Stabilized stannous fluoride dentifrice in relation to dental caries, dental erosion and dentin hypersensitivity: A systematic review.

PURPOSE: To review the scientific evidence for the efficacy of stabilized stannous fluoride (SnF2) dentifrice in relation to dental caries, dental erosion and dentin hypersensitivity. METHODS: Medline OVID, Embase.com, and the Cochrane Library were searched until January 2018. Two researchers independently selected studies according to inclusion and exclusion criteria, data were extracted, the risk of bias in eligible studies was assessed and a meta-analysis was performed wherever feasible. RESULTS: Three studies on dental caries, eight studies on dental erosion and 11 on dentin hypersensitivity were included. Risk of bias was judged as high for most of the caries and erosion studies and low or medium for the hypersensitivity studies. A similar or slightly higher anti-caries activity compared with non-stannous fluoride dentifrices was observed. Stannous fluoride showed a greater anti-erosive potential in seven of the eight studies. A mean difference score in favor of stannous fluoride dentifrices compared with controls was found in a meta-analysis including six 8-week hypersensitivity studies. CLINICAL SIGNIFICANCE: The use of stabilized stannous fluoride dentifrices to relieve dentin hypersensitivity and to prevent the initiation of dental erosion speaks in favor of this treatment strategy.

Polyhexamethylene guanidine phosphate irrigation as an adjunctive to scaling and root planing in the treatment of chronic periodontitis.

OBJECTIVE: To evaluate the efficacy of adjunctive polyhexamethylene guanidine (PHMG) phosphate irrigation in periodontal treatment. MATERIALS AND METHODS: The subjects comprised 59 patients with severe chronic periodontitis. Plaque index, bleeding on probing (BOP) and pocket probing depths (PPD) were recorded. The subjects were randomly allocated to one of three groups for scaling and root planning, with different adjunctive irrigants: 1% PHMG phosphate (19 subjects), 0.2% chlorhexidine (21 subjects) and distilled water (19 subjects). Patients were recalled after two weeks, one month and then after 4, 6 and 12 months. RESULTS: In all groups, treatment resulted in considerable improvement of the observed clinical parameters. There were no intergroup differences in plaque index and BOP at any time point, but significant differences in PPD at one, four and six months. By the end of the study no intergroup differences in PPDs persisted. While post study surgical treatment needs decreased in all three groups, no intergroup differences were observed in the number of deep periodontal pockets. CONCLUSIONS: Irrigation with PHMG phosphate significantly reduces PPDs in the short-term, but has no significant long-term effect on the mean pocket depth.

Interaction between chlorhexidine and fluoride in a mouthrinse solution-a 4-day and 6-week randomized clinical pilot study.

OBJECTIVE: The aim of the present investigation was to study if there is a reduced clinical effect and fluoride retention of a mouthrinse solution containing both chlorhexidine (CHX) and sodium fluoride (NaF). MATERIAL AND METHODS: Two clinical trials were designed as double-blind, randomized, cross-over studies. In study I, 16 healthy subjects were asked to rinse twice daily for 1 min during 4 days of no tooth brushing with four solutions: (1) 0.12% CHX + 0.2% NaF, (2) 0.2% NaF, (3) 0.12% CHX, and (4) placebo. In study II, another 16 healthy subjects rinsed with the same four solutions twice daily after tooth brushing during a 6-week period. Plaque formation, gingivitis, and microbiological samples from plaque and saliva, as well as fluoride retention, were analyzed. RESULTS: Both studies showed that both CHX + NaF and CHX mouthrinses had the same clinical effect with regards to plaque formation and microflora in plaque and saliva. Similarly, fluoride retention was not altered by the CHX + NaF mouthrinse compared to the NaF solution. CONCLUSION: The combination of CHX and NaF in a mouthrinse showed the same clinical effect as the CHX solution. The retention of fluoride in the oral cavity was not affected by the combination of NaF and CHX. CLINICAL RELEVANCE: A mouthrinse solution containing a mixture of CHX and NaF may be an interesting product for risk patients for caries and periodontal disease. However, this should be verified in further long-term clinical studies.

A randomized controlled cross-over study of the effect of alcohol-free chlorhexidine and essential oils on interleukin-1 levels in crevicular fluid.

Aim of the study was to determine the effect of an alcohol-free chlorhexidine mouth rinse and an essential oils containing mouth rinse on pro-inflammatory cytokine levels in gingival crevicularfluid in participants who continue to perform their regular mechanical oral hygiene regimes and normal dietary practice. Twenty adult volunteers (mean age: 59 years) participated in the double-blind randomised controlled cross-over study.Three mouth rinses were used during 16-day periods as an adjunctiveto regular mechanical oral hygiene: a solution with alcohol-free chlorhexidine (CHX; Paroex), a solution with essential oils (EO; Listerine), and water (negative control).The mouth rinse periods were separated by 3-month washout periods. At days o (baseline) and 17 (end) of each mouth rinse period, gingival crevicular fluid (GCF) was collected at different tooth sites and analyzed with ELISA technique for IL-1α, IL-1ß and IL-ira levels. No significant correlations between clinical parameters (QHI and GI) and cytokine concentra- tions were observed, regardless of mouth rinse regimen.The generalized linear models revealed that none of the mouth rinses had a statistically significant impact on IL-1 concentrations in GCF. Large inter-individual variations were observed for the levels of IL-iα, IL-1ß and IL-ira. Also the changes in concentrations between day o and day 17fo r the mouthrinses showed large intra-individual variations. It can be concluded that neither the alcohol-free chlorhexidine nor the mouth rinse contain- ing essential oils reduced the levels of IL-iα, IL1ß and IL-ira in GCF.

A randomized controlled clinical study of the effect of daily intake of Ascophyllum nodosum alga on calculus, plaque, and gingivitis.

OBJECTIVE: The aim of this study is to evaluate, in a randomized controlled cross-over study, the effect of daily intake of the alga Ascophyllum nodosum on supragingival calculus, plaque formation, and gingival health over a 6-month period. MATERIAL AND METHODS: Sixty-one adults with moderate to heavy calculus formation since their last yearly recall visit participated. In a randomized order over two 6-month periods, they swallowed two capsules daily, comprising a total of 500 mg dried marine alga powder (Ascophyllum nodosum, ProDen PlaqueOff®) or two negative control tablets. During the study, the participants maintained their regular oral habits. Their teeth were professionally cleaned at the start of each period and after the 6-month registrations. A wash out period of 1 month separated the two 6-month periods. Supragingival calculus (Volpe Manhold), gingivitis (Löe and Silness), gingival bleeding (Ainamo and Bay), and plaque (Quigley-Hein) were registered at screening and at the end of the two periods. Differences in oral health between the test and control periods were analyzed using a paired t test and Wilcoxon signed rank test. RESULTS: Fifty-five participants completed the study. After the alga intake, the mean calculus reduction was 52% compared to the control (p < 0.0001). Fifty-two participants showed less calculus formation in the alga group than in the control group. Plaque (p = 0.008) and gingival bleeding (p = 0.02) were also significantly less in the alga group. However, no significant difference was found between the groups for gingivitis (p = 0.13). CONCLUSIONS: The alga intake significantly reduced the formation of supragingival calculus and plaque and occurrence of gingival bleeding. The alga has a systemic effect on oral health. CLINICAL RELEVANCE: Daily intake of the alga Ascophyllum nodosum as an adjunct to customary oral hygiene showed a major reduction of supragingival calculus formation and reduced plaque formation. In addition, the calculus in the alga group was characterized by a more porous and less solid structure and was easier to remove than the calculus in the control group.

Effect of cleansing of biofilm formed on titanium discs.

OBJECTIVES: To study the combined effect of mechanical and chemical cleansing on a 4-day biofilm grown intra-orally on titanium discs with different surface characteristics. MATERIAL AND METHODS: Twenty subjects used a splint with two metal plates in the upper jaw. Each plate was placed in the premolar-molar region and carried four titanium discs with four different surface characteristics (OsseoSpeed(™), TiOblast(™), experimental and turned surface). After 4 days of biofilm growth, the discs were cleaned mechanically and chemically with saline or chlorhexidine. Following cleansing, microbial samples were obtained and analysed by culture. The titanium discs were processed for scanning electron microscope (SEM) analysis. The experiment was repeated 3 days later using delmopinol or a mixture of essential oils during cleansing. RESULTS: The combination of mechanical and chemical cleansing was ineffective in complete biofilm removal from all four titanium discs. The microbiological analysis did not reveal any statistically significant differences between surface types or between cleaning agents regarding logarithmic mean counts of CFU for specific bacteria, aerobes, anaerobes or the TVC. Aerobes were more numerous than anaerobes on all surface types. The SEM analysis disclosed that the remaining biofilm on moderately rough surfaces (OsseoSpeed(™), TiOblast(™) and experimental) was complex and firmly attached, while the biofilm on turned surface had a pattern of spread bacteria forming less clusters. CONCLUSIONS: Cleansing may call for prolonged time of chemomechanical debridement and/or more effective disinfectants to suppress biofilms on dental implant surfaces.

Clinical and biological indicators of dental caries and periodontal disease in adolescents with or without obesity.

OBJECTIVE: This study aims to assess clinical, microbiological and inflammatory parameters as indicators for caries and periodontal disease in adolescents with obesity. MATERIAL AND METHODS: Twenty-seven adolescents with obesity [body mass index (BMI) 37 ± 4 kg/m(2)] and 28 controls (BMI 20 ± 2 kg/m(2)) answered questionnaires and were investigated regarding salivary parameters, plaque pH drop after a 1-min glucose rinse, oral clinical parameters, inflammatory markers in gingival crevicular fluid (GCF) and sub-gingival mirobiota. RESULTS: Compared with controls, adolescents with obesity had a lower stimulated salivary secretion rate (1.55 ± 0.63 vs. 2.05 ± 1.05 mL/min, p < 0.05), higher concentrations of secretory immunoglobulin A (sIgA) (p < 0.001), more decayed tooth surfaces (3.4 ± 6.6 vs. 0.8 ± 1.1, p < 0.05) and more gingivitis (p < 0.01) after controlling for possible confounders. Overall, similar snacking habits, plaque amounts and numbers of deep periodontal pockets were observed. Following the glucose rinse, a slightly more pronounced drop in plaque pH was observed in the obesity group (p > 0.05). No differences in sub-gingival inflammatory or microbial indicators were detected (p > 0.01). CONCLUSIONS: More caries and gingival inflammation were observed in adolescents with obesity. Of the indicators tested, salivary secretion rate was lower and sIgA levels were higher in the obesity group. We are unable to confirm whether differences in caries and gingival inflammation are due to systemic changes that are associated with obesity or due to possible irregular dietary/oral hygiene habits. CLINICAL RELEVANCE: Customised oral health preventive programmes and appropriate collaboration with medical personnel in selecting the best diet, medication and psychological support can help improve the general well-being, including oral health, of children with obesity. This may even reduce the risk of oral diseases.

Label-free quantitative proteomics reveals differentially regulated proteins in experimental gingivitis.

We investigated the sequential protein expression in gingival crevicular fluid samples during the induction (I) and resolution (R) of experimental gingivitis. Periodontally and systemically healthy volunteers (n = 20) participated in a three-week experimental gingivitis protocol, followed by debridement and two weeks of regular plaque control. Gingival crevicular fluid (GCF) samples were collected at baseline, Day 7, 14, and 21 (induction; I-phase), and at Day 21, 25, 30, and 35 (resolution; R-phase). Liquid chromatography-tandem mass spectrometry (LC-MS/MS) for label-free quantitative proteomics was applied. A total of 287 proteins were identified including 254 human, 14 bacterial, 12 fungal, and 7 yeast proteins. Ontology analysis revealed proteins primarily involved in cytoskeletal rearrangements, immune response, antimicrobial function, protein degradation, and DNA binding. There was considerable variation in the number of proteins identified, both among subjects and within subjects across time points. After pooling of samples between subjects at each time point, the levels of 59 proteins in the I-phase and 73 proteins in the R-phase were quantified longitudinally. Our data demonstrate that LC-MS/MS label-free quantitative proteomics is valuable in the assessment of the protein content of the GCF and can facilitate a better understanding of the molecular mechanisms involved in the induction and resolution of plaque-induced gingival inflammation in humans.

Subgingival debridement of periodontal pockets by air polishing in comparison with ultrasonic instrumentation during maintenance therapy.

AIM: The objective was to determine clinical and microbiological effects and perceived treatment discomfort of root debridement by subgingival air polishing compared with ultrasonic instrumentation during supportive periodontal therapy (SPT). MATERIAL AND METHODS: The trial was conducted as a split-mouth designed study of 2-month duration including 20 recall patients previously treated for chronic periodontitis. Sites with probing pocket depth (PPD) of 5-8 mm and bleeding on probing (BoP+) in two quadrants were randomly assigned to subgingival debridement by (i) glycine powder/air polishing applied with a specially designed nozzle or (ii) ultrasonic instrumentation. Clinical variables were recorded at baseline, 14 and 60 days post-treatment. Primary clinical efficacy variable was PPD reduction. Microbiological analysis of subgingival samples was performed immediately before and after debridement, 2 and 14 days post-treatment. RESULTS: Both treatment procedures resulted in significant reductions of periodontitis-associated bacterial species immediately and 2 days after treatment, and in significant reduction in BoP, PPD and relative attachment level at 2 months. There were no statistically significant differences between the treatment procedures at any of the examinations intervals. Perceived treatment discomfort was lower for air polishing than ultrasonic debridement. CONCLUSION: This short-term study revealed no pertinent differences in clinical or microbiological outcomes between subgingival air polishing and ultrasonic debridement of moderate deep pockets in SPT patients.

Effect of post-brushing mouthrinse solutions on salivary fluoride retention.

Fluoride (F) toothpaste is one of the most effective means of caries prevention. There is also evidence that mouthrinse solutions with antimicrobial agents reduce plaque formation and gingivitis and may be used as adjuncts to daily self-performed oral hygiene for risk patients. The authors hypothesize that using these solutions--without or with just a low F concentration after brushing--will have a "wash-out" effect on F toothpaste. Mouthrinse solutions with more F might be beneficial in this respect. Two groups of 10 (Series 1) and 12 (Series II) healthy subjects were recruited. They brushed for 1 min with toothpastes containing either 1450 or 5000 ppm F. After brushing and spitting out the toothpaste, the participants in Series I rinsed for 30 sec with 10 ml of a variety of products with various F concentrations (0, 100, 226 or 900 ppm F). In Series II, they first rinsed with water after the brushing and directly thereafter with 20 ml of the post-brushing rinsing solution for 30 sec. Saliva samples in both series were collected at different time points up to 1 h and the F concentration was measured. There was significantly less F in saliva after rinsing with no F or with a low F concentration (100 ppm) compared with just brushing with a F toothpaste. Rinsing with 226 ppm F displayed significantly higher F concentrations in saliva compared with only toothbrushing. Products with a high F concentration (i.e. toothpaste with 5000 ppm F or a mouthrinse solution with 900 ppm F) produced the highest F retention in saliva compared with all other protocols. The quantity of mouthrinse solution (20 vs. 10 ml) did not seem to have any effect on the F retention. The results from both test series show that a post-brushing rinsing solution without F or with just 100 ppm F exerts a "wash-out" effect on toothbrushing with either 1450 or 5000 ppm F, which may be negative for all patients, especially those with a risk of caries. The general population will benefit more from higher concentrations of F in mouthrinse solutions and, based on the results of the present investigation, 226 ppm F (corresponding to 0.05% NaF) should be the lowest concentration used. Furthermore, caries risk patients are recommended to use a high-F toothpaste (5000 ppm F) or a post-brushing mouthrinse solution with 900 ppm F (corresponding to 0.2% NaF).

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.

Oral health in young adults with long-term, controlled asthma.

OBJECTIVE: To study oral health in young adults with long-term, controlled asthma. MATERIAL AND METHODS: Twenty 18- to 24-year-olds with a mean duration of asthma of 13.5 [standard deviation (SD) 5.4] years and 20 matched healthy controls were included. A clinical examination was performed and the prevalences of caries, erosions, gingival inflammation, cervicular fluid and periodontal pockets and the plaque formation rate were registered. The salivary flow rate and the numbers of mutans Streptococci and Lactobacilli in saliva were determined. Plaque pH was measured after a sucrose rinse for up to 40 min at two approximal sites. The participants were interviewed regarding dietary and oral hygiene habits. RESULTS: The mean (SD) DFS, including manifest and initial caries, was 8.6 (10.6) in the asthma group and 4.0 (5.2) in the control group (P = 0.09). Initial caries lesions were more common in the asthma group than in the control group: 6.0 (8.1) and 1.3 (2.0), respectively (P = 0.02). The asthma group had more gingivitis (P = 0.01) and a lower stimulated salivary secretion rate than the controls (P = 0.01). The asthmatics also had a somewhat, although not statistically significant, lower initial pH value in plaque and a more pronounced pH drop compared with the controls. In the asthma group, 65% reported frequent mouthbreathing, compared with 10% of the controls (P = 0.01). No differences were found in tooth-brushing or dietary habits between the groups. CONCLUSION: Young adults with long-term, controlled asthma had more initial caries, more gingival inflammation and a lower stimulated salivary secretion rate than individuals without asthma.

Local minocycline as an adjunct to surgical therapy in moderate to severe, chronic periodontitis.

OBJECTIVE: The aim of the study was to evaluate the effects of minocycline microspheres on periodontal probing depth reduction when used in combination with surgery in adults with moderate to severe, chronic periodontitis. MATERIAL AND METHODS: Sixty patients with a minimum of one non-molar periodontal site > or =6 mm in two oral quadrants received either local minocycline microspheres at baseline, immediately following each of two surgical therapies (Weeks 2 and 3), and at Week 5 or surgery alone. RESULTS: The mean probing depth reduction at Week 25 at sites > or =5 mm at baseline was 2.51 mm in the test group and 2.18 mm in the control group. Smokers in the test group had a significantly greater probing depth reduction (2.30 mm) than smokers in the control group (2.05 mm). The number of sites with probing depth reductions of > or =2 and > or =3 mm were significantly higher in the test group than in the control group. CONCLUSION: Applications of local minocycline as an adjunct to surgery in adults with moderate to severe, chronic periodontitis were associated with statistically significant greater reductions in probing depth than surgery alone.

Periodontal conditions in male adolescents using smokeless tobacco (moist snuff).

AIM: The aim of this study was to evaluate the potential association of the use of smokeless tobacco (moist snuff) on the periodontal conditions of adolescents. MATERIAL AND METHODS: A subject sample of one hundred and three 19-year-old male individuals (33 snuff users, 70 controls) living in Göteborg, Sweden, were clinically examined with regard to oral hygiene, gingivitis, probing pocket depth (PPD), clinical attachment loss (CAL) and gingival recession. Bitewing radiographs were obtained for assessments of alveolar bone level. Information about tobacco and oral hygiene habits was obtained by a structured questionnaire. Student 's t-test, chi(2)-test and logistic regression analysis were used for statistical analysis. RESULTS: The mean plaque and gingivitis scores in snuff-users were 59% (SD 21.0) and 47% (18.6), respectively, and in controls 64% (22.4) and 50% (18.3), respectively. The average PPD and CAL in snuff-users amounted to 2.3 mm (0.3) and 0.2 mm (0.1), respectively, and in controls 2.4 mm (0.3) and 0.1 mm (0.1) (p>0.05), respectively. The mean bone level was 1.3 mm (0.2) in both groups. The prevalence of subjects showing recession was 42% among snuff-users and 17% among controls (p=0.006). In snuff users, an average of 4% (0.9) of the teeth showed recession, compared with 1% (0.3) in controls (p<0.001). Limiting the analysis to the maxillary anterior tooth region, 33% of the snuff-users and 10% of the controls presented recessions (p=0.002). The use of snuff entailed an OR=5.1 to have gingival recessions. CONCLUSION: In the present population sample of adolescents, the use of smokeless tobacco (moist snuff) was not associated with the presence of periodontal disease except for a significantly high prevalence of gingival recessions.

The effect of a mouth rinse containing phenolic compounds on plaque formation and developing gingivitis.

BACKGROUND: The clinical effect of Listerine, a mouth rinse containing a mixture of phenolic compounds, is ascribed to its bactericidal properties. However, phenolic compounds are also known to interfere with the inflammatory process. OBJECTIVE: The purpose of this clinical trial was to evaluate the effect of regular mouth rinsing with Listerine on plaque and gingivitis during a 2-week period of no mechanical oral hygiene. MATERIAL AND METHODS: Twenty-one subjects were recruited for the study. On Day 0 of each 2-week experimental period, the participants were told to abstain from all mechanical plaque-control measures but to rinse twice a day with 10 ml of the assigned solution (test: Listerine, positive control:0.1% chlorhexidine (CHX), negative control: saline) for 60 s. Each experimental period was preceded by a 2-week period including oral hygiene instruction, scaling and professional mechanical tooth cleaning. Examinations included assessments of plaque and gingivitis (Days 0 and 14), sampling of plaque and collection of gingival crevicular fluid (GCF) (Days 0, 7 and 14). From the supragingival plaque samples, six different morphotypes of bacteria were counted using dark-field microscopy. The GCF collected was analysed with respect to the content of lactoferrin and albumin. RESULTS: During the experimental periods, it was observed that significantly less plaque formed and less gingivitis developed when the participants rinsed with the Listerine mouthwash than with saline solution. However, significantly more plaque formed during the Listerine than during the CHX rinse period, while there was no significant difference in the development of gingival bleeding between the Listerine and the CHX rinse regimens. Significantly smaller proportions of motile rods and fusiforms were found in the List and CHX groups than in the control (Ctrl) group. The increase of the lactoferrin/albumin ratio in the List group was significantly smaller than that in the Ctrl group but significantly larger than in the CHX group. CONCLUSION: It was suggested that the effect of Listerine on gingivitis is more pronounced than on plaque formation. This indicates that the phenolic compound may have anti-inflammatory effects.

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 a chlorhexidine regimen on de novo plaque formation.

OBJECTIVE: To evaluate the effect of a pretreatment regimen that combined meticulous mechanical tooth cleaning with the daily use of chlorhexidine (rinse, gargle and tongue application) on de novo plaque formation and on the recolonization of various microbiological species in plaque and saliva during a 4-day period of no oral hygiene. MATERIAL AND METHODS: Ten subjects aged 24-36 years with gingivitis were recruited. The study was designed as a double blind cross-over clinical trial including two phases. Each experimental phase comprised one preparatory period of 7 days and one plaque accumulation period of 4 days. During the preparatory period, the volunteers (i) performed meticulous mechanical tooth cleaning using toothbrush and dentifrice and (ii) were, in addition, given two sessions of professional tooth cleaning (PTC) The final PTC was delivered after bacterial sampling had been made on Day 0. In the Control group, no additional plaque control measures were included. In the Test group, the participants in addition to the mechanical measures (i) rinsed twice daily, for 60 s each time with a 0.2% chlorhexidine solution, (ii) gargled twice daily for 10 s with the chlorhexidine preparation, and finally (iii) brushed the dorsum of the tongue for 60 s, twice daily, with a 1.0% chlorhexidine gel. During the 4-day plaque accumulation period, the participants abstained from all mechanical and chemical plaque control measures. On Days 0, 1, 2 and 4 the quantity and quality of plaque formed was assessed by clinical means and by DNA probe techniques. The microbiota of the saliva was studied in samples obtained on Days 0 and 4. RESULTS: It was demonstrated that chlorhexidine used as a mouthrinse combined with gargling and tongue application during the preparatory period significantly retarded the amount of plaque that formed on tooth surfaces during the following 4 days of no oral hygiene. Further, the number of microorganisms present in the biofilm representing Days 0, 1 and 2 of the "plaque accumulation period" was apparently affected by the use of the antiseptic. Among the microorganisms influenced by the chlorhexidine regimen, a substantial number belonged to the genus Actinomyces. It was also observed that the adjunctive use of chlorhexidine reduced the number of bacteria present in saliva at the end of the preparatory period (i.e. on Day 0). After 4 days of no oral hygiene, the microbiota of the newly formed plaque in the Test and Control groups had many features in common. CONCLUSION: Habitat is critical in controlling the bacterial composition of the dental biofilm. The microbiota will tend to go back to the one that is characteristic of a given subject, once chemical antimicrobial means are withdrawn.

Effect of various chlorhexidine regimens on salivary bacteria and de novo plaque formation.

AIM: The aim of the present experiment was to study the effect of different chlorhexidine regimens on the number of bacteria in saliva, and on de novo plaque formation. MATERIAL AND METHODS: Ten subjects with gingivitis, but no signs of destructive periodontitis, were recruited. Following a screening examination, the volunteers were given oral hygiene instruction, meticulous scaling and professional mechanical tooth cleaning (PTC). The PTC was repeated once every 3 days during a 2-week period to establish healthy gingival conditions. The study was designed as a double-blind cross-over clinical trial including three phases. Each experimental phase comprised one preparatory period of 7 days and one plaque accumulation period (no oral hygiene measures) of 4 days. During all preparatory periods, the volunteers (i) performed mechanical tooth cleaning using a toothbrush and dentifrice and (ii) were, in addition, given two sessions of PTC. The final PTC was delivered after bacterial sampling had been made on Day 0. Preparatory period A: the participants continued the self-performed plaque control regimen that employed only mechanical means. Preparatory period B: the participants were in addition instructed to rinse and gargle, twice daily, with a 0.2% chlorhexidine mouthrinse. Preparatory period C: in addition to the above, the participants were instructed to brush the dorsum of the tongue for 60 s, twice daily, with a 1.0% chlorhexidine gel. Following each plaque accumulation period, there was a 10-day washout interval. The presence and amount of dental plaque (QHI) was scored after 1, 2 and 4 days of no oral hygiene. Samples of saliva were obtained on Day 0 and after 1 and 2 days. The samples were placed on Brucella agar plates and incubated (anaerobically) for 5 days. The total number of colony-forming units was determined and used to estimate the density of bacteria in saliva. RESULTS: In period A, the mean QHI increased from 1.0 (Day 1) to 1.4 (Day 2) and 2.1 (Day 4). The corresponding scores for periods B and C were 0.5, 0.8, 1.6 and 0.3, 0.8, 1.2, respectively. At all re-examination intervals more plaque formed during period A than during periods B and C. Further, during period C, less plaque formed than that during period B. Saliva samples from Day 0 in period A contained a larger number of TVC than the baseline samples in periods B and C. There was no significant difference in TVC among the groups on Day 2. CONCLUSION: The daily use of chlorhexidine as an adjunct to mechanical tooth cleaning markedly reduced the number of microorganisms that could be detected in saliva. The number of salivary bacteria may have influenced the amount of plaque that formed during an early phase of no oral hygiene.

Bacterial colonization during de novo plaque formation.

OBJECTIVE: To determine microbial changes that occur during plaque formation in a dentition free of gingival inflammation. MATERIAL AND METHODS: Ten subjects were recruited. The study included one preparatory period (2 weeks) and a plaque accumulation period (4 days). The volunteers exercised proper tooth cleaning methods, were scaled and received repeated professional mechanical tooth cleaning during the preparatory period. During the plaque accumulation period, the participants abstained from plaque control measures. Plaque was scored on the approximal surfaces of maxillary and mandibular premolars on Days 0, 1, 2 and 4 using a scale from 0 to 5 and according to the criteria of the Quigley and Hein Plaque Index (QHI). Supragingival plaque samples were obtained from the same intervals and surfaces and evaluated using a checkerboard DNA-DNA hybridization technique. RESULTS: The mean QHI increased from 0 to 1.6 (Day 4). The total number of organisms on Day 0 averaged 140 x 10(5) and increased to about 210 x 10(5) after 4 days without oral hygiene. The most dominant species on Day 0 were members of the genus Actinomyces. These organisms comprised almost 50% of the microbiota evaluated. None of the Actinomyces species increased significantly during the 4 days. Some Streptococcus species increased significantly over time as well as species of the genera Capnocytophaga, Campylobacter, Fusobacteria and Actinomyces actinomycetemcomitans. CONCLUSION: In the present investigation, the preparatory phase established a situation with minimal gingival inflammation and close to zero amounts of dental plaque. The Day 0 plaque samples exhibited high proportions of Actinomyces species. During the 4 days of no oral hygiene, there was a small increase in total numbers of organisms as well as a modest increase in the proportion of "disease-associated" taxa such as species of the "orange complex" species.