bluuebunny/crossref_metadata_2025 huggingface dataset:
The Immune Modulation of B‐Cell Responses by Porphyromonas gingivalis and Interleukin‐10
Authors: Champaiboon Chantrakorn , Yongvanitchit Kosol , Pichyangkul Sathit , Mahanonda Rangsini
Published: February 2005

Background: Polyclonal B‐cell activation induced by periodontopathic bacteria has been cited as being important for elevated numbers of B cells, but the role of bacteria in the pathogenesis of periodontal disease remains unknown. In this study, we used an in vitro model to investigate the activation of immune cells by the periodontopathic bacterium Porphyromonas gingivalis in healthy subjects.

Methods: Peripheral blood mononuclear cells (PBMC) or purified subsets of lymphocytes were stimulated with sonicated extracts of P. gingivalis for 24 hours. Cells were harvested and monitored for expression of CD69 by flow cytometry. Cytokine production (IL‐10, IL‐12, and IL‐15) in P. gingivalis‐stimulated PBMC cultures was measured by ELISA. To identify IL‐10 producer cells, a cell depletion experiment was used and confirmed by the ability of the purified cell population to produce IL‐10. To evaluate the effect of P. gingivalis and IL‐10, the proliferative response of purified B cells was assessed by [3H] thymidine uptake.

Results: PBMC cultured with P. gingivalis led to a large number of activated B and natural killer (NK) cells as monitored by CD69 expression. When positively sorted cells were used, the bacterium itself could directly activate only B cells but not NK cells, αβ, and γδ T cells. Measurement of B‐cell regulatory cytokine production in P. gingivalis‐stimulated PBMC cultures revealed a large amount of IL‐10 but no detectable IL‐12 or IL‐15; the major producing cells were monocytes, not B cells orαβ T cells. When IL‐10 was added to B cells in the presence of bacteria, significantly increased B‐cell proliferative responses were observed.

Conclusions: These results suggest that P. gingivalis, both directly and indirectly via macrophage IL‐10, may play an important role in polyclonal B‐cell activation associated with periodontal disease. J Periodontol 2000;71:468‐475.
Cyclic Tension Force Activates Nitric Oxide Production in Cultured Human Periodontal Ligament Cells
Authors: Kikuiri Takashi , Hasegawa Tomokazu , Yoshimura Yoshitaka , Shirakawa Tetsuo , Oguchi Haruhisa
Published: February 2005

Background: Nitric oxide (NO) is involved in a number of physiological and pathophysiological processes. The aim of this study was to examine the ability of human periodontal ligament (PDL) cells to produce NO and whether mechanical forces could induce NO production in the PDL cells.

Methods: Human PDL cells were seeded onto flexible bottoms of a culture plate and subjected to cyclic tension forces. NO production was evaluated by measuring concentration of NO2‐ and NO3‐ (NO2‐/NO3‐), the oxidized products of NO, in the culture medium. We employed reverse transcription polymerase chain reaction (RT‐PCR) methods to detect NO synthase mRNA in the PDL cells. NO synthase immunoreactivity was also evaluated in both stimulated and unstimulated PDL cells.

Results: In unstimulated PDL cell culture, NO2‐/NO3‐increased to 140% of the initial value in 12 hours. In contrast, NO2‐/NO3‐ showed a 3‐fold increase when the cells had been subjected to cyclic tension forces for 12 hours. The increase in NO production was blocked by NG‐monomethyl‐L‐arginine (5 × 10‐4 M), an inhibitor of NO synthase. Endothelial NO synthase (ecNOS) mRNA was expressed in both stimulated and unstimulated PDL cells, whereas inducible NO synthase (iNOS) mRNA was detected in neither culturing condition. We found strong ecNOS but not iNOS immunoreactivity in the stimulated PDL cells.

Conclusions: These results suggest that human PDL cells produce NO by ecNOS and that the production is enhanced by stimulating the cells with cyclic tension forces. Mechanically stimulated PDL cells may modulate the function of periodontium by the upregulated NO production. J Periodontol 2000;71:533‐539.
The Effect of Inter‐Implant Distance on the Height of Inter‐Implant Bone Crest
Authors: Tarnow D.P. , Cho S.C. , Wallace S.S.
Published: February 2005

Background: The biologic width around implants has been well documented in the literature. Once an implant is uncovered, vertical bone loss of 1.5 to 2 mm is evidenced apical to the newly established implant‐abutment interface. The purpose of this study was to evaluate the lateral dimension of the bone loss at the implant‐abutment interface and to determine if this lateral dimension has an effect on the height of the crest of bone between adjacent implants separated by different distances.

Methods: Radiographic measurements were taken in 36 patients who had 2 adjacent implants present. Lateral bone loss was measured from the crest of bone to the implant surface. In addition, the crestal bone loss was also measured from a line drawn between the tops of the adjacent implants. The data were divided into 2 groups, based on the inter‐implant distance at the implant shoulder.

Results: The results demonstrated that the lateral bone loss was 1.34 mm from the mesial implant shoulder and 1.40 mm from the distal implant shoulder between the adjacent implants. In addition, the crestal bone loss for implants with a greater than 3 mm distance between them was 0.45 mm, while the implants that had a distance of 3 mm or less between them had a crestal bone loss of 1.04 mm.

Conclusions: This study demonstrates that there is a lateral component to the bone loss around implants in addition to the more commonly discussed vertical component. The clinical significance of this phenomenon is that the increased crestal bone loss would result in an increase in the distance between the base of the contact point of the adjacent crowns and the crest of bone. This could determine whether the papilla was present or absent between 2 implants as has previously been reported between 2 teeth. Selective utilization of implants with a smaller diameter at the implant‐abutment interface may be beneficial when multiple implants are to be placed in the esthetic zone so that a minimum of 3 mm of bone can be retained between them at the implant‐abutment level. J Periodontol 2000;71:546‐549.
Pocket Oxygen Tension in Smokers and Non‐Smokers With Periodontal Disease
Authors: Hanioka Takashi , Tanaka Muneo , Takaya Keiko , Matsumori Yukiko , Shizukuishi Satoshi
Published: February 2005

Background: Smoking is associated with destructive periodontal disease. Pocket oxygen tension (pO2) is likely to be a major environmental determinant of the subgingival microflora, which is a primary etiological factor of the disease. This study aimed to compare the pocket pO2 in smokers and non‐smokers with periodontal disease.

Methods: Pocket oxygen tension was compared in 27 smokers and 34 non‐smokers by considering 2 confounding factors, probing depth and oxygen saturation of hemoglobin (So2), in the gingiva. The pO2 was determined using oxygen microelectrode by polarographic method with an electronic compensation circuit for subgingival temperature. Gingival So2 was determined using tissue reflectance spectrophotometry.

Results: No significant difference was found in the modified gingival index and the plaque index between smokers and non‐smokers. The pO2 was significantly lower in smokers (21.9± 9.6 mmHg) than in non‐smokers (33.4 ± 8.4 mmHg). The difference was highly significant (P <0.0001) and was consistent when the confounding factors were considered. Correlation between the pO2 and probing depth approached statistical significance in smokers (r = ‐0.36, P = 0.0674) and significance in non‐smokers (r = ‐0.41, P = 0.0174). Correlation of the pO2 to the gingival So2 was highly significant in non‐smokers (r = 0.57, P = 0.0005), but no association was found in smokers (r = ‐0.08, P = 0.6975).

Conclusions: These findings indicate that pO2 is lower in smokers than in non‐smokers, and that the pO2 in smokers is not influenced by gingival oxygen sufficiency. The present study may provide the basis of understanding environmental factors possibly associated with microbial flora in the pockets of smokers. J Periodontol 2000;71:550‐554.
Outcome Variables in Periodontal Research: Means and Threshold‐Based Site Changes
Authors: Machtei Eli E. , Schmidt Millicent , Hausmann Ernest , Grossi Sara , Dunford Robert , Davies Glenn , Chandler Julie , Genco Robert J.
Published: February 2005

Background: The exclusive use of mean measurements in periodontal research might at times be misleading, as changes in different sites in the same individual might nullify each other. The purpose of the present study was to compare disease progression and response to periodontal therapy using both individual site activity with thresholds and mean patient changes.

Methods: Seventy‐nine (79) subjects with established periodontitis were monitored for 1 year (no treatment [NTx] group); 108 subjects who received scaling, root planing, and quarterly prophylaxis were observed in a similar time interval (treatment [Tx] group). Probing depth (PD), attachment level (AL) and alveolar crestal height (ACH) were measured at baseline and 1 year using pressure‐sensitive probes and computer‐assisted image analysis of radiographs.

Results: Mean reduction in PD (0.50 mm) was observed in the Tx group compared to a small increase (‐0.04 mm) in the NTx group (P = 0.0001). Treatment resulted in mean AL gain (0.44 mm) compared to net AL loss (‐0.21 mm) in the NTx group (P = 0.0001). Subjects in the Tx group had twice as many sites with AL gain (beyond the threshold) compared to NTx subjects (16.64 ± 1.07% versus 8.11 ± 0.68%) which was highly significant (P = 0.0001, Student t test). Similarly, although in the opposite direction, percentage of sites with AL loss beyond threshold was 6.21 ± 0.47% (Tx group) and 14.02 ± 1.15% (NTx group) which was also highly significant (P = 0.0001, Student t test). Change in ACH was minimal for the Tx group (‐0.07 ± 0.03 mm) while NTx subjects experienced greater bone loss throughout the year (‐0.16 ± 0.02 mm); percentage of sites with ACH loss was similar for both groups, while the Tx group had 3 times the number of sites with ACH gain (11.76% versus 3.42%), suggesting that the reduction in mean bone loss in the Tx group did not result from a reduction in losing sites, but rather from an increase in gaining sites. The use of both means and binary data seems to supplement the information regarding the nature and mechanism of disease progression and arrest.

Conclusions: The characteristics of periodontal disease with its multifactorial patient, local, and site‐related etiology support the use of both mean and site‐based changes in clinical studies of periodontal disease and treatment. J Periodontol 2000;71:555‐561.
Citric Acid Demineralization and Subepithelial Connective Tissue Grafts
Authors: Caffesse Raul G. , De LaRosa Manuel , Garza Marianela , Munne‐Travers Anne , Mondragon Javier C. , Weltman Robin
Published: February 2005

Background: The present study was designed to evaluate the effect, if any, of citric acid root demineralization in the outcome of subepithelial connective tissue grafts performed to cover localized gingival recessions.

Methods: Thirty‐six patients participated, each providing one gingival recession; 19 received citric acid demineralization, while 17 did not. All were treated surgically with subepithelial connective tissue grafts and followed for 6 months. At baseline and 6 months, the following parameters were recorded: plaque index, gingival index, recession height, probing depth, recession width, and amount of keratinized tissue. Data were analyzed statistically to 1) evaluate the results achieved with each procedure individually over time and 2) compare the results obtained with the 2 procedures after 6 months.

Results: Results showed significant reductions in recession height after 6 months independently of whether citric acid was applied or not (2.79 ± 0.79 versus 2.56 ± 0.73). Similarly, recession width was significantly reduced (3.74 ± 1.19 versus 3.50 ± 0.73), and the width of keratinized tissue was significantly increased (2.47 ± 1.6 versus 2.3 ± 1.2). No significant changes in probing depth were found (‐0.16 ± 0.06 versus ‐0.13 ± 0.81). No significant differences were found when both techniques were compared in any one of the parameters analyzed (all P >0.30).

Conclusions: It is concluded that: 1) the subepithelial connective tissue graft procedure provides a satisfactory solution in the treatment of localized gingival recessions, and 2) citric acid demineralization does not affect the clinical outcome of the surgical technique. J Periodontol 2000;71:568‐572.
Periodontal Treatment Decisions for Molars: An Analysis of Influencing Factors and Long‐Term Outcome
Authors: Svärdström Gram , Wennström Jan L.
Published: February 2005

Background: The purpose of this retrospective study was 1) to analyze factors influencing the treatment decision for periodontitis‐affected molars and 2) to evaluate the long‐term outcome of the decision. The treatment alternatives included in the analysis were maintenance of the tooth with only non‐surgically/surgically performed scaling/root planing with or without furcation plasty, root separation/resection, and tooth extraction.

Methods: Data collected from a total of 1,313 first and second molars in 222 patients (mean age 45 years; range 14 to 73 years), referred for periodontal treatment, were analyzed with respect to treatment decisions for furcation‐involved teeth. The patients had been examined with respect to oral hygiene status, gingival conditions, probing depth, furcation involvement, and radiographic bone height before and after active periodontal treatment. Frequencies, mean values and standard deviations were calculated for the various variables assessed. Multiple regression models were formulated in order to analyze the influence of various variables on treatment decisions. One‐hundred and sixty (72%) of the patients agreed to participate in a follow‐up examination to determine the clinical and radiographic status of the molars 8 to 12 years after the active phase of treatment for evaluation of the long‐term outcome of the treatment decision.

Results: Twenty‐eight percent of the molars were extracted and 4% were root separated/resected. Factors found to significantly influence the decision of tooth extraction were tooth mobility, tooth position, lack of occlusal antagonism, degree of furcation involvement, and remaining bone support. Of the factors analyzed with respect to root separation/resection, molar position and degree of furcation involvement showed the strongest influence on the treatment decision. The 8‐ to 12‐year follow‐up examination revealed that 96% of the molars subjected to non‐resective therapy were still in function. The corresponding figure for root separated/resected molars was 89%. Loss of radiographic bone support during the 10‐year follow‐up period was 0.1 to 0.6 mm for the various molars with the highest value for maxillary second molars.

Conclusions: A conservative approach to the treatment of molars with even deep furcation invasions may show a high long‐term success rate, provided maintenance care is offered. J Periodontol 2000;71:579‐585.
Hepatocellular Carcinoma Metastatic to the Oral Mucosa: Report of a Case With Multiple Gingival Localizations
Authors: Maiorano Eugenio , Piattelli Adriano , Favia Gianfranco
Published: February 2005

Background: Metastases to the oral mucosa are rare, representing less than 1% of the tumors at this site. Most of these metastatic neoplasms originate in the lungs, kidneys, and liver.

Methods: The clinicopathologic features of an occult hepatocellular carcinoma, metastatic to the oral mucosa, are reported. The patient, a 70‐year‐old male, complained of 3 distinct polypoid, reddish lesions of the antero‐inferior alveolar crest and both the right and left postero‐superior attached gingiva, without bone involvement. The lesions were excised, with the clinical diagnosis of multiple vascular tumors, formalin‐fixed, paraffin‐embedded, cut and stained with hematoxylin and eosin. Consecutive sections were immunostained for α‐1‐antichymotrypsin, CEA, cytokeratins, EMA, hepatocyte antigen, PSA, S‐100 protein, and thyroglobulin, using the alkaline phosphatase/anti‐alkaline phosphatase technique.

Results: The morphologic features of the lesions were consistent with the diagnosis of carcinoma with trabecular and glandular patterns and bile secretion; furthermore, immunohistochemical reactivity for α‐1‐antichymotrypsin, cytokeratins, CEA, EMA, and hepatocyte antigen was demonstrated and the hepatic origin of the tumor was postulated. Ultrasonography demonstrated a liver mass, which was biopsied and treated by chemoembolization. While no further complications occurred in the oral mucosa, the patient died 8 months after the diagnosis for widespread diffusion of the tumor to the lungs and brain.

Conclusions: This case emphasizes the need to include metastatic tumors in the differential diagnosis of atypical neoplasms of the oral mucosa and to evaluate the opportunity of surgical treatment in order to preserve the functions of the mouth, even if the prognosis of the primary tumors remains unfavorable. J Periodontol 2000;71:641‐645.
Burkitt's Lymphoma Presenting With Jaw Lesions
Authors: Liu Rong‐Sen , Liu Hong‐Chen , Bu Jin‐Qu , Dong Si‐Ni
Published: February 2005

We report an unusual case of Burkitt's lymphoma (BL) presenting with jaw lesions in a 14‐year‐old Chinese boy. The patient presented initially with mobile teeth in all 4 jaw quadrants, with corresponding radiographic detection of alveolar bone crest destruction and periapical bone resorption in the absence of clinically detectable jaw tumors. Moreover, radiographs taken only 17 days later showed clearly distinguishable signs of more extensive alveolar bone destruction compared with the initial radiographs. J Periodontol 2000;71:646‐649.
Cyclosporine A‐Induced Gingival Hyperplasia Pemphigus Vulgaris: Literature Review and Report of a Case
Authors: Oettinger‐Barak Orit , Machtei Eli E. , Peled Micha , Barak Shlomi , L‐Naaj Imad Abu , Laufer Dov
Published: February 2005

Gingival hyperplasia appears in 8% to 85% of patients treated with cyclosporine. Most studies show an association between oral hygiene status and the prevalence and severity of this gingival overgrowth. Thus, besides attempting to substitute this drug with another whenever possible, treatment usually involves maintenance of strict oral hygiene coupled with scaling and root planing and removal of iatrogenic factors. Sometimes a second treatment phase involving periodontal surgery is necessary. Cyclosporine‐induced gingival overgrowth has been mainly described in post‐organ transplant patients. The present case describes, for the first time, a severe form of cyclosporineinduced gingival overgrowth arising in a 15 year‐old male with pemphigus vulgaris. Periodontal treatment included oral hygiene and scaling and root planing under local anesthesia. There was a significant reduction in gingival enlargement, as well as a reduction in plaque levels and inflammation. Cessation of drug administration, combined with continuous periodontal treatment, brought further improvement. This successful conservative treatment of cyclosporine‐induced gingival overgrowth in a pemphigus vulgaris patient suggests that early diagnosis and comprehensive treatment of these lesions may yield good response and reduce the need for periodontal surgery. J Periodontol 2000;71:650‐656.
Position Paper: Diabetes and Periodontal Diseases
Authors:   The Research, Science and Therapy Committee of The American Academy of Periodontology
Published: February 2005

Erratum: The Position Paper on Diabetes and Periodontal Diseases published in the August 1999 issue of the Journal of Periodontology (1999;70:935‐949) contained an erratum. The entire corrected paper is published below.

This position paper on diabetes mellitus was prepared by the Research, Science and Therapy Committee of The American Academy of Periodontology. It is intended to: 1) update members of the dental profession on the diagnosis and medical management of patients with diabetes mellitus; 2) summarize current knowledge on the relation between diabetes mellitus and periodontal diseases; 3) provide an overview of factors in diabetic patients relevant to understanding the pathogenesis of periodontal diseases in these subjects; 4) outline special considerations associated with treatment of periodontal diseases in diabetic patients; and 5) discuss possible approaches to the management of diabetic emergencies in the dental office. J Periodontol 2000;71:664‐678.
Use of a Fluorogenic Septapeptide Matrix Metalloproteinase Assay to Assess Responses to Periodontal Treatment
Authors: Bhide Vinay M. , Smith Lloyd , Overall Christopher M. , Birek Peter , McCulloch Christopher A.G.
Published: February 2005

Background: Quantification of gingival crevicular fluid matrix metalloproteinase activity may provide improved assessment of periodontal disease status and response to treatment. A fluorogenic matrix metalloproteinase substrate assay (FSA) has been developed using a methoxycoumarin‐containing septapeptide analog of the α2(I) collagen cleavage site. This substrate exhibits increased fluorescence following cleavage by many matrix metalloproteinases, and the enzyme activity can be readily estimated with a fluorimeter. Here we compared this assay with classical methods of periodontal assessment including bleeding on probing, crevicular fluid flow, and probing depth to assess its utility as an indicator of changes in periodontal status and treatment response.

Methods: Complete measurements of probing depth were obtained for Ramfjord teeth on subjects who had been previously treated for periodontitis. Subjects were subsequently divided into groups based on existing periodontal disease severity: gingivitis (n = 21), stable periodontitis (n = 41), and severe periodontitis (n = 50). Crevicular fluid volume, bleeding on probing, and FSA were measured at each Ramfjord tooth or substitute. After baseline measurements, subjects received subgingival scaling and prophylaxis; 3 months later, they were reassessed.

Results: FSA measurements were positively associated with severity of disease at baseline. After treatment there were substantial reductions of FSA in gingivitis (∼51%; P <0.01) and severe periodontitis (∼45%; P <0.001), but not in stable periodontitis (13%; P >0.2). All groups showed a positive association between FSA measurements and higher bleeding scores at individual sites. FSA measurements were also positively associated with crevicular fluid flow at baseline, but after treatment there was a ∼67% decrease (P <0.01) in the highest crevicular fluid flow class. There were significant reductions of FSA at follow‐up for sites with probing depths between 0 to 3 mm (23%; P <0.05) and 4 to 6 mm (31%; P <0.05). However, the largest reduction was for sites with probing depth between 7 to 9 mm (49%; P <0.001).

Conclusions: These results indicate that monitoring patients by measurement of matrix metalloproteinase levels in gingival crevicular fluid with the quenched fluorescent substrate assay provides estimates of inflammatory status, periodontal destruction, and response to treatment, especially in more severe periodontitis lesions. J Periodontol 2000; 71:690‐700.
The Detection and Comparison of Angiogenesis‐Associated Factors in Pyogenic Granuloma by Immunohistochemistry
Authors: Yuan Kuo , Jin Ying‐Tai , Lin Ming T.
Published: February 2005

Background: Pyogenic granuloma is a benign inflammatory lesion demonstrating obvious activity of angiogenesis. Female steroid hormones are believed to play important roles in the etiology because the lesion is frequently found in females with high levels of sex hormones. Few molecular mechanisms of the pathogenesis have been proposed and proven. The purpose of this study was to detect and compare the expression of angiogenesis‐associated factors among healthy gingiva, gingiva from periodontitis, and pyogenic granuloma to clarify the pathogenesis of pyogenic granuloma.

Methods: Fifteen specimens were collected from each of 3 groups of gingiva (healthy gingiva, periodontitis, and pyogenic granuloma). The subjects were age and gender matched. The specimens were processed for immunohistochemistry to detect and compare the expression of 2 angiogenesis enhancers, i.e., vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), 2 angiogenesis inhibitors, i.e., angiostatin and thrombospondin‐1 (TSP‐1), and estrogen receptor (ER). Using the subject as the unit of statistical analysis, either analysis of variance or chi‐square analysis was employed to show the statistically significant difference at a level P <0.05.

Results: The pyogenic granuloma group expressed significantly more VEGF and bFGF than healthy gingiva and periodontitis. The positive staining of VEGF was mostly localized in the cytoplasm of macrophages and fibroblasts while that of bFGF was in the extracellular matrix of lamina propria. Angiostatin was expressed significantly less in pyogenic granuloma than the other 2 groups and was mostly localized in the nuclei of endothelial cells and epithelial cells. There was no significant difference in the expression of TSP‐1 and ER among the 3 groups.

Conclusions: The results of this research suggest that the etiology of pyogenic granuloma is due to the imbalance between angiogenesis enhancers and inhibitors. Whether and how the angiogenesisassociated factors are regulated by female steroid hormones remain to be answered. J Periodontol 2000;71:701‐709.
The Effects of Sustained Release Doxycycline on the Anaerobic Flora and Antibiotic‐Resistant Patterns in Subgingival Plaque and Saliva
Authors: Walker Clay B. , Godowski Kenneth C. , Borden Loretta , Lennon Jennifer , Nangó Sonia , Stone Constance , Garrett Steven
Published: February 2005

Background: The purpose of this study was to determine the effects of periodontal treatment with a sustained‐release, biodegradable gel containing 8.5% doxycycline on the anaerobic flora and on antibiotic susceptibility patterns associated with subgingival plaque and saliva.

Methods: Forty‐five subjects with adult periodontitis were entered into a parallel design, single‐blind study of 6 months' duration. The subjects were randomized to receive either doxycycline treatment (n = 23) or oral hygiene instruction/reinforcement (n = 22). Saliva and subgingival plaque samples were collected prior to and at 7, 21, 91, and 182 days after initiation of treatment. The proportion of the cultivable flora resistant to 10 µg doxycycline/ml was determined relative to total anaerobic counts, and the 3 most predominant colony types resistant to doxycycline were individually enumerated. A representative of each was subcultured, identified to genus and species level, and tested for its susceptibilities to 6 antibiotics.

Results: A significant decrease (P <0.01) in total anaerobic counts following doxycycline treatment caused a transient increase in the proportion, but not in the actual counts, of doxycycline‐resistant bacteria recovered from both plaque and saliva at 7 and 21 days but not at 91 or 182 days. The same doxycycline‐resistant taxa were recovered at all sample periods including baseline. Regardless of treatment, the isolates were similarly distributed and belonged to the same bacterial groups.

Conclusions: Doxycycline treatment significantly reduced the anaerobic population in plaque but did not result in a change in either the number of resistant bacteria present or the acquisition of antibiotic resistance. J Periodontol 2000;71:768‐774.
An Evaluation of the Efficacy of a Curved Bristle and Conventional Toothbrush. A Comparative Clinical Study
Authors: Chava Vijay K.
Published: February 2005

Background: The aim of this study was to determine the plaque‐removing ability of a curved bristle toothbrush compared to a conventional, straight bristle, manual toothbrush.

Methods: The study group consisted of 100 volunteers 16 to 24 years of age from a professional engineering college. A fourweek post‐prophylaxis, parallel, longitudinal, double‐blind clinical study was conducted; all volunteers were instructed in specific oral hygiene techniques. Plaque was assessed at baseline and at the end of 1, 2, 3, and 4 weeks using the Quigley‐Hein plaque index after disclosing with erythrosin red. Gingival status was assessed at baseline and at the end of 1, 2, 3 and 4 weeks by using the gingival index of Löe and Silness.

Results: Comparative assessment showed a mean of 2.11 ± 0.086 mm for group 1 and 2.37 ± 0.216 mm for group 2, indicating a significant difference between the plaque‐removing efficacy of the curved bristle and straight bristle toothbrush.

Conclusions: The curved bristle toothbrush was significantly more effective in removing plaque overall than the conventional toothbrush. J Periodontol 2000;71:785‐789.
A Histopathological Investigation on the Effects of the Bisphosphonate Alendronate on Resorptive Phase Following Mucoperiosteal Flap Surgery in the Mandible of Rats
Authors: Kaynak Deniz , Meffert Roland , Günhan Meral , Günhan Ömer , Özkaya Özay
Published: February 2005

Background: The present study was designed to examine histopathologically whether local delivery of aminobisphosphonate (alendronate) could be effective in preventing the alveolar bone resorption associated with mucoperiosteal flaps.

Methods: Following mucoperiosteal flap elevation in the molar region of the rat mandible, a surgical pellet soaked with aminobisphosphonate was locally applied on the exposed bone surface and covered by flap. The determined parameters with a semi‐quantitative subjective method for the histopathological evaluation were as follows: existing inflammatory cell infiltration of the related periodontal tissue; fibrotic component content and bundles of collagen fibers; the number and morphology of osteoclasts of the alveolar bone and interdental septum; existing resorption lacunae (osteoclast surfaces); and existing osteoblastic activity (forming surfaces).

Results: The results showed that while there were no detectable statistically significant differences between the saline and alendronate‐treated groups on the existing inflammatory cell infiltration (ICI), number of osteoclasts, and osteoblastic activity, the results for the fibrotic and collagen component, osteoclast morphologies, and existing resorption lacunae were statistically significant.

Conclusions: These results suggest that local application of the aminobisphosphonate alendronate can be used as an adjunct in therapy for reducing bone resorption following surgery. It can also be suggested for consideration that, even for the surgical approaches in dentistry where bone graft materials and/or dental implants are needed, using bisphosphonate may achieve a new dimension in periodontal therapy in the near future. J Periodontol 2000; 71:790‐796.
The Clinical Effectiveness of Implants Placed Immediately Into Fresh Extraction Sites of Molar Teeth
Authors: Schwartz‐Arad Devorah , Grossman Yoav , Chaushu Gavriel
Published: February 2005

Background: Studies concerning immediate implantation describe its use in the anterior and premolar regions. However, its clinical effectiveness in immediately replacing molar teeth has rarely been challenged. The purpose of this study was to evaluate the survival rate of implants placed immediately after extraction of molar teeth to support a fixed ceramo‐metal prosthesis.

Methods: From 1989 to 1996, 56 immediate implants were placed in 43 patients following extraction of 51 molars; 46 molars were replaced by 1 implant and 5 molars replaced by 2 implants. All implants were restored with fixed prostheses (4 single crowns and 52 splinted). Mean follow‐up period was 15 months (range, 4 to 60 months). The influence of the following parameters on implant failure was evaluated: gender, arch, smoking, pre‐extraction vertical bone loss, implant length, and severity of complications between the two stages of surgery.

Results: The 5‐year cumulative survival rate (5‐year CSR) was 89%. The 5‐year CSR among men was 84% compared to 93.5% among women. The maxillary 5‐year CSR was 82% and the mandibular 92%. Among non‐smokers (50 implants), the 5‐year CSR was 90% compared to 83% among smokers (6 implants). Complications were evident in 8 (6 minor, 2 major) out of 50 non‐failing implants compared to 2 (minor) of the 6 failing implants. No differences were evident in the other study variables.

Conclusions: Immediate implantation in the molar region is an alternative, predictable surgical treatment. Immediate implantation in the posterior mandible has a better prognosis than in the posterior maxilla. J Periodontol 2000;71:839‐844.
Selective Cyclooxygenase‐2 Inhibition Prevents Alveolar Bone Loss in Experimental Periodontitis in Rats
Authors: Bezerra Mirna M. , de Lima Vilma , Alencar Veruska B.M. , Vieira Ivana B. , Brito Gerly Anne C. , Ribeiro Ronaldo A. , Rocha Francisco Airton C.
Published: February 2005

Background: Prostaglandins are implicated in periodontal bone destruction. We investigated the effect of a non‐selective cyclooxygenase (COX) inhibitor (indomethacin‐IND) or a type 2 COX inhibitor (meloxicam‐MLX) in an experimental periodontal disease (EPD) model.

Methods: Wistar rats were subjected to placement of a nylon thread ligature around the maxillary molars and sacrificed after 7 days. Alveolar bone loss (ABL) was measured in one quadrant as the distance between the cemento‐enamel junction and the alveolar bone. The other quadrant was processed for histopathologic analysis. Daily weight and white blood cell count were recorded. Groups were treated subcutaneously for 7 days with either IND (0.5, 1, or 2 mg/kg) or MLX (0.75, 1.5, or 3 mg/kg). Controls received no treatment. Macroscopic analysis of the gastric mucosa was done. The control group did not receive any manipulation, and a non‐treated group consisted of rats subjected to periodontitis that received no pharmacological treatment.

Results: In the non‐treated (NT) group, there was significant ABL, severe mononuclear influx, and an increase in osteoclast numbers. Significant neutrophilia and lymphomonocytosis occurred at 6 hours and at 7 days, respectively, as compared to controls. Significant weight loss persisted until the seventh day in the NT group. Both IND and MLX reduced ABL and histopathologic changes. Neutrophilia and lymphomonocytosis were also significantly reversed. Both IND and MLX induced earlier weight recovery. The stomachs of the IND (1 and 2 mg/kg) groups presented hemorrhage and ulcers, whereas in the MLX‐treated groups, there were mild petechiae just in the 3 mg/kg group.

Conclusions: COX inhibition prevented ABL in this experimental periodontal disease model. MLX displays similar efficacy and less gastric damage than IND. MLX may provide a better risk/benefit ratio in the treatment of human periodontitis than non‐selective COX inhibitors. J Periodontol 2000;71:1009‐1014.
Porous Bovine Bone Mineral in Healing of Human Extraction Sockets. Part 1: Histomorphometric Evaluations at 9 Months
Authors: Artzi Zvi , Tal Haim , Dayan Dan
Published: February 2005

Background: Extraction socket wound healing is characterized by resorption of the alveolar bone at the extraction site. This produces a decrease in ridge volume, deformations of ridge contours, and, thus, difficulties in delayed placement of root‐form implants in an ideal position. Cancellous porous bovine bone mineral (PBBM) applied to fresh extraction sockets has recently been proposed to minimize the reduction in ridge volume. The aim of this study was to investigate the influence of PBBM grafted particles on the histopathologic pattern of the intrasocket regenerated bone and to evaluate histomorphometrically the healed PBBM grafted extraction socket site at 9 months' post‐extraction.

Methods: PBBM particles (250 to 1,000 µ in size) were grafted in 15 fresh human extraction sockets in 15 patients. Socket wall bone height was measured from the crestal ridge level before the mineral particles were inserted. Primary soft tissue closure was performed to protect the grafted particles via a pediculated split palatal flap. At 9 months, socket bone walls were remeasured and cylinder bone samples of the previously PBBM‐grafted sites were obtained. Decalcified specimens were sectioned at a cross‐horizontal plane and stained with hematoxylin and eosin for histopathologic and histomorphologic examination. Tissue area percentage of bone, PBBM, and connective tissue (CT) was calculated for each specimen from the crestal to the apical region and changes in values compared.

Results: Average clinical overall bone fill of the augmented socket sites was 82.3%. Histologically, PBBM particles were observed in all specimens. Newly formed bone was characterized by abundance of cellular woven‐type bone in the coronal area, while lamellar arrangements could be identified only in the more apical region. New osseous tissue adhered to the PBBM. Histomorphometric measurements showed an increase of mean bone tissue area along the histological sections from 15.9% in the coronal part to 63.9% apically (average 46.3%). CT fraction decreased from 52.4% to 9.5% (average 22.9%) from the crestal to the apical region. PBBM area fraction varied from 26.4% to 35.1% (average 30.8%). Statistical analysis of the comparison between areas of bone, CT, and PBBM was performed in different points along the coronal‐apical axis. Differences were significant (P <0.01) at the most crestal, middle, and apical section cut areas, but not at the cervical section cuts. Bone area fraction increased in the apical direction as much as CT correlatively decreased. Unlike CT and bone, PBBM retained constant relative volume (approximately 30%), regardless of the depth of the specimen cores.

Conclusions: PBBM particles are an appropriate biocompatible bone derivative in fresh extraction sockets for ridge preservation. The resorbability of this xenograft could not be recognized in a 9‐month period. Further investigation is needed to clarify the resorptive mechanisms of PBBM. J Periodontol 2000;71:1015‐1023.
“Checkerboard” Assessments of Periodontal Microbiota and Serum Antibody Responses: A Case‐Control Study
Authors: Papapanou Panos N. , Neiderud Anne‐Marie , Papadimitriou Alexandra , Sandros Jens , Dahlén Gunnar
Published: February 2005

Background: We explored the association between subgingival microbial profiles and serum IgG responses to periodontal microbiota in relation to clinical periodontal status.

Methods: One hundred thirty‐one (131) periodontitis patients aged 29 to 74 years (mean 51.8) were ageand gender‐matched with 74 periodontally intact controls (range 26 to 77, mean 49.3). Smoking habits and health history were recorded and assessments of plaque, bleeding on probing, probing depth, and attachment level were performed at 6 sites per tooth on all present teeth, excluding third molars. Subgingival plaque samples were obtained from each tooth in one upper and one lower quadrant (maximum 14 samples/subject; 2,440 samples total) and analyzed with respect to 19 species by means of whole genomic DNA probes. Serum IgG antibodies against the same 19 species were assessed by an immunoassay.

Results: Cases displayed an average of 22.7 teeth, 20.3 sites with probing depth ≥6 mm, and 18.9 sites with attachment loss ≥6 mm. Corresponding figures for controls were 27.1, 0.1, and 1.0, respectively. Heavy smoking was 3 times more frequent among cases than controls (32.1% versus 9.6%). Higher levels of Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, Prevotella nigrescens, Prevotella melaninogenica, Bacteroides forsythus, Fusobacterium nucleatum, Treponema denticola, Eubacterium nodatum, Peptostreptococcus micros, and Campylobacter rectus were found in cases and higher levels of Eikenella corrodens, Veillonella parvula, and Actinomyces naeslundii in controls. Cases displayed higher IgG levels against P. gingivalis and Actinobacillus actinomycetemcomitans, while controls displayed higher levels against F. nucleatum, T. denticola, E. nodatum, and Capnocytophaga ochracea. Positive correlations between bacterial colonization and antibody responses were identified for 9 species in controls. In cases, however, statistically significant correlations were observed for only 3 species out of which only one was positive (V. parvula). Both bacterial levels and antibody responses declined in ages over 55 years. A logistic regression employing selected elements of bacterial colonization and antibody responses as independent variables resulted in 81.1% correct diagnosis, with sensitivity of 83.1%, specificity of 77.8%, positive predictability of 86%, and negative predictability of 73.7%. Smoking did not reach statistical significance in this model.

Conclusion: A combined microbial colonization/antibody response profile can effectively discriminate between periodontitis patients and periodontally intact controls. J Periodontol 2000;71:885‐897.
Evidence for the Role of Highly Leukotoxic Actinobacillus actinomycetemcomitans in the Pathogenesis of Localized Juvenile and Other Forms of Early‐Onset Periodontitis
Authors: Haraszthy Violet I. , Hariharan Govind , Tinoco Eduardo M.B. , Cortelli Jose R. , Lally Edward T. , Davis Elaine , Zambon Joseph J.
Published: February 2005

Background: Actinobacillus actinomycetemcomitans leukotoxin is thought to be an important virulence factor in the pathogenesis of localized juvenile and other forms of early‐onset periodontitis. Some highly leukotoxic A. actinomycetemcomitans strains produce 10 to 20 times more leukotoxin than other minimally leukotoxic strains. The distribution, clonality, and intrafamilial transmission of highly leukotoxic A. actinomycetemcomitans were examined in order to determine the importance of leukotoxin in the pathogenesis of periodontitis.

Methods: The polymerase chain reaction (PCR) was used to differentiate highly leukotoxic from minimally leukotoxic strains in examining 1,023 fresh A. actinomycetemcomitans isolates and strains from our culture collection. These were obtained from 146 subjects including 71 with localized juvenile periodontitis (LJP), 4 with early‐onset periodontitis, 11 with post‐localized juvenile periodontitis, 41 with adult periodontitis, and 19 periodontally normal subjects. The arbitrarily primed polymerase chain reaction (AP‐PCR) analysis of 30 oral isolates from each of 25 subjects was used to determine the intraoral distribution of A. actinomycetemcomitans clones. AP‐PCR was also used to examine the transmission of A. actinomycetemcomitans in 30 members of 6 families. The clonality of 41 highly leukotoxic A. actinomycetemcomitans strains was evaluated by both AP‐PCR and ribotyping.

Results: Highly leukotoxic A. actinomycetemcomitans was found only in subjects with localized juvenile and early‐onset periodontitis. Fifty‐five percent of the LJP subjects harbored highly leukotoxic A. actinomycetemcomitans isolates. Seventy‐three percent of the A. actinomycetemcomitans isolates in these subjects were highly leukotoxic. Highly leukotoxic A. actinomycetemcomitans infected younger subjects (mean age 13.95 years, range 5 to 28 years) than minimally leukotoxic (mean age 35.47 years, range 6 to 65 years). Most subjects were infected with only one A. actinomycetemcomitans genotype. However, PCR of whole dental plaques and subsequent analysis of up to 130 individual oral isolates suggested a possible shift in A. actinomycetemcomitans over time in that a few subjects harbored both highly leukotoxic and minimally leukotoxic strains. AP‐PCR analysis was consistent with intrafamilial A. actinomycetemcomitans transmission. Ribotyping and AP‐PCR analysis confirmed a previous report that highly leukotoxic A. actinomycetemcomitans consists of a single clonal type.

Conclusions: This study suggests that localized juvenile and other forms of Actinobacillus‐associated periodontitis are primarily associated with the highly leukotoxic clone of A. actinomycetemcomitans. J Periodontol 2000;71:912‐922.
Prospective Study on the Augmentation of the Maxillary Sinus With Calcium Sulfate: Histological Results
Authors: De Leonardis Dario , Pecora Gabriele E.
Published: February 2005

Background: The main goal of the sinus elevation procedure is the formation of vital bone to allow the tissue integration of endosseous implants to support prosthetic restorations in the edentulous posterior maxilla. The ideal graft material is yet to be found. The present study investigated the histologic results of a sinus augmentation procedure performed with calcium sulfate as the grafting material.

Methods: The clinical trial consisted of 2 groups: a first (control) group of 12 patients (15 sinuses) in which the material was carefully placed but not stratified. In the second (test) group, 45 patients (50 sinuses) were treated by modifying the application. The calcium sulfate was putty‐like in consistency and placed as it hardened in layers, avoiding fluid contamination. The histologic samples were collected, either at 9 months, at the uncovering procedure (for implants placed simultaneously with grafting material), or at 6 months at the time of implant insertion (for implants placed at a later stage).

Results: The augmentation procedure resulted in good, new tissue formation within the sinuses when clinically and radiographically evaluated. The technique used in the test group produced a reduction in the graft shrinkage during healing, therefore slowing down the material resorption rate. Histologically, new bone formation with progressive lamellar maturation was found in both groups. Some particles produced by calcium sulfate resorption were still present after 6 months in the test group specimens, but no longer detectable after 9 months. Samples from the control group showed a mean histomorphometric bone density of 34.25% ± 10.02, while samples from the test group showed a mean value of 55.54% ± 19.82.

Conclusions: The results of this study indicate that calcium sulfate appears to be an effective material for sinus augmentation, yielding vital bone suitable for implant integration. In addition, the technique used in the test group seemed to improve the quality and quantity of bone formation. J Periodontol 2000;71:940‐947.