Effect of localized experimental gingivitis on early supragingival plaque accumulation

Effect of guava and vitamin C supplementation on experimental gingivitis: A randomized clinical trial

OBJECTIVE

To study the effect of guava and synthetic vitamin C on the development of gingival inflammation during experimental gingivitis.

MATERIAL AND METHODS

Participants were randomly assigned to three groups supplemented daily with either 200 g guava, 200 mg synthetic vitamin C or water. The study included a 14 days pre-experimental period with oral hygiene instructions, scaling, prophylaxis and supplementation. Thereafter, experiment gingivitis was initiated, while continuing supplementation. At baseline, Day 7 and Day 14 of experimental gingivitis, Plaque Index (PlI) and Gingival Index (GI) were assessed. During the entire study, dietary fruit/vegetables intake was minimal.

RESULTS

PlI increased in guava, vitamin C and control group (ΔPlI: 1.30, 1.61 and 1.79, respectively). However, the guava group developed significantly less plaque compared to the control group. The GI increase in both guava and vitamin C group was significantly less than the increase in the control group (ΔGI: 0.10, 0.24 and 0.87, respectively).

CONCLUSION

In a population of young nonsmoking adults, consumption of either 200 g guava/day or 200 mg synthetic vitamin C/day, prior to and during the oral hygiene abstention period, has a preventive effect on the development of experimental gingivitis as compared to the control group that developed the usual amount of experimental gingivitis.

The effect of twice daily kiwifruit consumption on periodontal and systemic conditions before and after treatment: A randomized clinical trial

BACKGROUND

To assess the nutraceutical effects of twice/daily intake of kiwifruit on periodontal parameters and systemic health before and after initial periodontal treatment (IPT).

METHODS

At baseline, participants were randomly assigned to test and control group, and either consumed two kiwifruits/day for 5 months or no kiwifruit. In the first 2 months, no periodontal treatment was delivered (2 M). Subsequently, a session of full-mouth IPT within 24 hours was performed. Participants were then re-assessed after 3 months (5 M). Blood samples, evaluating systemic biomarkers and vital signs, were also collected atbaseline, 2 M, and 5 M.

RESULTS

Groups were balanced at baseline. At 2 M no within-groups differences could be detected for any parameter but the bleeding score, which decreased significantly in the kiwifruit group by 6.67% ± 11.90% (P < 0.01). Comparison of test and control group showed that 2 months of kiwifruit consumption resulted in significant lower values of bleeding, plaque, and attachment loss. After IPT both groups demonstrated substantial significant clinical benefits however the control group showed significant greater reductions of bleeding, plaque and attachment loss than the test group. Systemic biomarkers and vital signs did not show clinically relevant differences between test and control group.

CONCLUSIONS

Kiwifruit consumption reduces gingival inflammation despite the lack of any periodontal instrumentation or patient's behavioral changes. No adjunctive effect to periodontal treatment of dietary intake of kiwifruit was noted. (NCT NCT03084484).

Effects of two different post-surgical protocols including either 0.05 % chlorhexidine herbal extract or 0.1 % chlorhexidine on post-surgical plaque control, early wound healing and patient acceptance following standard periodontal surgery and implant placement

OBJECTIVES

The aim of this study was to compare early wound healing, tooth staining and patient acceptance with two different post-surgical maintenance protocols.

MATERIALS AND METHODS

Forty patients scheduled for flap surgery to treat periodontal pockets or accommodate dental implants were randomly assigned to receive the following two different post-surgical maintenance protocols: (a) 2 weeks rinsing with a 0.05 % chlorhexidine digluconate (CHX)/herbal extract combination (test) or (b) a 0.1 % CHX solution (control). Early wound healing was evaluated clinically and immunologically. Tooth staining and patient acceptance were assessed by means of visual analogue scale (VAS).

RESULTS

Both groups presented with comparable wound healing profiles. No statistically significant differences were observed between the two protocols regarding early wound healing and plaque index (p > 0.05). However, in the control group, statistically significantly more patients felt discomfort due to tooth staining (p = 0.0467). Compared with patients from the test group, patients in the control group reported statistically significant more irritation of taste at week 1 (p = 0.0359) and at week 2 (p = 0.0042).

CONCLUSIONS

The present findings indicate that the two CHX protocols resulted in comparable healing and inhibition of plaque formation. Tooth staining and subjective discomfort related to irritation of taste were more frequent in the control group.

CLINICAL RELEVANCE

A post-operative protocol including 0.05 % CHX/herbal extract may have the potential to improve patient compliance during post-operative maintenance.

Evaluation of clinical effectiveness and subjective satisfaction of a new toothbrush for postsurgical hygiene care: a randomized split-mouth double-blind clinical trial

The aim of this RCT was to evaluate plaque control and gingival health promotion effectiveness of a new toothbrush with extra-soft filaments in postsurgical sets. Ten consecutive patients with at least two scheduled symmetrical periodontal surgeries were selected. Following the first periodontal surgery, a test (TB1) or control (TB2) toothbrush was randomly assigned. After the second surgery, the remaining toothbrush was given. Patients were asked to gently wipe the surgical area from days 3 to 7 postoperatively and to gently brush using a roll technique from day 7 till the end of the study. Baseline evaluation took place on the day of surgery and follow-ups were performed at days 7, 14, and 30 postoperatively. A more evident PI reduction was recorded for test toothbrush where a regular decrease was observed till day 14; then, this parameter tended to stabilize, remaining however lower than that recorded for the control toothbrush. There were no statistical differences in the GI between test and control toothbrushes. All patients introduced the test toothbrush at surgical site at third day; the control toothbrush was introduced within a mean of 9 days. The introduction of the test toothbrush 3 days after periodontal surgery may be recommended.

Oral changes in individuals undergoing hematopoietic stem cell transplantation

INTRODUCTION

Patients undergoing hematopoietic stem cell transplantation receive high doses of chemotherapy and radiotherapy, which cause severe immunosuppression.

OBJECTIVE

To report an oral disease management protocol before and after hematopoietic stem cell transplantation.

METHODS

A prospective study was carried out with 65 patients aged>18 years, with hematological diseases, who were allocated into two groups: A (allogeneic transplant, 34 patients); B (autologous transplant, 31 patients). A total of three dental status assessments were performed: in the pre-transplantation period (moment 1), one week after stem cell infusion (moment 2), and 100 days after transplantation (moment 3). In each moment, oral changes were assigned scores and classified as mild, moderate, and severe risks.

RESULTS

The most frequent pathological conditions were gingivitis, pericoronitis in the third molar region, and ulcers at the third moment assessments. However, at moments 2 and 3, the most common disease was mucositis associated with toxicity from the drugs used in the immunosuppression.

CONCLUSION

Mucositis accounted for the increased score and potential risk of clinical complications. Gingivitis, ulcers, and pericoronitis were other changes identified as potential risk factors for clinical complications.

Comparison of microbial changes in early redeveloping biofilms on natural teeth and dentures

BACKGROUND

Surfaces and fluids can affect oral bacterial colonization. The aim of this study is to compare redeveloping biofilms on natural teeth and dentures.

METHODS

Supragingival plaque samples were taken from 55 dentate individuals and the denture teeth of 62 edentulous individuals before and after professional cleaning. Also, samples from seven "teeth" (samples included dentures) in randomly selected quadrants were collected after 1, 2, 4, and 7 days of no oral hygiene. Samples were analyzed using checkerboard DNA-DNA hybridization. Counts and proportions of 41 bacterial taxa were determined at each time point, and significant differences were determined using the Mann-Whitney U test. Ecological succession was determined using a modified moving window analysis.

RESULTS

Mean total DNA probe counts were similar precleaning but were higher in dentate individuals at all post-cleaning visits (P <0.01). Precleaning edentate biofilms had higher counts and proportions of Streptococcus mitis, Streptococcus oralis, and Streptococcus mutans, whereas dentate individuals had higher proportions of Tannerella forsythia, Selenomonas noxia, and Neisseria mucosa. By day 2, mean counts of all taxa were higher in natural teeth, and most remained higher at day 7 (P <0.01). Succession was more rapid and complex in dentate individuals. Both groups demonstrated increased proportions of S. mitis and S. oralis by day 1. N. mucosa, Veillonella parvula, and Eikenella corrodens increased in both groups, but later in samples from edentate individuals.

CONCLUSIONS

"Mature" natural and denture teeth biofilms have similar total numbers of bacteria but different species proportions. Post-cleaning biofilm redevelopment is more rapid and more complex on natural teeth than on denture teeth.

In vitro assessment of shiitake mushroom (Lentinula edodes) extract for its antigingivitis activity

Gingivitis is a preventable disease characterised by inflammation of the gums due to the buildup of a microbial biofilm at the gingival margin. It is implicated as a precursor to periodontitis, a much more serious problem which includes associated bone loss. Unfortunately, due to poor oral hygiene among the general population, gingivitis is prevalent and results in high treatment costs. Consequently, the option of treating gingivitis using functional foods, which promote oral health, is an attractive one. Medicinal mushrooms, including shiitake, have long been known for their immune system boosting as well as antimicrobial effects; however, they have not been employed in the treatment of oral disease. In the current study, the effectiveness of shiitake mushroom extract was compared to that of the active component in the leading gingivitis mouthwash, containing chlorhexidine, in an artificial mouth model (constant depth film fermenter). The total bacterial numbers as well as numbers of eight key taxa in the oral community were investigated over time using multiplex qPCR. The results indicated that shiitake mushroom extract lowered the numbers of some pathogenic taxa without affecting the taxa associated with health, unlike chlorhexidine which has a limited effect on all taxa.

Longitudinal changes in gingival crevicular fluid after placement of fixed orthodontic appliances

INTRODUCTION

Bacterial plaque is an etiologic factor in the development of gingival inflammation and periodontitis. The presence of orthodontic bands and brackets influences plaque growth and maturation. The purposes of this research were to monitor microbiologic and periodontal changes after placement of orthodontic attachments over a 1-year period and to link these changes to alterations in cytokine concentrations in the gingival crevicular fluid (GCF).

METHODS

This longitudinal split-mouth trial included 24 patients. Supragingival and subgingival plaque composition, probing depth, bleeding on probing, and GCF flow and composition were assessed at baseline (Tb) and after 1 year (T52). A statistical comparison was made over time and between the banded and bonded sites. Prognostic factors for the clinical reaction at T52 in the GCF at Tb were determined.

RESULTS

Between Tb and T52, the pathogenicity of the plaque and all periodontal parameters increased significantly, but intersite differences were not seen, except for bleeding on probing. The cytokine concentrations in the GCF did not differ significantly between the sites or between Tb and T52. The interleukin-6 concentration in the GCF at Tb was a significant predictive value for the GCF flow at T52 (P <0.05). The same relationship was found between the interleukin-8 concentration at Tb and the increase in probing depth at T52 (P <0.05).

CONCLUSIONS

Interleukin-6 and interleukin-8 concentrations before orthodontic treatment were shown to be significant predictive factors for some potential inflammatory parameters during treatment.

Gingival tissue transcriptomes in experimental gingivitis

AIMS

We investigated the sequential gene expression in the gingiva during the induction and resolution of experimental gingivitis.

MATERIAL AND METHODS

Twenty periodontally and systemically healthy non-smoking volunteers participated in a 3-week experimental gingivitis protocol, followed by debridement and 2-week regular plaque control. We recorded clinical indices and harvested gingival tissue samples from four interproximal palatal sites in half of the participants at baseline, Day 7, Day 14 and Day 21 (the "induction phase"), and at Day 21, Day 25, Day 30 and Day 35 in the other half (the "resolution phase"). RNA was extracted, amplified, reversed transcribed, amplified, labelled and hybridized using Affymetrix Human Genome U133Plus2.0 microarrays. Paired t-tests compared gene expression changes between consecutive time points. Gene ontology analyses summarized the expression patterns into biologically relevant categories.

RESULTS

The median gingival index was 0 at baseline, 2 at Day 21 and 1 at Day 35. Differential gene regulation peaked during the third week of induction and the first 4 days of resolution. Leucocyte transmigration, cell adhesion and antigen processing/presentation were the top differentially regulated pathways.

CONCLUSIONS

Transcriptomic studies enhance our understanding of the pathobiology of the reversible inflammatory gingival lesion and provide a detailed account of the dynamic tissue responses during the induction and resolution of experimental gingivitis.

The effect of 1% chlorhexidine gel and 0.12% dentifrice gel on plaque accumulation: a 3-day non-brushing model

AIM

The purpose of the study was to compare the effects of four treatments on 'de novo' plaque accumulation. Treatments included tray application of 1% chlorhexidine gel (CHX-Gel), 0.12% chlorhexidine dentifrice-gel (CHX-DFG), a regular dentifrice (RDF) tray application, or 0.2% chlorhexidine mouthwash (CHX-MW) in a 3-day non-brushing model.

MATERIAL AND METHODS

The study was designed as a single blind, randomized parallel clinical trial. After professional prophylaxis, subjects abstained from all other forms of oral hygiene during a 3-day non-brushing period. Subjects were randomly assigned to one of the four test groups (CHX-Gel, CHX-DFG, RDF applied in a fluoride gel tray or rinsing with a CHX-MW). After 3 days, the Quigley & Hein plaque index (PI) and Bleeding on Marginal Probing (BOMP) index was assessed. Subsequently, all subjects received a questionnaire to evaluate their attitude, appreciation and perception towards the products used employing a Visual Analogue Scale.

RESULTS

After 3 days, the full-mouth PI means were 0.88 for the CHX-gel regimen, 0.79 for CHX-MW, 1.16 for CHX-DFG and 1.31 for the RDF regimen. The two dentifrices (CHX-DFG and RDF) were significantly less effective than the CHX-Gel or the CHX-MW.

CONCLUSION

Within the limitations of the present 3-day non-brushing study design, it can be concluded that the effect of a 1% CHX-Gel application tray is significantly greater than that of 0.12% CHX-DFG or RDF in inhibiting plaque accumulation. The 1% CHX-Gel applied via a tray and 0.2% CHX-MW rinse were comparably effective.

Clinical and antibacterial effect of an anti-inflammatory toothpaste formulation with Scutellaria baicalensis extract on experimental gingivitis

It was the aim of the study to evaluate the clinical and antibacterial effect of a dentifrice containing an anti-inflammatory plant extract (SB) versus a placebo (PLA) using an experimental gingivitis model. Forty subjects (20 per group) discontinued all oral hygiene measures for four teeth for a period of 21 days using a shield (to generate a possible gingivitis) while they could brush the other teeth normally. After brushing, the shield was removed and teeth were treated with the randomly assigned toothpaste slurry for 1 min. Löe and Silness gingival index (GI), Silness and Löe plaque index (PI), and biofilm vitality (VF%) were assessed at days 0, 14, and 21, respectively. Subjects of the PLA group developed a GI of 0.82 ± 0.342 (day 14) and 1.585 ± 0.218 (day 21), while the data of the SB group were significantly reduced (0.355 ± 0.243 and 0.934 ± 0.342, p < 0.001). While PI was significantly reduced at all follow-up appointments, reductions in VF reached the level of significance only at day 21. The results suggest that the new toothpaste formulation was able to significantly reduce the extent of gingivitis, plaque development, and vital flora.

Factors affecting human supragingival biofilm composition. I. Plaque mass

BACKGROUND AND OBJECTIVE

Little is known about the factors that affect the microbial composition of supragingival biofilms. This study was designed to examine the relationship between total DNA probe counts of supragingival biofilm samples, clinical parameters and supragingival biofilm composition.

MATERIAL AND METHODS

Supragingival plaque samples were taken from 187 systemically healthy adult subjects (n = 4745 samples). All samples were individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. The relationship between total DNA probe counts and microbial composition was examined by subsetting the data into 10 groups based on 10 percentile increments of the total DNA probe counts. Differences among groups in terms of species counts and proportions were sought, as well as relationships of total plaque DNA probe count and clinical parameters.

RESULTS

There was a wide distribution in mean total DNA probe counts among the 187 subjects. With increasing total plaque levels there was a change in the proportions of individual species and microbial complexes. 'Small plaques' were characterized by high proportions of species in the yellow, orange, purple and 'other' complexes; plaques of moderate mass were characterized by high proportions of Actinomyces and purple complex species, while 'large plaques' exhibited increased proportions of green and orange complex species. Measures of gingival inflammation, pocket depth and recession were significantly positively associated with total DNA probe counts. Increased plaque numbers were related to increased pocket depth irrespective of presence or absence of gingival inflammation.

CONCLUSION

The proportions of individual species and microbial complexes in supragingival biofilms are influenced by the total numbers of organisms in the biofilm.

Influence of bracket design on microbial and periodontal parameters in vivo

AIM

To compare undisturbed plaque formation on teeth bonded with different types of orthodontic brackets with non-bonded control teeth, via a de novo plaque growth experiment over a 7-day period.

MATERIAL AND METHODS

A randomized controlled trial with split-mouth design was set up enroling 16 dental students. Within each subject sites with Speed(S) and GAC(G), brackets and control sites were followed. Clinical periodontal parameters were recorded at baseline, on days 3 and 7. Microbiological samples were taken from the brackets and the teeth on days 3 and 7.

RESULTS

Both anaerobe and aerobe colony-forming units (CFU) were significantly higher in S-sites than in G-sites (p=0.0002, p=0.02). The shift from aerobic to anaerobic species was observed earlier in S-sites than in G-sites. The aerobe/anaerobe CFU ratio was significantly lower in S-sites than in G-sites (p=0.01). On day 3, the crevicular fluid flow was significantly higher in S-sites than in control sites (p=0.01). On day 7, S-sites and G-sites showed a significantly higher crevicular flow than control sites (both p<0.0001). More hypertrophy was seen in S- than in G- and control sites (p=0.05). No significant differences for bleeding on probing were observed.

CONCLUSION

Bracket design can have a significant impact on bacterial load and on periodontal parameters.

Evaluation of the marginal gingival health using laser Doppler flowmetry

The purposes of this study were to compare the gingival blood flow (GBF) in test sites (teeth retaining fixed partial dentures) and control sites (contralateral natural teeth) and investigate whether there is any relationship between clinical indices and GBF values. Twelve healthy subjects (6 females and 6 males) aged 20 to 54 years were enrolled this study. The GBF was measured from the middle point of the marginal gingiva in the test and control sites using laser Doppler flowmetry (LDF). Additionally, plaque index, gingival index and probing depth measurements were recorded. Statistically significant difference (p<0.05) was found between the test and control sites for marginal GBF. In contrast, no significant difference (p>0.05) was found between test and control sites with respect to the clinical indices, except for plaque index. The findings of this study suggest that there is a significant relation between resin-bonded fixed partial dentures with margins located subgingivally and marginal GBF. Clinical indices are helpful to collect information about the clinical health status of gingival tissues, but GBF is a good tool to measure gingival tissue blood flow and assess periodontal health. In conclusion, laser Doppler flowmetry can be used together with clinical indices to evaluate the marginal gingival health.

A three-year prospective study of adult subjects with gingivitis II: microbiological parameters

AIM

To investigate whether the clinical benefits obtained with a periodontal prevention programme in subjects with periodontal health or minimal disease were accompanied by beneficial changes in the subgingival microbiota.

MATERIAL AND METHODS

One hundred and twenty-four subjects completed the study. Subjects were clinically and microbiologically monitored at baseline, 1, 2 and 3 years. Subgingival plaque samples were taken from the mesiobuccal aspect of every tooth and were analysed for the levels of 40 bacterial species using checkerboard DNA-DNA hybridization (total samples=13,477). The mean counts of each of the 40 test species were calculated for each subject at each time point. Significance of differences over time was sought using the Friedman test. p values were adjusted for multiple comparisons.

RESULTS

All clinical parameters, at the microbiologically sampled sites, improved over time. The clinical changes were accompanied by statistically significant decreases in the mean counts of 35 of the 40 test species. Major reductions occurred by year 2 for Actinomyces, Capnocytophaga, Campylobacter, Fusobacterium and Prevotella species. At year 3, there was a modest re-growth of the majority of the species.

CONCLUSIONS

The clinical improvements obtained through preventive measures were accompanied by a shift to a more host-compatible subgingival microbiota.

The effect of 0.12% chlorhexidine dentifrice gel on plaque accumulation: a 3-day non-brushing model

BACKGROUND

Maintaining an adequate low level of plaque through daily tooth brushing is often not feasible. Effective chemotherapeutic agents as an adjunct to mechanical plaque control would therefore be valuable. Chlorhexidine (CHX) mouthwash has proved to be an effective inhibitor of plaque accumulation.

AIM

The purpose of the present study was to assess the effect of application of 0.12% CHX dentifrice gel on de novo plaque accumulation.

MATERIAL AND METHODS

The study was designed as a single blind, randomized three-arm parallel clinical trial. At the beginning of the test period all volunteers received a thorough professional oral prophylaxis. Subjects were randomly assigned to one of three regimens. During a 3-day non-brushing period, subjects abstained from all forms of mechanical oral hygiene. One regimen (test group) used 0.12% chlorhexidine dentifrice gel (CHX-DGel, Perio.Aid) applied in a fluoride gel tray, the benchmark control group used a regular dentifrice applied in a fluoride gel tray (RegD, Everclean HEMA). The positive control group rinsed with a 0.12% chlorhexidine mouthwash (CHX-MW, Perio.Aid). The Quigley and Hein plaque index (PI) from all subjects was assessed after 3 days of de novo plaque accumulation. Subsequently, all subjects received a questionnaire to evaluate their attitude, appreciation and perception towards the products used employing a Visual Analogue Scale scores. After the experimental period, habitual oral hygiene procedures were resumed.

RESULTS

Ninety-six systemically healthy subjects completed the study. After 3 days, the full-mouth PI for the CHX-DGel regimen was 1.87 compared with 1.93 for the RegD regimen and 1.55 for the CHX-MW regimen. The two dentifrices (CHX-DGel and RegD) were significantly less effective as the CHX-MW (P=0.0006). No significant difference between scores of the dentifrices was found.

CONCLUSION

Within the limitations of the present 3-day non-brushing study design, it can be concluded that application of 0.12% CHX dentifrice gel is not significantly different from application of regular dentifrice on plaque accumulation. Use of a 0.12% CHX mouthwash is significantly more effective. CHX-DGel appears a poor alternative for a dentifrice. It is not an effective inhibitor of plaque growth and does not possess fluoride.

Modeling shifts in microbial populations associated with health or disease

Stable microbial communities associated with health can be disrupted by altered environmental conditions. Periodontal diseases are associated with changes in the resident oral microflora. For example, as gingivitis develops, a key change in the microbial composition of dental plaque is the ascendancy of Actinomyces spp. and gram-negative rods at the expense of Streptococcus spp. We describe the use of an in vitro model to replicate this population shift, first with a dual-species model (Actinomyces naeslundii and Streptococcus sobrinus) and then using a microcosm model of dental plaque. The population shift was induced by environmental changes associated with gingivitis, first by the addition of artificial gingival crevicular fluid and then by a switch to a microaerophilic atmosphere. In addition to the observed population shifts, confocal laser scanning microscopy also revealed structural changes and differences in the distribution of viable and nonviable bacteria associated with the change in environmental conditions. This model provides an appropriate system for the further understanding of microbial population shifts associated with gingivitis and for the testing of, for example, antimicrobial agents.

Chlorhexidine mouthrinse in combination with an SLS-containing dentifrice and a dentifrice slurry

OBJECTIVES

The aim of the present study was to compare the plaque-inhibitory effect of a 0.2% chlorhexidine digluconate (CHX) rinse when preceded by ordinary toothbrushing with a 1.5% sodium lauryl sulphate (SLS)-containing dentifrice to the effect of the same rinse when used alone, or when preceded by rinsing with an SLS-containing slurry.

METHODS

The study was an examiner blinded, randomized three-arm, parallel design. It used a 4-day plaque accumulation model to compare three different oral hygiene regimens, which were performed under supervision. One hundred and twenty healthy volunteers were enrolled in the study and were randomly assigned to one of each group. At the beginning of each test period, they received a thorough dental prophylaxis. The experiment was performed in one randomly assigned (upper or lower) jaw, called the study jaw. The opposite jaw, referred to as the dentifrice jaw, served only to introduce the influence of toothbrushing with a dentifrice on the anti-plaque efficacy of the CHX in the study jaw of the same mouth. At the end of the 4-day test period, plaque and gingival bleeding were scored in the study jaw. In all the regimens, the oral hygiene procedure was finalized by rinsing with a CHX 0.2% solution for 1 min. The study jaw was not brushed during the experiment. Regimen A (positive control) consisted of rinsing with CHX alone. In regimen B, rinsing with CHX was preceded by rinsing with an SLS-containing slurry, while in regimen C rinsing with CHX was preceded by toothbrushing with an SLS-containing dentifrice in the dentifrice jaw. No other oral hygiene measures were allowed. After 4 days of undisturbed plaque accumulation, the amount of plaque and level of gingival health were evaluated.

RESULTS

The overall plaque index for regimens A, B and C was 1.17, 1.62, and 1.14, respectively. There was no significant difference in plaque accumulation between the CHX alone regimen (A) and the SLS-dentifrice-CHX regimen (C). Regimen B differed significantly from regimens A and C. The overall bleeding index for regimens A, B and C was 0.24, 0.18, and 0.20, respectively. There was no significant difference between the three regimens.

CONCLUSIONS

The present study shows that the anti-plaque efficacy of a 0.2% CHX rinse was not reduced when preceded by everyday toothbrushing with a SLS-containing dentifrice. However, when preceded by rinsing with an SLS-containing slurry, the anti-plaque efficacy of a 0.2% CHX rinse was reduced.

The effect of systemic administration of ibuprofen in the experimental gingivitis model

BACKGROUND

Studies in humans have indicated that systemically administered flurbiprofen and ibuprofen may reduce gingivitis. De novo plaque formation is enhanced at tooth surfaces adjacent to inflamed gingivae.

OBJECTIVE

The aim of the present clinical trial was to evaluate the effect of systemic administration of ibuprofen on gingivitis and plaque build-up.

MATERIAL AND METHODS

Eleven subjects were recruited for the study and were given oral hygiene instruction, scaling and professional mechanical tooth cleaning (PTC). At the end of a preparatory period (Day 0), the participants were told to abstain from all mechanical plaque control measures during a 2-week experimental period but to rinse with an assigned mouth rinse (positive control: 0.1% chlorhexidine digluconate; negative control: saline) or administer ibuprofen (tablets of 200 mg twice daily). Mouth rinsing was performed twice a day (after breakfast and in the evening), for 60 s with 10 ml. Re-examination was performed after 14 days of experiment. After a 2-week "wash-out" period, the participants received a new PTC and a second 14-day experimental period was initiated. The experimental and "wash-out" periods were repeated until all volunteers had been involved in all three regimens. Dental plaque was scored using the Quigley & Hein Plaque Index system and gingivitis according to the Gingival Index (GI) system. Supragingival plaque was collected and prepared for dark-field microscopy. One hundred bacterial cells were counted and classified into six different groups: coccoid cells, straight rods, filaments, fusiforms, spirochetes and motile rods. Gingival crevicular fluid (GCF) was collected from the same sites that were sampled for plaque. The volume of GCF collected in each strip was measured and analysed regarding content of lactoferrin and albumin.

RESULTS

During the period when the panelists rinsed with saline they accumulated large amounts of plaque and developed marked signs of gingivitis. When they rinsed with chlorhexidine digluconate, small amounts of plaque formed and few sites received GI score > or =2. After the 2 weeks of ibuprofen administration, the panelists presented with significantly fewer sites that scored GI > or =2 but had formed similar amounts of plaque as during the negative control period.

CONCLUSION

It is suggested that ibuprofen administered via the systemic route has an effect on gingivitis but not on de novo plaque formation.

The effect of periodontal treatment on the salivary bacterial load and early plaque formation

AIM

The purpose of the present study was to investigate in periodontitis patients the relationship between the number of bacteria in the saliva and the amount of de novo plaque formation before and after treatment.

METHODS

At baseline, before any treatment was provided, patients rinsed with 10 ml sterile saline. After professional tooth cleaning the patients were instructed to abolish all tooth cleaning procedures for the subsequent 24 h. After this period, the rinsing procedure was repeated and the amount of de novo plaque was assessed. Three months after the initial periodontal therapy was completed the experiment was repeated. The microbiological evaluation of the rinsing samples was carried out by means of phase contrast microscopy and anaerobic culturing.

RESULTS

After treatment the amount of de novo plaque was less compared to before treatment, 0.40 and 0.65 respectively. Both before and after treatment more de novo plaque was present at sites with inflammation than at healthy sites. In order to evaluate the contribution of the numbers of salivary bacteria to the amount of de novo plaque formation an analysis was carried out for healthy sites. This analysis included only healthy sites as determined before treatment and the same sites after treatment. The results showed a significant reduction in the de novo plaque formation after treatment (0.49 before and 0.22 after treatment). Phase contrast microscopic evaluation showed that the number of bacteria in the rinsing samples after treatment was less than before treatment. After treatment also a reduction was found in the prevalence of Prevotella intermedia, Tannerella forsythensis and Peptostreptococcus micros in the rinsing samples.

CONCLUSION

The present study confirms the observation in the literature that the periodontal condition is of major importance in the rate of de novo plaque formation. In addition, the results suggest that the number of bacteria in the saliva may play a role.

Effects of post-surgical cleansing protocols on early plaque control in periodontal and/or periimplant wound healing

OBJECTIVE

The aim of this RCT was to evaluate early wound healing following specific post-surgical care protocols.

MATERIAL AND METHODS

Following periodontal flap surgery, 60 patients were randomly assigned to follow one of two post-surgical protocols. Subjects smoking >20 cigarettes per day were excluded. Patients following the control protocol rinsed twice daily for 1 min with 0.1% of chlorhexidine (CHX) for 4 weeks. In addition to CHX rinsing, patients assigned to the test protocol applied CHX locally using a special very soft surgical toothbrush (Chirugia) from days 3 to 14, and a soft toothbrush (Ultrasuave) from days 14 to 28, twice daily. Baseline measurements included gingival crevicular fluid (GCF) flow rate, probing depth, probing attachment level, presence of bleeding on probing and full-mouth plaque score. Measurements were repeated at 1, 2 and 4 weeks after surgery.

RESULTS

Both post-surgical protocols resulted in successful wound healing and optimal wound closure at 4 weeks. There were no statistical differences in the GCF flow rate between test and control protocols. There was a lower incidence of recession of > or =2 mm following the test protocol.

CONCLUSION

The use of specific post-surgical cleansing protocols including the introduction of mechanical cleansing at day 3, using local application of CHX in addition to daily rinsing with CHX may be recommended.

Modulation of clinical expression of plaque-induced gingivitis. II. Identification of "high-responder" and "low-responder" subjects

AIM

The aims of this study were to validate a randomized, split-mouth, localized experimental gingivitis model and to identify subjects with different gingivitis susceptibility.

MATERIAL AND METHODS

In each of 96 healthy subjects, one maxillary quadrant was randomly assigned as "test" (experimental gingivitis) and the contralateral quadrant as "control". Plaque index (PlI), gingival index (GI), gingival crevicular fluid volume (GCF), and angulated bleeding score (AngBS) were recorded in both quadrants at days 0, 7, 14, and 21. Cumulative plaque exposure (CPE), i.e. PlI over time, was calculated. Day-21 GCF was standardized according to CPE, and residuals of GCF on CPE were calculated. Two subpopulations were then defined, based on upper and lower quartiles of GCF-residual distribution and were, respectively, identified as "high-responder" (HR; n=24) and "low-responder" (LR; n=24).

RESULTS

At test quadrants, all parameters significantly increased throughout the trial, while in control quadrants, PlI, GI, and AngBS remained low. Significant differences were noted between test and control quadrants on days 7, 14, and 21 for all parameters. Significant increases in GI, AngBS, and GCF were observed in test quadrants over the course of the study in both HR and LR groups. Significant differences were noted between HR and LR groups for all gingivitis parameters on day 21 in test quadrants, without any significant differences in PlI or CPE between the groups.

CONCLUSIONS

We identified two subpopulations characterized by significant differences in clinical parameters of plaque-induced gingival inflammation, despite similar amounts of plaque deposits and plaque accumulation rates.

Plaque development in relation to the periodontal condition and bacterial load of the saliva

AIM

To investigate the influence of the oral bacterial load on plaque development in various groups of periodontitis patients and in healthy subjects.

MATERIAL AND METHODS

This study included subjects with a healthy periodontium, a healthy reduced periodontium after treatment, an inflamed reduced periodontium after treatment and untreated periodontitis. At the start of the study, subjects were instructed to rinse with 10 ml reduced transport fluid (RTF) for 10 s in order to evaluate the oral bacterial load. The microbiological evaluation included anaerobe culture and phase-contrast microscopy. Next, the amount of plaque and the clinical condition were evaluated. Thereafter, all supragingival plaque was removed and patients were instructed to refrain from all oral hygiene procedures for 19 h. Subsequently, the rinsing procedure and the evaluation of the amount of plaque were repeated.

RESULTS

The amount of plaque that developed in 19 h was significantly higher in the untreated periodontitis group as compared with the two healthy groups. In case of an inflamed reduced periodontium, sites with deep pockets developed more plaque in 19 h than sites with shallow pockets. The number of bacteria present in the rinsing samples of the two inflamed groups was considerably higher than of the two periodontally healthy groups. A significant correlation was found between the bleeding index at intake and the plaque index at 19 h. No correlations were found between gingival recession and the bacterial counts at intake, and the plaque index at 19 h.

CONCLUSION

The present findings support the concept that the periodontal condition is the dominating factor in relation to the rate of plaque formation. The number of bacteria present in the oral cavity as ascertained by means of a rinsing sample does not seem to play a role.

Controlling the plaque biofilm

AIM

To examine the effect of supragingival plaque removal in conjunction with different periodontal therapies on subgingival plaque composition in different subject populations.

METHOD

Four different studies are presented which examined the effect of repeated removal of supragingival plaque performed by professionals or by tooth brushing on subgingival plaque composition. The studies were performed in different populations including chronic periodontitis, periodontal maintenance and refractory subjects. For all studies, each subject was examined for clinical parameters at up to 168 sites and subgingival plaque samples were taken from the mesial aspect of each tooth and examined for their content of specific bacterial species using checkerboard DNA-DNA hybridisation techniques.

RESULTS

Repeated supragingival plaque removal used in conjunction with scaling and root planing only or combined with other periodontal therapies resulted in improvements in clinical parameters as well as significant decreases in the counts of subgingival species, including those associated with periodontal disease aetiology. Meticulous tooth brushing provided similar clinical and microbial improvements.

CONCLUSIONS

Meticulous removal of supragingival plaque has beneficial effects on clinical parameters of periodontal disease and on the nature of the microbiota that colonises both above and below the gingival margin and appropriately has been a major focus in the prevention and control of dental diseases, particularly periodontal disease.

Treatment of gingivitis with hyaluronan

OBJECTIVES

Hyaluronic acid (hyaluronan) is a glycosaminoglycan with anti-inflammatory and antiedematous properties. It was evaluated in a gel formulation for its effect in the treatment of plaque-induced gingivitis.

METHOD

In a randomised double-blind study, 50 male subjects with plaque-induced gingivitis were divided into two groups and used a verum or placebo gel twice daily additionally to oral hygiene for a 3-week treatment period. Clinical indices (API, Turesky index, PBI) and crevicular fluid variables (peroxidase, lysozyme) were determined at baseline and after 4, 7, 14 and 21 days, respectively.

RESULTS

Significant improvements could be found for all clinical variables in both groups. The verum group showed significant improvement in the study area for the plaque indices beginning with day 4 (P = 0.011) and the PBI beginning with day 7 (P = 0.001) in comparison with the placebo group. The crevicular fluid variables were significantly improved in the centre of the studied inflammation area in the verum group. Here all studied sites had significant decreases in peroxidase (176.72-128.75 and 188.74-128.75 U/L) and lysozyme (1.27-0.27 and 1.30-0.33 mg/L) activities after 7, 14 and 21 days (P between 0.034 and < 0.001), whereas in the placebo group only one site showed a significant decrease for lysozyme (1.74-0.75 mg/L) after 7 and 21 days (P = 0.048 and 0.025).

CONCLUSIONS

These data suggest that a hyaluronan containing gel has a beneficial effect in the treatment of plaque-induced gingivitis.

Dental biofilms at healthy and inflamed gingival margins

OBJECTIVES

The increased plaque formation observed in gingival inflammation is not fully understood. Receptor proteins in the dental pellicle might influence bacterial adhesion and subsequent plaque formation. The purpose of the present study was to examine proteins and microorganisms in dental biofilms, at healthy and inflamed gingival margins.

MATERIAL AND METHODS

To see whether marginal inflammation affects the composition of the pellicle and the early dental plaque, samples were taken from the gingival and incisal parts of teeth in periodontally healthy subjects, both in gingival health and during experimental gingivitis. Pellicle proteins were analysed using gel-electrophoresis, immunoblotting and image analysis. Bacteria were analysed by culturing and the PCR technique.

RESULTS

During gingivitis, the rate of plaque formation increased significantly. The semiquantitative amounts of proteins and the numbers of bacteria varied considerably between individuals and surfaces. The amount of total and individual pellicle proteins and the total numbers of bacteria were, however, increased during gingivitis and the increase in proteins was statistically significant on the incisal parts of tooth surfaces. Compared to a healthy gingiva, reduced numbers for Actinomyces spp. (incisal parts only) and streptococci and increased numbers of periodontopathogens in the 4 h dental biofilms were seen at the inflamed gingiva.

CONCLUSION

Increased gingival crevicular fluid flow during gingivitis affects pellicle formation and increased plasma proteins in the pellicle may modify bacterial attachment and early dental plaque composition.

Antibody-based diagnostic for 'refractory' periodontitis

OBJECTIVE

About 10-15% of US adults are 'refractory' to therapy for chronic periodontitis. Recently, studies suggest that these patients have elevated lysine decarboxylase activity in the sulcular microbiota. The aim of this study was to determine whether an elevated IgG antibody response to lysine decarboxylase, alone or with antibody to other bacterial antigens and baseline clinical measurements, would predict 'refractory' patients with high accuracy.

METHODS

Chronic periodontitis patients were treated using scaling and root planing (SRP) followed by maintenance SRP and 3-monthly re-examinations. If there was a loss of mean full mouth attachment or more than three sites appeared with > 2.5 mm new loss within a year, the subjects were re-treated (modified Widman flap surgery and systemically administered tetracycline). If attachment loss as above recurred, the subjects were 'refractory'. Baseline clinical measurements and specific antibody responses were used in a logistic regression model to predict 'refractory' subjects.

RESULTS

Antibody to a peptide portion of lysine decarboxylase (HKL-Ab) and baseline bleeding on probing (BOP) prevalence measurements predicted attachment loss 3 months after initial therapy [pIAL = loss (0) or gain (1)]. IgG antibody contents to a purified antigen from Actinomyces spp. (A-Ab) and streptococcal d-alanyl glycerol lipoteichoic acid (S-Ab) were related in 'refractory' patients (R2 = 0.37, p < 0.01). From the regression equation, the relationship between the antibodies was defined as linear (pLA/S-Ab = 0) or non-linear pLA/S-Ab = 1). Using pLA/S-Ab, pIAL and age, a logistic regression equation was derived from 48 of the patients. Of 59 subjects, 37 had 2-4 mm attachment loss and were assigned as 'refractory' or successfully treated with 86% accuracy.

CONCLUSION

HKL-Ab facilitated an accurate prediction of therapeutic outcome in subjects with moderate periodontitis.

An approach to differentiate between antibacterial and antiadhesive effects of mouthrinses in vivo

An experimental set-up allowing differentiation in vivo between antibacterial and antiadhesive properties of mouthrinses is described. The percentage of vital bacteria (= microbial vitality) and the bacterial counts were microscopically evaluated in saliva and in supragingival dental plaque both collected simultaneously at various times during de novo plaque formation. In a cross-over design, 12 healthy participants refrained from all oral hygiene for four separate periods of 2 x 4 h and 2 x 72 h after having rinsed with either an amine fluoride/stannous fluoride solution (Meridol) or 0.9% NaCl (placebo). Stimulated whole saliva was collected before and after the rinse. Together with whole-saliva samples, representative 4, 24 and 72-h-old plaque samples were separately taken from defined vestibular tooth surfaces that had been either exposed to the mouthrinse (unprotected sites) or temporarily covered with inert plastic films (protected sites) during rinsing. The pooled plaque and saliva were stained with fluorescent dyes to differentiate vital from dead micro-organisms which permitted the estimation of the percentages of vital bacteria. The total bacterial counts were quantified under the darkfield microscope. The Wilcoxon test was used for selected pairwise comparisons (alpha = 0.05). The percentage of vital bacteria in saliva fell significantly from 80-95% to about 50-60% as a result of the antibacterial activity of the test solution. These baseline values and those found in the presence of 4 and 24-h-old plaque were frequently lower than those recorded after the placebo rinse. In comparison to the placebo, microbial vitality was significantly reduced in early supragingival plaque formed on unprotected sites after applying the test solution. The similar total bacterial counts in 4-h-old plaque recorded after the use of the test solution on the unprotected and the protected areas did not point to an antiadhesive effect of the agent. It is concluded that this new experimental set-up allows decoding of the mode of action of a mouthrinse.

Is the chemical prevention of gingivitis necessary to prevent severe periodontitis?

Gingival inflammation seldom causes discomfort, social embarrassment or loss of function. As most sites with gingival inflammation do not progress to severe periodontal disease, gingivitis should not be considered a public health problem. Periodontitis is always preceded by gingivitis. But most gingivitis remains stable for years without progressing to periodontitis. The number of gingivitis sites that do convert is small. The levels of oral cleanliness achieved by the majority of populations in industrialized countries are below the threshold for severe destructive periodontal disease of personal and public health concern. Because methods of measuring the progression of periodontal disease are unreliable, definitive answers regarding conversion of gingivitis to severe periodontitis are lacking. Gingival inflammation frequently remains contained; most gingivitis remains stable for years without progressing to periodontitis. Decreasing gingivitis does reduce shallow pocketing, but the effect on severe periodontitis is not clear. Although the underlying justification for the reduction of plaque is to reduce gingival inflammation to prevent or reduce severe periodontitis and tooth loss, the basis for the approach is equivocal. A reasonably high level of plaque appears to be compatible with acceptably low levels of periodontal disease. Reducing nonspecific plaque levels to such levels is therefore a rational goal. The conventional methods of controlling periodontal disease involve mechanical removal of plaque and calculus. A complimentary ecological approach, using chemicals, would be to alter the environment of the pocket to prevent growth of putative pathogens. Any ecological approach should be sensitive to the dangers of disrupting the natural ecology of dental plaque. Some antimicrobial and antimetabolic agents such as fluoride, chlorhexidine and triclosan and zinc citrate can selectively suppress certain organisms or inhibit bacterial proteases implicated in tissue damage. The uncertainties about factors that convert gingival inflammation into periodontitis and periodontitis into severe periodontitis coupled with insufficient data from controlled clinical trials on the effectiveness of chemical reduction of gingivitis to prevent severe periodontitis leads one to conclude that more research is required before the need for the chemical prevention of gingivitis to prevent severe periodontitis can be justified.

Predominant cultivable microflora of supragingival dental plaque in Chinese individuals

The aim of this study was to determine the predominant supragingival cultivable bacterial flora in Chinese individuals, using the experimental gingivitis model. A total of 11 healthy dental students, mean age 22.5 years (range 20-25) were recruited. All were provided with once-a-week dental prophylaxis and oral hygiene reinforcement for 3 weeks to ensure gingival health. In the fourth week, after prophylaxis, the participants entered a 14-day period without any plaque control. A plaque sample was collected at days 1, 3, 7 and 14 from the buccal surface of the upper right canine, second premolar, first premolar and first molar, respectively. Each sample was then dispensed in tryptic soy-broth transport medium and grown anaerobically to obtain pure cultures, which were subsequently identified. Results showed that Gram-positive cocci and rods were the predominant cultivatable species (51-61%) in the samples throughout the 14-day period; with time there was a decreasing percentage of cocci and an increasing percentage of rods. Gram-negative cocci and rods increased in proportion with the plaque age (11-37%). Streptococcus spp. were the predominant Gram-positive cocci while Actinomyces were the predominant Gram-positive rods isolated. Fusobacterium and Capnocytophaga spp. were the two most frequent Gram-negative anaerobic rods cultured. The results compared with those from other analogous studies from the West suggest the possibility of interracial differences in supragingival plaque flora.