Site progression of loss of attachment over 5 years in 14- to 19-year-old adolescents

Partial (incomplete) removal of granulation tissue using modified minimally invasive surgical technique in treatment of infrabony defects (randomized control clinical trial)

AIM

This study aims to compare the clinical and radiographic outcomes after complete versus incomplete removal of granulation tissue (GT) during modified minimally invasive surgical technique (M-MIST) for management of periodontitis patients with deep pockets associated with infra-bony defects.

METHODOLOGY

Ten patients with a total of 14 deep non-resolving pockets (≥ 5 mm) associated with a vertical infra-bony defect were recruited for this study. They were randomized into 2 groups; a test group with incomplete removal of GT and a control group with complete removal of GT. Clinical parameters of clinical attachment level (CAL), residual probing depth (rPD) and buccal recession (Rec.) were recorded every 3 months. Radiographic periapicals were taken at baseline, 6 and 9 months. The significance level was set to 0.05.

RESULTS

None of the results showed statistical significance between the 2 groups (p > 0.05). The test group showed less CAL gain (2 ± 0.87 mm, p = 0.062), more reduction in rPD (3.1 ± 0.96 mm, p = 0.017) and more recession (0.857 ± 0.26 mm, p = 0.017) than control group CAL gain (2.4 ± 0.58 mm, p = 0.009), rPD reduction (2.9 ± 0.3 mm, p = 0.001) and recession (0.5 ± 0.34 mm, p = 0.203) respectively. Control group had linear reduction in depth defect (DD) (0.68 ± 0.287, p = 0.064) compared to an increase in DD in test group (-0.59 ± 0.5, p = 0.914).

CONCLUSIONS

No statistical significance were observed in healing parameters between complete removal of GT in M-MIST and incomplete (partial) removal of GT of deep pockets with infra-bony defects both clinically and radiographically. Further studies with larger samples are needed to confirm the results.

Cytotoxic effects of dental calculus particles and freeze-dried Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum on HSC-2 oral epithelial cells and THP-1 macrophages

BACKGROUND

Periodontitis is an inflammatory disease initiated by dental deposits. Microorganisms in the dental biofilm induce cell death in epithelial cells, contributing to the breakdown of epithelial barrier function. Recently, dental calculus has also been implicated in pyroptotic cell death in oral epithelium. We analyzed the cytotoxic effects of dental calculus and freeze-dried periodontopathic bacteria on oral epithelial cells and macrophages.

METHODS

HSC-2 (human oral squamous carcinoma cells) and phorbol 12-myristate 13-acetate-differentiated THP-1 macrophages were exposed to dental calculus or one of two species of freeze-dried bacterium, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum. Following incubation for 24 hours, we measured cytotoxicity via lactate dehydrogenase release. Cells were then incubated with glyburide, an NLRP3 inflammasome inhibitor, to assess the potential role of pyroptosis. We also conducted a permeability assay to analyze the effects on epithelial barrier function.

RESULTS

Dental calculus induced dose-dependent cell death in HSC-2 cells, whereas cell death induced by freeze-dried bacteria was insignificant. Conversely, freeze-dried bacteria induced more cell death than dental calculus in THP-1 macrophages. Cell death induced by dental calculus but not by freeze-dried bacteria was inhibited by glyburide, indicating that these are different types of cell death. In the permeability assays, dental calculus but not freeze-dried bacteria attenuated the barrier function of HSC-2 cell monolayers.

CONCLUSION

Due to the low sensitivity of HSC-2 cells to microbial cytotoxicity, dental calculus had stronger cytotoxic effects on HSC-2 cell monolayers than freeze-dried A. actinomycetemcomitans and F. nucleatum, suggesting that it plays a critical role in the breakdown of crevicular/pocket epithelium integrity.

Metatranscriptomic analyses of the oral microbiome

Although the composition of the oral human microbiome is now well studied, regulation of genes within oral microbial communities remains mostly uncharacterized. Current concepts of periodontal disease and caries highlight the importance of oral biofilms and their role as etiological agents of those diseases. Currently, there is increased interest in exploring and characterizing changes in the composition and gene-expression profiles of oral microbial communities. These efforts aim to identify changes in functional activities that could explain the transition from health to disease and the reason for the chronicity of those infections. It is now clear that the functions of distinct species within the subgingival microbiota are intimately intertwined with the rest of the microbial community. This point highlights the relevance of examining the expression profile of specific species within the subgingival microbiota in the case of periodontal disease or caries lesions, in the context of the other members of the biofilm in vivo. Metatranscriptomic analysis of the oral community is the starting point for identifying environmental signals that modulate the shift in metabolism of the community from commensal to dysbiotic. These studies give a snapshot of the expression patterns of microbial communities and also allow us to determine triggers to diseases. For example, in the case of caries, studies have unveiled a potential new pathway of sugar metabolism, namely the use of sorbitol as an additional source of carbon by Streptococcus mutans; and in the case of periodontal disease, high levels of extracellular potassium could be a signal of disease. Longitudinal studies are needed to identify the real markers of the initial stages of caries and periodontal disease. More information on the gene-expression profiles of the host, along with the patterns from the microbiome, will lead to a clearer understanding of the modulation of health and disease. This review presents a summary of these initial studies, which have opened the door to a new understanding of the dynamics of the oral community during the dysbiotic process in the oral cavity.

Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions

Periodontal health is defined by absence of clinically detectable inflammation. There is a biological level of immune surveillance that is consistent with clinical gingival health and homeostasis. Clinical gingival health may be found in a periodontium that is intact, i.e. without clinical attachment loss or bone loss, and on a reduced periodontium in either a non-periodontitis patient (e.g. in patients with some form of gingival recession or following crown lengthening surgery) or in a patient with a history of periodontitis who is currently periodontally stable. Clinical gingival health can be restored following treatment of gingivitis and periodontitis. However, the treated and stable periodontitis patient with current gingival health remains at increased risk of recurrent periodontitis, and accordingly, must be closely monitored. Two broad categories of gingival diseases include non-dental plaque biofilm-induced gingival diseases and dental plaque-induced gingivitis. Non-dental plaque biofilm-induced gingival diseases include a variety of conditions that are not caused by plaque and usually do not resolve following plaque removal. Such lesions may be manifestations of a systemic condition or may be localized to the oral cavity. Dental plaque-induced gingivitis has a variety of clinical signs and symptoms, and both local predisposing factors and systemic modifying factors can affect its extent, severity, and progression. Dental plaque-induced gingivitis may arise on an intact periodontium or on a reduced periodontium in either a non-periodontitis patient or in a currently stable "periodontitis patient" i.e. successfully treated, in whom clinical inflammation has been eliminated (or substantially reduced). A periodontitis patient with gingival inflammation remains a periodontitis patient (Figure 1), and comprehensive risk assessment and management are imperative to ensure early prevention and/or treatment of recurrent/progressive periodontitis. Precision dental medicine defines a patient-centered approach to care, and therefore, creates differences in the way in which a "case" of gingival health or gingivitis is defined for clinical practice as opposed to epidemiologically in population prevalence surveys. Thus, case definitions of gingival health and gingivitis are presented for both purposes. While gingival health and gingivitis have many clinical features, case definitions are primarily predicated on presence or absence of bleeding on probing. Here we classify gingival health and gingival diseases/conditions, along with a summary table of diagnostic features for defining health and gingivitis in various clinical situations.

Plaque-induced gingivitis: Case definition and diagnostic considerations

OBJECTIVE

Clinical gingival inflammation is a well-defined site-specific condition for which several measurement systems have been proposed and validated, and epidemiological studies consistently indicate its high prevalence globally. However, it is clear that defining and grading a gingival inflammatory condition at a site level (i.e. a "gingivitis site") is completely different from defining and grading a "gingivitis case" (GC) (i.e. a patient affected by gingivitis), and that a "gingivitis site" does not necessarily mean a "GC". The purpose of the present review is to summarize the evidence on clinical, biochemical, microbiologic, genetic markers as well as symptoms associated with plaque-induced gingivitis and to propose a set of criteria to define GC.

IMPORTANCE

A universally accepted case definition for gingivitis would provide the necessary information to enable oral health professionals to assess the effectiveness of their prevention strategies and treatment regimens; help set priorities for therapeutic actions/programs by health care providers; and undertake surveillance.

FINDINGS

Based on available methods to assess gingival inflammation, GC could be simply, objectively and accurately identified and graded using bleeding on probing score (BOP%) CONCLUSIONS: A patient with intact periodontium would be diagnosed as a GC according to a BOP score ≥ 10%, further classified as localized (BOP score ≥ 10% and ≤30%) or generalized (BOP score > 30%). The proposed classification may also apply to patients with a reduced periodontium, where a GC would characterize a patient with attachment loss and BOP score ≥ 10%, but without BOP in any site probing ≥4 mm in depth.

Metatranscriptome of the Oral Microbiome in Health and Disease

The last few decades have witnessed an increasing interest in studying the human microbiome and its role in health and disease. The focus of those studies was mainly the characterization of changes in the composition of the microbial communities under different conditions. As a result of those studies, we now know that imbalance in the composition of the microbiome, also referred to as microbial dysbiosis, is directly linked to developing certain conditions. Dysbiosis of the oral microbiome is a prime example of how this imbalance leads to disease in the case of periodontal disease. However, there is considerable overlap in the phylogenetic profiles of microbial communities associated with active and inactive lesions, suggesting that the difference in periodontal status of those sites may not be explained solely by differences in the subgingival microbial composition. These findings suggest that differences in functional activities may be the essential elements that define the dysbiotic process. Researchers have recently begun to study gene expression of the oral microbiome in situ with the goal of identifying changes in functional activities that could explain the transition from health to disease. These initial results suggest that, rather than a specific composition, a better understanding of oral dysbiosis can be obtained from the study of functional activities of the microbial community. In this review, we give a summary of these initial studies, which have opened a new door to our understanding of the dynamics of the oral community during the dysbiotic process in the oral cavity.

Time to shift: from scaling and root planing to root surface debridement

Non-surgical periodontal treatment has traditionally been based on the notion that bacterial plaque (dental biofilm) penetrates and infects dental cementum. Removal of this infected cementum via scaling and root planing (SRP) was considered essential for re-establishing periodontal health. In the 1980s the concept of SRP was questioned because several in vitro studies showed that the biofilm was superficially located on the root surface and its disruption and removal could be relatively easily achieved by ultrasonic instrumentation of the root surface (known as root surface debridement (RSD). Subsequent in vivo studies corroborated the in vitro findings. There is now sufficient clinical evidence to substantiate the concept that the deliberate removal of cementum by SRP is no longer warranted or justified, and that the more gentle and conservative approach of RSD should be implemented in daily periodontal practice.

Periodontal diseases in children and adolescents: a clinician's perspective part

Contrasting forms of periodontal disease can affect children and adolescents with varying prevalence, severity and extent, leading to a diverse prognosis in these age groups. For an early diagnosis and treatment of periodontal conditions in young patients, it is essential for the dental practitioner to be able to identify and classify the disease correctly at the earliest opportunity, applying basic principles along with understanding of aetiology and risk factors. The first part of this article discusses the classification, plaque-induced and non-plaque-induced gingival diseases, localized and generalized forms of chronic, as well as aggressive, periodontitis.

CLINICAL RELEVANCE

Knowledge of different forms of periodontal diseases affecting children and adolescents may help to distinguish between different forms of diseases and have value in screening and early diagnosis of the disease.

Oral hygiene and periodontal status of 12 and 15-year-old Greek adolescents. A national pathfinder survey

AIM

To investigate oral hygiene and periodontal status of 12- and 15-year old Greek adolescents, in relation to sociodemographic and behavioural parameters.

METHODS

A stratified cluster sample of 1,224 12-year old and 1,257 15-year old adolescents of Greek nationality were selected and examined by calibrated examiners. Periodontal and oral hygiene status were assessed using the Community Periodontal Index (CPI) and the simplified Debris Index (DIs) respectively. The socio-demographic and behavioural data collected included region, location, gender, parental educational level, tooth brushing frequency and reason for dental attendance.

RESULTS

The majority of adolescents aged 12 (75.0%) and 15-years (61.4%) had fair oral hygiene levels. The most frequently observed condition in both ages was calculus with or without bleeding (42.8% in the younger and 53.3% in the older age group). Bleeding on probing was found in 41.5% of the 12-year-olds and in 30.0% of the 15-year-olds. The occurrence of shallow and/ or deep periodontal pockets was very low (0.2%). Multivariable modelling revealed that gender, location and tooth brushing frequency were strongly associated with oral hygiene status in both ages; girls, those living in urban areas and brushing teeth more frequently had significantly lower DI-s. Tooth brushing frequency was also associated with periodontal status in both ages, while living in urban areas was associated with better periodontal health only in the 15-year-olds.

CONCLUSIONS

The study demonstrated that oral hygiene conditions among Greek children and adolescents are not satisfactory and that the occurrence of gingivitis is high. More efforts on oral health education and oral hygiene instruction are needed to improve their periodontal and oral hygiene status.

The association between self-reported tooth loss and cognitive function in the REasons for Geographic And Racial Differences in Stroke study: an assessment of potential pathways

BACKGROUND

Several mechanisms may associate tooth loss and related oral inflammation with cognitive impairment. The authors studied the relationship between tooth loss and cognitive function.

METHODS

The REasons for Geographic And Racial Differences in Stroke study is a national longitudinal study of more than 30,000 African American and white adults 45 years or older. Data for tooth loss, cognitive function and potential confounding variables were available for 9,853 participants at the time of analysis. The authors used incremental linear regression modeling to investigate the cross-sectional association between self-reported tooth loss and cognitive function.

RESULTS

In unadjusted analysis (mean learning followed by recall; α level of significance of .05), the loss of six to 16 teeth and the loss of more than 16 teeth were associated with poorer cognitive function compared with the loss of no teeth. Attenuated associations persisted after the authors adjusted for demographic and systemic risk factors. The full model, which was adjusted for socioeconomic status (SES), revealed no association between tooth loss and cognitive function.

CONCLUSION

Tooth loss may be associated with cognitive function; however, this association is mediated by age and SES.

CLINICAL IMPLICATIONS

Tooth loss due to periodontal disease may be a marker for low SES, and the interplay of these factors with advanced age may confer risk of having poorer cognitive function. Further studies are needed to clarify these associations.

The effect of smoking on periodontal health of 15- to 16-year-old adolescents

BACKGROUND

Smoking is a severe risk factor for periodontal health in adults, but data on the effect of smoking on periodontal health in teenage populations are sparse. The aim of this study was to investigate the effect of duration and quantity of smoking on periodontal health in teenagers and possible differences between genders.

METHODS

The oral health of 501 adolescents (15- to 16-year-old boys [n = 258] and girls [n = 243]) was examined. A structured questionnaire about self-reported smoking and health habits was filled out, and bitewing x-rays were taken. Clinical examinations included measuring periodontal indexes, such as visible plaque index, bleeding on probing, root calculus (RC), probing depth, and attachment loss. Results were analyzed by generalized linear logistic regression.

RESULTS

Twenty-five percent of boys and 27% of girls were smokers. The boys and girls who smoked had higher RC values than non-smokers (P <0.001). The adjusted scores for smoking boys and girls were 17.3 (95% confidence interval [CI]: 8.6 to 31.7) and 13.6 (95% CI: 5.5 to 29.7), respectively. The adjusted scores for non-smokers were 10.4 (95% CI: 5.7 to 18.3) and 7.7 (95% CI: 3.3 to 17.3), respectively. Smoking boys and girls also had more periodontal pockets > or =4 mm than non-smokers: the score for boys was 4.6 (95% CI: 2.2 to 9.1), and the score for girls was 5.4 (95% CI: 1.1 to 23.2; P <0.001).

CONCLUSION

Smoking significantly impaired periodontal health in teenagers.

Aggregatibacter actinomycetemcomitans and its relationship to initiation of localized aggressive periodontitis: longitudinal cohort study of initially healthy adolescents

Aggregatibacter actinomycetemcomitans is frequently associated with localized aggressive periodontitis (LAP); however, longitudinal cohort studies relating A. actinomycetemcomitans to initiation of LAP have not been reported. A periodontal assessment was performed on 1,075 primarily African-American and Hispanic schoolchildren, ages 11 to 17 years. Samples were taken from each child for A. actinomycetemcomitans. A cohort of 96 students was established that included a test group of 38 A. actinomycetemcomitans-positive students (36 periodontally healthy and 2 with periodontal pockets) and 58 healthy A. actinomycetemcomitans-negative controls. All clinical and microbiological procedures were repeated at 6-month intervals. Bitewing radiographs were taken annually for definitive diagnosis of LAP. At the initial examination, clinical probing attachment measurements indicated that 1.2% of students had LAP, while 13.7% carried A. actinomycetemcomitans, including 16.7% of African-American and 11% of Hispanic students (P = 0.001, chi-square test). A. actinomycetemcomitans serotypes a, b, and c were equally distributed among African-Americans; Hispanic students harbored predominantly serotype c (P = 0.05, chi-square test). In the longitudinal phase, survival analysis was performed to determine whether A. actinomycetemcomitans-positive as compared to A. actinomycetemcomitans-negative students remained healthy ("survived") or progressed to disease with attachment loss of >2 mm or bone loss (failed to "survive"). Students without A. actinomycetemcomitans at baseline had a significantly greater chance to remain healthy (survive) compared to the A. actinomycetemcomitans-positive test group (P = 0.0001). Eight of 38 A. actinomycetemcomitans-positive and none of 58 A. actinomycetemcomitans-negative students showed bone loss (P = 0.01). A. actinomycetemcomitans serotype did not appear to influence survival. These findings suggest that detection of A. actinomycetemcomitans in periodontally healthy children can serve as a risk marker for initiation of LAP.

Periodontal Disease Progression Among Young Subjects With No Preventive Dental Care: A 52-Month Follow-Up Study

BACKGROUND

The aim of the present study was to assess the incidence, severity, and extension of periodontal disease among young subjects.

METHODS

Three hundred sixty subjects from a public school in Belo Horizonte, Brazil were examined. Forty-four subjects with bone loss (BL) and/or clinical attachment loss (CAL) > or = 4 mm, and no dental care during the following 52 months, were considered the reference sample and were recalled for a second examination. At both examinations, statistical analyses were performed for CAL and BL for subject, tooth, and site. Comparisons of CAL at subject, tooth, and site levels were performed with the Wilcoxon test for matched samples. Comparisons of BL at subject, tooth, and site levels were performed with the McNemar and Student t tests for dependent samples.

RESULTS

Findings indicated an increase in the number of sites with CAL >4 mm from baseline to follow-up. Sites that exhibited BL increased from 2.14% at baseline to 7.5% at follow-up (P <0.001). The severity of periodontitis was characterized by increased CAL values at affected sites at both examinations (P <0.001) and an increase in BL over time (mean BL at 35 affected sites was 2.6 mm at baseline and 3.5 mm at follow-up; P = 0.001). In addition, a 34% incidence of BL was verified.

CONCLUSIONS

The incidence, severity, and extension of CAL and BL were significant findings. They indicate the importance of early detection of the disease and the need for preventive health care programs geared toward young subjects.

Aggressive Periodontitis in an Urban Population in Southern Brazil

BACKGROUND

There are limited data about the epidemiology and risk factors for aggressive periodontitis (AgP) in Latin American and Brazilian populations. The aim of this study was to assess the prevalence of AgP and the risk associated with demographic variables, smoking behavior, and other periodontal variables in a young urban population in southern Brazil.

METHODS

A representative sample of 612 subjects aged 14 to 29 years were sampled using a multistage probability method. A full-mouth clinical examination of six sites per tooth and an interview were performed in a mobile examination center. Subjects in the age groups 14 to 19 years and 20 to 29 years were classified with AgP if they had four or more teeth with attachment loss > or =4 mm or > or =5 mm, respectively.

RESULTS

AgP was found in 5.5% of the subjects. The disease occurred equally among males and females, but was twice as prevalent among non-whites than whites. In the age groups 20 to 24 years and 25 to 29 years, the AgP subjects had a significantly higher prevalence of tooth loss (90.2% versus 40.4% and 86.1% versus 43.4%, P <0.01) and mean number of missing teeth (2.6 versus 0.9 and 3.4 versus 1.5, P <0.05) than subjects without attachment loss. The AgP subjects also had significantly higher percentages of sites with dental plaque (P <0.0001), gingival bleeding (P <0.05), and supragingival calculus (P <0.0001) than normal subjects. The risk for AgP was higher in the 25- to 29-year than the 14- to 19-year age groups (odds ratio [OR] = 6.2), in the low than middle or high socioeconomic status (OR = 4.5), in moderate or heavy smokers than nonsmokers (OR = 3.1), and in subjects with > or =10% versus <10% sites with supragingival calculus (OR = 3.6).

CONCLUSION

Socioeconomic status, smoking, and dental calculus were significant risk indicators of aggressive periodontitis in this population. Suitable periodontal prevention programs implementing these risk indicators may prevent or reduce the prevalence of aggressive periodontitis in this and similar populations.

Persistent colonization with Tannerella forsythensis and loss of attachment in adolescents

Colonization with Tannerella forsythensis may characterize the conversion of periodontally healthy sites into diseased sites. This three-year study describes the prevalence of T. forsythensis and its relationship to clinical loss of attachment (LOA) in a group of adolescents considered at risk of developing early chronic periodontitis. Adolescents with (LOA+) and without (LOA-) loss of attachment were examined at baseline and 1.5 and 3 yrs subsequently. On each occasion, attachment loss was measured on selected teeth, and the presence of T. forsythensis in their subgingival plaque samples was determined by PCR. T. forsythensis prevalence in LOA+ subjects at baseline (64%) increased to 82% and 86% on subsequent examinations. In contrast, prevalence of T. forsythensis in LOA- subjects was always significantly lower (25%, 36%, and 32%, respectively). The odds of loss of attachment were 8.16 times greater in subjects infected with T. forsythensis at each examination. These results suggest that T. forsythensis is strongly associated with loss of attachment in this adolescent population.

The Application of Multilevel Modeling in the Analysis of Longitudinal Periodontal Data – Part I: Absolute Levels of Disease

BACKGROUND

Statistical analyses of periodontal data that average site measurements to subject mean values are unable to explore the site-specific nature of periodontal diseases. Multilevel modeling (MLM) overcomes this, taking hierarchical structure into account. MLM was used to investigate longitudinal relationships between the outcomes of lifetime cumulative attachment loss (LCAL) and probing depth (PD) in relation to potential risk factors for periodontal disease progression.

METHODS

One hundred males (mean age 17 years) received a comprehensive periodontal examination at baseline and at 12 and 30 months. The resulting data were analyzed in two stages. In stage one (reported here), the absolute levels of disease were analyzed in relation to potential risk factors; in stage two (reported in a second paper), changes in disease patterns over time were analyzed in relation to the same risk factors. Each approach yielded substantially different insights.

RESULTS

For absolute levels of disease, subject-level risk factors (covariates) had limited prediction for LCAL/PD throughout the 30-month observation period. Tooth position demonstrated a near linear relationship for both outcomes, with disease increasing from anterior to posterior teeth. Sites with subgingival calculus and bleeding on probing demonstrated more LCAL and PD, and supragingival calculus had an apparently protective effect. Covariates had more "explanatory power" for the variation in PD than for the variation in LCAL, suggesting that LCAL and PD might be generally associated with a different profile of covariates.

CONCLUSION

This study provides, for a relatively young cohort, considerable insights into the factors associated with early-life periodontal disease and its progression at all levels of the natural hierarchy of sites within teeth within subjects.

Prevalence and extent of lifetime cumulative attachment loss (LCAL) at different thresholds and associations with clinical variables: changes in a population of young male military recruits over 3 years

AIM

The aims of this study were to monitor the prevalence and progression of lifetime cumulative attachment loss (LCAL) in a group of young British male military recruits over a 3-year period, and to determine the relationship between signs of LCAL and selected periodontal variables.

METHODS

100 subjects, aged 16-20 years (mean 17 years) at baseline, were examined at 0 (baseline), 12 and 30 months. LCAL, probing depth, plaque, bleeding on probing, gingival colour and supra- and subgingival calculus were assessed on the mesio-buccal, disto-buccal, mesio-lingual and disto-lingual surfaces of all teeth present, excluding third molars. Data were analysed cross-sectionally at each examination.

RESULTS

Over the period of the study, the prevalence of LCAL > or =1 and 2 mm ranged from 95-100%, whereas LCAL > or =3 mm ranged from 40-47%. The extent of LCAL > or =1 mm ranged from 76-86%. However, the extent of LCAL > or =2 mm was dramatically lower (10.5-12.7%), and LCAL > or =3 mm was uncommon (0.5-0.9%). Examining the number of subjects according to the number of sites affected above a threshold, showed that a small number of subjects have a large number of sites above threshold. Using Pearson's rank correlation coefficient a significant correlation (p<0.05) was found between LCAL and the periodontal variables of gingival bleeding and supra- and subgingival calculus.

CONCLUSIONS

These data suggest that the onset and progression of chronic periodontitis can be seen in young adults, and in this group gingival bleeding and supra- and subgingival calculus are the variables most strongly associated with early periodontitis.

The natural history of periodontal disease in man. Risk factors for progression of attachment loss in individuals receiving no oral health care

BACKGROUND

Few investigations have reported on risk factors for periodontal attachment loss over time in subjects with no home or professional dental care. The purpose of this report was to identify potential risk factors for progression of periodontal attachment loss among male Sri Lankan tea laborers who participated in a 20-year investigation of the natural history of periodontal disease.

METHODS

Data for this report were obtained from the 154 subjects who participated in the 1970 baseline and the final 1990 examinations and included data from their interim examinations performed in 1971, 1973, 1977, 1982, and 1985. Oral health assessments included: 1) attachment levels in millimeters on mesial and mesio-buccal surfaces of all but third molar teeth; 2) plaque index (PI); 3) gingival index (GI); 4) calculus index (CI); 5) caries index (DMFS); and 6) presence or absence of teeth. Other variables included age, history of smoking, and/or use of betel nut. Statistical analyses used multivariate repeated measures analysis of variance (ANOVA).

RESULTS

The final adjusted model indicated that attachment loss increased significantly with age (X2 = 74.0; df = 1), GI (X2 = 45.5; df = 1), CI (X2 = 52.7; df = 1) and follow-up time (X2 = 219.8; df = 6, P<0.0001 for all variables).

CONCLUSIONS

Age, GI, CI, and time were significantly associated with mean attachment loss over 20 years. Neither PI, history of smoking, or history of betel nut use were significantly associated with attachment loss over time.

Subgingival calculus: where are we now? A comparative review

OBJECTIVE

To critically analyse the formation, composition, ethnic variations and pathogenic potential of subgingival calculus in comparison with supragingival calculus.

DATA SOURCES

Using CD-ROM and index medicus, scientific papers relating to subgingival calculus or subgingival and supragingival calculus written in the English language since 1960 were considered, with the emphasis on more recent articles.

STUDY SELECTION

Studies were selected for their relevance and contemporary nature re:composition and formation of dental calculus and comparisons of ethnic groups with regard to dental calculus, especially subgingival calculus. Some similar studies were not included.

DATA EXTRACTION

Abstracts of studies were kept brief unless particularly important to the review. Population, methodology, statistics and accurate conclusions were used as important guides to the quality and validity of studies.

DATA SYNTHESIS

Similarities and differences between supragingival and subgingival calculus in composition and formation were shown. Different morphological types of subgingival calculus were demonstrated. There was evidence for an association between calculus formation and ethnicity with regard to supragingival and subgingival calculus, and an association between subgingival calculus composition and ethnicity was indicated.

CONCLUSIONS

An association between ethnicity and subgingival calculus formation and composition was found. Further research into the reasons for these ethnic differences in dental calculus and the role of the mineral constituents especially of subgingival calculus would be valuable.

Development of a classification system for periodontal diseases and conditions

Classification systems are necessary in order to provide a framework in which to scientifically study the etiology, pathogenesis, and treatment of diseases in an orderly fashion. In addition, such systems give clinicians a way to organize the health care needs of their patients. The last time scientists and clinicians in the field of periodontology and related areas agreed upon a classification system for periodontal diseases was in 1989 at the World Workshop in Clinical Periodontics. Subsequently, a simpler classification was agreed upon at the 1st European Workshop in Periodontology. These classification systems have been widely used by clinicians and research scientists throughout the world. Unfortunately, the 1989 classification had many shortcomings including: 1) considerable overlap in disease categories, 2) absence of a gingival disease component, 3) inappropriate emphasis on age of onset of disease and rates of progression, and 4) inadequate or unclear classification criteria. The 1993 European classification lacked the detail necessary for adequate characterization of the broad spectrum of periodontal diseases encountered in clinical practice. The need for a revised classification system for periodontal diseases was emphasized during the 1996 World Workshop in Periodontics. In 1997 the American Academy of Periodontology responded to this need and formed a committee to plan and organize an international workshop to revise the classification system for periodontal diseases. The proceedings in this volume are the result of this reclassification effort. The process involved development by the Organizing Committee of an outline for a new classification and identification of individuals to write state-of-the-science reviews for each of the items on the outline. The reviewers were encouraged to depart from the preliminary outline if there were data to support any modifications. On October 30-November 2, 1999, the International Workshop for a Classification of Periodontal Diseases and Conditions was held and a new classification was agreed upon (Fig. 1). This paper summarizes how the new classification for periodontal diseases and conditions presented in this volume differs from the classification system developed at the 1989 World Workshop in Clinical Periodontics. In addition, an analysis of the rationale is provided for each of the modifications and changes.

Effect of a triclosan/copolymer dentifrice on the incidence of periodontal attachment loss in adolescents

The aim of this study was to assess the effectiveness of a dentifrice containing 0.3% triclosan, 2.0% copolymer and 0.243% sodium fluoride (Colgate Total) in the prevention of periodontal attachment loss in adolescents. A 3-year, double-blind, randomised, controlled, clinical trial was conducted on 641 adolescents, initially aged 11-13 years. The participants were enrolled from schools in economically deprived areas of Manchester, England, which had a high % of Asian pupils originating from India, Pakistan and Bangladesh. After the baseline examination, which included assessments of pocket depth, attachment loss and subgingival calculus, the adolescents were randomly allocated to use either a triclosan/copolymer or control dentifrice. The control was identical to the test dentifrice with the exception that it did not contain triclosan/copolymer. Participants were re-examined after 18 and 36 months. After 3 years, a total of 239 adolescents remained in the test and 241 in the control group. The prevalence of attachment loss increased from 2% at baseline to 24% after 3 years. The mean increment of attachment loss during the study was 0.025 mm per site in the control group and 0.018 mm per site in the test group. A linear regression model showed a statistically significant difference in attachment loss between the test and control group, in adolescents with high mean pocket depths at baseline. No adverse effects attributable to the test or control dentifrices were observed during the study. This study has demonstrated that unsupervised use of a triclosan/copolymer dentifrice can significantly reduce periodontal attachment loss, particularly in adolescents with high mean pocket depths.

Prevalence of suspected periodontal pathogens identified using ELISA in adolescents of differing ethnic origins

The aim of this study was to determine the prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia in a group of adolescents and investigate the association of these organisms with various clinical parameters. A total of 527, 11-13-year-old children, of whom 333 (63%) were white Caucasian, 187 (35%) Indo-Pakistani and 7 (1%) Afro-Caribbean, participated in the study. Subgingival plaque samples, collected from the mesio-buccal of both upper first permanent molars using sterile paper points, were stored in phosphate buffered saline with 0.01% thiomersal and analysed for the presence of A. actinomycetemcomitans, P. gingivalis and P. intermedia using ELISA. The mesio-buccal sites of both upper 1st permanent molars were also examined and the presence/absence of supragingival plaque, subgingival calculus, bleeding on probing and pocket depths greater than 3 mm were recorded. The % of white Caucasian children in whom the monoclonal antibody identified at least 1 site with A. actinomycetemcomitans, P. gingivalis and P. intermedia were 4%, 3% and 2%, respectively, and for Indo-Pakistanis were 3%, 17% and 2%. The difference for P. gingivalis was statistically significant (p < 0.001). The associations between the clinical parameters and the 3 organisms were considered separately for both upper first molar sites. The prevalence of P. gingivalis was higher for sites with subgingival calculus, pockets > 3 mm and bleeding on probing (p < 0.01).

The detection of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia using an ELISA in an adolescent population with early periodontitis

The aim of the study was to compare the occurrence and levels of A. actinomycetemcomitans, P. gingivalis, and P. intermedia in the subgingival plaque from sites with and without early periodontitis in adolescents using an ELISA. 47, 15- to 16-year-old adolescents (39 Indo-Pakistani, 8 white Caucasian) were examined for clinical attachment level, probing depth, supragingival plaque, subgingival calculus and bleeding on probing on the mesio-buccal and disto-buccal aspects of the 1st molars and the incisors. Based on the clinical data, 2 sites per subject were selected for subgingival plaque sampling 3 weeks later: in 32 subjects with loss of attachment > or = 1 mm, a diseased site (D) and a healthy comparison control site (C) were sampled; in 15 subjects in whom loss of attachment had not yet developed, 1 of the upper molar sites was selected, called the at-risk site (R), together with a C site. The presence and levels of A. actinomycetemcomitans, P. gingivalis, and P. intermedia were determined using an ELISA. The loss of attachment subgroup had significantly more pockets > or = 4 mm, subgingival calculus and bleeding on probing (p < 0.05). Significantly more of the D than C sites had P. gingivalis both at detectable and at measurable levels (p < 0.05). In subjects who had no loss in clinical attachment levels, fewer sampled sites harboured any of the suspected periodontopathogens investigated, and no significant differences were found between the R or C sites (p > 0.05). Although there was a significantly higher prevalence and extent of loss of attachment > or = 1 mm in the Indo-Pakistani subjects compared with the Caucasians (p < 0.05), no differences could be identified in the distribution of the bacteria. It is concluded that monitoring of the subgingival plaque may be useful in studies of early periodontitis in adolescents, and the role of P. gingivalis needs to be elucidated in prospective longitudinal investigations.

Indices to measure gingival bleeding

Gingival bleeding is an objective, easily assessed sign of inflammation that is associated with several periodontal diseases. Many bleeding indices have been devised; some assess bleeding as simply present or absent, whereas others use grading in an attempt to assess severity of bleeding. The choice of which index to use depends on whether the purpose is an epidemiological survey, a clinical study, diagnosis and treatment, or patient motivation. Bleeding may be elicited manually with toothpicks, dental floss or a periodontal probe, but a controlled-force probe, although more expensive, causes less trauma and less false-positive bleeding from healthy tissues. As a predictor of periodontal disease progression, bleeding on probing has low sensitivity owing to a high frequency of false-positive responses, but has high specificity in that failure to bleed indicates health. There is evidence that smokers have less, or delayed, gingival bleeding when compared with non-smokers; therefore smoking needs to be controlled for in studies of gingival bleeding. Measurement of gingival bleeding tendency should be an integral part of a comprehensive oral examination. In clinical practice, the use of a graded bleeding index is more likely to identify sites that are at risk of further destructive activity. For monitoring individual patients, both for response to initial therapy and during maintenance, a modified Sulcus Bleeding Index (mSBI) with three bleeding scores is recommended in preference to dichotomous scoring of bleeding.