Evaluation of a simple modified radiographic alignment system for routine use.

Radiographic frames used for longitudinal studies may be in part unreadable for measuring crestal bone change. Sites may not be present on the film, or the measurement reliability may be compromised because of dissimilar geometry. Several techniques used to address this problem are expensive, time-consuming, and required great skill. For the present study a commercially-available alignment system was simply modified by addition of a reference pin in the bite block, facilitating the repositioning of the film holder for a second exposure. This study determined the ability of the modified instrument to: 1) improve the geometrical correspondence between serial radiographs; and 2) reduce the frequency of missed sites in the film. Two pairs of x-rays were taken for each of 40 subjects, 1 pair with the standard alignment instrument of an assigned site and 1 pair with the modified instrument of the contralateral site. Measurements of alveolar bone height were performed using the "side by side" technique. The modified instrument yielded significantly smaller measurement differences and a significantly better geometrical correspondence than the conventional system (P < 0.05). Also, the modified instrument yielded significantly greater (P < 0.01) readable sites (86%) as compared to the conventional instrument (62%). The simply-modified instrument facilitates the correct interpretation of serial radiographs.

Suppression of subgingival Actinobacillus actinomycetemcomitans in localized juvenile periodontitis by systemic tetracycline.

The current study assessed the clinical and microbiological effects of systemic antimicrobial therapy alone in Actinobacillus actinomycetemcomitans-infected adolescents with periodontal disease. The study involved 6 localized juvenile periodontitis patients 13-18 years of age, who harbored high numbers of A. actinomycetemcomitans in subgingival plaque samples. The periodontal lesions were microbiologically monitored by selective culture, and clinically assessed for probing pocket depth and periodontal attachment level 3 months prior to baseline, and at 3, 6, 12, and 24 months posttreatment. Tetracycline-HCl (250 mg/QID) was prescribed until 1 week after subgingival A. actinomycetemcomitans was no longer detectable or for a maximum of 8 weeks. During 3 months prior to treatment, pocket depth was unchanged, and was then significantly reduced from an average of 7.1 mm to 5.1 mm 12 months after treatment (p = 0.02). The mean change in clinical attachment level was a gain of 1.4 mm between baseline and 12 months (p = 0.02). 3 of the 6 patients were still infected with A. actinomycetemcomitans after 8 weeks of antibiotic therapy and 4 subjects were infected at 12 months. Numbers of A. actinomycetemcomitans were still suppressed in most lesions. There was a strong association between mean numbers of A. actinomycetemcomitans in periodontal pockets and mean change in probing attachment level at any given time point. For 22 available comparisons, derived from all time points, there was a strong association (r = 0.68) between subgingival A. actinomycetemcomitans and change in probing attachment level.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevention of transmission of resistant bacteria between periodontal sites during subgingival application of antibiotics.

This study was designed to investigate whether antibiotic resistant micro-organisms are able to contaminate and survive on syringe tips used for subgingival deposition of antibiotics, and to test simple and effective means of disinfecting the syringe tip between applications. In the first part of the study, syringe tips used for application of Minocycline subgingival formula in 20 adult periodontitis patients were cultured for bacteria resistant to this drug before and after disinfecting them with ethanol. The results showed that 80% of the unwashed syringes were culture positive for minocycline resistant bacteria, whereas only 1 ethanol washed syringe tip was contaminated. In part II of the study, after dispensing minocycline periodontal formula in 20 patients, 10 of the syringe tips were washed with ethanol while 10 were left untreated. All syringes were stored in a refrigerator for 8 days, whereafter the tips were sampled for resistant bacteria. 20% of the unwashed tips were contaminated after 8 days incubation at 4 degrees C. None of the ethanol washed syringe tips were culture positive. We conclude that syringe tips may be contaminated with antibiotic resistant bacteria after dispensing the antibiotic in periodontal pockets. The transmission of these bacteria to other periodontal sites may be avoided by disinfecting the syringe tip with ethanol between applications. We have also shown that antibiotic resistant bacteria may survive on the syringe tip following 8 days storage in a refrigerator, suggesting that syringes used for subgingival deposition of an antibiotic should not be stored for reuse.

Alternative methods for screening periodontal disease in adults.

Clinical measurements of periodontal attachment loss, while not always representing the histological changes, are used to establish the diagnosis of adult periodontitis. Such measurements are difficult to perform accurately and are labor intensive. To counter these problems, index teeth and index sites have been employed in an attempt to estimate the severity of the periodontal condition without the need to resort to elaborate attachment measurements. Unfortunately, such indices usually tend to underestimate prevalence while often overestimating severity. The purpose of the present study was to examine the correlation of alternative clinical, radiographic and microbiological parameters, with periodontal disease using the diagnostic criteria of established periodontitis. 508 adults included in this study received thorough periodontal examination which included probing pocket depth, clinical attachment level, plaque, gingival and calculus scores, together with radiographic analysis and assays of subgingival periopathogenic microorganisms. Radiographic alveolar bone loss and probing pocket depth had the highest correlation with clinical attachment loss (phi = 0.72 and phi = 0.75 respectively). Plaque scores (phi = 0.17), like gingival scores (phi = 0.06) and calculus scores (phi = 0.42) had poor correlation with established periodontitis. Periodontopathogenic species demonstrated high specificity and negative predictive values; but low sensitivity and positive predictive values make for an overall low correlation of these species with established periodontitis. However, when used in a logistic regression model, the presence of P. gingivalis (odds ratio = 6.25) has shown to contribute significantly to the estimate of probability for established periodontitis. The use of these various alternative parameters for screening of periodontal disease is discussed in light of their sensitivity, specificity and predictive value.

Topical application of tetracycline-HCl in human periodontitis.

Previous in vitro studies have suggested that tetracycline-HCl (TTC-HCl) is adsorbed and actively released from root dentin. The aim of the current study was to evaluate the binding to and release of TTC-HCl from human root dentin surfaces in vivo, and to evaluate the clinical utility of TTC-HCl irrigation as an adjunct to scaling and root planing. Experiment I utilized two contralateral mandibular single-rooted teeth which were examined in four adults with severe generalized periodontitis. One tooth in each patient was carefully scaled and root planed, under local anesthesia, and the other used as an unscaled control. Each subgingival root surface was irrigated for 5 min with an aqueous TTC-HCl solution at a concentration of 100 mg/ml. Gingival crevicular fluid samples were collected on paper strips for the next three weeks. The TTC-HCl concentrations in each sample were determined by the inhibition zone of B. cereus cultured on agar plates. The TTC-HCl concentrations in gingival crevicular fluid collected 15 min after irrigation were 3100 +/- 670 micrograms/ml from the scaled lesions and 4700 +/- 1300 micrograms/ml from the unscaled root surfaces. The antibiotic concentrations decreased logarithmically over the next 7 days; 1500 +/- 270 micrograms/ml and 1100 +/- 330 micrograms/ml at 2 h, 880 +/- 350 micrograms/ml and 1300 +/- 360 micrograms/ml at 6 h and 19 +/- 5 micrograms/ml and 31 +/- 26 micrograms/ml at 1 week for scaled and unscaled root surfaces, respectively. Results for week two and three indicated an average of over 8 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinobacillus actinomycetemcomitans and localized juvenile periodontitis. Clinical, microbiologic and histologic studies.

The present studies examined Actinobacillus actinomycetemcomitans and its role in localized juvenile periodontitis (LJP). The distribution of the bacteria was studied in healthy normals, patients with adult periodontitis, diabetics, and those with LJP. Over 95% of the LJP patients harbored A. actinomycetemcomitans, whereas only 17% of healthy subjects, 21% of adult periodontitis patients, and 5% of diabetics were positive. All members of a LJP family harboring the organism yielded isolates of the same biotype and serotype. The transmission of the bacteria was studied after transfer of the bacteria, with periodontal probes from infected to healthy gingival sites, within the oral cavity of LJP patients. Newly colonized gingival sites, 50% of those involved, became free of A. actinomycetemcomitans after only 3 weeks. A purposely forceful inoculation contributed to a more predictable colonization (89%), but only prolonged the colonization with one week. Treatment of LJP lesions with scaling and root planing resulted in minimal clinical and microbiological changes during a 16 week follow-up period. However, gingival curettage and modified Widman flap surgery suppressed A. actinomycetemcomitans in 75% and 89% of the sites, and resulted in resolution of periodontal pocket depth and gain in attachment level. Gingival tissue specimens, from 35 LJP sites, 3 control sites, and one monkey biopsy, were studied to verify the hypothesis of gingival infiltration of A. actinomycetemcomitans. Bacteria were identified immunohistologically with rabbit antisera serospecific to the three A. actinomycetemcomitans serotypes. Positive staining was observed in the tissue from all but one LJP patient. Twenty-eight (80%) lesions were positive for A. actinomycetemcomitans antigens in the gingival connective tissue, often with antigens located both between and within cells. The specimen from a culture positive control demonstrated no signs of invasion, similar to the monkey specimen. Transmission electron microscopic examination verified gram-negative bacteria that appeared as single microbes or small clusters in the connective tissue. The viability of the invading bacteria was studied by selective culture of minced tissue specimens and a series of washing solutions, after a rigorous surface disinfection. The washings successfully removed the bacteria in most cases, and after mincing 73% of the biopsies showed to be culture positive. The culture recovery of A. actinomycetemcomitans from minced tissues correlated exceedingly well with the presence of specific antigens in the gingival tissues from corresponding gingival biopsies. To further demonstrate the importance of A. actinomycetemcomitans in LJP, six culture positive LJP patients were treated by systemic tetracycline alone.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of removable partial denture framework design on gingival inflammation: a clinical model.

A clinical trial using the experimental gingivitis model developed for periodontal clinical research was performed to evaluate the effect of a removable partial denture mandibular major connector design on the surrounding gingival tissues. A comparison of the state of health of adjacent gingival tissues was made between the linguoplate (control) and cingulum bar (test) major connectors. Clinical parameters were recorded in a single-blind crossover experimental gingivitis trial. Subjects were brought to a level of optimal gingival health and then randomly assigned to use one framework design while refraining from any oral hygiene. Measurements were made at 7-day intervals for 21 days. The subjects were returned to optimal oral health and repeated the experimental period with the alternate design. Results showed a greater increase in mean gingival inflammation with the control than with the test removable partial denture, suggesting that the cingulum bar has fewer detrimental effects on gingival tissues than the linguoplate major connector. Results of this study suggest that the experimental gingivitis model can be a useful and valid system for studying the potential effects of a removable partial denture design on surrounding oral tissues.

Computerized methodology for detection of alveolar crestal bone loss from serial intraoral radiographs.

The aim of this study was to develop a computerized measurement system for analysis of unstandardized serial radiographic images. A new approach for estimating the error associated with the determination of alveolar crest loss is described. The study shows that a difference of 0.87 mm in cemento-enamel junction-crest measurement between unstandardized serial radiographs taken within accepted clinic routine is required for a significant loss in crestal bone height. The ability to detect with significance a difference of less than 1 mm in crestal bone height makes the appropriate use of traditional bite-wing radiographs a useful diagnostic tool for the assessment of periodontal maintenance.

Dental plaque and calculus: risk indicators for their formation.

The aim of this study was to determine the levels of plaque and subgingival calculus accumulation and to evaluate their correlations with periodontal disease, as well as to evaluate the correlations with race, age, and gender in an attempt to identify risk indicators for plaque and calculus formation. A total of 508 adults 25-73 years of age was examined, and plaque assessment, gingival bleeding assessment, probing pocket depth, and attachment levels were determined. The mean percent visible plaque was 73.5% (range, 8.3-100%), mean percent of bleeding surfaces 38.5% (range, 0-100%), and the mean percent teeth with subgingival calculus 39.6% (range, 0-100%). The mean probing pocket depth in the group was 2.5 +/- 0.6 mm (SD), and mean clinical attachment loss was 2.1 +/- 1.1 mm. The majority (63%) were classified as having "Moderate" periodontal disease, 7% were "Healthy", and the remaining 30% had "Established" periodontal disease. Plaque and calculus showed statistically significant relationships to the three disease categories (p less than 0.001). Multiple step-wise regression analyses on the correlations between plaque and periodontal disease, race, age, and gender resulted in an overall correlation coefficient of r = 0.25 (p less than 0.001). Disease status ("Established") contributed most (p = 0.003), followed by race (Blacks; p = 0.015), gender (Males; p = 0.022), and age (55-73 yr; p = 0.022), to the correlation with plaque. For subgingival calculus, the overall correlation coefficient was r = 0.44 (p less than 0.001). However, only two of the variables--namely, disease status (p less than 0.001) followed by race (p = 0.017)--showed statistically significant correlations.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of a social cognitive intervention on oral health status, behavior reports, and cognitions.

An intervention designed to test the influence of cognitive restructuring on protective oral health behaviors was conducted with 108 patients with mild to moderate gingivitis. Subjects in the experimental group viewed slides of active, mobile bacteria taken from their mouths on 5 occasions: before and after prophylaxis and at 3 appointments, one month apart. A specially trained hygienist discussed with these participants the process of periodontal disease, the role of bacteria, and self-efficacy (self-control) for oral hygiene self-care. Both experimental and control group subjects received instruction in oral self-care procedures. Assessments of oral health using Löe and Silness' plaque and gingival indices (PI and GI) were taken throughout the study and at 3- and 6-month follow-up visits. Self-efficacy, oral hygiene intentions, attitudes, and values comprised the set of cognition variables. Plaque and gingival indices mean differences between groups approached significance at visit 6. Analyses were also performed using percent of gingival surfaces scored at "0" (no visible bleeding on probing). A trend occurred for group differences in percent "0" scores at visit 6, with the experimental group maintaining higher percent zeros (better health) at this 3-month follow-up. At visit 7 (9-month follow-up), PI and GI differences disappeared. No significant differences were found between groups for oral health cognitions or behavior reports over time. The data suggest that the cognitive-behavioral intervention produced a delayed relapse in protective oral self-care behaviors, and by extension, oral health status. Such a delay could be clinically relevant in promoting adherence to oral hygiene behavior between professional visits.

Analysis of site specific periodontal bacteria sampling schemes.

A great deal of controversy has existed in the periodontal literature as to whether the site or the subject should be the unit of analysis. Using the site as the unit of analysis assumes that observations of sites within the same subject are independent and ignores between subject variation. The purpose of this report is to evaluate the influence that the unit of analysis has on estimating the number of necessary site specific bacterial samples from each subject. The number of bacterial samples per subject was defined as the number of samples that would insure a clinician at a 95% confidence level that, if the bacteria were present in a subject, it would be discovered. From two data sets in which 20 to 30 bacterial samples were taken from each subject and data generated from a simulation, appropriate within-subject sample size was determined. In one data set the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, and Prevotella intermedia was determined by indirect immunofluorescence. In the other data set the presence of A. actinomycetemcomitans, P. gingivalis, and P. intermedia was determined using DNA probes. Results of this study demonstrate that there is a large between subject variation in site specific bacterial prevalence, as indicated by an elevated intraclass correlation. Simulated data in this report demonstrated that the number of necessary bacterial samples per subject increased with increasing values of intraclass correlation. The number of necessary within subject samples also increased with decreasing prevalence rate. For A. actinomycetemcomitans, which had a low prevalence rate (0.11 to 0.18), the number of necessary samples per subject was very high (31 to 35).(ABSTRACT TRUNCATED AT 250 WORDS)

Subgingival distribution of periodontal pathogenic microorganisms in adult periodontitis.

The association between specific plaque microorganisms and periodontal diseases has been the subject of much recent interest due to its potential importance in the diagnosis and classification of these diseases. In order to optimize microbiological tests in periodontal therapy, it is important to know how many subgingival plaque samples must be assayed from a single patient in order to ascertain infection with a periodontal pathogen. To answer this question the present study assessed the distribution of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, and Prevotella intermedia in multiple subgingival plaque samples. The samples were quantitatively assessed for specific bacteria by indirect immunofluorescence, a technique previously found to correlate well with cultural assessment of these same organisms. Subgingival plaque from the mesial pockets/sulci of all teeth except third molars was sampled in 12 patients with adult periodontitis, 22 to 28 sites/patient for a total of 315 samples. These patients demonstrated an average mesial probing depth and loss of attachment of 3.7 +/- 1.2 mm and 3.1 +/- 1.5 mm, respectively (mean +/- SD). P. gingivalis, P. intermedia, and B. forsythus were demonstrated in one or more sites from all patients, while A. actinomycetemcomitans was found in one or more sites in 8 of 12 patients. The proportion of positive sites per subject varied, but it was, on average, similar for the 3 black-pigmented organisms and ranged from 44% to 54%. In contrast, A. actinomycetemcomitans was identified, on average, in only 11.4% of the sites in these same patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical criteria for the definition of "established periodontitis".

The objective of The Present study was to define criteria for the diagnosis of "established periodontitis." This term will define subjects who have demonstrated clinical attachment loss, and as such can be considered to have periodontitis. Using these criteria, healthy and established periodontitis subjects were compared with respect to gender, race, and age. Five hundred and eight subjects including 248 females and 260 males between the ages of 25 to 73 (mean 44.6 years), were examined in this study. The clinical examination included: plaque assessment index (PAI); gingival assessment index (GAI); probing pocket depth (PPD); and clinical attachment level (CAL). The mean and frequency distribution of these parameters were analyzed by age and gender. CAL (mean 2.12 mm) showed constant and significant increases with age, ranging from a mean of 1.63 mm in subjects 25 to 34 years of age to a mean of 2.65 mm in subjects 65 to 74 years of age. Males exhibited higher mean values than females for all the measured parameters, which were statistically significant for PAI, PPD, and CAL. The frequency distribution of subjects with PPD and CAL beyond certain threshold levels showed an exponential decline and was correlated to both the severity of the most involved site as well as the number of sites beyond threshold levels. The clinical entity of "established periodontitis" is suggested based on the presence of CAL greater than or equal to 6 mm in 2 or more teeth and one or more sites with PPD greater than or equal to 5 mm. In the present study, 30.5% of the subjects fell into this category.(ABSTRACT TRUNCATED AT 250 WORDS)

Humoral immunity of older adults with periodontal disease to Porphyromonas gingivalis.

The effect of age on the humoral response to Porphyromonas gingivalis was assessed in groups of adults (25 to 54 years and 55 to 74 years) with periodontal disease and compared with that in age-matched healthy controls. To determine whether there was an antibody response against P. gingivalis, we measured serum antibodies against whole cells of P. gingivalis 381, A7A1-28, and W50. In addition, antibody levels against purified P. gingivalis outer membrane proteins (i.e., the 43-kDa fimbrial protein and a 75-kDa protein) were also evaluated. Elderly subjects showed the same response to P. gingivalis as younger subjects. Immunoglobulin G (IgG) antibodies to both purified proteins were also elevated in both diseased groups as compared with the normal groups. Total serum IgG, IgA, and IgM levels were also determined by an enzyme-linked immunosorbent assay for all four groups. Total serum IgG levels were elevated in older adults with periodontitis and total IgA levels were elevated in both groups of older adults compared with the younger groups of similar disease status. Total serum IgM levels were comparable for the four groups. Antinuclear antibody titers were assessed in the two groups of older adults and were also found to be higher for the group with periodontitis. These studies show that older adults as well as younger adults have markedly elevated specific antibodies of the IgG and IgA classes to antigens of P. gingivalis, a putative pathogen in both groups. Furthermore, older adults with periodontitis have significantly elevated levels of total serum IgG which may possibly be related to higher levels of autoantibodies.

Dental bacterial plaques. Nature and role in periodontal disease.

Antony van Leeuwenhoek first described oral bacteria. However, not until almost 200 years later was the famous Koch postulate introduced. Since then, research has extensively been performed regarding the development and microbiology of dental plaques. In spite of the complexity of the developing flora of supragingival plaque, culture studies have shown a remarkably orderly succession of organisms. Lately, the concept of microbial specificity in the etiology of periodontal diseases has been widely suggested, i.e., that different forms of periodontal disease are associated with qualitatively distinct dental plaques. Cross-sectional and longitudinal studies of the predominant cultivable microflora reveal that only a small number of the over 300 species found in human subgingival plaques are associated with periodontal disease. Among the commonly mentioned are: Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, Bacteroides intermedius, Capnocytophaga sp., Eikenella corrodens, Fusobacterium nucleatum, and Wolinella recta, as well as certain gram-positive bacteria such as Eubacterium species. Anti-infective therapy for many systemic infections equals the use of antimicrobial drugs. However, for localized infections like periodontal diseases, treatment may consist of a combination of mechanical wound debridement and the application of an antimicrobial agent. The general effectiveness of mechanical anti-infective therapy and successful oral hygiene in the management of periodontal disease is well established in the literature and has met the test of success in clinical practice for most cases of periodontitis in adults. The definition of periodontal pathogens as either opportunistic pathogens, or as exogenous pathogens carries with it significant implications.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of subgingival irrigation on A. actinomycetemcomitans.

The effects of repeated subgingival irrigation on Actinobacillus actinomycetemcomitans was examined. 24 periodontal pockets harboring A. actinomycetemcomitans in 3 juvenile and 4 adult periodontitis patients were studied. The protocol included bi-weekly subgingival irrigation with hydrogen peroxide of the periodontal sites until the micro-organism was no longer detected by selective culture, or for 6 months. A. actinomycetemcomitans was gradually suppressed to below detection following the irrigation regime and could no longer be detected in 46% of the sites at completion of the irrigation protocol. The sites were microbiologically re-examined 5 months after cessation of the irrigation regime. A. actinomycetemcomitans re-occurred in only 2 of the sites from which it had originally been suppressed below detection. The results indicate: (1) that the irrigation regime tested has some potential to suppress A. actinomycetemcomitans in periodontal pockets; (2) that the effect of the irrigation protocol generally lasted for 5 months; (3) that the reduction rate of A. actinomycetemcomitans to below detectable levels seems related to the initial number of cultivable bacteria from the periodontal pocket.