bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bactericidal Action of Bicarbonate Ion on Selected Periodontal Pathogenic Microorganisms
Authors: Newbrun Ernest , Hoover Charles I. , Ryder Mark I. 
Published: March 2012

Organisms representative of soil, skin and fecal flora and of supragingival and subgingival flora were tested for inhibition of growth and killing by various salts (NaHCO3, NaCl, MgSO4). The antimicrobial activities of KHCO3, NaF, sodium lauryl sulfate (SLS) and chloramine T were also compared with that of NaHCO3, and the rate at which NaHCO3 exerts its bactericidal effect was studied. Suspected periodontal pathogens were more susceptible to salts than were control non‐oral bacteria. Supragingival plaque organisms showed intermediate susceptibility. Periodontal pathogens were more susceptible to NaHCO3 than to NaCl; NaHCO3 and KHCO3 showed similar activity against all strains tested. Accordingly, the antibacterial activity of NaHCO3 is not simply an osmotic effect and is due to the bicarbonate ion.NaF, SLS and chloramine T had greater antimicrobial activity than NaHCO3. Supragingival bacteria required at least 6‐hour exposure to 1.0 m NaHCO3 to produce 99% lethality (decrease colony‐forming units by 2 log10), whereas selected periodontal pathogens were killed more rapidly (30–120 minutes). The higher the concentration of bicarbonate, the faster the lethality. Morphologic examination by transmission electron microscopy of organisms exposed to bactericidal salt concentrations revealed marked fibrillar condensations within the cytoplasm and shrinkage of the cytoplasm from the outer membrane.For NaHCO3 to be clinically effective, a high concentration must be introduced into the periodontal pocket and maintained there long enough to kill periodontal pathogens. Furthermore, NaHCO3 must be reapplied often enough to prevent recolonization by these pathogens. An advantage of NaHCO3 over NaF, SLS and other antimicrobial agents is its safety, availability and low cost.
Epithelial Reattachment After Gingivectomy in the Rat
Authors: Sabag N. , Mery C. , García M. , Vasquez V. , Cueto V. 
Published: March 2012

It is known that an epithelial reattachment occurs a few days after gingivectomy. Depending upon the surgical procedure and the animal species used, different times have been proposed to obtain a complete reattachment. Nevertheless, it is not known whether there is a correlation between the time required and the sequence of morphologic events involved in this process.To investigate this matter, gingivectomies were performed in the maxillary molars of rats. Specimens were taken 1 to 14 days after the operation and processed for light and electron microscopy.The new junctional epithelium appeared at the 5th day, but the earliest signs of reattachment complex formation were evident at the 8th day. Rudimentary hemidesmosomes and lamina lucida appeared in epithelial cells bordering remnants of fibrin. Anchoring filaments that formed between the earliest hemidesmosomes and the subjacent fibrin crossed the lamina lucida. Simultaneously, segments of lamina densa appeared. At the 11 th day insertion of tonofilaments into the attachment plaques and insertion of anchoring filaments in the lamina densa were observed. At the 14th day, full development of the reattachment complex was evident.
Connective Tissue Regeneration to Periodontally Diseased Roots, Planed and Conditioned With Citric Acid and Implanted Into the Oral Mucosa
Authors: López Néstor J. 
Published: March 2012

This investigation used autogenous submucosal implants of root sections to study the connective tissue healing to periodontally diseased roots which had previously been planed and demineralized with citric acid.Eighteen implants were performed, with each being removed 2 to 24 weeks after implantation. The results showed new connective tissue attachment to the old cementum and to the dentin. After 18 weeks, in all specimens new cementum had formed on the dentin, with collagen fibers attached to it. No deposition of new cementum on the old cementum was noted. The formation of new cementum on roots placed in an environment without periodontal ligament cells might be ascribed to the inductive principle of demineralized dentin. The results suggest that a diseased root which has been planed and conditioned with citric acid is likely to form a new connective tissue attachment, even if it is placed in an environment without periodontal ligament cells. They also suggest that the factor inhibiting potential new connective tissue attachment is the condition of the root surface, rather than the lack of an adjacent progenitor cell population.
Comparative Differential Dark‐Field Microscopy of Subgingival Bacteria From Tooth Surfaces With Recent Evidence of Recurring Periodontitis and From Nonaffected Surfaces
Authors: Listgarten Max A. , Levin Sandra , Schifter Catherine C. , Sullivan Pamela , Evian Cyril I. , Rosenberg Edwin S. 
Published: March 2012

Ninety‐two subjects with a history of treatment for chronic periodontitis were monitored on a regular basis for an average period of 10.7 months. During this monitoring period, in spite of their participation in a preventive maintenance program, 19 subjects out of 92 showed evidence of significantly increased probing depth (≥ 3 mm from base line measurements) on at least one tooth surface, or approximately 1% of the dental units at risk in this population. A comparison of differential microscopic counts of subgingival bacteria from the affected tooth surfaces with a pooled sample of 6 other surfaces with the greatest probing depth, in the same mouth, taken at the same appointment, revealed no significant differences between proportions of coccoid cells, spirochetes, motile rods or other cell types.These findings suggest that disease recurrence, as measured by a comparatively rapid increase in probing depth, might be accounted for on the basis of the following hypotheses: (1) an alteration in the host response without a detectable change in the composition of the subgingival microbiota, (2) a qualitative change in the microbial flora not detectable by a microscopic assay, (3) relatively brief episodes of disease activity which may be accompanied by brief, transient, qualitative changes in the local microbiota that cannot be readily detected by biannual examinations.
Influence of Frequent Sugar Intakes on Experimental Gingivitis
Authors: Sidi A. D. , Ashley F. P. 
Published: March 2012

Few studies have investigated directly the possible role of dietary sugar in the etiology of periodontal disease, although an association between the amount of plaque formed and the frequency of sugar intake has been demonstrated. The purpose of this study was to examine the influence of frequent sugar intakes on experimental gingivitis in young adults. Twenty male dental students took part in a single blind crossover study which involved two 3‐week experimental periods with random allocation to high or low sugar diets.The experimental site was the lower anterior area. The labial aspects of the lower anterior teeth were examined at baseline and Weeks 1, 2 and 3. Inflammation was assessed by recording bleeding on probing at 12 sites at 2 levels of severity—“pin prick” and “excess.” In addition gingival crevicular fluid flow was recorded and plaque amount was assessed.At 3 weeks significantly higher bleeding scores at the two designated levels were found with the high sugar diet but no significant differences were observed with crevicular fluid flow and plaque amount. It was concluded that frequent sugar intakes result in increased gingival inflammation in experimental gingivitis, as measured by gingival bleeding on probing.
Oxygen Tension (pO2) in Untreated Human Periodontal Pockets
Authors: Mettraux G. R. , Gusberti F. A. , Graf H. 
Published: March 2012

The purpose of this study was to assess the oxygen tension in untreated human periodontal pockets and test the hypothesis that the subgingival environment is anaerobic in nature. Twenty‐six patients with advanced chronic inflammatory periodontal disease participated. A total of 111 untreated pockets, 5 to 10 mm in depth, were selected for the pO2 measurements. Pocket depths, Plaque‐Index and Gingival‐Index were recorded.The pO2 at the base of the 111 pockets ranged from 5 to 27 mm Hg, with an average of 13.3 mm Hg (1.8% 02). Mean pocket depth was 6.9 mm. Moderately deep pockets (5–6 mm) had a mean p02 of 15.0 mm Hg, whereas deep pockets (7–10 mm) showed a significantly lower pO2 of 11.6 mm Hg. No correlation was found between the pO2 and the Plaque‐Index. Higher Gingival‐Index scores tended to be associated with higher pO2 values.The pO2 in untreated periodontal pockets was low. However, it does not represent a completely anaerobic environment. Deep pockets contained less oxygen than moderately deep sites.
Effects of Citric Acid Treatment on Autogenous Free Graft Coverage of Localized Recession
Authors: Ibbott C. G. , Oles R. D. , Laverty W. H. 
Published: March 2012

Citric acid root conditioning prior to free gingival autografi (FGA) coverage of denuded roots may increase the likelihood of reattachment, but controlled studies to determine the value of the procedure have not been done on human subjects. This investigation was done to compare the effects of FGA root coverage with and without citric acid pretreatment.Nineteen patients with 30 affected teeth participated in the study. Fifteen teeth received FGAs without citric acid pretreatment and 15 teeth received FGAs with citric acid pretreatment. Measurements of gingival recession and sulcus depth were made preoperatively and 30, 60 and 90 days following the surgical procedure.Free gingival autografts with and without citric acid pretreatment each significantly reduced the amount of exposed root, but no differences between groups were found. Except for the 90‐day single tooth control group, mean sulcus depths were significantly decreased at 30, 60 and 90 days, but there were no differences noted between single tooth citric acid and control groups or multiple tooth citric acid and control groups.Citric acid treatment of affected roots prior to FGA coverage does not appear to be justifiable.
A Morphologic Study of the Mesial Root Surface of the Adolescent Maxillary First Bicuspid
Authors: Booker Brooks W. , Loughlin Dan M. 
Published: March 2012

Treating periodontitis which involves the mesial concavity of the maxillary first bicuspid can be very challenging. Fifty extracted adolescent maxillary first bicuspids were sectioned in 2‐mm thick sections apical to the cementoenamel junction (CEJ). The mesial concavity depth and the cementum and dentin thickness were measured in the sections.The single‐rooted bicuspids have a concavity 0.35 mm deep at the CEJ and a concavity 0.59 mm deep 4.7 mm apical to the CEJ. Two‐rooted bicuspids furcate at 7.9 mm and have a concavity 0.44 mm deep at the CEJ which increases to 1.08 mm at the 4.7 mm level. Cementum thickness averages from 0.9 mm at the CEJ to 1.1 mm at the 9.4‐mm level. Most bicuspids also have a distal concavity which is deepest at the 4.7‐mm level.The results imply that any attachment loss around the maxillary first bicuspid involves surfaces which are most likely concave. These concave surfaces make both plaque removal and various periodontal therapeutic procedures difficult.
The Role of Crevicular Fluid Iron in Periodontal Disease
Authors: Mukherjee Sabyasachi 
Published: March 2012

This article presents a brief review of literature on the role of iron in infection and reports the concentration of iron in crevicular fluid (CF) in humans and beagle dogs. Crevicular fluid from human subjects was collected from gingivitis and periodontitis sites. The CF from beagle dogs was collected from gingivitis and active periodontitis (ligature‐induced) sites.The results showed that the concentration of iron in human CF was often higher than in human serum. Also, a comparison between CF collected from gingivitis sites and periodontitis sites revealed a significantly higher concentration of iron in CF collected from the periodontitis sites. The studies in ligature‐induced periodontitis in beagle dogs revealed at least a 3‐fold increase in iron concentration in CF following ligation compared to the preligation values.Based on the available literature it is suggested that high concentration of iron in CF is not due to serum transferrin or polymorphonuclear leukocyte lactoferrin. Also, this high concentration of iron in CF might play an important role in enhancement of growth and virulence of microorganisms of the subgingival plaque and the initiation of active periodontitis.
Rapid Identification of Periodontal Pathogens in Subgingival Dental Plaque: Comparison of Indirect Immunofluorescence Microscopy with Bacterial Culture for Detection of Bacteroides gingivalis
Authors: Zambon J. J. , Reynolds H. S. , Chen P. , Genco R. J. 
Published: March 2012

A large body of research implicates Bacteroides gingivalis in the etiology of adult periodontitis, however, the application of this information to clinical diagnosis and treatment has been hampered by the need for a simple, rapid, and reliable means of detecting this microorganism. In the present study, indirect immunofluorescence microscopy using species specific, polyclonal antisera and a monoclonal antibody was evaluated in the clinical identification and quantitation of B. gingivalis in human subgingival dental plaque.One hundred and twenty subgingival plaque samples were obtained from predetermined sites by means of sterile paper points from 20 human subjects including 10 adult periodontitis patients and 10 periodontally normal subjects. The proportions of cultivable B. gingivalis in each sample were determined following anaerobic culture on nonselective blood agar media and selective media containing kanamycin. These results were then compared to quantitative estimates of B. gingivalis by indirect immunofluorescent microscopic evaluation of heat‐fixed plaque smears. Using both immunofluorescence microscopy and bacterial culture, the present study confirms the importance of B. gingivalis in adult periodontitis previously described by culture. The organism was cultivable from 70% of the adult periodontitis patients but not from any of the normal adults. In contrast, indirect immunofluorescence microscopy detected the organism in up to 40% of the subgingival sites in 100% of the adult periodontitis patients as well as four sites in the periodontally normal subjects. The sensitivity of indirect immunofluorescence microscopy compared to culture ranged from 91 to 100% while the specificity varied from 87 to 89%. The numbers of B. gingivalis identified by immunofluorescence microscopy were directly proportional to the severity of periodontal disease as measured by clinical indices. Linear regression analysis of the immunofluorescent data suggests that the probability of a subject having adult periodontitis approaches 100% when B. gingivalis comprises 9% or more of the subgingival microflora.The present study indicates that indirect immunofluorescence microscopy using speciesspecific serodiagnostic reagents is useful in the clinical detection of B. gingivalis in human subgingival dental plaque. The data also suggests that certain cases of adult periodontitis can be diagnosed solely on the basis of this laboratory test.
Serum and Gingival Fluid Antibodies as Adjuncts in the Diagnosis of Actinobacillus actinomycetemcomitans Associated Periodontal Disease
Authors: Genco Robert J. , Zambon Joseph J. , Murray Patricia A. 
Published: March 2012

Serum antibody titers to Actinobacillus actinomycetemcomitans were measured in 200 subjects by an enzyme‐lined immunosorbent assay (ELISA) using whole microorganisms as antigen. Comparisons were made between titers found in periodontally normal subjects and titers in subjects with localized juvenile periodontitis (LJP), postlocalized juvenile periodontitis, generalized juvenile periodontitis or adult periodontitis. It was found that titers to all three serotypes of A. actinomycetemcomitans were elevated in LJP patients' sera, while serum antibody levels in other diseased groups were not significantly elevated to any of the serotypes. Patient sera were also examined for serum antibody to oral Haemophili previously shown to cross‐react with A. actinomycetemcomitans. Similar antibody titers were found in both normal subjects and in patients with various forms of periodontal disease to Haemophilus aphrophilus, H. influenzae and H. parainfluenzae. The A. actinomycetemcomitans antibodies which were elevated in LJP patients could not be correlated with antibody titers to cross‐reacting Haemophili, suggesting that these antibodies are A. actinomycetemcomitansspecific.Serum antibody responses in six of the LJP patients were assessed to autologous strains of A. actinomycetemcomitans. Each patient was found to be infected with only a single serotype of A. actinomycetemcomitans, and specific antibodies to the infecting serotype were found in the patients' sera. In families, the LJP patients had significantly elevated IgG, IgA and IgM serum antibody titers to A actinomycetemcomitans, while the IgG and IgA antibody titers in periodontally normal siblings were at levels comparable to those found in normal subjects. However, IgM serum antibodies were elevated in the periodontally normal siblings of LJP patients suggesting that the formation of IgM antibodies to A. actinomycetemcomitans may precede the clinical appearance of localized juvenile periodontitis. Gingival crevicular fluid and serum antibody levels to A. actinomycetemcomitans were compared in LJP patients. Comparable titers of IgG, IgA and IgM antibodies were found in serum and gingival fluid in most subjects; however, gingival fluid samples sometimes showed higher titers than serum, likely resulting from local antibody synthesis.The value of serum antibody determinations to A. actinomycetemcomitans in the diagnosis of Actinobacillus‐associated periodontitis was also assessed. The predictive value of a positive test (significantly elevated anti‐A actinomycetemcomitans IgG) was 86%, while the specificity was 89%. These results suggest that the measurement of serum or gingival crevicular fluid antibodies to A. actinomycetemcomitans may be valuable in the diagnosis of Actinobacillusassociated periodontal disease.
Efficacy of Clindamycin Hydrochloride in Refractory Periodontitis: 12‐Month Results
Authors: Gordon Jeffrey , Walker Clay , Lamster Ira , West Theodore , Socransky Sigmund , Seiger Mia , Fasciano Robert 
Published: March 2012

The purpose of this study was to evaluate the use of Clindamycin hydrochloride as an adjunct to conventional periodontal therapy in the treatment of patients who had previously been unsuccessfully treated with scaling, periodontal surgery and the use of tetracycline.Thirteen patients with a history of “refractory” periodontitis were thoroughly scaled and monitored by repeated attachment level measurements for the presence of active destructive periodontitis. Disease activity was defined as a 3‐mm loss in attachment from baseline measurements or the occurrence of a periodontal abscess. When active disease was detected, each patient was scaled again and placed on Clindamycin hydrochloride 150 mg qid for 7 days.Following the adjunctive use of Clindamycin in combination with scaling, the incidence of gingival sites demonstrating active disease in the group of 13 patients decreased from an annual rate of 10.7 to 0.5%. Each patient demonstrated a decreased incidence of active sites per unit of time. Clinical parameters such as probing depth, gingival redness, bleeding on probing and suppuration showed dramatic improvement at 12 months after Clindamycin therapy. The percentage of pockets with probing depths greater than 6 mm, 4 to 6 mm and 1 to 3 mm changed from 11 to 2%, 38 to 24% and 51 to 74% respectively, following Clindamycin therapy as compared to scaling alone.The percentage of sites bleeding on probing decreased from 33% after scaling alone to 8% following Clindamycin and scaling. Gingival redness decreased from 36 to 1% of sites. Suppuration also decreased from 8% of buccal or lingual surfaces after scaling alone to 1% of surfaces following scaling and Clindamycin.Clindamycin treatment resulted in a significant change in the microbial flora as demonstrated by darkfield microscopy. Prior to Clindamycin therapy, active sites averaged 35% spirochetes, 23% motile rods, 38% nonmotile rods and 4% coccoid cells. At 12 months postclindamycin treatment, spirochetes averaged 8%, motile rods 6%, nonmotile rods 57% and coccoid cells 28% of the organisms present.Our findings indicate that Clindamycin is useful as a treatment modality in cases which do not respond to conventional treatment methods. Due to possible adverse side effects, Clindamycin should be reserved for those patients for whom treatment modalities of lesser risk have been unsuccessful and in whom the subgingival flora is susceptible to this agent.
Clinical Responses Following Periodontal Treatment by Local Drug Delivery
Authors: Goodson J. M. , Hogan P. E. , Dunham S. L. 
Published: March 2012

A 4‐quadrant, single‐blind study was designed to test the efficacy of periodontal disease therapy by local drug delivery. A delivery system made of extruded ethylene vinyl acetate fibers loaded with 25% USP tetracycline hydrochloride was placed and maintained in periodontal pockets for 10 days. The clinical effects of this form of therapy were compared with treatment by periodontal scaling. In addition, the effect of treatment by combined local delivery and scaling was investigated. Untreated quadrants were included as control.Placement of tetracycline‐loaded ethylene vinyl acetate fibers into periodontal pockets established a drug concentration of approximately 0.06%. By covering the delivery system with a periodontal dressing, this concentration level was maintained throughout the 10‐day therapeutic period. The average tetracycline dose used was 2.4 mg/tooth treated. Following fiber therapy, treated sites improved clinically, as evidenced by a gain in periodontal attachment and a decrease in periodontal pocket depth. The rate of new lesion formation at fiber‐treated sites decreased from a pretreatment rate of 26.5% of sites/year to a posttreatment rate of 4.8% of sites/year.Periodontal scaling also produced clinical improvement, as indicated by significant attachment gain, pocket depth reduction and a decreased rate of new lesion formation. However, in no case were clinical results by scaling superior to results by local drug delivery, and by several measures local drug delivery was found to provide a better clinical response. Principal measures by which the clinical response using local drug delivery exceeded that by scaling were in early (3–6 months) attachment gain and in the degree of reduction of new lesion formation.The combination of fiber therapy with scaling reduced the rate of new lesion formation; however, attachment gain appeared delayed in comparison with either scaling alone or fiber therapy alone. This delay in healing was probably due to mechanical interference by the delivery system, which was packed into the periodontal pocket immediately following scaling. Although delayed, the final attachment gain was equal to that of other treatment modalities. Untreated sites exhibited clinical signs of significant improvement which appeared 6 to 12 months after the therapeutic period. Attachment level gains were consistently less than at periodontal sites which had been treated but were nevertheless significant when compared to pretreatment levels. It is suggested that host response mechanisms triggered by periodontal scaling may have been responsible for this effect.