In vitro proliferation of periodontal ligament-like tissue on extracted teeth

ObjectiveTransplantation of autologous teeth is a routine component of orthodontic treatment. The aim of this study was to develop a method for the regeneration of damaged periodontal ligament (PDL) on extracted teeth using a three-dimensional culture system.DesignWe used the maxillary first premolars or third molars extracted from patients for orthodontic treatment. The extracted teeth were stained with toluidine blue to measure the residual PDL area. After confirming damage of the periodontal tissue on the root surface of the extracted teeth, we tried to regenerate the periodontal tissue. Other extracted teeth were inserted into a cell strainer filled with cellulose-based carrier materials to regenerate the periodontal tissue. The strainer was then placed in a 90-mm culture dish filled with culture medium and incubated at 37 °C and 5% CO2 for about 1 month. The cultured teeth were observed under a stereomicroscope and examined by scanning electron microscopy (SEM), and were stained to detect alkaline phosphatase (ALP) activity.ResultToluidine blue staining revealed that the residual periodontal membrane covered an average of 50.4% of the root surface area of each tooth. After culturing extracted teeth with our culture system, globular structures were found on the entire tooth root surface by stereomicroscopy, and PDL-like filamentous tissue was also detected by SEM. The entire tooth root surfaces of the cultured teeth were positive for ALP activity.ConclusionsWe have developed a useful culture method to stimulate the proliferation of cells in PDL-like tissue on the roots of extracted teeth.     

A method for evaluation of periodontal problems on extracted teeth

Abstract It is shown that many periodontal problems can be evaluated by examining stained, extracted teeth. Presence or absence of gingival inflammation around the tooth before extraction can be established after extraction on the basis of presence or absence of plaque. Loss of attachment and its relationship to local etiological factors can also be established. The method is particularly useful for experimental investigation on periodontal problems in man.     

Management of molar teeth with periodontal disease

Over the years patients' attitudes towards maintaining a functional and aesthetic masticatory apparatus have improved, and their expectations of delivery of care by the dental professional have risen. With the advance of new techniques and materials, the periodontist can now offer an ever-expanding range of treatments in the management of molar teeth with periodontal disease. This paper considers such treatment in relation to the levels of disease present and within the overall context of adult restorative dental healthcare.     

Tetracyclines: double blind clinical study to evaluate the effectiveness in periodontal surgery.

Twenty consecutive hospital patients who were to have periodontal surgery were assigned to one of two groups in a double blind clinical study. Ten were placed on tetracycline 250 mg, 6 times per day for 5 days. The other ten were given an identical appearing placebo 6 times per day for 5 days. The capsules were placed in a brown envelope so that neither the patient nor the periodontist knew which medication was being administered. The patients were randomly assigned to one of the two groups and were evaluated subjectively and objectively on the 3rd day and the 7th day. Statistically there were no differences between the two groups. In both groups there was some inflammation on the 3rd day but on the 7th day, it had subsided. Tetracycline is not recommended for routine prophylactic use in periodontal surgery.     

The identification of periodontal attachment loss from clinical measurements

Clinical readings of pocket depth and loss of periodontal attachment were recorded on the approximal sites of 21 teeth scheduled for extraction. Corresponding laboratory measurements of pocket depth and loss of periodontal attachment were made on the teeth after extraction. Clinical measurements were within 1mm of their corresponding laboratory values on 95% of occasions. Clinical readings of loss of periodontal attachment of 0 or 1mm showed poor agreement with corresponding laboratory measurements. It was concluded that the presence of loss of periodontal attachment can only be reliably identified where a clinical reading of 2mm or greater is recorded.     

The use of different measurements and definitions of periodontal disease in the study of the association between periodontal disease and risk of myocardial infarction

BACKGROUND: The role of periodontal disease as an independent risk factor for cardiovascular disease (CVD) has been under debate because of the inconsistency of findings across studies. One of the major issues is the method used to assess or define periodontal disease. The present study assesses if the observed association between periodontal disease and incident myocardial infarction (MI) depends on the measurements and/or criteria used to define periodontal disease. METHODS: A population-based case-control study to evaluate the association between PD and risk of MI was conducted between 1997 and 2001 in Western New York with 537 cases and 800 controls, aged 35 to 69 years. Cases were survivors of incident MI from local hospitals in Erie and Niagara counties. Controls were randomly selected from residents of the same counties. Periodontal disease was assessed using interproximal clinical attachment loss (CAL), probing depth (PD), alveolar crest height (ACH), and number of missing teeth. From these measurements, four different case definitions of periodontal disease were created. RESULTS: Using the continuous forms of periodontal measurements, the odds ratios (ORs) (95% confidence interval) of the association with incident MI were 1.46 (1.26 to 1.69), 2.19 (1.66 to 2.89), 1.30 (1.14 to 1.49), and 1.04 (1.02 to 1.07) for mean CAL, PD, ACH, and number of missing teeth, respectively. Regardless of the case definition of periodontal disease, the estimates of the association with incident MI were statistically significant. CONCLUSIONS: The observed association between periodontal disease and incident MI was consistent across different measurements and/or case definitions of periodontal disease used. The magnitude of the association varies depending on the measurements or the criteria used to define periodontal disease.     

The use of six selected teeth in population measures of periodontal status

Selected teeth have been used to represent the entire dentition in many epidemiological and clinical investigations. The present study sought to assess the relationship between the six selected teeth described by Ramfjord and the entire dentition for the Plaque Index, Gingival Index, Calculus Index and Loss of Attachment. The computations were performed on measurements obtained in investigations of the natural history of periodontal disease in Norway and Sri Lanka. A consistently strong correlation was observed between the tooth subset and whole mouth for all indices in both populations. This relationship persisted even though single members or pairs of the subset of teeth were removed from the calculations. Some bias, however, was observed with all indices. Plaque and gingival indices obtained from the six teeth underestimated whole mouth scores in the low range (less than 1.0) and overestimated scores in the high range (greater than 2.0). Use of the tooth subset for calculus and loss of attachment consistently overestimated scores for the entire dentition.     

Disinfection/sterilization of extracted teeth for dental student use

Extracted human teeth are used in many preclinical courses. While there has been no report of disease transmission with extracted teeth, sterilization of teeth used in the teaching laboratory should be a concern. The purpose of this study was to determine the effectiveness of different sterilization/disinfection methods of extracted human teeth using Bacillus stearothermophilus, a bacteria resistant to heat and frequently used to test sterilizers. In this study, 110 extracted molars with no carious lesions were collected and stored in buffered saline. An endodontic occlusal access preparation was cut into the pulp chamber of each tooth. Pulp tissue in the chamber was removed with a broach. Approximately 1 x 10(5) B. stearothermophilus endospores in culture medium were injected into the pulp chamber, sealed with Cavit G, and then placed in sterile saline for twelve hours. Ten teeth were placed into each of eleven groups. Seven groups were immersed for one week in one of the following solutions: a) sterile saline (control group), b) 5.25% NaOCl, c) 2.6% NaOCl, d) 1% NaOCl, e) 10% buffered formalin, f) 2% gluteraldehyde, g) 0.28% quaternary ammonium. Four additional groups were treated by h) 10% formalin for two days, i) 10% formalin for four days, j) autoclaving at 240 degrees F and 20 psi for twenty minutes, and k) autoclaving at 240 degrees F and twenty psi for forty minutes. Each tooth was then aseptically split and placed in an individual test tube with growth medium. Samples were examined for evidence of growth (turbidity) at forty-eight hours. Only autoclaving for forty minutes at 240 degrees F and 20 psi or soaking in 10 percent formalin for one week were 100 percent effective in preventing growth. A chi-square analysis of the data indicates these two methods were significantly better than all other methods (p<0.001).     

Differential periodontal temperature measurements in the assessment of periodontal disease activity: an experimental and clinical study

The difference in surface temperatures between the bottom of periodontal pockets and the attached gingiva adjacent to the openings of the pockets were determined both in monkeys with experimental marginal periodontitis, and clinically in patients with marginal periodontitis. For this purpose a custommade, temperature-measuring device was developed which enabled immediate recording of temperature differences as well as periodontal pocket depths, bleeding, and attachment levels. The measurements were performed periodically. The differential temperature measurements were correlated to change in periodontal attachment over time. It was shown that differential periodontal temperatures are well correlated to change in periodontal attachment over time. It was furthermore concluded that differential periodontal temperature measurements have the potential of serving as a predictor of activity of marginal periodontitis. However, more extensive data are required to assess the sensitivity and specificity of the method.     

Pulp reactions to different preparation techniques on teeth exhibiting periodontal disease

To evaluate the histopathological outcome of two preparation techniques (featheredge preparation/shoulder preparation) on teeth exhibiting pulp reactions due to age and periodontal disease, 11 teeth were prepared for full veneer crowns. Laboratory made resin crowns were fixed with a zinc phosphate cement for a period of 90 days. After extraction, adjacent pulpal areas were histopathologically rated according to the BRD criteria comprising the parameters (i) Bacterial invasion, (ii) Regenerative parameters, (iii) Degenerative parameters. Degenerative reactions were more correlated with tooth preparation than with advanced periodontal disease. The severity of endondontal reactions depends more on remaining dentin thickness than on the type of preparation.     

The periodontal ligament of teeth connected to osseointegrated implants

Abstract The aim of the present investigation was to analyze the periodontal tissues at immobilized teeth connected to osseointegrated implants. 10, 1-year old beagle dogs, were used. Bilaterally, the mandibular 2nd (₂P₂) and 3rd pre-molars (₃P₃) and 1st molars (₁M₁) were extracted. 2 titanium fixtures were installed in the edentulous segment of the right side of the mandible, one about 10 mm mesial and the other about 10 mm distal to 4P (test tooth). 3 months later, abutment connection was performed and healing allowed for one month. The dogs were randomly divided into 2 groups of 5 each, group A and group B. In group A, a fixed gold splint, rigidly connecting the tooth and the 2 implants, was installed on day 0 and ₄P was hereby immobilized. The controlateral 4th premolar (P4) served as the non-splinted control tooth. Plaque control measures continued until the end of the experiment (day 180). In group B, plaque control measures were abandoned 1 month after abutment connection and a 4-month period of experimental periodontal tissue breakdown was initiated. This was accomplished by placing cotton floss ligatures submarginally around ₄P and P₄. At the end of this 4-month period, the ligatures were removed, and an apically positioned flap procedure was performed. Healing was allowed for another 2 months. Plaque control measures were re-established and continued throughout the experiment. A given day was termed day 0 and ₄P was rigidly connected to the adjacent implants in the manner described for group A. At the end of a subsequent 6-month period, radiographs of ₄P and P₄ were taken and biopsies harvested from all the dogs. The results of measurements, made in histological sections, revealed that the splinting of mandibular premolars to osseointegrated implants failed to induce marked alterations (qualitative and quantitative) in the gingiva and periodontal tissues of the immobilized teeth. These findings offer a biological explanation for the fact that a fixed bridge, utilizing both teeth and implants as abutments, seems to function well in the rehabilitation of partially edentulous patients.     

Phenotypic analysis of B-cells extracted from human periodontal disease tissue

B-cells extracted from periodontal disease tissue were analyzed for the presence of activation markers using a range of monoclonal antibodies. In adult periodontitis (AP), 6% of B-cells expressed the IL-2 receptor (CD25) compared with 1-2% in peripheral blood and healthy or marginal gingivitis (H/MG) gingival B-cells. There was also an increase in the mean percentage of IgD-positive B-cells and a decrease in CD21 and CD22 expression. In both AP and H/MG lesions, 20-22% of the B-cells expressed CD23 compared with less than 5% in peripheral blood. As B-cells are activated by day 3 in culture and start differentiating into immunoglobulin-secreting cells by day 6, B-cell phenotypes were assayed at these times in this study. Following stimulation with the periodontopathic bacterium Porphyromonas gingivalis, the expression of CD23, CD21 and CD22 on B-cells extracted from AP lesions remained relatively constant over the 6-d culture period. However, with Fusobacterium nucleatum stimulation, there was a significant decrease in CD23, CD21 and CD22 expression after 3 d in culture, which corresponds to the activation time for B-cells. These results show that B-cells extracted from periodontal disease tissue display a range of activation markers and on stimulation, demonstrate differing responses to individual periodontopathic bacteria.