Effective plaque control is essential for prevention of gingivitis and periodontitis. The aim of this 24-week follow-up parallel study was to evaluate the efficacy of three topical gels in the treatment of gingivitis as compared to placebo gel.One hundred twenty subjects diagnosed with chronic generalized gingivitis were selected and randomly divided into four groups: Group 1--placebo gel, Group 2--chlorhexidine (CHX) gel, Group 3--metronidazole (MTZ) gel and Group 4--chlorhexidine-metronidazole (CHX-MTZ) gel. Clinical evaluation was undertaken using the gingival index (GI) of Löe and Silness and the plaque index (PI) at baseline, 6 weeks, 12 weeks and 24 weeks. Microbiological analysis was also done at the same time intervals. A subjective evaluation was also undertaken by questionnaire.Groups treated with all three gels (CHX, MTZ and CHX-MTZ) showed significant clinical and microbiological improvement as compared to the group treated with a placebo gel. The reduction in PI, GI and microbiological count in the group treated with the CHX-MTZ combination gel was significant when compared to those treated with CHX and MTZ gels.Topical application of CHX or MTZ alone or in combination may have a role in the management of gingivitis.

OBJECTIVE:

The aim of this study was to examine the effect of ursolic acid (UA) and oleanolic acid (OA), triterpenoid compounds that are isolated from many edible and medicinal plants, on cariogenic microorganisms and biofilms.

METHODS:

A microtitre plate dilution assay was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of UA and OA against two Actinomyces spp. and four Streptococcus spp. The antibacterial activity of UA and OA was assessed by crystal violet staining, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM).

RESULTS:

UA and OA displayed differential antibacterial activities against the six tested bacteria, with UA showing greater antibacterial activity than OA. Furthermore, the two drugs had greater antibacterial activity against Actinomyces spp. than Streptococcus spp. UA and OA at 1/4 MIC can reduce bacterial biofilm formation, whereas higher UA concentrations displayed antibacterial activity against Actinomyces viscosus and Streptococcus mutans in mature biofilms. For instance, 2.0 mg ml(-1) UA was sufficient to kill an A. viscosus biofilm.

CONCLUSIONS:

UA and OA inhibit the growth of cariogenic microorganisms, which suggests that UA and OA have considerable potential as antibacterial agents for dental caries prevention.

Actinomycosis is a rare anaerobic bacterial infection typically caused by Actinomyces israelii. Although part of normal flora in the oral cavity, and respiratory and digestive tracts, A israelii can give rise to pathologic infections most commonly reported in the oral cavity from odontogenic causes. We present a rare case of invasive actinomycosis presenting with extensive midface destruction involving the maxilla and paranasal sinuses, with mucosal necrosis mimicking an aggressive neoplasm. The diagnosis is usually reached only after histopathologic analysis showing characteristic sulfur granules with filamentous gram-positive, non-acid-fast bacteria. We review the literature on its epidemiology, clinical presentation, diagnosis, treatment, and prognosis.

This study compared the antimicrobial effects of three commercial dentifrice formulations: sodium fluoride/triclosan/copolymer (TCN/C), stannous fluoride/sodium hexametaphosphate/zinc lactate (SnF(2)/SHMP) and sodium fluoride (NaF).Thirty-five adults (15 men and 20 women; average age 33 years and pockets <5 mm) completed this double-blind, triple-crossover study. After washout, baseline samples from four sites, plaque, saliva, tongue and buccal mucosa, were collected and evaluated for six microbial types, anaerobes, Streptococci, Actinomyces, hydrogen-sulphide (H(2) S)-producing bacteria, Fusobacteria and Veillonella. A specific dentifrice was randomly assigned for twice-daily use for 13 days. On day 14, 12 h after brushing, samples were collected for microbiological evaluations. Alternate dentifrices followed this identical protocol.For all four oral sites and six organisms evaluated in each site, the TCN/C demonstrated significant reductions (49-83%) as compared with the other treatments (p < 0.01). The SnF(2)/SHMP group showed significant reductions of 14-43% for 14 of 24 outcomes as compared with the NaF group (p < 0.01), with no differences in 10 outcomes.The TCN/C dentifrice formulation consistently demonstrated significant reductions for a range of microorganisms in diverse oral sites in comparison with the NaF, or the SnF(2)/SHMP dentifrice formulations as seen 12 h after brushing.

The aim of this study was to evaluate in vitro the antimicrobial efficacy of a modified 3-mix paste and to compare it with an iodoform paste (Ultrapex) against anaerobic microorganisms isolated from root canals of infected or necrotic primary teeth.An in vitro experimental assay was performed over isolated and identified anaerobic microorganisms of 21 samples, in order to compare the antimicrobial ability of both root canal filling materials, using a disc-diffusion method.A total of 21 microbial samples (15 polymicrobial and 6 monomicrobial) were obtained, from which 19 different strains were identified. Modified 3-mix paste showed an excellent antimicrobial effect against most of both kinds of microbial samples, although some of them exhibited resistance; on the other hand, Ultrapex showed only minimal antimicrobial ability (null or low categories). Clostridium ramosum exhibited the most resistance to both materials.The bactericidal effect of the modified 3-mix paste was superior to Ultrapex, with a statistically significant difference, against anaerobic microorganisms isolated from infected root canals of primary teeth.

Dental caries is the most prevalent human infection. It is a multifactorial disease in which the microbial composition of dental plaque plays a major role in the development of clinical symptoms. The bacteria most often implicated in the development of caries are that group of streptococci referred to as the mutans streptococci, in particular Streptococcus mutans and Streptococcus sobrinus. One approach to the prevention of caries is to reduce the numbers of mutans streptococci in plaque to a level insufficient to support demineralization of the tooth. In this study, zoocin A, a peptidoglycan hydrolase, combined with lauricidin, a cell membrane active lipid, was shown over a 72 h period to selectively suppress the growth of S. mutans in a triple species biofilm. Growth of the non-target species Streptococcus oralis and Actinomyces viscosus was not inhibited. In treated systems the amount of extracellular polysaccharide matrix produced was much reduced as determined by use of fluorescein isothiocyanate conjugated wheat germ agglutinin. The pH of treated biofilms remained above neutral as opposed to a value of 4.3 in untreated controls. We conclude that use of antimicrobial compounds that specifically target cariogenic bacteria should be further explored.

To compare the subgingival microbiological outcomes of azithromycin or placebo as adjuncts to scaling and root planing (SRP) in the treatment of aggressive periodontitis (AgP), and to secondarily evaluate the microbiological effect of supragingival scaling in AgP patients.Twenty-four AgP subjects 13-26 years of age received a 15-day programme of supragingival scaling (SC) and were then randomly assigned to SRP with systemic azithromycin or placebo. Subgingival samples were taken with sterile paper points at baseline, 15 days after SC, and at 3, 6 and 12 months following SRP. Microbiological analysis was performed by the checkerboard DNA-DNA hybridization.Changes in bacterial levels from baseline to 15 days after SC were similar in the 2 groups. When subjects were analysed as a single group, significant reductions after SC were observed for Actinomyces gerencseriae, Capnocytophaga ochracea, and Treponema denticola. During the 12-month follow-up, levels of most of the bacteria decreased in both groups in a similar pattern. For instance, Actinomyces israelli, Veillonella parvula, Streptococcus gordonii, C. ochracea, Eikenella corrodens, Eubacterium nodatum, Fusobacterium periodonticum and Fusobacterium nucleatum ssp. polymorphum decreased significantly within the groups.Azithromycin was ineffective in lowering the subgingival levels of important putative periodontal pathogens in young AgP subjects compared to placebo.Scaling and root planing with adjunctive systemic azithromycin provides little additional benefit compared to placebo in reductions of major subgingival periodontal pathogens.

To investigate the effects of chlorhexidine (CHX), Listerine and Fluoride Listerine on putative root-caries pathogens in the biofilm in the artificial mouth model.A total of 24 human dentine discs were prepared. A biofilm composed of Streptococcus mutans, Streptococcus sobrinus, Lactobacillus rhamnosus and Actinomyces naeslundii was cultured on the surfaces of human dentine discs in an artificial-mouth model. Sucrose was supplied by computer-controlled release on a daily basis to simulate the real-life situation. Three treatment reagents, CHX, Listerine and Fluoride Listerine, were supplied at a flow rate of 15 ml/h for 6 min twice a day. The dentine discs with biofilm were removed from the artificial mouth after being cultured for 1, 2, 3, 4, 5 and 6 days. The bacteria in the biofilm were analysed by plating on BHIS agar and the colony-forming units of each species were counted.The total number of bacteria in the CHX group was significantly lower than in the other three groups (including control). There was no decline in the number of bacteria in the Listerine group. S. mutans was reduced significantly in the CHX group compared with the control group. The number and proportion of A. naeslundii in the CHX group were significantly lower than in the other three groups. The proportion of L. rhamnosus in the CHX group was significantly higher than in the other three groups.CHX has the most significant effect on inhibition of the putative root-caries bacteria, with the exception of L. rhamnosus. Both Listerine and a combination of fluoride and Listerine could not effectively reduce the numbers of bacteria in the biofilm. The effects of CHX, Listerine and Fluoride Listerine on root caries prevention need further investigation.

Procedural accidents have a negative effect on healing and might contribute to the persistence of infections in inaccessible apical areas, requiring surgical intervention. This report describes a case of persistent apical periodontitis of a lower left first molar associated with the sinus tract and a periapical lesion that required nonsurgical endodontic retreatment and apical surgery for resolution.The tooth had received endodontic treatment 3 years ago and had to be retreated using the crown-down technique with chemical auxiliary substance (2% chlorhexidine gel), foramen patency, and enlargement and was filled in a single appointment. The occlusal access cavity was immediately restored with composite resin. After 1 month, it could be observed that the sinus tract persisted and, radiographically, the lesion remained unaltered. Therefore, endodontic microsurgery was indicated. Apical microsurgery was performed under magnification with the use of a dental operating microscope including apicectomy, root end with ultrasound, and sealing with mineral trioxide aggregate. A microbiological sample was collected from the apical lesion. The resected distal root apex was observed by scanning electron microscopy.The following species were detected: Actinomyces naeslundii and Actinomyces meyeri, Propionibacterium propionicum, Clostridium botullinum, Parvimonas micra, and Bacteroides ureolyticus; scanning electron microscopic analysis revealed bacterial biofilm surrounding the apical foramen and external radicular surface. Gutta-percha overfilling at the apex because of a zip caused during initial endodontic treatment could be observed. A 6-month follow-up showed apparent radiographic periapical healing, which progressed after 24 months.Gram-positive anaerobic bacteria and extraradicular biofilm seem to participate in the maintenance of persistent periapical pathology, and endodontic retreatment followed by periapical microsurgery proved to be a successful alternative in the resolution of persistent extraradicular infections.