Anti-plaque agents in the prevention of biofilm-associated oral diseases

The prevention of dental caries and periodontal diseases is targeted at the control of dental plaque. In this context, chemical agents could represent a valuable complement to mechanical plaque control. The active agents should prevent biofilm formation without affecting the biological equilibrium within the oral cavity. Depending on the goals of the preventive measures, various strategies may be considered. Anti-plaque agents with properties other than bactericidal or bacteriostatic activities may be used in primary prevention. In this approach, a modest anti-plaque effect may be sufficient or even desirable, as it would decrease the side effects of the active agent. Antimicrobial agents are best indicated in secondary and tertiary prevention, as the objectives are to restore health and to prevent disease recurrence. The rational is to prevent or delay subgingival recolonization by pathogenic micro-organisms. The development of in vitro oral biofilm models certainly represents a major advance for studying and testing oral anti-plaque agents in recent years. The results of these studies have shown that chlorhexidine, hexetidine, delmopinol, amine fluoride/stannous fluoride, triclosan, phenolic compounds, among others, may inhibit biofilm development and maturation as well as affect bacterial metabolism.     

Chemotherapeutic agents for controlling plaque and gingivitis

There has been a vigorous search for many years for chemical agents that could supplement or even supplant patient-dependent mechanical plaque control and thus reduce or prevent oral disease. 5 categories of agents or approaches have been considered: (1) broad spectrum antiseptics, (2) antibiotics aimed at specific bacteria, (3) single or combinations of enzymes that could modify plaque structure or activity, (4) non-enzymatic dispersing or modifying agents and (5) agents that could affect bacterial attachment. The success of these approaches can be evaluated clinically by the use of standard scoring methods for measuring plaque and gingivitis and their safety established by soft tissue and microbiologic examination. Antiseptic agents have received the bulk of the attention over the years. At present, only 2 antiseptics, the bis-biguanide, chlorhexidine gluconate (Peridex) and a combination of phenol related essential oils (Listerine), have developed sufficient supporting data in 6-month (or longer) studies to gain the approval of the Council On Dental Therapeutics of the American Dental Association. On the basis of short-term studies, cetylpyridinium chloride, zinc and copper salts, sanguinarine and octenidine warrant continued study as does stannous fluoride at an appropriate concentration. On the basis of current research, a new generation of more specific antibacterial agents that interfere with attachment to pellicle can be developed. It is hard to predict, however, that they will affect gingivitis, at least until there is more information on what specific organisms should be targeted.     

On the prevention of caries and periodontal disease

In 1971-72, a total of 375 adult subjects were recruited for a clinical trial aimed at assessing the effect of a preventive program, based on plaque control and topical application of fluoride, on the incidence of caries and periodontal disease. After a baseline examination, the volunteers were subjected to scaling, root planning and conventional caries therapy. During the course of the subsequent 6 years, they were recalled for preventive measures once every 2-3 months. After the 6-year follow-up examination, however, it was decided to extend the interval between the preventive sessions. Thus, during the next 9-year period, about 95% of the participants returned for preventive measures only 1 to 2 times per year. A small subgroup of about 15 subjects, who, during the initial 6 years had developed new caries lesions or had exhibited additional periodontal attachment loss, however, were also during the following 9 years recalled 3-6 times per year for oral hygiene control and preventive therapy. The re-examination performed in 1987 disclosed that the 317 subjects, who participated during the entire 15-year period, had a low incidence of caries and almost no further loss of periodontal tissue support. It was suggested that improved self performed oral hygiene, daily use of fluoridated dentifrice and regularly repeated professional tooth cleaning effectively prevented recurrence of dental disease.     

Effect of controlled oral hygiene procedures on caries and periodontal disease in adults

Abstract The present report describes the result of a clinical trial in which a group of adults have been maintained on a proper oral hygiene standard over a 6-year period. In 1971–72, 375 individuals were recruited to a test group and 180 to a control group. During the 6 years of trial, 65 persons from the test group and 34 controls were lost. The patients were divided into three age groups; I <35 years, II 36–50 years, III >50 years. The members of the test and control groups were first subjected to a Baseline examination which included assessments of oral hygiene, gingivitis, periodontal disease and caries. Following this examination all caries lesions were treated and ill-fitting dental restorations adjusted. Each patient was also given a detailed case presentation and a dental prophylaxis. The control group patients were not involved in any further dental health programs during the subsequent 6-year period. Once a year, however, they were recalled to a public dental health clinic for examination and received symptomatic dental treatment. The test group participants, on the other hand, were given a preventive treatment, repeated once every 2–3 months which included (1) instruction and practice in oral hygiene techniques and (2) meticulous prophylaxis. The patients were re-examined 3 and 6 years after the baseline examination. At the Follow-up examinations the parameters studied at the Baseline examination were recorded again. The findings demonstrated that a preventive program which stimulates individuals to adopt proper oral hygiene habits may resolve gingivitis and prevent progression of periodontal disease and caries. Traditional dental care, on the other hand, did not prevent the progression of caries and periodontitis in adults.     

Representativeness of the "Ramfjord teeth" for epidemiologic studies of gingivitis and periodontitis

Data from the Veterans Administration Dental Longitudinal Study of 736 men each examined four times were analyzed to determine how representative the six "Ramfjord Teeth" (RT) were of the rest of the dentition for epidemiologic studies of gingivitis and periodontitis. Correlation coefficients were calculated between scores for gingival inflammation generated by the RT and scores for the teeth in the rest of the mouth; the correlation coefficients between the two scores tended to be high. Sensitivity, specificity and predictive values were calculated for periodontal pathology classified on the basis of the pocket depths of the six RT. Reliance on the RT resulted in systematic underestimation of the prevalence and incidence of deep periodontal pockets. The RT are more than adequately representative of the rest of the dentition for epidemiologic studies of gingivitis, but are inadequate surrogates of the rest of the mouth for epidemiologic studies of periodontitis.     

Mycoplasma in relation to gingivitis and periodontitis

In this study, mycoplasma were enumerated in the gingival crevicular fluid (GCF) of gingivitis and periodontitis patients. GCF samples were obtained from the mesial (approximal) gingival crevice or periodontal pocket of the maxillary right first permanent molar. Samples were cultured anaerobically on a medium selective for mycoplasmas as well as on a non-selective medium to obtain a total anaerobic count. Mycoplasmas were present in the GCF of both gingivitis and periodontitis patients, but a greater % was obtained from the GCF of patients with periodontitis. The proportions of mycoplasma appeared to be independent of the disease activity as expressed by bleeding on probing (PBI), but to be related to probable pocket depth, as shown by the higher %s in periodontitis than gingivitis for a given PBI. On the basis of an increased proportion in relation to disease severity, mycoplasmas would therefore appear to be amongst those micro-organisms associated with CIPD.     

Clinical, microbiological and immunological profile of healthy, gingivitis and putative active periodontal subjects

Thirteen periodontally healthy subjects were monitored clinically for 6–12 months. Clinical measurements at 6-weekly intervals included duplicate PD measurements, presence of plaque, redness, and bleeding on probing. Baseline measurements consisted of 2 visits I wk apart. Microbial samples were taken from 11 of the subjects who had completed at least 8 months of monitoring. Levels of serum antibodies to 12 periodontal species were determined from 10 subjects. Standard deviations of replicate PD measurements, computed for each subject, ranged from 0.2–0.3 mm over the monitoring period. Plaque and redness increased during monitoring, and showed a weak association with PD change. Baseline and follow-up distributions of PD changes indicated that changes of > 1.5 mm could reasonably be considered to represent active sites. Five subjects demonstrated at least 1 site deepening by 1.5 mm over the period monitored, and these were considered putative active subjects. Sites from 2 subjects showed PD increases in the 6 wk just before sampling, and these were considered to represent active sites. Species associated with putative active subjects included Actinomyces naeslundii, Veillonella parvula, Selenomonas noxia and Prevotella nigrescens. Streptococcus sanguis , S. gordonii and Peptostreptococcus micros were associated with inactive subjects. S. gordonii and S. oralis were associated with health, whereas P. nigrescens was associated with gingivitis. Elevated serum antibodies were detected to A. actinomycetemcomitans in 4 subjects. The predominant microbiota of putative active subjects included some species previously associated with gingivitis, and some species previously associated with progressing periodontitis.     

Partial recording of gingivitis and dental plaque in children of different ages and in young adults

In epidemiologic studies, total recordings of the amount of dental plaque and the degree of gingival inflammation tend to be too time-consuming. Various partial recording methods have accordingly been suggested. However, the validity of these methods when applied to different age groups has not been investigated sufficiently. The aim of the present study was to test whether different systems for partial recording of plaque and gingivitis can take the place of a full-mouth recording in children of different ages and in young adults. Ninety children, divided into three age groups (4-6, 7-9, 14-16 yr), and 30 adults (20-22 yr) were examined. The degree of gingival inflammation was recorded using the Gingival Index and the amount of dental plaque using the Plaque Index. Two partial recording methods were tested. One of these covered the teeth suggested by Ramfjord, modified for children with a primary dentition, and the other the front segment of the maxilla. The results were compared with those from an examination of all tooth surfaces. In all age groups excellent agreement was found between the partial recording method suggested by Ramfjord and a full-mouth recording of both the gingival state and the amount of dental plaque. Examination of the maxillary front segment was less accurate and resulted in a systematic underestimate.     

Mouthrinses and periodontal disease

It is known that mouthwashes can influence gingivitis; however, their role in the three different kinds of periodontitis is unclear. Some solutions have demonstrated some effect on necrotising periodontitis, yet none have been shown to influence early onset periodontitis. The literature provides us with a wide range of in vitro concentrations of substances used pure or in various mixtures in mouthwashes. Although only a few solutions can be used in a curative approach, most mouthwashes represent an essential tool in prophylaxis and thus also in post-periodontal treatment (maintenance phase). However, severe qualitative differences exist between the diverse families of mouthwashes. Many studies have shown that the use of a mouthwash associated with regular tooth cleaning was more beneficial than the utilisation of mouthrinse alone.     

Subgingival microflora and periodontal disease

Abstract This article describes the subgingival microflora of the healthy periodontium, gingivitis, advanced adult periodontitis, and juvenile periodontitis. A total of seven to nine subjects were examined in each of the four periodontal clinical entities listed. The individual bacteriological samples included material from the base of a single periodontal pocket. The sampling, the treatment of the samples, and the bacteriological cultivations were carried out using continuous anaerobic techniques. Briefly, the healthy gingival sulcus harbored a scant microflora dominated by Gram-positive organisms (85%), usually Streptococcus and facultative Actinomyces species. The development of gingivitis was accompanied by a marked increase in the total number of Gram-negative organisms. Fusobacterium nucleatum, Bacteroides melaninogenicus ss. intermedius, Haemophilus species, and other Gram-negative organisms comprised about 45% of the total gingivitis isolates. Streptococcus and facultative and anaerobic Actinomyces species constituted the majority of the Gram-positive gingivitis isolates. The micro-flora of advanced adult periodontitis was comprised mainly of Gram-negative anaerobic rods (about 75%), B. melaninogenicus ss. asaccharolyticus and F. nucleatum being the most predominant isolates. The deep pocket microflora in juvenile periodontitis was also made up mainly of Gram-negative organisms (about 65%), but was of a nature different from that of adult periodontitis, being predominated by isolates of Bacteroides species and other organisms of unknown species. The present article also concerns factors of importance for the colonization of Gram-negative anaerobic rods in the oral cavity and periodontal pockets. In vitro experiments showed that cells of B. melaninogenicus ss. asaccharolyticus and other Gram-negative organisms attached in high numbers to epithelial cells, hydrosyapatite (HA) surface, and Gram-positive bacteria when suspended in phosphate-buffered saline; however, the bacterial attachment to epithelial cells and HA was strongly inhibited in the presence of human saliva and serum. In contrast, saliva and serum had little effect upon the attachment of Gram-negative bacteria to Gram-positive bacterial cells. These findings agreed well with data from an in vivo study, in which streptomycin-labeled cells of B. melaninogenicus ss. asaccharolyticus were introduced into the mouth of two volunteers. A significantly higher number of B. melaninogenicus cells was recovered from dental plaque than from the other oral surfaces studied. The present series of studies has pointed to certain Gram-negative organisms as potential pathogens in rapidly progressing periodontal lesions. The available data on oral microbial ecology suggest that the presence of dental plaque containing Gram-positive organisms may be essential for the attachment and colonization of several Gram-negative species after their initial introduction into the mouth and the periodontal pocket area. The clinical relevance of these findings is discussed.     

李施德林漱口水辅助治疗牙龈炎的疗效观察

目的:观察李施德林漱口水辅助治疗牙龈炎的疗效。方法:选择18～60岁的符合纳入标准的牙龈炎病人60例,随机分为试验组和对照组,试验组在牙周基础治疗后含漱李施德林漱口水,对照组行牙周基础治疗后清水含漱,分别于治疗后1、2周,观察病人的菌斑指数和牙龈指数,进行统计学分析。结果:治疗后1、2周,试验组的菌斑指数和牙龈指数明显低于对照组。结论:李施德林漱口水可作为牙龈炎病人牙周基础治疗后的辅助局部用药。     

Microbial etiology of periodontal disease

Abstract Longitudinal studies with humans indicate that gingivitis is associated with an increased dental plaque mass. Also, prior to the onset of gingivitis, changes in the microflora towards a more complex bacterial composition frequently occur. On the other hand, recent cross sectional cultural studies generally do not reveal clear-cut differences between the composition of the subgingival microflora associated with healthy or inflamed gingivae. Also, some studies have demonstrated an enhanced cell-mediated immune response during the course of gingivitis to a variety of subgingival plaque bacteria. It has also been observed that plaques allowed to form on cleaned teeth for 2 or 3 days do not differ substantially in their microbial composition. However, long-term thorough oral hygiene performed at intervals of 48 h permits maintenance of gingival health, whereas that instituted at intervals of 72 h will lead eventually to gingivitis. Collectively, this evidence supports the concept that the etiology of gingivitis is bacteriologically nonspecific. Thus a large increase in the accumulation of bacteria on the tooth surface per se may have a greater pathogenic effect on the periodontal tissues than the relatively minor and inconsistent shifts in the microbial composition. The transition from gingivitis into periodontitis may be induced by changes in the pathogenic potential of subgingival plaque. Gram-negative rods appear to be specifically associated with periodontitis. A growing body of evidence implicates especially Bacteriodes asaccharolyticus as one of the responsible pathogens. Juvenile periodontitis (periodontosis) seems to be a distinct disease entity. Recent findings suggest abnormalities in peripheral blood polymorphonuclear leucocytes (PMNL) of patients with juvenile periodontitis. The subgingival microflora is different from that associated with periodontitis and the findings so far implicate Actinobacillus actinomycetemcomitans as an important pathogen. The bacterial etiology of acute necrotizing ulcerative gingivitis (ANUG) is still unclear. Satisfactory cultural studies have yet to be performed. The presence of spirochetes in the ulcerative lesions of the junctional epithelium does not necessarily imply that they play an important role in this disease entity. Future research on the bacteriology of periodontal disease should concentrate on longitudinal studies; particular attention should be paid to the change of gingivitis into periodontitis whereby animals as well as humans can be used. Improvements of sampling methods as well as precise and simple identification techniques of microorganisms are required.     

Contemporary practices for mechanical oral hygiene to prevent periodontal disease

It is well established that dental plaque on teeth leads to gingivitis and periodontitis, and that several mechanical and chemical methods of plaque control can prevent gingivitis. The aim of the current review is to summarize and synthesize the available scientific evidence supporting practices for mechanical oral hygiene to prevent periodontal diseases. Evidence for contemporary practices of mechanical oral hygiene to prevent periodontal disease relies on studies of gingivitis patients. General recommendations concerning the ideal oral hygiene devices and procedures are still inconclusive. However, toothbrushing and interdental cleaning remain the mainstays of prevention of periodontal diseases. The primary approach requires individually tailored instruction for implementation of a systematic oral hygiene regimen.     

Dentifrices containing new agents for the control of plaque and gingivitis: microbiological aspects

Antimicrobial agents have been proposed as playing an important role in controlling plaque and gingivitis. Unfortunately, a large number of potential compounds are unsuitable for use in dentifrices because they lack "substantivity", produce undesirable side-effects, or are incompatible with toothpaste ingredients. New agents that have been successfully incorporated into dentifrices include plant extracts, phenolic compounds and metal salts. Several products are currently being based on the phenol, Triclosan. Triclosan has a broad spectrum of antimicrobial activity against yeasts and oral bacteria. To enhance its clinical efficacy, Triclosan has been combined either with a co-polymer or with another compatible antimicrobial agent, zinc citrate. The co-polymer acts to increase the oral retention of Triclosan, and has resulted in further reductions in salivary bacterial counts in vivo. Zinc salts also have antimicrobial activity, and at low concentrations, can inhibit glycolysis and bacterial proteases. In mixed culture chemostat studies, Triclosan selectively inhibited Gram-negative periodontopathic bacteria; additive effects were obtained when zinc citrate and Triclosan were combined. In an experimental human gingivitis study, a zinc citrate/Triclosan dentifrice reduced plaque accumulation and gingivitis compared to a placebo paste; the ratio of anaerobic/aerobic bacteria and the proportions of Actinomyces species in plaque were also reduced. The prolonged use of a zinc citrate/Triclosan dentifrice neither significantly altered the ecology of supragingival plaque nor led to the selection of Triclosan-resistant bacteria. The data suggest that dentifrices containing new antimicrobial agents could be of clinical relevance in the prevention and control of plaque and gingivitis.     

A three-year prospective study of adult subjects with gingivitis. I: clinical periodontal parameters

AIM: The objective of this study was to monitor prospectively clinical parameters in subjects without signs of destructive periodontal disease who were involved in a primary prevention programme, and to determine the changes that occurred between yearly examinations over a 3-year period. MATERIAL AND METHODS: One hundred and twenty-six subjects aged at least 20 years with a maximum of two tooth sites with probing pocket depth (PPD)>4 mm and no proximal sites with clinical attachment loss participated in the study. Primary prevention was provided at baseline of the study and then every 6 months. Plaque, bleeding on probing (BoP) and PPD were scored at baseline, 1, 2 and 3 years. RESULTS: There were no significant changes in the plaque score over the 3 years. After year 1, the BoP score was significantly improved with 5.6%, while no further improvement in BoP was found at years 2 and 3. The mean PPD decreased from 2.3 to 2.1 mm over the 3 years (p<0.05). CONCLUSION: Although some individuals exhibiting minor signs of periodontal pathology may have benefited from the primary prevention, the overall clinical improvement was limited for such subjects in the present 3-year study.     

The Cardiff Dental Survey: oral hygiene, gingival and periodontal health in relation to smoking in young adults

Abstract: Objective: To examine the relationship between tobacco smoking, oral hygiene, gingival and periodontal health in young adults. Study design: Cross‐sectional (conducted in the course of a cohort study). Setting: Cardiff, UK, 1989 and 2000. Methods: Plaque was recorded, as was presence or absence of bleeding on probing and loss of attachment (LA). Information concerning tobacco smoking was obtained from questionnaire data. Results: At age 19–20 years, smokers had statistically significantly (P < 0.01) higher whole mouth mean plaque scores than non‐smokers. Whole mouth mean bleeding scores, however, were similar in smokers and non‐smokers. The relationship of plaque to smoking was very similar at age 30–31, yet bleeding scores were approximately 25% lower in smokers than in non‐smokers (P < 0.01). Whole mouth LA scores showed small, statistically non‐significant differences between smokers and non‐smokers. At the age of 30–31 years, gender and social class had a negligible confounding effect on oral hygiene, gingival and periodontal health in smokers and non‐smokers. Conclusions: Smokers consistently demonstrated poorer oral hygiene than non‐smokers. The effect of smoking in reducing gingival bleeding was already apparent at age 19–20 years despite the fact that, at this time, subjects might be assumed to have been exposed to a relatively small dose of tobacco over a short period of time. In the follow‐up study conducted at the age of 30–31 years, the impact of smoking on the periodontal tissues was, as expected, more pronounced.     

The effect of subgingival debridement on periodontal disease parameters and the subgingival microbiota

Abstract The aim of the present investigation was to analyse the effect of subgingival scaling and root planing in subjects who prior to treatment exercised meticulous supragingival plaque control. 300 subjects were examined at baseline and after 1 and 2 years without treatment. After the year 2 examination, 62 subjects were randomly selected for therapy. They were given detailed instruction in proper self-performed toothcleaning measures and were carefully monitored during the subsequent 2 years. Following the year-4 examination, 2 quadrants, 1 maxillary and 1 mandibular in each subject, were randomly selected for additional therapy. The teeth in the selected quadrants were exposed to subgingival scaling and root planing. The subgingival therapy was repeated until a site no longer bled on gentle probing. This basic therapy was completed within a 2-month period. All subjects were re-examined after another 12-month interval. The examinations at year 4 and 5 included assessment of plaque, gingivitis, probing pocket depth and analysis of samples obtained from the subgingival microbiota at 134 selected sites. The findings from the present study demonstrated: (i) that subgingival scaling and root planing were effective in eliminating subgingival plaque and gingivitis; (ii) that professional therapy resulted in a pronounced reduction of probing depth at sites which at year 4 had a probing depth >3 mm; (iii) that in non-scaled quadrants, the extension of self-performed plaque control resulted in a continued improvement of the periodontal conditions at sites which at year 4 were < 5 mm deep.     

Effect of Listerine® on dental plaque and gingivitis

abstract — The present study was performed in 10 adults in order to evaluate the effect of an antiseptic mouthrinse (Listerine®) on the rate of dental plaque formation and gingivitis development during a 2-week period when all efforts towards active mechanical oral hygiene were withdrawn. The study was performed as a crossover study and was carried out during four consecutive 2-week periods. During the first and third periods (preparatory periods) the participants were subjected to repeated professional tooth cleanings in order to establish plaque- and gingivitis-free dentitions. During the second and fourth periods (test and control periods) the participants were not allowed to brush their teeth but rinsed their mouths three times a day with Listerine or a placebo mouthwash. Plaque Index, Gingival Index, gingival fluid flow, and crevicular leukocytes were assessed on d 0, 2, 4, 7, and 14. On d 7 and 14, dental plaque was removed from the right and left jaws respectively and the wet weights determined. The chemotactic activity elaborated by the plaques was studied in Boyden chambers. During the Listerine test period, significantly lower Plaque and Gingival Index values were scored and lower amounts of plaque could be sampled in comparison to the control period.     

Dental prophylaxis for youths in their late teens I. Clinical effect of different preventive regimes on oral hygiene, gingivitis and dental caries

Abstract The effect of a dental prophylactic program based on systematic plaque control has been tested during a 3-year period on youths aged 16–19 years. During their last year at comprehensive school they received professional tooth cleaning every third week by specially trained dental hygiene nurses. At the end of this first experimental year the subjects were offered continued prophylaxis of the same type against caries and gingivitis during 2 more years. Interested subjects were divided equally at random into test groups A and B. In the second year group A received professional tooth cleaning once a month and in the third year once each 6 months. Group B was offered, both in the second and third years, only two prophylactic sessions each year according to this model. Test group C comprised the subjects who expressed no interest in continued professional tooth cleaning. A control group, group D, consisted of pupils of the same ages from a neighboring school area. These received in the first experimental year a prophylactic program based on mouthrinsing each second week with 0.2% sodium fluoride solution. After this first year neither test group C nor the control group D participated in any organized dental health care program. After the first year there were significant differences among the groups, the plaque and gingival indices in the control group D being significantly higher than in test groups A, B and C. At the end of the third year significant improvements in these indices had taken place in groups A and B. The corresponding values in groups C and D did not differ significantly at the three recordings. Significant correlations existed between the plaque and gingivitis scores at the end of the experimental period within the respective groups. Significantly more dental caries (new DPS) developed in the control group D than in test groups A and B during the period of the experiment: on average 3.3 versus 1.0 and 1.2 new DFS, respectively. The figure for caries increment in group C was 2.0. Regardless of grouping, individuals with caries increment during the experimental period had a significantly higher number of risk factors, here defined as the total of upper or lower quartile values for lactobacillus counts, secretion rate and buffering capacity of the saliva, than individuals without caries increment.