Clinical alterations in relation to the morphological composition of the subgingival microflora following scaling and root planning

The aim of the present study was to relate shifts in the composition of subgingival plaque in periodontal pockets to alterations of the clinical periodontal conditions following a single course of subgingival scaling and root planing during a period of professional supragingival plaque control. For this purpose, 36 pairs of contralateral periodontal pockets in 10 subjects with moderately advanced periodontitis were assessed for the degree of gingival inflammation, probing pocket depths, bleeding on probing, attachment levels and the amount of supragingival plaque. In addition, samples of subgingival plaque were analyzed morphologically by dark-field microscopy. All patients received detailed information about proper oral hygiene and every 1-2 weeks, professional removal of supragingivally located deposits. When the oral hygiene standard had been sufficiently improved, 1 course of subgingival scaling on 1 side of each jaw only (test side) was carried out. Clinical and microbiological examinations were repeated after the scaling as well as after 2 and 6 months, while patients were recalled for supragingival prophylaxis every 2nd to 4th week. Our data showed that a single course of subgingival scaling and root planing resulted in reduced probing depths, a gain in clinical attachment and a shift in the composition of the subgingival microflora to a composition found in relatively healthy periodontal conditions. In relatively shallow pockets, however, a possible influence of repeated sampling on the subgingival microflora could not be ruled out. Bleeding on gentle probing was a reliable parameter for predicting a subgingival microflora where motile bacteria hold an increased portion.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of supragingival plaque control on the subgingival microbiota in subjects with periodontal disease

The present investigation was performed to study the effect on the subgingival microbiota, of a plaque control program which included meticulous oral hygiene instruction, supragingival scaling and professional monitoring during a 2 year period. 300 subjects were examined for periodontal disease and monitored for 2 years without treatment. After the 2 year examination, 80 subjects were invited to participate in a treatment program intended to improve the standard of their self-performed plaque control. 40 of the invitees had a gingivitis and only minor attachment loss, while 40 subjects had moderate signs of periodontitis. 62 subjects volunteered for this treatment. 23 of the volunteers (Group AB) had several sites with deep pockets (> 4 mm). 39 of the volunteers had gingivitis but shallow pockets only (Group C). Group AB contributed 31 shallow pocket sites (A-sites) and 40 deep pocket sites (B-sites), while Group C contributed 63 shallow sites (C-sites). After the clinical examination, samples of the subgingival microbiota were harvested from the 134 A, B and C sites. The 62 subjects were enrolled in a supervised oral hygiene program. Supragingival scaling was carried out. Oral hygiene instruction was provided and repeated on an individual need basis so that all subjects reached and maintained a supragingival plaque score which was < 20%. 24 months after the year 2 examination, the 62 subjects were examined again using both clinical and microbiological examination procedures. The findings demonstrated that carefully performed supragingival plaque control changed the quantity and the composition of the supragingival microbiota.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recolonization of a subgingival microbiota following scaling in deep pockets

The present investigation was carried out to study some aspects of the recolonization of a subgingival microbiota following subgingival instrumentation in sites with deep pockets. 16 patients were recruited for the study. From each patient 4 inflamed gingival sites with deep pockets were selected. These sites were examined for plaque, overt gingivitis, bleeding on probing and probing depth. Samples of the subgingival microbiota were obtained and examined in the darkfield microscope and in a Neubauer chamber. Following the Baseline examination the teeth of all 4 jaw quadrants were carefully scaled and planed. Subgingival instrumentation was carried out under local anesthesia and required between 2-4 appointments. The patients were subsequently divided into 2 groups (Groups A and B) consisting of 9 and 7 subjects, respectively. During the first 16 weeks of maintenance the patients of Group A were not supervised regarding their self-performed plaque control measures and they accumulated supragingival plaque. The patients of Group B, however, were during these 16 weeks recalled once every 2 weeks for professional tooth cleaning. In addition they rinsed twice daily with a 0.2% solution of chlorhexidine digluconate. Reexaminations including assessments of the same parameters as those studied at Baseline were performed after 2, 4, 8, 12 and 16 weeks. After the 16-week examination the patients of Group A received a new sequence of subgingival scaling and root planing. During the subsequent 16 weeks the patients of Group A were also recalled for professional tooth cleaning. They were reexamined 18, 20, 24, 28 and 32 weeks after the Baseline examination. Subgingival scaling followed by carefully supervised oral hygiene measures resulted in a marked improvement of periodontal conditions. This improvement was accompanied by a pronounced and sustained reduction in the motile segments of the subgingival microbiota. In the presence of supragingival plaque (Group A), however, a subgingival microbiota containing large numbers of spirochetes and motile rods was soon (4-8 weeks) reestablished. A small number of sites with deep pockets (greater than or equal to 8 mm) was not substantially reduced in depth following subgingival instrumentation. In these sites which were kept free from supragingival deposits a subgingival microbiota with a large proportion of motile bacteria soon recurred.     

Supragingival cleaning 3 times a week

It is generally believed that supragingival plaque control has little effect on the subgingival microflora of deep periodontal pockets. However, this may not be true for moderately deep pockets (4-5 mm), which may represent a pathological state between gingivitis and marginal periodontitis. In 6 patients with poor oral hygiene and severe gingival inflammation, 4 matched sites (1 in each quadrant), were chosen which demonstrated at least 20% spirochetes and 15% black-pigmented Gram-negative bacilli. During the first 12 weeks (phase 1), supragingival calculus was removed from the right half of the mouth and then the teeth were professionally cleaned three times a week. At the beginning of phase 2, supragingival calculus was also removed from the left quadrants and the entire mouth was subjected to the same protocol used in phase 1. At no time did patients receive oral hygiene instructions. Clinical parameters were assessed and microbiological samples were taken at 3-week intervals. Samples were submitted to darkfield microscopy and anaerobic culturing. Analysis by multiple linear regression and the Wilcoxon signed-rank test revealed significant changes in the composition of the subgingival microbiota at cleaned sites. While Gram-positive organisms increased proportionally, a number of putative periodontal pathogens, such as P. gingivalis and spirochetes decreased.     

The effect of subgingival debridement with hand and ultrasonic instruments on the subgingival microflora

The effect of hand or ultrasonic instrumentation on the subgingival microflora of periodontal pockets was investigated. Pockets with probing depths of 6-9 mm were selected in 12 patients and were randomly assigned per patient to the experimental and control groups. After oral hygiene instruction, instrumentation of the experimental pockets was carried out either by ultrasonic or by hand instruments in a split-mouth design. The treatment effect on the subgingival microbiota was evaluated by microscopic and culture studies of subgingival plaque samples, while in addition, supragingival plaque, bleeding after probing and probing pocket depth were scored. Examinations were carried out before and 7, 21 and 49 days after treatment. The hand and ultrasonic treatments were equally effective in reducing probing pocket depths and bleeding scores. At the end of the experimental period, the probing depths of 54% of the hand-treated pockets and 43% of the ultrasonic-treated pockets were reduced to 4 mm or less while the bleeding scores were reduced to 29% and 22%, respectively. The analysis of microscopical and cultural data did not show any differences between hand and ultrasonic debridement. Both treatments reduced the microscopical counts of rods, spirochetes and motiles and reduced the total colony-forming units and number of black-pigmented Bacteroides and Capnocytophaga, resulting in a subgingival microbiota consistent with periodontal health.     

The effect of supragingival plaque control on the composition of the subgingival flora in periodontal pockets

The effect of mechanical supragingival plaque control on the composition of the subgingival microflora in untreated 4-6 mm deep periodontal pockets was investigated. 13 subjects with chronic periodontitis were recruited for the study. Periodontally-diseased sites were subjected to professional plaque control 3 x weekly for a period of 3 weeks. Contralateral sites received no prophylaxis and served as controls. No instructions in oral hygiene procedures were given to the patients who maintained their habitual oral hygiene regime during the observation period. Clinical examination and darkfield microscopic analysis of bacterial samples were performed every week. The PlI scores for the experimental sites were reduced markedly, while those for the control sites remained stable throughout the observation period. No changes in the other clinical parameters were detected during the study. The composition of the subgingival microflora at the control sites did not change during the experimental period. In contrast, at the test sites, the proportion of spirochetes+motile rods decreased continuously. This decrease reached statistical significance at the end of the experiment. The results indicate that at periodontally diseased sites with an established subgingival ecosystem, supragingival plaque removal may influence the composition of the subgingival microflora.     

Effect of long-term tetracycline therapy on human periodontal disease

The present investigation was performed to study the effect of long-term, low dosage tetracycline therapy on advanced periodontal disease in humans. 14 volunteers participated in the trial. Each of the participants had at least 4 pairs of diseased sites around contralateral premolars and incisors with deep pockets and advanced bone loss. The trial extended over a 50-week period and was designed as a double-blind split-mouth study. A Baseline examination included assessments of oral hygiene, gingival conditions, probing depth, attachment level and analysis of the composition of the subgingival microbiota in samples obtained from 8 selected diseased sites. All participants received oral hygiene instruction. In each patient 2 quadrants of the mouth, chosen at random, were treated by scaling and root planing. The 2 remaining quadrants were left unscaled. Following the Baseline examination the patients were randomly distributed into 2 groups of 7 members each. In one of the groups the patients received tetracycline on a daily basis during a 50-week period. The participants of the control group received placebo. Reexaminations were performed 2, 10, 20, 30 and 50 weeks after the Baseline examination. The findings demonstrated that in patients with advanced periodontal disease long-term tetracycline therapy in the absence of scaling resulted in the establishment of a subgingival microbiota almost devoid of motile bacteria and in markedly reduced signs of gingivitis, probing depth and attachment loss. In fact, the alterations observed as a result of tetracycline administration to patients with excellent self-performed plaque control were similar to those obtained by conventional scaling and root planing in the control group.     

The effect of supragingival plaque control on the subgingival microflora

The effect of plaque control on the apical microflora of deep periodontal pockets was studied. 8 subjects exhibiting signs of chronic periodontitis were chosen for the study, each subject having at least one pocket greater than 6 mm. These subjects were placed on a plaque control programme consisting of 3 visits, during which oral hygiene instructions were given. On two visits, the teeth of these subjects were scaled and polished. Bacteriological samples from the apex of a deep pockets from each subject were collected before the commencement of the plaque control programme and again at 8 and 16 weeks after the last scale and polish. No significant difference in the microbial flora was observed before and after plaque control, but marked fluctuation in bacterial composition was noted at the 3 samplings. It was concluded that supragingival plaque reduction was not sufficient to produce significant changes in the subgingival plaque composition of deep periodontal pockets.     

Effect of triclosan on the subgingival microbiota of periodontitis-susceptible subjects

Abstract The present study evaluated the long-term effect of (i) meticulous self-performed, supragingival plaque control and (ii) the use of a triclosan/copolymer containing dentifrice in adult subjects susceptible to destructive periodontitis. 40 individuals were recruited into the trial. 3-5 years prior to the baseline examination, they had all been treated by nonsurgical means- for advanced periodontal disease. During the subsequent maintenance phase, all subjects had at different time intervals exhibited sites with recurrent periodontitis. At a baseline examination. 6 surfaces per tooth were examined regarding bleeding on probing, probing pocket depth, and probing attachment level. The deepest pocket site in each quadrant (i.e. 4 sites per subject) was selected and samples of the subgingival bacteria were taken. At baseline, all volunteers received detailed information on proper oral hygiene techniques. This information was repeated on an individual need basis during the course of the subsequent 36-months. No professional subgingival therapy was delivered between the baseline and the 36-month examinations. The subjects were randomly distributed into 2 equal groups of 20 individuals each, 1 test and 1 control group. The members of the test group were supplied with a fluoridated dentifrice containing triclosan/copolymer (Total®. Colgate), while the controls received a corresponding dentifrice but without triclosan/copolymer. The findings demonstrated that in subjects with advanced and recurrent periodontitis, carefully practiced supragingival plaque control had some effects on the subgingival microbiota, but also that this was insufficient to prevent disease progression. In a corresponding group of subjects, however, who used a triclosan/copolymer dentifrice, the subgingival microbiota was reduced in both quantitative and qualitative terms and recurrent periodontitis was almost entirely prevented.     

Microbiological and clinical effects of topical subgingival antimicrobial treatment on human periodontal disease

This study was undertaken to evaluate the microbiological and clinical effects of a subgingivally applied mixture of H2O2-NaCl and NaHCO3 followed by subgingival irrigation with 1% Betadine in the treatment of periodontal disease. 20 adults with moderate to severe periodontal disease were included in a split mouth design study. All patients were given oral hygiene instruction and were subjected to supragingival scaling in all 4 quadrants, and subgingival scaling and root planing of half the dentition. 10 patients were instructed to use the chemical antimicrobial mixture twice a day instead of dentifrice, and also received professional application of the mixture once every 14 days for 3 months in connection with reinstruction in oral hygiene procedures. The remaining 10 patients received oral hygiene instructions combined with professional tooth cleaning without use of chemicals once every 14 days during a 3-month period. The effect of treatment was evaluated by monitoring the subgingival microflora, clinical periodontal parameters, and by computer assisted subtraction analysis of serial standardized radiographs to determine changes in mass of the supporting alveolar bone. The present study revealed that subgingival debridement combined with mechanical plaque control resulted in decreased numbers of subgingival microorganisms including spirochetes and motile rods, and arrested the progressive breakdown of the periodontal tissues. Topical antimicrobial agents used in combination with subgingival scaling further reduced the subgingival microflora and substantially improved early periodontal healing including gain of probing attachment level and gain in radiographic alveolar bone mass during the 12 months of observation. No clinical improvement but a tendency to further periodontal breakdown was found in the unscaled quadrants, even in those which were subjected to a personal application of the topical antimicrobial mixture. This study indicates that professional and personal subgingival application of a mixture of H2O2-NaCl and NaHCo3 will significantly enhance the microbiological and clinical effects of periodontal scaling and root planing. These agents, and the topical mode of antimicrobial therapy seem promising in the management of human periodontal diseases.     

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.     

Maintenance of healed periodontal pockets after a single episode of root planing

The present study evaluated the clinical stability of healed periodontal pockets over a 3 month time period to determine whether this time interval is appropriate for periodontal maintenance therapy. The clinical characteristics of 128 pockets (3-7 mm depth) distributed in 10 patients, were monitored immediately before and 4, 8 and 16 weeks after a single episode of subgingival root planing. The clinical parameters measured were: pocket depth and bleeding after probing with 15, 25 and 50 gm and manual probing, gingival margin location, clinical attachment level, and gingival and plaque indices. Oral hygiene instruction and supragingival cleaning were given at each time point. An average aggregated score for each subject and for each parameter was calculated at each time point. A repeated measure all within analysis of variance was done, and the Tukey multiple range test was used to assess the significance of differences among and between the means. The significant decreases in plaque, gingival and bleeding indices, and pocket depth as well as the significant gingival recession and gain of clinical attachment which were present at the 4 week point were maintained at 8 and 16 weeks after root planing. It was concluded that the favorable clinical changes which occur in periodontal pockets within 1 month after a single episode of subgingival root planing combined with improved oral hygiene can be maintained for an additional 3 month time period.     

Periodic subgingival antimicrobial irrigation of periodontal pockets

The present investigation was undertaken to study the clinical effect of professionally performed periodic subgingival irrigation per se and as an adjunct to scaling and root planing. 10 patients suffering from moderate-severe periodontal disease participated in the study. Following an initial 3-month period of supervised supragingival plaque control, a total of 102 periodontal sites with probing pocket depth greater than or equal to 6 mm and "bleeding on probing" were selected and subjected to a Baseline examination comprising assessments of oral hygiene and gingival conditions, probing depths and probing attachment levels. The pockets in the various jaw quadrants were randomly assigned to one of the following treatment groups: (1) periodic subgingival irrigation with hydrogen peroxide, (2) periodic subgingival irrigation with chlorhexidine, (3) periodic subgingival irrigation with saline and (4) no subgingival treatment. During the first part of the study (baseline-32 weeks), no mechanical debridement of the subgingival area was performed. The irrigation treatment was carried out by the operator 3 times per week during weeks 1 + 2 and 5 + 6 of the trial. In the 2nd part of the trial (32-52 weeks), the sites were subjected to scaling and root planing combined with professional irrigation during weeks 32-38. The previously non-irrigated control sites were not subjected to adjunctive irrigation when mechanically debrided. During the entire study, the patients were recalled for professional tooth cleaning once every 4 weeks. Re-examinations were carried out at 4, 6, 32, 40 and 52 weeks. The results revealed that repeated professional irrigation of unscaled periodontal pockets with chlorhexidine or hydrogen peroxide resulted in a temporarily reduced frequency of bleeding sites, but not in any clinically significant changes in probing assessments. A similar improvement of bleeding scores was observed in the saline-irrigated control group. Scaling and root planing, in combination with an optimal supragingival plaque control, resulted in a marked resolution of the clinical symptoms of periodontal disease. Adjunctive irrigation with chlorhexidine or hydrogen peroxide did not improve the healing result above and beyond that obtained after mechanical debridement alone or in combination with saline irrigation. Hence, the study failed to demonstrate that professionally performed periodic subgingival irrigation with chlorhexidine or hydrogen peroxide, used alone or in combination with thorough mechanical debridement, has a significant therapeutic effect.     

Use of metronidazole as a probe in the study of human periodontal disease

Abstract The present investigation was performed to test the hypothesis that the persistence of inflammatory periodontal disease in human subjects is incompatible with the elimination of the anaerobic segments of the subgingival microbiota. 16 human subjects participated in the trial. They were selected on the basis of advanced periodontal disease which had produced at least 4 pairs of contra lateral teeth with advanced disease. At the Baseline examination the diseased sites were characterized by assessment of plaque, gingivitis, probing depth and attachment level. In addition, the composition of the subgingival microbiota was determined. One pair of sites was subjected to biopsy. In the tissue samples the size of the inflammatory cell infiltrate was assessed. Following the Baseline examination the patients were randomly distributed into 2 treatment groups, test and control. The patients of the test group received metronidazole for 3 periods of 2 weeks each, separated by intervals of 8 weeks. In addition, all patients received detailed oral hygiene instruction and a series of subgingival scalings involving 2 quadrants of the dentition, either the right or the left jaw quadrants, Reexaminations were performed 2, 10, 20, 30 and 50 weeks after the Baseline examination. Biopsies from the predetermined sites were obtained at the reexaminations performed 2,20 and 50 weeks after the initiation of the therapy. The results demonstrated that the elimination of metronidazole sensitive bacteria from the subgingival microbiota resulted in the disappearance of clinical and histopathological signs of periodontal disease. Metronidazole has a unique bactericidal range against anaerobic bacteria. The present findings, therefore, emphasize the central role played by the anaerobic segments of the subgingival plaque for the maintenance of the inflammatory component of periodontal disease.     

Improved metabolic control, clinical periodontal status and subgingival microbiology in insulin-dependent diabetes mellitus

The effect of improved metabolic control on the clinical periodontal condition and the subgingival microflora of diseased and healthy periodontal pockets in 6 ambulatory insulin-dependent diabetes mellitus (IDDM) patients was prospectively studied. Duplicate measurements with a time-interval of 3 days were made every 4 moths for assessment of the metabolic status, the clinical periodontal condition and the subgingival microflora. During the study, patients maintained personal oral hygiene measures as they usually did before the study. Neither supplementary dental prophylaxis nor oral hygiene measures were applied during the investigation. Long-term metabolic control (HbAlc) improved significantly with intensive conventional insulin treatment. Gingival redness decreased significantly whereas gingival swelling showed a not significant trend to decrease. It is suggested that microvascular changes associated with improved metabolic control in diabetes mellitus may mediate the observed change in gingival redness. No effect could be demonstrated for probing pocket depth, probing attachment level, bleeding on probing and the plaque index. Statistical analysis of the effect of improved metabolic control on the subgingival microflora revealed that only the % of streptococci increased significantly in diseased periodontal pockets. In general, no significant changes were found in either healthy or diseased pockets with regard to the bacterial flora associated with periodontal disease. The results of the present study indicate that improved metabolic control in IDDM patients may have no potential impetus for an improved clinical periodontal condition nor on the subgingival bacterial flora. It is concluded that the periodontal condition in IDDM patients may only ameliorate when local oral hygiene measures are applied.     

Longitudinal study of untreated periodontitis

The principal aim of this study was to investigate the use of certain clinical and microbiological criteria to predict periodontal breakdown during a 1-year period. A further aim was to establish whether the act of collecting subgingival plaque samples periodically throughout the observation period would have any effect on the clinical or microbiological variables. Only the clinical data is presented in this paper. The study population comprised 11 volunteers (aged 32-51 years) with persistent advanced periodontitis and inadequate plaque control in spite of a previous intensive course of hygiene therapy. From the left jaw quadrants, 89 teeth were selected, yielding 148 bleeding pockets of 4 mm depth or more. From the right jaw quadrants, 74 teeth were selected, yielding 117 bleeding pockets of 4 mm depth or more. All subjects were examined on 7 occasions at 2-monthly intervals when plaque index scores, dichotomous measurements of gingival redness, pocket depths and attachment levels were recorded. Bacteriological sampling was carried out at each visit for each site only in the left jaw quadrants while the right jaw quadrants were sampled only at the first and last visits. During the study, no subgingival instrumentation was performed, except at 3 sites which exhibited loss of attachment of 3 mm. These teeth were withdrawn from the study for ethical reasons. At the completion of the study, the sequential changes in probing attachment level at each site were subjected to regression analysis to determine the direction and extent of attachment change which had taken place at each site.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of supragingival plaque control on the composition of the subgingival microflora in human periodontitis

The aim of this study was to evaluate the effect of supragingival plaque control on the composition of the subgingival microflora. 8 subjects with moderate to severe periodontitis were chosen for the study. Sites with periodontal destruction (GI greater than 2; probing depth greater than 6.5 mm; vertical alveolar bone loss on radiographs) were submitted to professional plaque control 3 X a week for 3 weeks. Contralateral sites received no prophylaxis and served as controls. Patients maintained usual oral hygiene during the observation period: it consisted exclusively of tooth brushing once or twice a day with no use of interdental cleaning aids. Clinical examination and bacterial sampling were performed every week. At the end of the study, PlI scores for the experimental sites showed a marked diminution compared with the control sites. No variations were observed in GI or probing depth in test or control sites during the study. The composition of subgingival plaque in both groups showed no significant variations during that period.     

The effect of supragingival plaque control on the subgibgival microflora in human periodontitis

Abstract The aim of the present trial was to study if carefully practiced supragingival plaque control influenced the subgingival microbiota at periodontal sites with suprabony, infrabony, or furcation pockets. 12 subjects, 5 males and 7 females aged 44 to 69 years (mean age 55 years) participated in the study. None of the participants had during the last 12 months received periodontal therapy, and none of the subjects had used antibiotics during a 3-month period preceding the study. Following a screening examination. 6 to 8 sites per subject were selected which had a probing depth of 5 mm. Among these sites. 1–3 sites had a supra-bony location. 1–3 sites had an infrabony location, and 1–3 sites were associated with a furcation defect. The selected sites were exposed to a baseline examination at which the following parameters were recorded: plaque, gingivitis, probing pocket depth and probing attachment level. A bacterial sample was obtained from each of the selected sites: 2 sterile paper points were inserted into the pocket and kept in place for 30 seconds. The paper point samples were removed, placed in a vial containing an anaerobically prepared transport medium, and processed using routine procedures. Following the baseline examination, each subject was given a case presentation, received thorough supragingival scaling and was instructed to practice proper plaque control with the use of toothbrush and dentifrice. During the subsequent 30 weeks they were recalled 2–3 × per week for professional tooth cleaning. Each session was handled by a dental hygienist and required about 15 min. Re-examinations were performed after 30 weeks. The findings indicated that professionally delivered and frequently repeated supragingival tooth cleaning, combined with careful self-performed plaque control had a marked effect on the subgingival microbiota of moderate to deep periodontai pockets. Thus, at sites with suprabony and infrabony pockets, as well as at furcation sites, the meticulous and prolonged supragingival plaque removal reduced the total number of microorganisms that could be harvested, as well as the % of sites with P. gingivalis.     

The effect of plaque control after scaling and root planing on the subgingival microflora in human periodontitis

The aim of the present study was to evaluate the effect of a strict supragingival plaque control regimen on bacterial repopulation following scaling and root planing. 7 patients with moderate to severe inflammatory periodontal disease received a full-mouth scaling and subgingival curettage. Using a split-mouth design, 2 sites of opposite quadrants were submitted to professional supragingival plaque control 3 X a week while the contralateral sites served as controls. Clinical and bacterial examination were performed on days 7, 14, 28, 49, 56, 63 and 70 following therapy. All clinical parameters (P1I, GI, probing depth, attachment levels) showed significant improvement after scaling and root planing. Shifts in the subgingival bacterial population observed by dark field were also noticed following curettage: there was a decrease in the proportions of spirochetes and motile rods and an increase in that of coccoid cells. However, bacterial distribution tended to return to base line values towards the end of the observation period. No difference in the pattern of bacterial recolonization of the subgingival area could be detected between the sites under strict supragingival plaque control and the control sites.     

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.