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

AIM: The aims of this study were to validate a randomized, split-mouth, localized experimental gingivitis model and to identify subjects with different gingivitis susceptibility. MATERIAL AND METHODS: In each of 96 healthy subjects, one maxillary quadrant was randomly assigned as "test" (experimental gingivitis) and the contralateral quadrant as "control". Plaque index (PlI), gingival index (GI), gingival crevicular fluid volume (GCF), and angulated bleeding score (AngBS) were recorded in both quadrants at days 0, 7, 14, and 21. Cumulative plaque exposure (CPE), i.e. PlI over time, was calculated. Day-21 GCF was standardized according to CPE, and residuals of GCF on CPE were calculated. Two subpopulations were then defined, based on upper and lower quartiles of GCF-residual distribution and were, respectively, identified as "high-responder" (HR; n=24) and "low-responder" (LR; n=24). RESULTS: At test quadrants, all parameters significantly increased throughout the trial, while in control quadrants, PlI, GI, and AngBS remained low. Significant differences were noted between test and control quadrants on days 7, 14, and 21 for all parameters. Significant increases in GI, AngBS, and GCF were observed in test quadrants over the course of the study in both HR and LR groups. Significant differences were noted between HR and LR groups for all gingivitis parameters on day 21 in test quadrants, without any significant differences in PlI or CPE between the groups. CONCLUSIONS: We identified two subpopulations characterized by significant differences in clinical parameters of plaque-induced gingival inflammation, despite similar amounts of plaque deposits and plaque accumulation rates.     

Modulation of clinical expression of plaque-induced gingivitis. I. Background review and rationale

OBJECTIVES: The purpose of this article is to provide the necessary background and rationale for the accompanying studies, which are ultimately aimed at identifying genetic and environmental factors determining gingivitis susceptibility. MATERIALS AND METHODS: The literature on factors reported to modify the clinical expression of gingivitis, i.e., factors that determine individual variability in gingival inflammatory response to plaque, is presented. RESULTS: Clinical evidence suggests that the gingival inflammatory response to plaque accumulation may differ substantially among individuals. However, most of the available studies are of small scale and not purposely designed to address the issue. Systemic factors implicated in modulation of the clinical expression of gingivitis include metabolic, genetic, environmental and other factors. The significance of such factors in designing and conducting a large-scale experimental gingivitis trial and means to account for them are discussed. CONCLUSION: Although several factors have been implicated, genetic or environmental factors underlying differences in gingivitis expression are not fully elucidated. The accompanying studies aim to identify and characterize, among participants in a specifically designed large-scale experimental gingivitis trial, subjects that differ significantly in their gingival inflammatory response to plaque. This is the first step in an effort to determine genetic or environmental factors underlying such differences.     

Modulation of clinical expression of plaque-induced gingivitis: response in aggressive periodontitis subjects

AIM: The aim of this study was to characterize the gingival inflammatory response to de novo plaque accumulation in subjects treated for aggressive periodontitis (AP). The gingival inflammatory response of the AP subjects was retrospectively compared with that of periodontally healthy individuals (PH) matched for exposure to plaque and of periodontally healthy subjects previously identified as "high responders" (HR) and "low responders" (LR). MATERIALS AND METHODS: 13 AP subjects and 26 matched PH subjects participated in a 21-day experimental gingivitis trial. Plaque index (PlI), Gingival index (GI), gingival crevicular fluid volume (GCF) and angulated bleeding score (AngBS) were recorded at days 0, 7, 14 and 21. Cumulative plaque exposure (CPE), i.e. PlI over time, was also calculated. RESULTS: GCF was significantly higher in AP compared with PH group at each observation interval (p< or =0.001). In addition, GCF was significantly higher in AP group compared with either LR or HR groups at each observation interval (p<0.001). CONCLUSIONS: These results suggest that susceptibility to gingival inflammation in response to de novo plaque accumulation may be related to susceptibility to periodontitis.     

Role of IL-6, TNF-A and LT-A variants in the modulation of the clinical expression of plaque-induced gingivitis

AIM: The purpose of the present study was to assess the association of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-A) and lymphotoxin alpha (LT-A) gene polymorphisms with the clinical parameters of gingivitis in a large experimental gingivitis trial and with each of two subgroups, "high responder" (HR, n=24) and "low responder" (LR, n=24), with distinct susceptibility to gingivitis. MATERIAL AND METHODS: Ninety-six systemically and periodontally healthy non-smokers, 46 males (mean age: 23.9+/-1.7) and 50 females (mean age: 23.3+/-1.6), were included in a randomized split-mouth localized 21-day experimental gingivitis trial. Plaque index, gingival index, gingival crevicular fluid volume and angulated bleeding score were recorded. HR and LR subgroups were characterized by substantially different severities of gingival inflammation despite a similar plaque accumulation rate. All subjects were genetically characterized for IL-6(-174), IL-6(-597), TNF-A(-308) and LT-A(+252) polymorphisms. RESULTS: None of the variants analysed, either as single polymorphisms or as a combined genotype, was associated with the clinical parameters in the overall population. For the polymorphisms studied, genotypic distributions in HR and LR subjects were not significantly different. CONCLUSIONS: The present results suggest an absence of association between IL-6, TNF-A and LT-A polymorphisms and subject-based clinical behaviour of the gingiva in response to de novo plaque accumulation.     

Effect of a preventive program based on professional toothcleaning and fluoride application on caries and gingivitis

The effect of a preventive program was studied in 12-14-yr-old children. 104 children (test group) participated in this program. After four visits in the first 6 wk, the children visited the oral hygienist five times a year to receive professional oral prophylactic treatment and instructions. Additionally a fluoride application (Duraphat) was given two times a year. Children of a control group (n = 117) received no prophylactic treatment. Diet was not controlled in either test or control group. After 2 yr mean caries increment amounted to 2.7 +/- 2.8 new DFS in the test group and 5.0 +/- 4.2 new DFS in the control group, respectively. The most pronounced differences between the two groups could be found on the proximal surfaces. In all, caries was reduced by 46% during the 2-yr period. Plaque accumulation and frequency of gingivitis were significantly reduced only in the test group (67% and 55%, resp.). The data revealed that the program reduced both caries and gingivitis to a remarkable extent.     

Modulation of clinical expression of plaque-induced gingivitis: effects of personality traits, social support and stress

BACKGROUND: Studies have shown an association between an acute stressful event and gingivitis. However, the possible effects of personality traits associated with stress resistance/susceptibility and current level of stress on the clinical expression of plaque-induced inflammation remain to be examined. The aim of this study was to characterize the subject-based clinical behaviour of the gingiva during experimental gingivitis in relation to personality profile, psychological stress and coping behaviour. METHODS: Ninety-six systemically and periodontally healthy subjects (mean age: 23.6+/-1.7 years), 46 males and 50 females, non-smokers, participated in a randomized, split-mouth, localized experimental gingivitis trial. Prior to the trial, subjects were asked to complete self-administered questionnaires evaluating personality traits (Hardiness scale and Courtauld Emotional Control Scale), subjective stress (Visual Analogue Scale-Total Distress), social support (Multidimensional Scale of Perceived Social Support, MSPSS) and life events (Life Experiences Survey (LES)). The influence of psychosocial factors was investigated in the overall population as well as in two sub-populations with different inflammatory response to plaque accumulation. RESULTS: No significant relationships were found between gingival inflammation variables and psychological measures. No significant differences were detected between subjects with different susceptibilties to plaque-associated gingivitis for any considered psychological variable. A significant association between plaque variables and LES (negative) or MSPSS (positive) was found; however, the variance explained by the model was low. CONCLUSIONS: Differences in the current level of stress and psychosocial variables indicative of stress susceptibility do not account for variability in plaque accumulation and gingival inflammation during experimental gingivitis in young adults.     

Oral hygiene, gingivitis, and periodontitis in persons with Down syndrome

This study was conducted to determine and compare the prevalence, severity, and extent of gingivitis and periodontitis in patients with Down syndrome and patients who did not have Down syndrome. The authors also assessed the relationship of these conditions and compared them to the age, gender, and oral hygiene profiles in both groups. Using a case-control study design, the authors examined 32 individuals with Down syndrome (DS) and matched each with a participant from the control group (CG) according to age and gender. Researchers determined the Simplified Oral Hygiene Index, Gingival Index, and measured the level of gingival attachment for each participant. The authors found that the relationship between the presence of dental plaque and the severity of gingivitis was moderate among participants with DS. While the overall characteristics of the periodontal and gingival health status were not markedly different between the two groups, the extent and severity of gingivitis and the extent of periodontitis were greater in the group with DS than in the CG.     

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

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

Effect of oral hygiene instruction and professional toothcleaning on caries and gingivitis in schoolchildren

Abstract The present study was performed lo assess the effect on caries and gingivitis of plaque control measures such as oral hygiene instruction, toothcleaning practice and professional toothcleaning. 104 children, 13-14 years old, participated in the trial. Prior to the start of the preventive treatment all children were examined regarding oral hygiene, gingivitis and caries. The caries examination was limited to the proximal surfaces of molars and premolars. Following this baseline examination the children were randomly divided into two treatment groups, A and B. Both groups of children were recalled for professional toothcleaning once every 2 weeks during an 18-month period. In each child the professional toothcleaning was restricted to either the right or the left jaws by random selection. In addition, the children of Group A at each recall appointment received careful oral hygiene instruction and practice in proper toothcleaning methods. In conjunction with the professional toothcleaning an abrasive paste was used including fluoride. The children were re-examined 18 months after the baseline examination. The result of the present investigation demonstrated that professional toothcleaning repeated every second week is a prophylactic measure which in children substantially improves the oral hygiene status, and effectively reduces clinical signs of gingivitis and caries. It was also observed that while oral hygiene instruction and practice in proper toothcleaning techniques reduced plaque and gingivitis, no such effect could be detected regarding the development of caries.     

The effect of various plaque control measures on gingivitis and caries in schoolchildren

The aims of the present study were (1) to analyze the separate effects on plaque, caries, and gingivitis of several measures (oral hygiene instruction, professional tooth cleaning with mechanical instruments, topical application of sodium monofluorophosphate - MFP) which have been incorporated in a prophylactic treatment program, described by AXELSSON & LINDHE1, and (2) to prevent caries and gingivitis by applying the combined treatment but replacing the professional mechanical tooth cleaning with chemical cleaning using a chlorhexidine-containing gel. 164 children, 13-14 years old, divided into four groups, participated in a 2-year trial. All participants were recalled once every 2nd week for preventive treatment provided by dental nurses. During the 1st year Group 3 and 4 received prophylactic treatment identical to that described by AXELSSON & LINDHE1. During the 2nd year the professional tooth cleaning was omitted but oral hygiene instruction was given every 2nd week. During the 1st year Groups 1 and 2 were treated with 0.5% chlorhexidine but during the 2nd year they were subjected to professional tooth cleaning with mechanical instruments. Throughout the trial Groups 1 and 3 rinsed once every 2nd week with a 2% MFP solution. The results showed that by oral hygiene instruction and frequently repeated professional tooth cleanings it was possible to substantially reduce the frequency of gingivitis and prevent caries. When this treatment was used, mouthrinsings with 2% MFP had no additional effect on caries. The substitution of the mechanical cleaning procedure with topical application of a 0.5% chlorhexidine gel failed to (1) remove supragingival plaque accumulations, (2) reduce the frequency of gingivitis, and (3) retard the rate of caries development. The data also revealed that interdental cleaning with mechanical instruments was of decisive importance in the prevention of approximal surface caries.     

Effect of delmopinol hydrochloride mouthrinse on plaque formation and gingivitis in "rapid" and "slow" plaque formers

Abstract The aim of the present study was to investigate differences in the plaque and gingivitis inhibiting effect of delmopinol rinsing between “rapid” and “slow” plaque formers. 23 subjects (12 “rapid” and 11 “slow” plaque formers) were selected from 71 healthy young adults. The selection was based on the plaque index on the buccal surfaces of all premolars and 1st molars after 3-days without plaque control. The 23 subjects were randomly assigned into 3 groups with different mouthrinses, i.e., 0.1% delmopinol, 0.2% delmopinol, and placebo. The study was double-blind with parallel design between the “rapid” and “slow” plaque formers and cross-over design between 2 active periods and a placebo period. Each rinsing period lasted for 5 days. During the 3 test periods, the subjects refrained from all oral hygiene and rinsed 2 × daily with either one of the 3 solutions. Gingival crevicular fluid (GCF) was collected from buccal surfaces of upper canines and premolars and bleeding on probing (BOP) recorded at 6 sites around each tooth before and after each test period. Plaque assessment, including plaque index (PI) and standardized color slides for planimetric analyses obtained from the canines and premolars, were only recorded after each test period. Results showed that the mean PI and planimetry values for both the “rapid” and “slow” plaque formers were lower than the placebo, for either the 0.1% or the 0.2% delmopinol mouthrinse. The differences between the “rapid” and “slow” plaque formers were not statistically significant. There was a small reduction in BOP in both groups for the delmopinol periods, as against a slight increase in the placebo period: the difference between the placebo group and the 2 groups of plaque formers was not statistically significant (p>0.6 for both 0.1% and 0.2% delmopinol). Results suggested that both 0.1% and 0.2% delmopinol reduce plaque formation and gingivitis to a similar extent in subjects with extreme rates of plaque formation.     

Serum antibodies to plaque bacteria in subjects with dental caries and gingivitis

abstract – Correlations were sought between indices of gingival inflammation and dental caries experience and serum antibody titers to five species of oral bacteria. The material comprised 53 young adult males. A statistically significant, negative correlation was observed between the antibody titer to a pool of Veillonella strains and dental caries experience. Multiple regression analyses failed to reveal significant associations between periodontal disease and serum antibody titers. However, the data suggested a combined association of the titers to the strains of Veillonella and a strain of Fusobacterium with the periodontal index.     

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

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

Four years of monthly professional toothcleaning and topical fluoride application in Brazilian schoolchildren.

The effect on gingivitis of monthly professional toothcleaning, without oral hygiene instruction, was evaluated in 103, 7- to 11-year-old Brazilian children. Plaque and gingivitis (PlI and GI) were recorded initially and after 1, 2, 3 and 4 years. The baseline examination showed a similar high level of plaque (PlI approximately 1.55) and low level of gingivitis (GI approximately 0.32) around permanent teeth of both test and control groups. The test children were given monthly professional toothcleaning followed by topical application of fluoride gel (APF), totaling 32 sessions. At all annual follow-up examinations, the mean PlI in the test group was significantly lower than in the control group. However, even in the test group, at least 80% of the tooth surfaces harbored plaque. In spite of this, no child in the test group showed overt gingivitis (mean individual GI greater than or equal to 1.0) and the distribution of "GI score = 2" was very low. In the control group the percentage of children with overt gingivitis increased from 3% at the baseline to 20% at the final examination and areas scoring GI = 2 doubled in number. It is suggested that for young children, monthly thorough removal of plaque is sufficient to prevent the development of gingivitis.