Showing papers in "Journal of Clinical Periodontology in 1998"

Microbial complexes in subgingival plaque

Abstract: It has been recognized for some time that bacterial species exist in complexes in subgingival plaque. The purpose of the present investigation was to attempt to define such communities using data from large numbers of plaque samples and different clustering and ordination techniques. Subgingival plaque samples were taken from the mesial aspect of each tooth in 185 subjects (mean age 51 +/- 16 years) with (n = 160) or without (n = 25) periodontitis. The presence and levels of 40 subgingival taxa were determined in 13,261 plaque samples using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Clinical assessments were made at 6 sites per tooth at each visit. Similarities between pairs of species were computed using phi coefficients and species clustered using an averaged unweighted linkage sort. Community ordination was performed using principal components analysis and correspondence analysis. 5 major complexes were consistently observed using any of the analytical methods. One complex consisted of the tightly related group: Bacteroides forsythus, Porphyromonas gingivalis and Treponema denticola. The 2nd complex consisted of a tightly related core group including members of the Fusobacterium nucleatum/periodonticum subspecies, Prevotella intermedia, Prevotella nigrescens and Peptostreptococcus micros. Species associated with this group included: Eubacterium nodatum, Campylobacter rectus, Campylobacter showae, Streptococcus constellatus and Campylobacter gracilis. The 3rd complex consisted of Streptococcus sanguis, S. oralis, S. mitis, S. gordonii and S. intermedius. The 4th complex was comprised of 3 Capnocytophaga species, Campylobacter concisus, Eikenella corrodens and Actinobacillus actinomycetemcomitans serotype a. The 5th complex consisted of Veillonella parvula and Actinomyces odontolyticus. A. actinomycetemcomitans serotype b, Selenomonas noxia and Actinomyces naeslundii genospecies 2 (A. viscosus) were outliers with little relation to each other and the 5 major complexes. The 1st complex related strikingly to clinical measures of periodontal disease particularly pocket depth and bleeding on probing.

The mucosal attachment at different abutments: an experimental study in dogs

Abstract: . The present experiment was performed to examine if the material used in the abutment part of an implant system influenced the quality of the mucosal barrier that formed following implant installation. 5 beagle dogs were included in the study. The mandibular premolars and the 1st. 2nd and 3rd maxillary premolars were extracted. Three fixtures of the Branemark System® were installed in each mandibular quadrant (a total of 6 fixtures per animal). Abutment connection was performed after 3 months of healing. In each dog the following types of abutments were used: 2 “control abutments” (c.p. titanium). 2 “ceramic abutments” (highly sintered Al2O3), 1 “gold abutment”, and 1 “short titanium abutment”. This “short titanium abutment” was provided with an outer structure made of dental porcelain fused to gold. Following abutment connection a plaque control program was initiated and maintained for 6 months. The animals were sacrificed and perfused with a fixative. The mandibles were removed and each implant region was dissected, demineralized in EDTA and embedded in EPON®. Semithin sections representing the mesial, distal, buccal and lingual aspects of the peri-implant tissues were produced and subjected to histological examination. The findings from the analysis demonstrated that the material used in the abutment portion of the implant influenced the location and the quality of the attachment that occurred between the periimplant mucosa and the implant. Abutments made of c.p. titanium or ceramic allowed the formation of a mucosal attachment which included one epithelial and one connective tissue portion that were about 2 mm and 1–1.5 mm high, respectively. At sites where abutments made of gold alloy or dental porcelain were used, no proper attachment formed at the abutment level, but the soft tissue margin receded and bone resorption occurred. The abutment fixture junction was hereby occasionally exposed and the mucosal barrier became established to the fixture portion of the implant. It was suggested that the observed differences were the result of varying adhesive properties of the materials studied or by variations in their resistance to corrosion.

Subgingival microbiota in healthy, well‐maintained elder and periodontitis subjects

Abstract: This investigation compared the site prevalence of 40 subgingival species in 30 periodontally healthy (mean age 36+/-9 years), 35 elders with a well-maintained periodontium (mean age 77+/-5) and 138 adult periodontitis subjects (mean age 46+/-11). Subgingival plaque samples were taken from the mesial aspect of each tooth (up to 28 samples) in the 203 subjects at baseline. The presence and levels of 40 subgingival taxa were determined in 5003 plaque samples using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Clinical assessments including dichotomous measures of gingival redness, bleeding on probing, plaque accumulation and suppuration, as well as duplicate measures of pocket depth and attachment level, were made at 6 sites per tooth. The % of sites colonized by each species (prevalence) was computed for each subject. Differences in prevalence and levels among groups were sought using the Kruskal-Wallis test. Commonly detected species, such as Actinomyces naeslundii genospecies 2, Streptococcus sanguis and Streptococcus oralis did not differ significantly among subject groups. After adjusting for multiple comparisons, 4 species were significantly elevated and at greater prevalence in the periodontitis group. Mean % of sites (+/-SEM) colonized by Bacteroides forsythus was 10+/-3, 12+/-2 and 40+/-2 (p or = 5% of sampled sites. Mean prevalence for Porphyromonas gingivalis in healthy, elder and periodontitis subjects was 4+/-2, 5+/-2 and 23+/-2 respectively (p<0.001); for Treponema denticola 12+/-4, 10+/-3 and 30+/-2 (p<0.001) and for Selenomonas noxia 6+/-2, 7+/-2 and 19+/-2 (p<0.01). Similar differences among subject groups were observed when only sites with PD 0-4 mm were analyzed. The data suggest an etiologic role for B. forsythus, P. gingivalis, T. denticola and S. noxia in adult periodontitis.

Microbiota of health, gingivitis, and initial periodontitis.

Abstract: This study compared the subgingival microbiota in periodontal health, gingivitis and initial periodontitis using predominant culture and a DNA probe, checkerboard hybridization method. 56 healthy adult subjects with minimal periodontal attachment loss were clinically monitored at 3-month intervals for 12 months. More sites demonstrated small increments of attachment loss than attachment gain over the monitoring period. Sites, from 17 subjects, showing > or = 1.5 mm periodontal attachment loss during monitoring were sampled as active lesions for microbial analysis. Twelve subjects demonstrated interproximal lesions, and 5 subjects had attachment loss at buccal sites (recession). Cultural studies identified Bacteroides forsythus, Campylobacter rectus, and Selenomonas noxia as the predominant species associated with active interproximal lesions (9 subjects), whereas Actinomyces naeslundii, and Streptococcus oralis, were the dominant species colonizing buccal active sites. A. naeslundii, Campylobacter gracilis, and B. forsythus (at lower levels than active sites) were the dominant species cultured from gingivitis (10 subjects). Health-associated species (10 subjects) included Streptococcus oralis, A. naeslundii, and Actinomyces gerencseriae. DNA probe data identified higher mean levels of B. forsythus and C. rectus with active (7 subjects) compared to inactive periodontitis sites. Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were detected infrequently. Cluster analysis of the cultural microbiota grouped 8/9 active interproximal lesions in one subcluster characterized by a mostly gram-negative microbiota, including B. forsythus and C. rectus. The data suggest that B. forsythus C. rectus and S. noxia were major species characterizing sites converting from periodontal health to disease. The differences in location and microbiota of interproximal and buccal active sites suggested that different mechanisms may be involved in increased attachment loss.

Relationship between smoking and dental status in 35‐, 50‐, 65‐, and 75‐year‐old individuals

Abstract: The aim of the present study was to examine the dental status and smoking habits in randomized samples of 35-, 50-, 65-, and 75-year-old subjects (n = 1093), recruited for a cross-sectional epidemiological study in the County of Varmland, Sweden. The following clinical variables were recorded by 4 well-calibrated dentists: number of edentuolous subjects, number of missing teeth, probing attachment level, furcation involvement, CPITN scores, DMF surfaces, plaque and stimulated salivary secretion rate (SSSR). In addition, the subjects reported in a questionnaire their tobacco habits, oral hygiene habits, dietary habits etc. The percentage of smokers in 35-, 50-, 65-, and 75-year-olds was 35%, 35%, 24% and 12%, respectively. In 75-year-olds, 41% of the smokers were edentulous compared to 35% of non-smokers. The difference in number of missing teeth between smokers and non-smokers was 0.6 (p=0.15), 1.5 (p=0.013), 3.5 (p=0.0007) and 5.8 (p=0.005) in the 4 age groups. Smokers had the largest mean probing attachment loss in all age groups. The differences between smokers and non-smokers in mean attachment level were 0.37 (p=0.001), 0.88 (p=0.001), 0.85 (p=0.001) and 1.33 mm (p=0.002) in the 35-, 50-, 65-, and 75-year-olds, respectively. Treatment need assessed by CPITN was in all age groups greatest among smokers. The number of intact tooth surfaces was fewer in 35-, 50-, and 75-year-old smokers than in non-smokers. The number of missing surfaces (MS) was higher in 50-, 65-, and 75-year-old smokers than in non-smokers. In addition, 35-year-old smokers exhibited a significantly larger number of decayed and filled tooth surfaces (DFS) than non-smokers. Male smokers had significantly higher SSSR than non-smoking males (p=0.012). Plaque index and oral hygiene were similar in smokers and non-smokers. Smokers reported a more frequent intake of sugar containing soft drinks (p=0.000) and snacks (p=0.003) than non-smokers. The opposite was reported for consumption of fruit (p=0.003). It was concluded that smoking is a significant risk indicator for tooth loss, probing attachment loss and dental caries.

Healing response to non‐surgical periodontal therapy in patients with diabetes mellitus: clinical, microbiological, and immunologic results

Abstract: The aim of the present study was to monitor clinical, microbiological, medical, and immunological effects of non-surgical periodontal therapy in diabetics and healthy controls. 20 IDDM (insulin dependent, n = 7) or NIDDM (non-insulin dependent, n = 13) diabetic patients (median duration 11.5 years, range of HbA1C: 4.4-10.6%) with moderate to advanced periodontal disease and 20 matched healthy control patients, were subjected to supragingival pretreatment and subsequent subgingival therapy. Periodontal examinations (API, PBI, BOP, PPD, PAL), microbiological examinations (culture), medical routine examinations, and immunological examinations (oxidative burst response of PMNs to TNF-alpha and FMLP) were performed at baseline, 2 weeks after supragingival, and 4 months after subgingival therapy. 4 months after completion of non-surgical therapy, the following compared to baseline significant (p or = 4 mm decreased from 41.9% to 28.3% in diabetics, and from 41.6% to 31.8% in controls. Microbiologically, similar reductions of periopathogenic bacteria were found in diabetics and controls. Neither periodontal data nor the oxidative burst response of PMNs showed any significant difference (p > 0.05) between diabetics and control patients. In this study, periodontal therapy had no significant influence on medical data of diabetics. In conclusion, this study indicates that metabolically well-controlled diabetics might respond to non-surgical periodontal therapy as well as healthy control patients.

Interleukin-1beta+3953 allele 2: association with disease status in adult periodontitis.

Abstract: Adult periodontitis is a complex multifactorial disease whose etiology is not well defined. The pro-inflammatory and bone resorptive properties of interleukin-1 beta (IL-1beta) strongly suggest a role for this cytokine in the pathogenesis of periodontal disease. In the study reported here, the frequency of IL-1beta genotypes including allele 2 of the IL-1beta+3953 restriction fragment length bi-allelic polymorphism was significantly increased in patients with advanced adult periodontitis compared to those with early and moderate disease. Furthermore, allele 2 was associated with increased production of IL-1beta by activated peripheral blood polymorphonuclear cells of patients with advanced disease, although this increase failed to reach statistical significance. Finally, the data obtained revealed significant linkage disequilibrium between allele 2 of the IL-1beta+3953 polymorphism and allele 2 of the bi-allelic IL-1alpha-889 polymorphism in both patients and orally healthy controls. These findings provide new insight into the possible role of IL-1alpha and beta gene polymorphisms in the susceptibility to adult periodontitis.

The effect of supragingival plaque control on the progression of advanced periodontal disease

Abstract: The aim of the present trial was to study the effect of meticulous supragingival plaque control on (i) the subgingival microbiota, and (ii) the rate of progression of attachment loss in subjects with advanced periodontal disease. An intra-individual group of sites exposed to non-surgical periodontal therapy served as controls. 12 patients with advanced periodontal disease were subjected to a baseline examination (BL) including assessments of oral hygiene status, gingival condition (BoP), probing depth, clinical attachment level and subgingival microbiota from pooled samples from each quadrant. The assessments were repeated after 12, 24 and 36 months. Following BL, a split mouth study was initiated. The patients received oral hygiene instruction, supragingival scaling and case presentation. 2 quadrants in each patient were identified as "test" and the remaining 2 as "control" quadrants. Subgingival therapy was performed in all bleeding sites in the control quadrants. Oral hygiene instructions and plaque control exercises were repeated once every 2 weeks during the initial 3 months of the study. Thereafter the plaque control program was repeated once every 3 months for the duration of the 3 years. Sites demonstrating loss of clinical attachment > or =2 mm in the test quadrants were treated subgingivally. The results showed that in both test and control quadrants repeated oral hygiene instructions and supragingival plaque removal procedures resulted in low plaque scores throughout the study. The gingival bleeding scores and the frequency of periodontal pockets > or =4 mm was, however, significantly higher in the test quadrants than in the control quadrants. At the end of the 3 year study, the control quadrants showed significantly more reduced (> or =2 mm) pockets than the test quadrants, 265 versus 96. The number of sites in the test quadrants showing probing attachment loss > or =2 mm was more than 4x greater than in the control quadrants (59 versus 13). The microbiological findings indicate a more pronounced reduction only for P. gingivalis in the control quadrants. None of the other 4 marker bacteria consistently reflected or predicted the clinical parameters. The present study shows that only supragingival plaque control fails to prevent further periodontal tissue destruction in subjects with advanced periodontal disease.

Clinical and microbiological features of refractory periodontitis subjects

Abstract: The purpose of this investigation was to compare the clinical parameters and the site prevalence and levels of 40 subgingival species in successfully treated and refractory periodontitis subjects. 94 subjects received scaling and root planing and if needed, periodontal surgery and systemically administered tetracycline. 28 refractory subjects showed mean full mouth attachment loss and/or > 3 sites showing attachment loss > 2.5 mm within 1 year post-therapy. 66 successfully treated subjects showed mean attachment level gain and no sites with attachment loss > 2.5 mm. Baseline subgingival plaque samples were taken from the mesial aspect of each tooth and the presence and levels of 40 subgingival taxa were determined using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The mean levels and % of sites colonized by each species (prevalence) was computed for each subject and differences between groups sought using the Mann-Whitney test. Most of the 40 species tested, including Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Bacteroides forsythus, were equally or less prevalent in the refractory group. Prevotella nigrescens was significantly more prevalent in successfully treated subjects, while refractory subjects harbored a larger proportion of Streptococcus species, particularly Streptococcus constellatus. The odds of a subject being refractory was 8.6 (p or = 3.5% of the total DNA probe count. Since few microbiological differences existed between treatment outcome groups using DNA probes to known species, the predominant cultivable microbiota of 33 subgingival samples from 14 refractory subjects was examined. 85% of the 1649 isolates were identified using probes to 69 recognized subgingival species. The remaining unidentified strains were classified by analyzing 16S rRNA gene sequences. Many sequenced isolates were of taxa not considered a common part of the oral microbiota such as Acinetobacter baumanni, Gemella haemolysans, Enterococcus faecalis, Staphylococcus warneri, Pseudomonas aeruginosa and novel species in the genera Bartonella, Ralstonia, Neisseria, Eubacterium, Rothia, Gordona, Gemella, Corynebacterium, Leptotrichia, and Actinomyces. Refractory subjects constituted a heterogeneous group based on their subgingival microbiota. As a group, they did not harbor more of the "classic" periodontopathogens, although elevated proportions of S. constellatus were found.

The use of metronidazole and amoxicillin in the treatment of advanced periodontal disease. A prospective, controlled clinical trial.

Abstract: The present clinical trial was performed to study the effect of systemic administration of metronidazole and amoxicillin as an adjunct to mechanical therapy in patients with advanced periodontal disease. 16 individuals, 10 female and 6 male, aged 35-58 years, with advanced periodontal disease were recruited. A baseline examination included assessment of clinical, radiographical, microbiological and histopathological characteristics of periodontal disease. The 16 patients were randomly distributed into 2 different samples of 8 subjects each. One sample of subjects received during the first 2 weeks of active periodontal therapy, antibiotics administered via the systemic route (metronidazole and amoxicillin). During the corresponding period, the 2nd sample of subjects received a placebo drug (placebo sample). In each of the 16 patients, 2 quadrants (1 in the maxilla and 1 in the mandible) were exposed to non-surgical subgingival scaling and root planing. The contralateral quadrants were left without subgingival instrumentation. Thus, 4 different treatment groups were formed; group 1: antibiotic therapy but no scaling, group 2: antibiotic therapy plus scaling, group 3: placebo therapy but no scaling, group 4: placebo therapy plus scaling. Re-examinations regarding the clinical parameters were performed, samples of the subgingival microbiota harvested and 1 soft tissue biopsy from 1 scaled and 1 non-scaled quadrant obtained 2 months and 12 months after the completion of active therapy. The teeth included in groups 1 and 3 were following the 12-month examination exposed to non-surgical periodontal therapy, and subsequently exited from the study. Groups 2 and 4 were also re-examined 24 months after baseline. The findings demonstrated that in patients with advanced periodontal disease, systemic administration of metronidazole plus amoxicillin resulted in (i) an improvement of the periodontal conditions, (ii) elimination/suppression of putative periodontal pathogens such as A. actinomycetemcomitans, P. gingivalis, P. intermedia and (iii) reduction of the size of the inflammatory lesion. The antibiotic regimen alone, however, was less effective than mechanical therapy with respect to reduction of BoP - positive sites, probing pocket depth reduction, probing attachment gain. The combined mechanical and systemic antibiotic therapy (group 2) was more effective than mechanical therapy alone in terms of improvement of clinical and microbiological features of periodontal disease.

Gingival dimensions after root coverage with free connective tissue grafts.

Abstract: Traumatic injury in the presence of a thin and narrow zone of gingival tissue may lead to gingival recession. Especially in class I and II recessions, root coverage may be accomplished with connective tissue grafts. In order to prevent recurrent recession, altering gingival dimensions width and thickness might be of advantage. In the present study, dimensions of gingiva were followed for 1 year after root coverage with connective tissue grafts. The study population consisted of 18 patients with a total of 28 class I or II recessions. Gingival width and depth of the recession were measured with a caliper, and thickness of the marginal tissue with an ultrasonic device. Periodontal probing depth was determined with a pressure-controlled electronic probe. Mean (+/-sd) recession depth at baseline was 3.1+/-1.4 mm. After 12 months, coverage amounted to 74+/-30%. Width of gingiva rose from 2.1+/-1.0 mm to 3.2+/-1.4 mm, whereas thickness was increased from 0.8+/-0.3 mm to 1.5+/-0.7 mm, on average. No significant alteration of periodontal probing depth was observed but a mean gain of clinical attachment of 1.7+/-1.1 mm was ascertained. In a multiple regression analysis, recession depth and presence of the recession in the maxilla, but not tooth type significantly influenced relative root coverage (R2=0.34, p<0.01). Attachment gain after surgery depended on baseline attachment loss and was negatively influenced by smoking. The present results point to the possibility of doubling gingival thickness after root coverage with connective tissue grafts.

The clinical and microbiological effects of non‐surgical periodontal therapy in smokers and non‐smokers

Abstract: 28 patients, 13 smokers and 15 non-smokers with untreated advanced periodontal disease, were subjected to a series of oral hygiene instructions and treated with non-surgical periodontal therapy. Baseline values regarding clinical data did not differ significantly between the groups. 6 months following therapy the full-mouth bleeding score among smokers was 36.5% as compared to 22.7% for non-smokers (p < 0.05). Probing depth was reduced by 1.9 mm for smokers and by 2.5 mm for non-smokers. This difference was statistically significant (p < 0.05). The level of P. gingivalis and P. intermedia/nigrescens was reduced in both groups as compared to baseline. A. actinonmycetemcomitans, however demonstrated a slight increase in mean values at 6 months. This was especially notable for smokers in which A. actinomycetemcomitans were more difficult to eradicate. Conclusively, the microbiological response found in this study seems to be in conformity with the clinical response with little influence of the smoking habits.

The effect of a one‐stage full‐mouth disinfection on different intra‐oral niches Clinical and microbiological observations

Abstract: A treatment for periodontal infections often consists of consecutive rootplanings (per quadrant, at a 1- to 2-week interval), without a proper disinfection of the remaining intra-oral niches (untreated pockets, tongue, saliva, mucosa and tonsils). Such an approach, could theoretically lead to a reinfection of previously-treated pockets. The present study aims to examine the effect of a full-mouth disinfection on the microbiota in the above-mentioned niches. Moreover, the clinical benefit of such an approach was investigated. 16 patients with severe periodontitis were randomly allocated to a test and a control group. The patients from the control group were scaled and rootplaned, per quadrant, at 2-week intervals and obtained oral hygiene instructions. The patients from the test group received a full-mouth disinfection consisting of: scaling and rootplaning of all pockets in 2 visits within 24 h, in combination with tongue brushing with 1% chlorhexidine gel for 1 min, mouth rinsing with a 0.2% chlorhexidine solution for 2 min and subgingival irrigation of all pockets (3x in 10 min) with 1% chlorhexidine gel. Besides oral hygiene, the test group rinsed 2x daily with 0.2% chlorhexidine and sprayed the tonsils with a 0.2% chlorhexidine for 2 months. Plaque samples (pockets, tongue, mucosa and saliva) were taken at baseline and after 2 and 4 months, and changes in probing depth, attachment level and bleeding on probing were reported. The full-mouth disinfection resulted in a statistically significant additional reduction/elimination of periodontopathogens, especially in the subgingival pockets, but also in the other niches. These microbiological improvements were reflected in a statistically-significant higher probing depth reduction and attachment gain in the test patients. These findings suggest that a disinfection of all intra-oral niches within a short time span leads to significant clinical and microbiological improvements for up to 4 months.

The effect of working parameters on root substance removal using a piezoelectric ultrasonic scaler in vitro.

Abstract: This study assessed defect depth and volume resulting from root instrumentation using a piezoelectric ultrasonic scaler with a slim scaling tip in vitro. Combinations of the following working parameters were analyzed: lateral forces of 0.5 N, 1 N, and 2 N; tip angulations of 0 degrees, 45 degrees, and 90 degrees; power settings of low, medium and high; and instrumentation time of 10 s, 20 s, 40 s, and 80 s. Defects were quantified using a 3D optical laser scanner. Overall, lateral force had the greatest influence on defect volume compared to instrument power setting and tip angulation (beta-weights 0.49 +/- 0.04, 0.25 +/- 0.04, and 0.14 +/- 0.04, respectively). The effects on defect depth were highest for tip angulation followed by lateral force and instrument power setting (beta-weights 0.48 +/- 0.04, 0.34 +/- 0.04, and 0.25 +/- 0.04, respectively). Interestingly, at all power settings, the highest defect volume and depth by far were found after combining 45 degrees tip angulation with 2 N of lateral force. The efficacy of the assessed piezoelectric ultrasonic scaler may be adapted to the various clinical needs by adjusting the lateral force, tip angulation, and power setting. To prevent severe root damage it is crucial to use the assessed scaler at a tip angulation of close to 0 degrees.

Treatment of deep and shallow intrabony defects. A multicenter randomized controlled clinical trial.

Abstract: This prospective multicenter intra-individual randomized controlled clinical trial was designed to compare the efficacy of guided tissue regeneration (GTR) with bioresorbable barrier membranes versus access flap surgery, in intrabony defects. 2 similar defects were selected in each of 23 patients and randomly assigned to 1 of the 2 treatments. Surgery consisted of an identical procedure except for the omission of the barrier membrane in the flap control sites. At 1-year, probing pocket depth reductions were 4.3+/-2.3 mm in GTR treated sites and 3.0+/-1.5 mm in the flap control sites (p=0.02, paired t-test). Clinical attachment level (CAL) gains were 3.0+/-1.7 mm in the GTR sites and 1.6+/-1.8 mm in the control sites (p=0.009, paired t-test). A subset analysis, performed according to the initial depth of the intrabony component of the defects (INFRA), indicated that in shallow defects (INFRA or =4 mm) they were consistently greater (1.9+/-1.9 mm). The % CAL gains, calculated as the % of the baseline intrabony component depth, however, were almost identical in the 2 subpopulations (45.8+/-64.7% in shallow and 43.8+/-37.6% in deep defects). Similarly, in the GTR sites, linear CAL gains were greater in deep (3.7+/-1.7 mm) than in shallow defects (2.2+/-1.3 mm), but no differences were observed in terms of % CAL gains (76.7+/-27.7% and 75.8+/-45%, respectively). The frequency distribution of CAL changes expressed as %s of the baseline INFRA indicates that most of the sites treated with GTR (73% in shallow and 92% in deep defects) gained 50% or more CAL. Furthermore, many defects (64% of shallow and 33% of deep defects) reached 100% of CAL gain. The present study demonstrated that: (i) GTR with bioresorbable barrier membranes resulted in a significant added benefit in comparison with access flap alone; (ii) the linear amounts of CAL gains were greater in deep than in shallow defects; (iii) CAL gains expressed as %s of the baseline depths of the intrabony component, were similar in shallow and deep defects; (iii) the regenerative procedure tested in the present study resulted in CAL gains equal to the depth of the intrabony component of the defect in some, but not in most of the instances.

Risk of severe periodontal disease in a Swedish adult population. A cross-sectional study

Abstract: In this study, potential risk factors for severe periodontal disease were identified in a cross-sectional sample from the county of Jonkoping, Sweden. 547 adults 20-70 years of age were categorised clinically and radiographically by level of periodontal disease experience. These levels were used to divide the sample into groups--individuals without any reduction in periodontal bone level (60%) and those with severe periodontal bone loss (13%)--which were then used in univariate and multivariate logistic regression analyses as dependent variable. Demographic, socio-economic, general health, smoking habits, clinical, and dental care variables were used in the different regression analyses. In the univariate model, age (20-70 years) was found to be correlated with more severe periodontal disease experience (odds ratio: 1.13; 95% CI: 1.10-1.17). The association with periodontal disease was more pronounced for the older age groups (50, 60, and 70 years). A negative financial situation was also related to severe periodontal bone loss when regressed univariately (odds ratio 2.20 [95%: 1.04-4.68]). Moderate-heavy smoking (> or =10 cigarettes/day) appeared to be associated with severe periodontal destruction with an odds ratio of 9.78 (95% CI: 3.62-36.42). Of the clinical variables in the univariate model, higher mean levels of supragingival dental plaque and the presence of subgingival calculus were related to more severe periodontal disease with odds ratios of 1.02 (95%: 1.01-1.03) and 2.96 (95%: 1.50-5.88), respectively. When the same variables were regressed multivariately, age (continuous) (odds ratio 1.17 [95% CI: 1.12-1.22]), moderate-heavy smoking (odds ratio 11.84 [95% CI: 4.19-33.50]), and higher mean levels of plaque (odds ratio 1.02 [95% CI: 1.00-1.03]) remained significant. Light smoking (1-9 cigarettes/day) was not significantly associated with severe periodontal disease in the 2 regression models. The present study demonstrated that smoking, greater age, and higher mean levels of plaque are potential risk factors for severe periodontal disease in this specific population.

Clinical expression of TNF-alpha in smoking-associated periodontal disease.

Abstract: . The level of TNF-α in gingival crevicular fluid (GCF) was analyzed with respect to smoking in patients with untreated moderate to severe periodontal disease including 30 current smokers, 19 former smokers and 29 non-smokers, in the age range 31–79 years, Concomitantly the occurrence of the periopathogens Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Prevotella intermedia (Pi) and the GCF levels of albumin, IgA and IgG were analyzed. With regard to clinical characteristics, there were no statistically significant differences between smoking groups. The occurrence of patients positive for the periopathogens Aa, Pg and Pi was 28.2%, 41.0% and 91.0%, respectively. There were no statistically significant differences between smoking groups with regard to occurrence or relative frequency of these periopathogens. An exception was a significantly lower occurrence of Aa in former smokers as compared to non-smokers. The chief novelty of the study was the observation of a clearly increased level of TNF-α in GCF associated with smoking. Both current and former smokers exhibited significantly higher levels of TNF-α in comparison to non-smokers, whereas the levels of albumin, IgA and IgG were the same irrespective of smoking. In conclusion, the present observations in patients with moderate to severe periodontal disease suggest that smoking is associated with elevated GCF levels of the cytokine TNF-α.

Long-term effects of root-resective therapy in furcation-involved molars. A 10-year longitudinal study.

Abstract: The present investigation was designed to evaluate the long-term effect of root-resective therapy in the treatment of furcation-involved molars. The patient sample included 72 patients, 21-62 years of age, who presented periodontal lesions in the posteriors segments of the mouth including furcation involvement of various degrees. After an initial examination, each patient was subjected to a series of full-mouth scaling and root planing. They were recalled 1-3 months later for a presurgical examination and subsequently underwent the corrective phase of therapy. During the surgical procedure, the furcation-involved teeth were subjected to root-resective therapy in conjunction with osseous recontouring and apically positioned flaps (test sites). A surgical procedure identical to the test procedure was performed in the non-furcation-involved teeth (control sites) with the exception of the root resection. At the completion of the active phase of treatment, 175 test and 175 control sites were available for the study. After a period of 6 months of healing and plaque control supervision following surgical procedures, the patients were recalled for a baseline examination. They were then enrolled in a maintenance program including professional tooth cleaning every 26 months. The patients were re-examined 3, 5 and 10 years post-operatively. The results of the assessments demonstrated that the survival rate, during the 10-year period of observation, reached 93% at test and 99% at control sites. The positive treatment outcome at the root-resected, furcation-involved teeth as well as at non-furcation-involved teeth was probably the consequence of the reestablishment of a tissue morphology favorable for oral hygiene and careful plaque control by the patients.

Distribution of periodontal disease in a Swedish adult population 1973, 1983 and 1993

Abstract: The aim of this study was to compare changes in periodontal status in a Swedish population over a period of 20 years. Cross-sectional studies were carried out in Jonkoping County in 1973, 1983, and 1993. Individuals were randomly selected from the following age groups: 20, 30, 40, 50, 60, and 70 years. A total of 600 individuals were examined in 1973, 597 in 1983, and 584 in 1993. The number of dentate individuals was 537 in 1973, 550 in 1983, and 552 in 1993. Based on clinical data and full mouth intra-oral radiographs, all individuals were classified into 5 groups according to the severity of the periodontal disease experience. Individuals were classified as having a healthy periodontium (group 1), gingivitis without signs of alveolar bone loss (group 2), moderate alveolar bone loss not exceeding 1/3 of the normal alveolar bone height (group 3), severe alveolar bone loss ranging between 1/3 and 2/3 of the normal alveolar bone height (group 4), or alveolar bone loss exceeding 2/3 of the normal bone height and angular bony defects and/or furcation defects (group 5). During these 20 years, the number of individuals in groups 1 and 2 increased from 49% in 1973 to 60% in 1993. In addition, there was a decrease in the number of individuals in group 3, the group with moderate periodontal bone loss. Groups 4 and 5 comprised 13% of the population and showed no change in general between 1983 and 1993. The individuals comprising these groups in 1993, however, had more teeth than those who comprised these groups in 1983; on the average, the individuals in disease group 4 had 4 more teeth and those in disease group 5, 2 more teeth per subject. In 1973, these 2 groups were considerably smaller, probably because of wider indications for tooth extractions and fewer possibilities for periodontal care which meant that many of these individuals had become edentulous and were not placed in a group. Individuals in groups 3, 4, and 5 were subdivided according to the number of surfaces (%) with gingivitis and periodontal pockets (> or =4 mm). In 1993, 20%, 42%. and 67% of the individuals in groups 3, 4, and 5 respectively were classified as diseased and in need of periodontal therapy with >20% bleeding sites and >10% sites with periodontal pockets > or =4 mm. In conclusion, an increase in the number of individuals with no marginal bone loss and a decrease in the number of individuals with moderate alveolar bone loss can be seen. The prevalence of individuals in the severe periodontal disease groups (4, 5) was unchanged during the last 10 years; however, the number of teeth per subject increased.

Evaluation of 2 methods to assess gingival bleeding in smokers and non-smokers in natural and experimental gingivitis

Abstract: The purpose of the present study was to compare the bleeding tendency as elicited by probing the marginal gingiva (BOMP) and probing to the bottom of the pocket (BOPP) in smokers and non-smokers in natural gingivitis and during experimental gingivitis. 11 smokers (sm) and 14 non-smokers (nsm) were recruited. When they had less than 20% approximal bleeding sites, they entered a 14-day trial period of 'experimental gingivitis'. Subjects returned 30 days later, after resuming normal oral hygiene procedures, for a final gingival assessment. A split-mouth design was chosen using 2 contra-lateral quadrants for each index (being either BOMP or BOPP). A consistently higher bleeding score of approximately 10% was observed by probing to the bottom of the pocket. At day 14 with both indices, a significant difference between smokers and non-smokers was detected (BOMP: sm=15%, nsm=30%; BOPP: sm=27%, nsm=44%). The increment between gingival health and experimental gingivitis was significantly higher in non-smokers than in smokers but comparable for both indices (BOMP: sm=8%, nsm=23%; BOPP: sm=9%, nsm=26%). Probing to the bottom of the pocket results in significantly more bleeding in gingival health and gingivitis as compared to probing of the marginal gingiva. This shows that evaluation of the gingival condition with BOMP, the method of choice with respect to gingivitis, can be used as a parameter for inflammation when comparing smokers and non-smokers. The suppressed inflammatory response to plaque accumulation, as observed in smokers, indicates that they should be identified as a separate group when they participate as panelists in (experimentally induced) gingivitis studies.

Differential clinical treatment outcome after systemic metronidazole and amoxicillin in patients harboring Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis

Abstract: . 48 adult patients with untreated periodontitis harboring subgingival Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis as assessed by PCR were randomly assigned to receive full-mouth sealing alone (control) or scaling with systemic metronidazole plus amoxicillin and supragingival irrigation with chlorhexidine digluconate (test). In patients harboring A. actinomycetemcomitans intraorally at baseline, the adjunctive antimicrobial therapy resulted in a significantly higher incidence of probing attachment level (PAL) gain of 2 mm or more compared to scaling alone over 12 months (P< 0.05). In addition, suppression of A. actinomycetemcomitans in subgingival plaque below delectable levels was associated with an increased incidence of PAL gain. In contrast, patients initially harboring P. gingivalis but not A. actinomycetemcomitans in the oral cavity showed a significantly higher incidence of PAL loss following adjunctive antimicrobial therapy compared to scaling alone (P<0.05). When the presence of pathogens at baseline was disregarded in the analysis, adjunctive antimicrobial therapy did not significantly enhance clinical treatment outcome. The results indicated that adults with untreated periodontitis harboring A. actinomycetemcomitans may benefit from the adjunctive antimicrobial therapy for a minimum of 12 months, whereas, the regimen may adversely affect the clinical treatment outcome of patients harboring P. gingivalis but not A. actinomycetemcomitans.

Lifestyle, gender and occupational status as determinants of dental health behavior.

Abstract: The aim was to compare how general lifestyle, gender and occupational status determine dental health behavior. All the 1012 55-year-old citizens of Oulu (a medium-sized Finnish town) were invited to participate in this study. 780 of them did so. Information about frequency of toothbrushing, use of extra cleaning methods, use of sugar in coffee or tea, and time of the last dental visit, lifestyle, occupational status and gender was gathered from the 533 dentate subjects. Lifestyle was measured by means of questions about physical activity, tobacco smoking, alcohol consumption and dietary habits. Females and people with a healthy lifestyle brushed their teeth more often. Extra cleaning methods were used more often by people with a healthy lifestyle, whereas gender and occupational status had a weaker association. Males and people with a lower occupational status used sugar in coffee or tea more often. The time from the last dental visit was longer among workers and men; lifestyle had no significant association. At the population level oral cleaning habits are a matter of a health-oriented lifestyle and gender-related behavior. The dental visiting habit has a weaker association with general lifestyle.

Changes in the prevalence of residual pockets and tooth loss in treated periodontal patients during a supportive maintenance care program

Abstract: Bleeding on probing and the presence of deep periodontal pockets are considered to be the best site-specific indicators for periodontal disease progression during the maintenance phase of periodontal therapy. A major emphasis of supportive periodontal care (SPC) programs, therefore, has been the control of bleeding pockets. This investigation retrospectively evaluated the changes in the prevalence of bleeding on probing, periodontal pockets, bleeding periodontal pockets and the prevalence of tooth loss in a random sample of 273 periodontal patients participating in a supportive maintenance care program at a University Clinic. During an observation period of 67+/-46 months (range 5 months to 23 years), the overall incidence of all causes of tooth mortality was 0.23+/-0.49 teeth per patient per year of observation. 56% of subjects, however, did not experience any tooth loss, while less than 10% of patients lost more than 3 teeth. Thus, participation in the SPC program was effective in preventing tooth loss in the majority of patients. During the SPC period, however, a significant increase in the prevalence of periodontal pockets, and of bleeding on probing positive periodontal pockets, in particular, was observed. At completion of active periodontal therapy, 56.4% of patients were free from bleeding pockets. This decreased to a mere 13.6% at the latest SPC evaluation. The observed increases in the number of bleeding pockets was significantly associated with: longer times since completion of active periodontal therapy, more advanced periodontal diagnosis, higher %s of bleeding sites in the dentition, cigarette smoking, lack of inclusion of periodontal surgery in the active treatment phase, tooth loss, and the response to the active phase of periodontal treatment. The data presented in the paper indicate that the observed increase in the prevalence of bleeding pockets and tooth loss was not homogeneously distributed in the studied SPC population. Rather, high risk groups of individuals could be identified. It is suggested that better knowledge of risk indicators may lead to improved and more efficient risk management efforts during periodontal maintenance care.

Influence of smoking on the outcome of periodontal surgery. A 5-year follow-up

Abstract: The 5-year outcome following periodontal surgery was evaluated in 57 patients that had received regular maintenance care throughout the follow-up period. The study population included 20 smokers, 20 former smokers and 17 non-smokers in the age range 37-77 years. The clinical characteristics evaluated were supragingival plaque, gingival bleeding and pocket probing depth. The region assigned for surgery was, in addition, radiographically evaluated in terms of periodontal bone height. Furthermore, the occurrence of the periopathogens Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Prevotella intermedia (Pi) and the gingival crevicular fluid (GCF) levels of tumor necrosis factor alpha (TNF-alpha) were assessed at follow-up. Plaque index was 28.5% at baseline and 32.9% at follow-up, indicating a good standard of oral hygiene, and gingival bleeding 31.7% and 24.9%, respectively, suggesting a low to moderate level of gingival inflammation. In regions assigned for surgery, pocket probing depth decreased significantly from on average 5.6 mm to 4.3 mm (p<0.0001) and periodontal bone height increased significantly from on average 62.5% to 67.5% (p<0.0001). In terms of bone height, the outcome was less favorable among smokers compared with non-smokers. There was a predominance of smokers among patients exhibiting loss of bone height after the 5 years of maintenance. No significant associations were found between the therapeutical outcome and supragingival plaque or subgingival occurrence of periopathogens. The associations between GCF levels of TNF-alpha and probing depth and bone height were unclear, whereas the level of TNF-alpha was significantly elevated in smokers.

Gingival inflammation and subgingival calculus as determinants of disease progression in early‐onset periodontitis

Abstract: This study was undertaken to test the hypothesis that gingival inflammation and dental calculus are important determinants of the development and progression of early-onset periodontitis. The study sample included 156 individuals who were 13-20 years old at baseline and who were examined 2x during 6 years to assess the attachment loss, gingival state and the presence of dental calculus. 33 (21%), 62 (40%), and 61 (39%) individuals were classified as having localized, generalized, or incidental EOP, respectively. The results showed an increase in the % of teeth with overt gingivitis and subgingival calculus, and also an increase in the % of teeth showing attachment loss during the 6-year period in all classification groups. Of teeth with 0-2 mm attachment loss at the beginning of the study and which developed > or = 3 mm attachment loss during the following 6 years, there were 2x as many teeth with overt gingival inflammation, and 4x more teeth with subgingival calculus at baseline than teeth without. Gingivitis and subgingival calculus when present at both examinations resulted in a stronger association with the development of new lesions than presence of these variables at baseline. Teeth with gingivitis at baseline had a significantly higher mean attachment loss during 6 years than teeth without gingivitis (p<0.0001), and teeth with subgingival calculus at baseline had a significantly higher mean attachment loss than teeth without subgingival calculus (p<0.0001). The presence of gingivitis and subgingival calculus at baseline and 6 years later was associated with the occurrence of even higher disease progression during this period. The association between gingival inflammation and subgingival calculus and the development and progression of attachment loss during the study period in the generalized and the localized EOP groups was significantly higher than the association in the incidental EOP group. In an appreciable % of the sites in all 3 groups, however, the presence of the 2 factors was not associated with attachment loss during 6 years. The results suggest a significant association between gingival inflammation and subgingival calculus and the development and progression of early-onset periodontitis.

Relationship between the plaque removal efficacy of a manual toothbrush and brushing force

Abstract: This survey investigated the association between the efficacy of plaque removal and toothbrushing forces during a normal brushing regime. The 94 subjects participating in this study were requested not to brush 24 h prior to the experiment. Panelists brushed for 1 min with a manual toothbrush. Before and after brushing, plaque was assessed using the Turesky modification of the Quigley & Hein plaque index. A second 1-min exercise of brushing was carried out to assess the toothbrushing force. The mean plaque reduction was 39%, with vestibular surfaces being cleaned most effective (69%) and the lingual surfaces the least (21%). The mean brushing force was 330 g. No correlation was observed between efficacy and brushing force (r=0.14, p=0.16). The relationship between pre- and post-brushing plaque was stronger (r=0.68, p<0.001). Multiple regression analysis entering squared values of force as an independent variable into the equation, indicated that the relation between efficacy and force was not linear. A curve could be fitted to the plot (p=0.0004), demonstrating that up to a certain level of force, an increase of force is associated with an increase in efficacy (r=0.33, p<0.01). Beyond this point, application of higher forces resulted in reduced efficacy (r=-0.49, p=0.03). As was calculated in this particular test this 'transition' level of force was 407.4 g. The absence of a correlation between brushing force and plaque removal efficacy suggests that in a 'user model' brushing situation, other factors than brushing force are of major influence on the amount of plaque removed.

Hyper-reactive peripheral neutrophils in adult periodontitis: generation of chemiluminescence and intracellular hydrogen peroxide after in vitro priming and FcgammaR-stimulation.

Abstract: . We have earlier reported a higher Fcγ-receptor (FcγR)-mediated generation of reactive oxygen species, measured as luminol-enhanced chemiluminescence (CL) from peripheral neutrophils in adult periodontitis patients. The aims of this study were to confirm our previous results and lo elucidate the mechanism of this phenomenon by measuring CL in parallel with the intracellular production of hydrogen peroxide, after stimulation with opsonized bacteria. To determine whether the higher CL was associated with altered responsiveness to priming, the cells were preincubated with tumor necrosis factor α (TNFα) and lipopolysaccharide (LPS). While CL was significantly higher in subjects with periodontitis, there was no difference in hydrogen peroxide production between the patients and the controls, indicating that the hyperreactivity is related to the generation of other oxygen species than H2O2 and/or to processes in the outer cell membrane. The responsiveness to priming with LPS on CL was slightly but not significantly higher in the periodontitis group, suggesting that priming could be of value for distinguishing subjects with periodontitis. When assaying intracellular production of H2O2, TNFα and LPS had both a priming and an activating effect. There were no significant differences between the two groups. In conclusion, this study shows a higher FcγR-mediated CL of peripheral neutrophils from adult patients with periodontitis, thus confirming our earlier results. The hyperreactivity seems to be related to the outer cell membrane or to oxygen species other than H2O2.

GTR treatment of degree III furcation defects following application of enamel matrix proteins. An experimental study in dogs.

Abstract: The aim of the present study was to evaluate the effect of enamel matrix proteins (EMD) on periodontal wound healing in degree III furcation defects in dogs. The experiment was performed in 5 foxhound dogs. 2 months prior to the start of the experiment, the 2nd and 4th lower premolars were extracted. Degree III furcation defects were created in the 3rd mandibular premolars (3P3). The furcation defects were subsequently exposed to reconstructive surgery. Buccal and lingual full thickness flaps were elevated in the lower premolar regions. The exposed root surfaces of the experimental teeth were planed. A notch was placed in the roots at the base of the defect. In one side of the mandible (Test group), phosphoric acid gel was applied over the root surfaces for 15 s. The acid was removed by flushing the root surfaces with sterile saline. Subsequently, a gel of EMD was applied to cover all instrumented root surfaces. Following gel application, a resorbable barrier membrane was adjusted to cover the buccal and lingual entrances of the furcation defect. The flaps were repositioned to cover the barrier and sutured. The contralateral premolar (Control group) received the same treatment, but acid etching was not performed and EMD was not applied prior to barrier installation. 4 months after reconstructive surgery, the animals were sacrificed and biopsies from the 3P3 regions harvested. The biopsies were placed in a fixative, demineralized in EDTA, dehydrated and embedded in paraffin. 3 mesiodistal sections, representing the central portion of the furcation site, were selected for histological analysis of the defect. The furcation defects of both the Test and Control groups were clinically closed and were found to harbor bone and periodontal ligament tissue which appeared to be in structural continuity with a newly formed root cementum. The relative amounts of mineralized bone, bone marrow and periodontal ligament tissue that had formed were similar in the Test and the Control group. In the Test group, however, the cementum that had formed in the apical portion of the furcation defect was different from the corresponding tissue in the coronal portion, and also different from the cementum observed in the Control group. In the apical portion of the test defect a thin (12 microm) acellular cementum had been laid down, while in the coronal portion a thick (32 microm) cellular cementum, similar to the cementum found in the Control group, could be observed. The current observation, hence, seems to confirm that EMD when applied onto an instrumented and acid etched dentine surface may create an environment conducive for the formation of acellular cementum.

Psychosocial factors, dental plaque levels and smoking in periodontitis patients

Abstract: Psychological disturbances may lead patients to neglect oral hygiene. This study investigated whether a number of psychosocial factors (depression, state and trait anxiety, total and average perceived stress, and loneliness) could predict dental plaque levels in patients with adult onset rapidly progressive periodontitis (RPP) and routine chronic adult periodontitis (RCAP), before periodontal treatment. It was also examined whether RPP and RCAP patients differed on plaque and smoking. Plaque was scored in a sample of 6 teeth in each of 80 subjects, 40 with RPP, 40 with RCAP, before psychosocial questionnaire completion. Multiple regression was performed between plaque as the dependent and psychosocial factors, gender, education, form of periodontitis and smoking as independent variables. Only gender contributed significantly to prediction of plaque, t=-2.70, p=0.01, partial regression coefficient -0.37, 95% CI: -0.64 to -0.10, indicating that plaque was on average 0.37 lower for females than males, after adjusting for the other predictor variables. It was confirmed that RPP and RCAP patients did not differ significantly on plaque, univariate t-test(69.99)= 0.65, p=0.13. However, RPP patients smoked significantly more than RCAP patients t(69.72)=2.36, p=0.02. There was also a marginally significant correlation between depression and smoking, r=0.16, p=0.07. One possible reason advanced for the lack of an association between psychosocial factors and plaque, and the absence of a difference in plaque between RPP and RCAP patients is the fact that the patients involved in the present study were seen as secondary referrals. The gender difference in plaque levels and the greater incidence of smoking in RPP patients may be of significance in planning interventions with patients with periodontitis.

Evaluation of the incidence of gingival abrasion as a result of toothbrushing.

Abstract: The aims of the present study were: (1) to establish the incidence of gingival abrasion as a result of toothbrushing, using a manual and electric toothbrush; (2) to establish the influence of filament end-rounding on the incidence of gingival abrasion and the efficacy of toothbrushing; (3) to assess whether the speed of the electric brush has a feedback-effect on the brushing force used and to correlate the incidence of gingival abrasion with force. 2 experiments were carried out. In the first experiment, 50 subjects brushed for 3 weeks every other day with either a manual (Butler 411) or an electric toothbrush (Braun/Oral-B Ultra Plaque Remover-D9). All received brief instructions and were asked to abstain from oral hygiene 24 hrs before their appointment. After disclosing the teeth and gums with Mira-2-Tone solution, plaque and gingival abrasion were assessed. Next, the panelists brushed in a random split-mouth order. After brushing and a second disclosing, plaque and abrasion were re-assessed. The results showed that the incidence of gingival abrasion was comparable for the manual and the D9. Using a similar design as in experiment no. 1, in experiment no. 2 a new group of 47 subjects brushed for 3 weeks alternating between the Braun/Oral-B Plaque Remover-D7 and D9. At the appointment, the subjects first brushed in a split-mouth order with the D9 with 2 different types of endrounding. Plaque and abrasion were assessed. Immediately following this brushing exercise, the subjects re-brushed with the D7 (2800 rot/min) and the D9 (3600 rot/min) during which brushing force was measured. The results of this experiment showed that endrounding has no effect on plaque removal but does effect the incidence of gingival abrasion. Brushing force is not influenced by the speed of the brushhead and no correlation with the incidence of gingival abrasion was observed. In conclusion, the results of this study show that gingival abrasion is not influenced by brushing force, but is affected by filament endrounding.