinase-8 (MMP-8) is activated, leading to collagenolytic destruction of host tissues. In periimplantitis patients, the active form of MMP-8 is elevated in peri-implant sulcus fluid (PISF). In this study, MMP-8 in PISF from titanium abutments and those coated with zirconium nitride (ZrN) was compared in vivo in a split-mouth design in 60 patients at 6 weeks, 6 months, and 12 months after prosthetic restoration. At each time point, MMP-8 values in PISF differed significantly between titanium and ZrN abutment surfaces. For example, mean MMP-8 values reached 10 to 12 ng/mL in titanium and only 6.6 to 7.5 ng/mL with ZrN. Similarly, the 75th percentile MMP-8 concentrations were 12 to 15 ng/mL and 8 to 9 ng/mL for titanium and ZrN, respectively. Based on this finding, ZrN-coated abutments seem to exert a beneficial effect regarding collagenolytic tissue destruction driven by MMP-8 in situ.

Objectives: The concept of platform switching has been introduced to implant therapy, however long-term data are sparse. The aim of this study was to biochemically investigate the inflammatory response mediated by MMP-8 to platform switching after 3 years of loading, in order to understand the long-term effect of implant/abutment mismatching on peri-implant health., Methods: A total of 70 implants had been inserted in the posterior maxilla in 26 patients and were randomly assigned to one of the four treatment regimens (implant diameter 3.8 [control group], 4.3 [Test group 1, T(1)], 4.8 [Test group 2, T(2)] and 5.5 mm [Test group 3, T(3)]). All implants were restored using a 3.8 mm abutment. In the test groups, this restoration resulted in a mismatching of 0.25-0.85 mm of implant-abutment diameters., Results: Thirty-six months after prosthetic rehabilitation, peri-implant sulcular fluid samples were taken from two aspects of all implants and from periodontally healthy adjacent teeth. Samples were processed in a conventional ELISA using monoclonal antibodies recognizing the active entity of MMP-8. In the test groups, MMP-8 mean values were 2.76 ng for T(1) (SD: 2.91), 3.30 ng for T(2) (SD: 1.94) and 3.18 ng for T(3) (SD: 2.46). For the control group, MMP-8 mean value was 3.6 ng (SD: 2.23), whereas 3.38 ng (SD: 2.2) was recorded at the adjacent teeth. There were no statistically significant differences in MMP-8 values between the groups (P=0.113, Kruskal-Wallis)., Conclusions: The presence of an implant/abutment mismatching specific for this prosthetic concept is compatible with long-term peri-implant health as demonstrated by analysis of a sensitive biomarker of the peri-implant inflammatory response., (© 2011 John Wiley & Sons A/S.)