bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzyme activity in human gingival crevicular fluid: considerations in data reporting based on analysis of individual crevicular sites
Authors: Lamster Ira B. , Oshrain Richard L. , Gordon Jeffrey M.
Published: December 2005

Abstract Using a reproducible approach to collection, processing and analysis of gingival crevicular fluid (GCF). this study examined 284 fluid samples from individual crevicular sites for the presence of the enzymes lactate dehydrogenase (LDH), B‐glucuronidase (BG) and arylsulfatase (AS). 88 of the sites were from periodontally healthy individuals (probing depth 1–3 mm), while 98 sites from patients with periodontitis were examined before and 2 weeks after scaling and root planing (probing depths 1–3 mm. 4–6 mm and 7–10 mm). This study demonstrated the sensitivity of the enzyme assays. When GCF was collected with a 30‐s insertion of the filter strip, 90% of the sites from the control subjects demonstrated LDH activity, 85% demonstrated BG activity and 73% demonstrated AS activity. For the 1–3 mm sites from the patients with periodontitis. 100% of sites from which fluid was collected demonstrated LDH and BG activity, and 90% of sites had AS activity before therapy. After therapy, 100% of sites demonstrated LDH activity, 90% had BG activity and 83% had AS activity. All sites in the 4–6 mm and 7–10 mm categories demonstrated activity of all 3 enzymes. The data were analyzed in terms of enzyme activity/30‐s sample and as concentration of enzyme in a standard volume of GCF. Enzyme activity/30‐s sample was a different and possibly more sensitive indicator of periodontal pathology than standard clinical parameters. There was a disassociation between clinical parameters and the data for enzyme analysis when it was reported as concentration.
Periodontal disease in Down's syndrome: a review
Authors: Reuland‐Bosma Wimke , van Dijk Johan
Published: December 2005

Abstract Cross‐sectional as well as longitudinal studies indicate that the prevalence of periodontal disease in persons with Down's syndrome (DS) under the age of 30 years is extremely high. It is even noted in the deciduous dentition. The progression of the disease is rapid, especially in the younger age groups. Severe periodontal breakdown with horizontal bone loss is often present in the lower anteriors. The large amount of plaque and calculus alone cannot explain the severity of periodontal disease in DS persons. Many contributing factors are reported. Abnormal capillary morphology, disorders in connective tissue and anatomical aspects of teeth are some of those considered to be of influence. Alteration in immunological response may also play a rôle in the progression of the disease process. Disorders in the polymorphonuclear leucocyte function and monocyte function have been reported in persons with DS. T‐cell functioning declines after the first 10 years of life. T‐cell lymphocyte counts are low and an immature subset of T‐lymphocytes is present. This latter effect occurs especially in institutions where the immunological system is under stress. The altered immune response together with higher calculus scores may explain the difference in severity of periodontal disease between institutionalized DS children and those living at home.
The antimicrobial and clinical effects of a single subgingival irrigation of chlorhexidine in advanced periodontal lesions
Authors: Lander P. E. , Newcomb G. M. , Seymour G. J. , Powell R. N.
Published: December 2005

Abstract The antimicrobial effects of subgingival chlorhexidine (CH) irrigations on the pathogenic flora in advanced periodontal lesions were assessed. Changes in the patterns of colonization within the subgingival sites were monitored by differential dark‐field microscopy, in 16 patients, over a period of 10 weeks. In addition, changes in the clinical parameters of the diseased sites were also monitored.

Initial base‐line evaluations were made for both the clinical and microbiological parameters. 4 sites of moderate to advanced periodontal disease were selected in each patient. These were randomly irrigated with a single dose of either 0.2% CH gel, 0.2% CH solution, or physiological saline, while 1 site was left as a control. The patients were seen weekly, until the 5th week, then at the 7th and 10th weeks. At each appointment, a microbiological sample was taken from the subgingival region of each site, together with an assessment of the clinical indices. Results indicated that a single irrigation of an 0.2% solution of CH or 0.2% CH gel had a marked effect in decreasing the % of spirochaetes and, to some extent, motile bacteria. There was a concomitant shift in colonization to cocci, fusiform and filamentous organisms in pockets that were irrigated; this coincided with a reduction in the % of bleeding sites. Various patterns of colonization were observed which have been described and may assist in differential dark field (DDF) monitoring of lesions. Bleeding on blunt probing was found to be correlated with a flora dominated by spirochaetes. No other correlations were found over the 10‐week period between the other parameters.

The therapeutic effect of a single application of CH gel and solution did not exceed 10 weeks and a peak response was recognised at 2 to 4 weeks. It was concluded that treatment regimes involving CH irrigation could be undertaken on a monthly basis. No differences in efficacy could be found between the use of CH gel and solution.
Metronidazole: a double‐blind trial in untreated human periodontal disease
Authors: Watts Trevor , Palmer Richard , Floyd Peter
Published: December 2005

Abstract The effect of metronidazole was assessed in 20 subjects with untreated periodontitis, in a double‐blind trial. Subjects received a 1‐week course of drug or placebo immediately after baseline examination, and were reassessed 1 month and 3 months later. A 0.25 N constant force probe and darkfield microscopy were used. At 1 month, a difference was observed between the deepest individual pockets in experimental and control groups, with regard to change in probing depth and the proportions of non‐motile organisms. At 3 months, differences were observed in 1–3 mm baseline pockets, where a greater proportion of control pockets increased in probing depth, and in 4–6 mm pockets, where a greater proportion of baseline bleeding pockets had ceased to bleed in the experimental group. The differences were of limited clinical significance when compared to studies where metronidazole was used as an adjunct to other therapy, and the results were equivocal with regard to the specific plaque hypothesis, since inhibition of connective tissue attachment loss was not unambiguously demonstrable.
Chlorhexidine compared with other locally delivered antimicrobials
Authors: Addy M.
Published: December 2005

Abstract Based on the association of bacterial plaque with the initiation of chronic gingivitis and progression of chronic periodontitis, chemical antiplaque agents have been employed both in prevention of periodontal disease and its treatment. In supragingival plaque control regimens, chlorhexidine has not been superceded as a chemical anti‐plaque agent, although other compounds have been shown to be useful. The local side‐effects of chlorhexidine and other cationic antiseptics, however, limit their long‐term use for prevention. Extrinsic tooth staining in particular remains the greatest problem. Short‐term anti‐plaque uses for chlorhexidine include (1) as an adjunct to mechanical cleaning in the initial oral hygiene phase of treatment, (2) in situations where mechanical oral hygiene is difficult, including (i) postsurgery. (ii) intermaxillary fixation, (iii) fixed orthodontic therapy, (iv) physically and mentally handicapped individuals, (v) systemic diseases with oral manifestations such as leukaemia. More recent interest in chlorhexidine has resulted from the delivery of compounds subgingivally in the treatment of chronic periodontitis. Such methods have extended the use of chlorhexidine into areas inaccessible to the action of antimicrobial drugs delivered locally by conventional means, such as tooth brushing or mouth rinsing. Available evidence suggests that chlorhexidine may not be as effective as some antimicrobial drugs whose activity is more specific for those organisms considered particularly pathogenic to the periodontal tissues.
Topical antimicrobial therapy and diagnosis of subgingival bacteria in the management of inflammatory periodontal disease
Authors: Rosling B. G. , Slots J. , Christersson L A. , Gröndahl H. G. , Genco R. J.
Published: December 2005

Abstract Bacterial specificity in human periodontal diseases suggests the possibility of diagnosing and treating periodontitis as specific infections and using microbiological diagnostic means to evaluate the efficacy of periodontal therapy. In a series of clinical trials, the usefulness of topical antimicrobial agents in combination with surgical and non‐surgical conventional periodontal therapy were tested. The healing result was estimated by monitoring probing attachment levels (PAL). The usefulness of clinical and microbiological parameters to evaluate post‐treatment healing result was tested. 9 of the patients exhibiting sites with recurrent periodontal disease were then evaluated for clinical and microbiological parameters to define accurate means to differentiate between active and inactive periodontal disease. The results showed that the frequency of periodontal lesions with significant loss of PAL after treatment was less in patients treated with antimicrobial agent. Specific microbiological parameters showed stronger correlation than clinical parameters with gain and/or loss of PAL post‐treatment. Thus Actinobacillus actinomycetemcomitans and Bacteroides gingivalis occurred in periodontal lesions with progressing disease after treatment, but were rarely detected in samples from pockets of the same depths which did not exhibit further loss of PAL over a study period of 1 year. This study points to the usefulness of topical antimicrobial agent as an adjunct to mechanical subgingival debridement in the treatment of periodontitis in adults. The results also indicate the utility of diagnostic microbiology in the assessment of periodontal disease activity post‐treatment.
Inhibition of fibroblast attachment
Authors: Heaney T. G.
Published: December 2005

Abstract Reattachment is at present an ephemeral goal. There is. therefore. much interest in clarifying the events which determine patterns of cellular repopulation of denuded cementum during periodontal healing, and thus determine the outcome of reattachment surgery. It has previously been reported that human saliva inhibits the initial attachment or subsequent locomotion of human gingival fibroblast‐like cells on plastic substrata in vitro, and that this property is a function of a high molecular weight sulphated glycoprotein in saliva. Recent work reported here shows that saliva in vitro also inhibits attachment to human cementum in serum‐free medium. This effect can be reversed by superficial citric acid (pH 1.0) demineralisation of saliva‐treated cementum. However, demineralisation itself does not augment cell attachment to either saliva‐coated or normal cementum compared with controls. It is postulated that (i) adsorption of saliva on cementum in vivo may lead to periodontal wound healing by repair (long junctional epithelium) rather than by regeneration of ligament and cementum; (ii) a novel explanation for the previously reported efficacy of citric acid in wound healing might be related to its ability to remove adsorbed saliva from the root surface and thus permit early root colonisation by connective tissue cells.
The significance of coronal growth of periodontal ligament tissue for new attachment formation
Authors: Isidor Flemming , Karring Thorkild , Nyman Sture , Lindhe Jan
Published: December 2005

Abstract The present study was designed to examine whether coronal growth of granulation tissue originating from the periodontal ligament is a prerequisite for new attachment formation.

In each of 4 monkeys, 1 central incisor and 2 first molars in the maxilla and the mandible were selected for experimentation. Angular bony defects were surgically produced to the mid‐root level around each single root after crown resection and root separation of the multirooted teeth. The periodontal ligament tissue and the root cementum were removed to the bottom of the bony defects. In half the number of the teeth, an elastic ligature was placed tightly around each root at the bottom of the defects (test roots). In the remaining teeth, an elastic ligature was placed loosely around each root at the same level (control roots). All roots were subsequently covered by laterally displaced flaps. After 3 months of healing, the animals were sacrificed and the jaws removed and placed in fixative. Following decalcification, histological sections of the experimental roots and their surrounding periodontal tissues were produced.

The histological analysis disclosed that new attachment had former to a level coronal to the elastic ligature in 10 of 14 control roots but in only 1 of 18 test roots. The results indicate that the repopulation of a detached root surface by cells from the periodontal ligament is a prerequisite for new attachment formation.
Clinical and microbiologic effects of single‐dose metronidazole or scaling and root planing in treatment of adult periodontitis
Authors: Walsh M. M. , Buchanan S. A. , Hoover C. I. , Newbrun E. , Taggart E. J. , Armitage G. C. , Robertson P. B.
Published: December 2005

Abstract Sites affected with adult periodontitis were observed for 3 months to compare their clinical and microbiologic responses to (1) a single 2 g dose of metronidazole, (2) scaling and root planing, or (3) no treatment. 2 sites with probing depths ≥5 mm in each of 18 female subjects (6 in each treatment group) were evaluated clinically (plaque and bleeding indices, probing depth, attachment loss) and microbiologically (%s of cocci, motile rods, non‐motile rods and spirochetes, and of obligate anaerobic colony‐forming units, black‐pigmented Bacteroides, Fusobacterium and Actinobacillus actinomycetemcomitans in subgingival plaque). No significant differences in these variables existed between the 3 groups at baseline. The no‐treatment (control) group showed no substantial clinical or microbiologic changes during the study. After 1 month, scaling and root planing had effected significant clinical improvement and significant shifts in the subgingival flora to a pattern more consistent with periodontal health; these changes were still evident at 3 months. In contrast, 1 month after metronidazole, there was some clinical improvement and a significant increase in cocci and a decrease in motile rods, but at 3 months these changes were no longer evident. The results show that the benefits of scaling and root planing are sustained for at least 3 months. However, the benefits of a single 2 g dose of metronidazole are both few and transient, indicating that this regimen, while effective against anaerobic infections in other organ systems, is not clinically or microbiologically effective in the treatment of adult periodontitis.
A perspective on periodontal diagnosis
Authors: Listgarten Max A.
Published: December 2005

Abstract Periodontal diseases are best considered as the outcome of an imperfect host‐parasite interaction. In most cases, diagnosis involves labelling certain clinical manifestations without a complete understanding of the causes of the disease. Therefore, treatment based on the “diagnosis” is not necessarily logical or effective. As the causes which underly the disease become more evident, the underlying mechanisms of disease can be used to refine our diagnostic methods. For example, deficiencies in host defenses, or the presence or increased proportions of certain bacterial pathogens may be indicative of imbalances in the normal host‐parasite equilibrium. For a laboratory test to be reliably applied to the diagnosis of a clinical condition, it is essential that an absolute criterion of the clinical disease first be established. Then the sensitivity and the specificity of the test can be determined using appropriate experimental designs. The demonstration of a good correlation between a test outcome and a clinical condition is, of itself, insufficient grounds to use the test for diagnostic purposes.
Radiographic quantification of alveolar bone level changes
Authors: Albandar Jasim M. , Rise Jostein , Gjermo Per , Johansen Jan R.
Published: December 2005

Abstract The “random burst” theory has recently been proposed as an explanation of the pattern of periodontal disease progression. The theory predicts that the progression of bone loss at individual sites is not dependent upon previous bone loss and age. A longitudinal radiographic study was designed to test this hypothesis, and to describe the changes in bone level over 2 years in a group of 180 subjects (18–68 years of age) who were not under systematic periodontal treatment.

The results indicated that 94% of the sites did not show significant changes in the alveolar bone level during the observation period. The mean annual bone loss for the total population was 0.11 mm. By regressing longitudinal bone loss upon age, it was shown that the rate of bone loss increased rapidly between 33 and 56 years of age while a different pattern was shown for the age intervals 18–32 and 57–68 years. Also, the rate of bone loss increased with increasing initial bone loss. This was less evident in the oldest age group. It was concluded that the progression of bone loss in the present material is consistent with a “burst” theory. However, the progression did not occur randomly with regard to previous loss of alveolar bone and time.
The effects of periodontal treatment on mucous membrane thickening in the maxillary sinus
Authors: Falk Hanne , Ericson Sune , Hugoson Anders
Published: December 2005

Abstract This study was performed to elucidate the effect of periodontal treatment on the sinus mucosa. 21 patients with periodontal lesions of the upper molars and/or premolars and chronic mucous membrane thickening in the maxillary sinus diagnosed radiographically participated in the study. No teeth in the regions studied showed pulpal or periapical changes. Altogether, the patients exhibited 36 maxillary sinuses with mucous membrane thickening. 15–20 months after the final periodontal treatment, a marked reduction of the plaque index, gingival index and probing depth was recorded. Radiographic examination of the sinus mucosa before and after periodontal treatment showed that successful periodontal treatment in all quadrants resulted in normalisation of the sinus mucosa. Periodontal treatment was not successful in 2 quadrants. In one of these cases the thickness of the mucosa was unchanged and in the other case, further thickening of the mucosa seemed to have occurred. The study shows that severe periodontitis of the upper molars and/or premolars may initiate mucous membrane thickening in the maxillary sinus, and that successful periodontal treatment results in normalisation of the sinus mucosa.
Epidemiology of gingivitis
Authors: Stamm John W.
Published: December 2005

Abstract In recent years, tremendous strides have been made in understanding the etiology of gingivitis. This increase in knowledge has come, for the most part, from basic research in oral microbiology, immunology, histology and pathology. Over the past decade, less progress has been made in further refining the epidemiological relationships between gingivitis and various host and environmental factors. The major restraint has been the great difficulty in reliably measuring gingival inflammation. This problem has resulted in great inter‐ and intra‐study variation in diagnosing the prevalence and severity of gingivitis in human populations. Consequently, it is almost impossible to estimate longitudinal trends in gingivitis and it is nearly as difficult to make comparisons among different population groups studied by different examiners. Nevertheless, by focusing on the most apparent and robust epidemiological relationships, an instructive overview of the epidemiology of gingivitis can be gained. A number of host and environmental factors have been studied in relation to gingivitis and some of these will be reviewed.

With respect to age, there is general concensus that marginal gingivitis begins in early childhood, increases in prevalence and severity to the early teenage years, thereafter subsiding slightly and leveling off for the remainder of the second decade of life. Gingivitis during the adult period is much more difficult to characterize due to paucity of data. Estimates of the general prevalence of adult gingivitis vary from approximately 50 to 100% for dentate subjects. In terms of gingivitis prevalence, the dentate elderly do not deviate appreciably from the general adult pattern. When adjusted for cohort effects, gingival disease appears to be on the decline.

With the exception of the puberty period, females generally exhibit lower gingivitis prevalence and severity than males. An appreciable number of women exhibit more severe gingivitis during periods of pregnancy.

Accurate data comparing gingivitis prevalence between blacks and whites indicate that the former generally experience higher mean levels of gingival inflammation. Frequently, this difference has been partially explained by co‐factors such as oral hygiene, socio‐economic status and access to dental care. Longitudinal data on race and gingivitis prevalence are not particularly reliable. Bacteria in the gingival crevice and on the gingival margin are most directly responsible for gingivitis. Epidemiologically, this factor may be indirectly assessed by an oral hygiene index. Not surprisingly, the oral hygiene score is most closely correlated with gingivitis among all epidemiological factors. Additional factors which have been assessed for their impact on gingivitis are smoking habits, fluoride use and recent antibiotic history.
Current status of indices of plaque
Authors: Fischman Stuart L.
Published: December 2005

Abstract Microbial plaque has been described by the Council on Dental Therapeutics of the American Dental Association in their recently drafted Guidelines for acceptance of products for the management of dental plaque and gingivitis. The choice of an index system to be used in plaque trials should be made in terms of the objective of the trial, the size of the population, the period of the study, and the type and extent of change anticipated. The indices currently in use estimate the quantity of plaque in terms of tooth area covered or the thickness of material in the area measured. The Silness and Loe and the modified Turesky methods have been suggested as acceptable indices for the estimation of cleansing ability.
A comparison of 3 clinical indices for measuring gingivitis
Authors: Bollmer B. W. , Sturzenberger O. P. , Lehnhoff R. W. , Bosma M. L. , Lang N. P. , Mallatt M. E. , Meckel A. H.
Published: December 2005

Abstract A clinical study was conducted among 200 adult males and females to compare the intrusive gingival index (GI) for estimating gingivitis with the non intrusive and only visually applied papillary‐marginal‐gingivitis index (PMGI). The GI examinations were performed by a senior examiner with long experience and a junior examiner, while the PMGI was graded by only a senior examiner with long experience. A 4th examiner was included for grading bleeding sites by gentle intrusion at the orifice of the gingival crevice. Following the baseline examination by all examiners, the subjects were randomly assigned to either a group that received an oral prophylaxis immediately or to a group that received an oral prophylaxis 6 weeks after the baseline. All subjects were regraded by all examiners 4 days after the 2nd group received a prophylaxis. This delayed prophylaxis design created a difference in the responses between treatment groups. Both the GI examiners and the PMGI examiner concluded there was significantly less gingivitis in the group receiving a prophylaxis second. There were also significantly fewer bleeding sites in the group receiving a prophylaxis second as determined by both GI examiners and the bleeding‐sites examiner.
Design and analysis of plaque and gingivitis clinical trials*
Authors: Chilton Neal W. , Fleiss Joseph L.
Published: December 2005

Abstract It is most important that the proper design of a clinical trial be developed prior to the start of the study. Such a design is one that will not tend to find a treatment to be effective when it really is ineffective, and will not tend to miss a good treatment when it really is effective. The questions to be answered by a clinical trial must be decided in advance and will help determine the design. Trials should take into consideration how the agent is to be used: carefully controlled, ordinary use, subject or professionally applied, etc. The double‐blind parallel randomized trial is preferred to the double blind cross‐over design, except possibly for a professionally applied treatment which does not leach into the saliva or affect the oral microflora. Blocking or stratification tends to increase the efficiency of a clinical trial, and also may produce more information on the agent's effectiveness. Stratification is preferred to blocking, particularly when subjects enter the trial serially over time. Subjects should be stratified by age, sex and baseline level of plaque or gingivitis. Stratification permits a check on whether the effect of treatment is atypically strong or weak for certain types of patients. Where possible, the same examiner should examine the same patients throughout the study. Examiners should be self‐calibrated to reduce intra‐examiner error. Plaque and gingivitis trials should be at least of 6 months duration and may be preventive or therapeutic in nature. The preferred statistical analysis when 2 treatments are being compared is a comparison of mean changes in plaque or gingivitis scores by the independent sample t‐test. An analysis of covariance using the baseline scores as the covariate may improve power somewhat. When pairwise f‐tests are performed in comparing several treatments, multiple comparison criteria are indicated. Parametric rather than nonparametric tests are preferred since they usually have more power. The square root of whole mouth means in gingivitis clinical trials is the preferred transformation to obtain greater power and to produce approximately normal distributions.
Design of clinical trials for chronic diseases: implications for periodontal disease
Authors: Goldberg Judith D. , Weiss Arnold I. , Koury Kenneth J.
Published: December 2005

Abstract In order to make effective use of the statistical theory of design of clinical trials for chronic diseases such as periosontal disease, certain issues must be considered. Any clinical trial requires that the disease definition be well‐specified; that patient eligibility be explicit; that the observation times be explicit; that the duration and endpoint of therapy be specified; that the duration of subsequent followup observation be specified; and that the unit of observation (e.g., tooth, set of teet, patient) be defined. In a chronic disease, the potential biases that can readily be introduced by self‐selection of patients who enter the trial and/or who return for subsequent observation become more important, because subjects are required to remain on treatment and/or observation for prolonged periods. Further, the cyclical nature of some chronic diseases may require special attention to baseline definitions of active disease and disease outcome.

These issues are illustrated with examples from clinical trials of hypertension, breast cancer screening, and Polycythemia Vera. Implications for periodontal disease are discussed.
Pathogenesis of periodontitis
Authors: Listgarten Max A.
Published: December 2005

Abstract Periodontitis is an inflammatory disease of the periodontium which is characterized by a progressive destruction of the tissues supporting the tooth. Its primary etiology is an ill‐defined series of microbial infections which may be composed of only some of the more than 300 species of bacteria currently recognized in the oral cavity. The disease is currently considered to progress as periodic, relatively short episodes of rapid tissue destruction followed by some repair, and prolonged intervening periods of disease remission. Despite the apparent random distribution of episodes of disease activity, the resulting tissue breakdown exhibits a symmetrical pattern of alveolar bone loss and pocket formation which is common to several forms of periodontitis, although the distribution of the most affected teeth and surfaces may vary among diseases (e. g., juvenile periodontitis versus adult periodontitis or rapidly progressive periodontitis). Several reports have indicated that bacterial cells can be found in the pocket wall of periodontitis lesions. The translocation of bacteria into the tissues from the pocket environment is quite common, as evidenced by the common occurrence of bacteremias in patients with periodontitis following relatively minor events such as chewing and oral hygiene procedures. However, it is important to distinguish between the passive introduction of bacteria into periodontal tissues and frank invasion as might occur in an acute infection, since the pathological implications may be quite different.
Design of clinical trials of traditional therapies of periodontitis
Authors: Lindhe Jan , Socransky Sigmund , Wennström Jan
Published: December 2005

Abstract The present paper on the design of clinical trials of periodontal therapy first addresses the issue of the etiology of periodontal disease. It is suggested that most if not all forms of destructive periodontal disease are caused by microorganisms and that there are different forms of disease with different microbial etiologies. The progressive nature of destructive periodontal disease is subsequently discussed and it is emphasized that, in a given patient, periodontal sites which show signs of inflammation and attachment loss may not over a period of several months and years show further sign of attachment loss. The present methods of assessing periodontal disease do not allow us to discriminate between potentially active and inactive sites in untreated patients. The significance and variability of indicators of periodontal disease such as bleeding on probing, probing pocket depth and probing attachment level measurements are discussed. The errors inherent in the various measurements are analyzed and suggestions are presented describing how alterations in any of the above parameters could be identified and presented in a clinical trial. Of concern for the statistical analysis of clinical data of periodontal disease is the definition of the “experimental unit”. For a number of years, the “experimental unit” in periodontal trials was the patient. It is clear, however, that different sites within the same individual show different patterns of disease progression and lesion morphology and often respond differently to periodontal therapy. Statistical analyses must consequently be designed which recognize differences in site‐to‐site infection and lesion morphology within a common host. Until such analyses are available, the investigator should be wary of pooling data within the same individual, since such pooling may obscure meaningful alternatives which may take place in individual periodontal sites.

Some goals of periodontal therapy are subsequently identified. 4 goals are discussed more in detail, namely:

to establish conditions which will allow the patient to maintain a dentition without further breakdown of the periodontium;

to reduce pocket depth to establish an anatomy in the dentogingival region which with proper maintainance care will prevent the re‐establishment of the subgingival infection;

to gain attachment as a result of treatment;

to assess the effect of a certain chemotherapeutic agent on periodontal disease.
The effect of dentifrices containing zinc citrate on plaque growth and oral zinc levels
Authors: Saxton C. A. , Harrap G. J. , Lloyd A. M.
Published: December 2005

Abstract. Zinc salts have previously been shown to possess antiplaque activity in solution but this activity has as yet not been reported for dentifrices. The purpose of the present investigation was to establish the effect of dentifrices containing zinc citrate (ZCT) on plaque growth and on the concentration of zinc in saliva and plaque. Plaque growth inhibition was studied over periods of time approximating to intervals for normal oral hygiene procedures. Zinc in saliva and plaque was measured by atomic absorption spectroscopy.

Elevated zinc levels in saliva were observed for 3–4 h after brushing with the zinc citrate dentifrice. Similarly, raised levels of zinc were encountered in plaque 1 h following contact with a slurry of a dentifrice containing ZCT. Increased concentrations of zinc were observed in plaque fluid and plaque residue.

The plaque growth data from 88 participants in 5 studies revealed that plaque regrowth over 16 h or 22 h was reduced by dentifrices containing 0.5% ZCT, compared to placebo dentifrices. Dentifrices which contained 0.5% ZCT or 0.4% stannous fluoride, had similar inhibitory effects on plaque.

Further analysis of the data showed that subjects with high rates of plaque growth benefited more from the zinc dentifrices than those with low rates of plaque growth. It is suggested that the effect on plaque was related to zinc concentration in the dentifrice rather than total dose applied, and that the main effect of zinc was to inhibit the extension of existing plaque.
False results associated with darkground microscopy of subgingival plaque
Authors: Omar A. A. , Newman H. N.
Published: December 2005

Abstract. This study considers false results which may arise due to problems in the preparation or examination of specimens for darkground microscopy of subgingival plaque. Subgingival plaque samples obtained with a sterile curette were placed in 0.1–0.3 ml sterile full or 1/4 strength Ringer's solution: 0.85% saline, 1% gelatin in 0.85% saline, formal saline or pyrogen‐free water for injection. Test slides were prepared from the original dispersion, and control slides from the corresponding sterile solution. Optimal dispersion solution, syringe dispersion frequency and the effect on motility of delay in processing samples were tested. Slides were also prepared from dispersions of 11 representative subgingival “periodontopathic” organisms. Problems in sampling included variability in counts between sites with comparable pocket depths, contamination of the sample and reduction of the sample volume after scaling. Problems in dispersion included contamination, uneven distribution of the different morphotypes and destruction of delicate organisms. Problems in slide preparation included slide contamination, limitation in the number of samples that can be assessed by one examiner at a given time without loss of activity of motile cells, and preparation of a cell monolayer. Problems in identification and counting included confusion of Brownian movements with motility, coccoid particles with cocci, spirochetes with campylobacter, flagella with flagella‐like structures, size of cocci, counting of fragmented spirochetes and non‐motile flagellated organisms and motile cells, and also bias in counting. Problems in morpbotype grouping included the observation that many (10 of the 11 representative) periodontitis‐related organisms were in the non‐motile groups and not all cells of the motile species (Campylobacter, Capnocytophaga) showed motility.

The results indicate that each stage of subgingival plaque darkground microscopy, sampling, dispersion, slide preparation, counting, morphotype grouping and interpretation may lead to false results if not representative or reproducible. Procedures are suggested for the minimisation of problems in the preparation and examination of subgingival plaque specimens for darkground microscopy.
The cleaning efficiency of different toothbrushes in children
Authors: Bastiaan Ross J.
Published: December 2005

Abstract. A 2‐way, blind, cross‐over study was carried out to compare the plaque‐removing effects of a double‐headed toothbrush with a popular single‐headed flat toothbrush in 34, 11‐ to 13‐year‐old boys. Both brushes were used with a modified Bass technique for 3 weeks each. The results of the study indicated that lingually, the double‐headed brush was superior to the single‐headed brush whilst bucally no difference was found. Although the overall plaque‐removing effect of both brushes was similar. 95% of the children preferred the single‐headed brush to the double‐headed brush.
Long‐term periodontal status of labially erupted canines following orthodontic treatment
Authors: Årtun Jon , Osterberg Stig K. , Joondeph Donald R.
Published: December 2005

Abstract. Periodontal status was studied at the mesiobuccal. midbuccal and distobuccal aspects of contralateral pairs of canines in 22 postorthodontic patients aged 30 to 51 years with a mean time of 26.4 years (SD, 5.6) out of active treatment. The pretreatment models showed one canine erupting severely to the labial (“ectopic”) with a contralateral canine in good arch alignment (control). None of the patients experienced relapse of the “ectopic” canine in a labial direction, and none had missing teeth, malalignment, overhanging restorations or open tooth contacts adjacent to the canines evaluated. Periodontal parameters were examined using a Michigan #0 probe with Williams markings. A non‐standardized light force was used and the measurements were rounded to the nearest millimeter. The results demonstrated statistically significant differences between the canines in probing attachment and bone levels (mean, 0.75; SD, 0.92; P<0.01) and width of attached gingiva (mean. 0.50; SD, 1.07; p<0.05) at the midbuccal aspects. The reason for these differences could only be speculated upon.
In vivo differentiation of progenitor cells of the periodontal ligament
Authors: Aukhil I. , Simpson D. M. , Suggs C. , Pettersson E.
Published: December 2005

Abstract. The present study was designed to test the hypothesis that during regeneration of cementum, the progenitor cells from periodontal ligament must come in contact with root dentin in order to differentiate into cementoblasts. After reflecting mucoperiostea flaps, fenestration wounds were made in the buccal cortical plates of mandibular canines in 6 beagle dogs. The exposed root surfaces were curretted to remove all cementum. The exposed root surface on one side was demineralized with citric acid while the contralateral wound had saline treatment. The exposed root surfaces were then dried and pieces of Nucle‐pore membrane (pore size 0.1 μ) were attached to part of the exposed root surface to prevent contact of progenitor cells with root dentin. The fenestration wounds were then covered with Millipore filter to facilitate the population of wounds by progenitor cells from the periodontal ligament. Histologic analysis was performed after 3 months of healing.

In specimens where the Nuclepore membrane had remained attached to root dentin, no new cementum was seen over the membrane. At the borders of the wounds and in specimens where the Nuclepore membrane had detached from root dentin. new connective tissue attachment was consistently seen. Also, root resorption was very rarely observed in both the acid‐treated and control specimens.

The present findings suggest that contact with root dentin may be necessary for progenitor cell differentiation into formative cells like cementoblasts.
New views on the construction of human gingival epithelium
Authors: Andersson Anders , Klinge Björn , Warfvinge Karin
Published: December 2005

AbstractThe effects on the basal and spinous layers of human keratinized oral epithelium of 2 glutaraldehyde‐based fixatives with buffers hypoosmolar and isoosmolar to blood, respectively, have been investigated. The first‐mentioned solution produced an electron microscopic image corresponding to the classical view, that is an epithelium consisting of closely‐packed cells having short and stubby membrane projections and separated by an extremely narrow intercellular space. In the Langerhans cells, the specific granules appeared racket‐shaped and had a unilaminar limiting membrane with a periodic structure along its internal face. There are strong reasons to believe that these morphological characteristics are swelling artifacts. The last‐mentioned fixative produced keratinocytes provided with numerous microvilli and membrane ruffles and disk‐shaped Langerhans cell granules surrounded by a trilaminar membrane. Concomitantly, the intercellular space appears very wide and there is evidence for the view that this is a more realistic picture of the in vivo situation and not a gross distortion caused by shrinking during the tissue processing. Broad interstices can explain certain basic events as rapid cell motility within the epithelium and offer efficient pathways for rapid transport of substances.
Thresholds of hypersensitive teeth to 2 forms of control led stimulation
Authors: Orchardson R. , Collins W. J. N.
Published: December 2005

Abstract 2 new methods are described for measuring the sensitivity of dentine to mechanical (probe) and cold‐air stimulation. The methods are suitable for clinical use and could be used in the evaluation of desensitising treatments. In addition to qualitative differences in the pattern of sensitivity of teeth to these stimuli, considerable variation was observed in the distribution of pain thresholds to probe and air stimulation. Thresholds were not significantly affected by the age or sex of the subjects, but mean thresholds of teeth sensitive to only one stimulus were significantly greater than thresholds of teeth sensitive to both stimuli; these differences were most marked in female subjects. Factors such as the qualitative differences in sensitivity to various stimuli and quantitative differences in the degree of sensitivity to the stimuli require to be considered in clinical evaluation of desensitizing treatments.
Examiner agreement in estimating changes in periodontal bone from conventional and subtraction radiographs
Authors: Gröndahl K. , Gröndahl H.‐G. , Wennstrom J. , Heijl L.
Published: December 2005

Abstract It has previously been shown that computer‐assisted subtraction of serially‐obtained radiographs yields a higher degree of accuracy in the detection of small changes in the marginal periodontal bone than conventional radiographs. This study concerns another important aspect of such diagnostic methods, namely the intra‐ and inter‐examiner agreement rates. On 10 patients with moderate to severe periodontal bone loss involved in a clinical trial to evaluate the effectiveness of subgingival antimicrobial irrigation, conventional radiographs were taken at baseline and after 32 and 52 weeks. The changes in terms of gain or loss of bone occurring between the examination at baseline and that after 32 weeks, as well as those occurring between the examination performed after 32 weeks and that made after 52 weeks, were evaluated by means of conventional radiographs and by subtraction images. Both types of image were interpreted by each of 4 observers. The images were read a 2nd time after a period of at least 2 weeks. The inter‐observer as well as the intra‐observer agreement were assessed by calculating 3 different measures of agreement: the overall agreement, the specific agreement and the ‐a value. Regardless of measure, higher inter‐observer agreement rates were found for all observers when the subtraction technique was employed. A similar pattern was found with respect to the intra‐observer agreement rates.
Hygiene status associated with different types of bonded, orthodontic canine‐to‐canine retainers
Authors: Årtun Jon , Spadafora Agnes T. , Shapiro Peter A. , McNeill R. William , Chapko Michael K.
Published: December 2005

Abstract The present study was performed to test whether bonded, orthodontic canine‐to‐canine retainers made of spiral wire tended to accumulate more plaque than retainers made of plain wire, and whether the presence of such retainers caused any damage to the teeth involved, 44 patients were classified in eight strata according to age, gender and gingival status. From each stratum, the patients were randomly divided into 4 groups, each of which received either retainers made of thick plain wire bonded only to the canines, thick twisted wired bonded only to the canines, thin twisted wire bonded to each tooth or removable retainers. Accumulation of plaque and calculus along the gingival margin and gingival inflammation were scored in lingual areas from canine to canine at time of fixed appliance removal and again 4 months after retainer insertion. In addition, accumulation of plaque and calculus and development of caries along the retainer wires were scored after 4 months. The results revealed no differences between the groups for any of the variables. No differences in accumulation of plaque was found between baseline and follow‐up examinations. Gingival bleeding was scored less frequently after 4 months in retention than at time of debonding.
The capability of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius to indicate progressive periodontitis; a retrospective study
Authors: Bragd Lennart , Dahlén Gunnar , Wikström Maude , Slots Jörgen
Published: December 2005

Abstract This study evaluated the statistical association of Actinobacillus actinomycetemcomitans. Bacteroides gingivalis and Bacteroides intermedius with progressive periodontitis. 146 adults with a history of advanced periodontitis contributed 105 “nonprogressing” and 130 “progressing” periodontal sites, Periodontal disease activity was assessed by radiographic changes in crestal alveolar bone level. The subgingival proportion of the 3 test bacteria was determined by selective and nonselective culturing. The relationship between bacterial proportions and disease progression was evaluated using subgrouping and multiple‐regression analyses. All 3 test bacteria had to be considered in order to distinguish nonprogressing and progressing periodontitis with a reasonably high sensitivity. A recovery rate below 0.01% for A. actinomycetemcomilans. 0.1% for B. gingivalis and 2.5% for B. intermedius defined a site with nonprogressing disease with 87% sensitivity and 84% specificity. By utilizing transformed values of the bacterial recovery rates and optimal test criteria determined by multiple regression analysis. it was possible to obtain sensitivities between 83% and 95% and specificities between 86% and 69%. These 3 bacterial species might serve as valuable components of a periodontitis activity test based on microbiological variables.