Flow cytometric DNA analysis of pediatric intracranial ependymomas

OBJECTIVE

To examine the clinicopathologic features and perform flow cytometric DNA analysis of pediatric intracranial ependymomas to determine whether any of these parameters were predictors of clinical outcome.

METHODS

Flow cytometric DNA analysis was performed on 17 paraffin-embedded tumors from patients aged 7 months to 16 years.

RESULTS

Seven cases were aneuploid, while the remaining 10 were diploid. Proliferative fractions varied from 1% to 17%.

CONCLUSIONS

No correlation between histologic features such as mitotic activity, cellularity, pleomorphism, vascular proliferation, and length of survival was observed. However, the presence of a diploid DNA stemline, elevated proliferative fraction, or young age were associated with a poor clinical outcome and shortened survival times (P < 0.05). Additional studies of larger patient groups with extended follow-up are necessary to confirm these findings.

Periodontal status of HIV-1 and HIV-2 seropositive and HIV seronegative female commercial sex workers in Senegal

Comprehensive studies of 92 commercial sex workers in Senegal, Africa included an oral examination in which we obtained measurements of decayed, missing, and filled (DMF) teeth; plaque index; gingival index; recession; probing depth (PD); clinical attachment loss (CAL); and the presence of HIV-associated periodontal lesions, under conditions wherein the examiner was unaware of the subject's HIV status. Twenty-seven subjects (29%) were HIV seropositive, 19 of whom were positive for HIV-1, 7 positive for HIV-2, and 1 positive for both. Most subjects were not taking any medications and previous dental care was limited. HIV-seronegative and HIV-seropositive subjects were similar in mean age, number of DMF teeth, percentage of sites with visible plaque, and number of sites with recession. However, the frequency of sites with gingival bleeding, with PD > or = 6 mm, and with CAL > or = 6 mm was significantly greater in seropositive than seronegative subjects. No differences were observed between HIV-1 and HIV-2 positive subjects. About 26% of HIV-seropositive subjects and about 5% of the seronegative subjects exhibited at least one site with concurrent PD > or = 6 mm and CAL > or = 6 mm. HIV-associated periodontal lesions were seen in 3 HIV-seropositive subjects (2 linear gingival erythema, 1 necrotizing periodontitis). One HIV-seronegative subject exhibited necrotizing gingivitis. In this population with multiple risks to oral health, both HIV-1 and HIV-2 infections were associated with a significantly increased prevalence of periodontal disease.

Oral effects of smokeless tobacco use by professional baseball players

This is a review of studies conducted from 1988-90 on the oral consequences of snuff and chewing tobacco use among professional baseball players. About half of the players studied were smokeless tobacco (ST) users, the majority of whom used snuff. Compared with non-users, players who used ST showed a significantly higher prevalence of leukoplakia, which was related to placement of the ST quid, and the frequency, amount, duration, and type of ST used. Sites adjacent to these mucosal lesions showed an increased prevalence of gingival recession with associated attachment loss, cervical abrasion, and root caries than did comparable sites in non-users. Extrinsic stain and occlusal attrition were also more frequent in ST users than in non-users. While ST use placed players at significantly increased risk for mucosal lesions and other oral problems, no differences were found between ST non-users and users in measurements of batting, fielding, and pitching performance during the baseball season.

Unexpected hemoglobin electrophoresis results following red cell exchange in a sickle cell anemia patient with acute chest syndrome

Acute chest syndrome is a well described complication of sickle cell anemia. It is characterized by fever, pulmonary infiltrates, pleuritic chest pain and abnormal pulmonary auscultation. Transfusion therapy, either simple transfusion of red blood cells or a total red blood cell exchange, is a cornerstone therapy for these patients. Exchange transfusion is preferred when an acute reduction of the hemoglobin S (HbS) concentration is the therapeutic goal since it allows one to rapidly reduce the percent HbS without increasing blood viscosity or volume (Wayne, Kevy and Nathan, Blood 1993; 81:1109-1123). Hemoglobin electrophoresis may be used to monitor the effectiveness of the exchange in decreasing HbS. The post-exchange HbS electrophoresis results which were obtained in this case initially caused confusion. In this report we discuss the findings and the reasons why such results may be occasionally expected in future similar situations.

Diversity and critical forces in dental education

Critical issues that affect dental education and the connection between science and practice include the community, managed patient care, public skepticism and fiscal support, and shifting demography in patterns of oral disease as well as the background of students entering the dental profession. During the past several decades, there have been major shifts in the patterns of oral disease, most recently described in results of the NHANES III dental survey. The diversity and background of students entering the dental profession have changed dramatically as well, and present estimates of change in U.S. population are no less volatile. Funding for dental education in constant dollars is decreasing nationally, with declining support from state and federal sources and a much greater reliance on clinical and development income. Recent recommendations by the Institute of Medicine and Pew Health Commission and reactions to those recommendations by representative dental organizations-particularly the American Dental Association, American Association of Dental Schools, and the American Association of Dental Examiners-have significant implications for the structure of dental education. All of these factors are tempered by the emergence of managed patient care and the implications of that environment to increasing the level of academic excellence of students, improving the quality of care delivered to patients, and enhancing the scholarly contributions of faculty. These forces may represent an opportunity to maintain a well-documented national excellence in oral health care, expand the educational options to meet student demand and interest, increase the biological and behavioral background of our graduates, and explore new educational approaches to preclinical and clinical training.

013 (CD99) positivity in hematologic proliferations correlates with TdT positivity

The monoclonal antibody 013, which detects the cell surface glycoprotein p30/32mic2 (CD99) is a characteristic, if nonspecific, marker for peripheral neuroepithelioma and Ewing's sarcoma. 013 was first produced against a human thymus leukemia antigen and has also been found in immature terminal deoxynucleotidyl transferase (TdT)-positive T cells and in a small group of hematopoietic precursor cells in the bone marrow. 013 is reactive in lymphoblastic lymphomas and acute leukemias, as well as in a variety of other hematologic malignancies. Because the distribution of 013 positivity in hematopoietic proliferations is similar to that of TdT, we hypothesized that 013 might correlate with TdT positivity. We studied 67 lymphoblastic lymphomas and acute lymphoblastic leukemias, 6 chronic myelogenous leukemias in blast crisis, a variety of acute myeloid leukemias, 5 granulocytic sarcomas, and a spectrum of 94 diffuse lymphomas other than lymphoblastic type. With the use of heat-induced epitope retrieval and automated immunostaining, we compared the results obtained with 013 and TdT, a well-established marker of lymphoblastic lymphomas and acute lymphoblastic leukemias that can also be successfully demonstrated in tissue sections by use of a similar technique. In our study, all of the 013-positive cases were also TdT positive. 013 reacted with 44 (71%) of 62 of the TdT-positive lymphoblastic lymphomas and acute lymphoblastic leukemias cases studied. We also found 013 to be positive in one case of TdT-positive acute myeloid leukemia, in two cases of chronic myelogenous leukemia in blast crisis, and in three TdT-positive granulocytic sarcomas. 013 was negative in all of the other high-grade malignant lymphomas and in TdT-negative leukemias. With use of our technique, 013 positivity appears to be restricted to hematologic proliferations that demonstrate TdT positivity. 013 may be a helpful additional marker in the diagnosis of TdT-positive leukemias and lymphomas in conventionally processed tissue sections.

Smokeless tobacco use: how it affects the performance of major league baseball players

The authors examined the effect of smokeless tobacco use on the athletic performance of major league baseball players during the 1988 season. They evaluated performance records of 158 players on seven major league teams who played or pitched at least 10 games or innings during the 1988 season. ST use, they concluded, is not related to player performance in major league baseball but does place players at significantly increased risk for mucosal lesions and other oral pathology.

Effect of free gingival grafts on naturally-occurring recession in miniature swine

Miniature swine exhibit naturally-occurring, progressive recession on facial surfaces of the permanent mandibular incisors. The purpose of this study was to determine whether placing a free gingival graft to augment the width of keratinized gingiva of mandibular incisors in miniature swine would prevent or retard recession at the grafted site compared to an untreated contralateral control site. In 8 litter-mate miniature swine, free gingival grafts were placed on the facial surface of the permanent central and lateral incisors on one side of the mandible. The contralateral mandibular incisors did not receive any treatment and served as controls. Clinical measurements, including eruption, recession, pocket depth, attachment level, and keratinized gingival width were obtained preoperatively, 2 to 3 weeks after surgery to assess the success of gingival augmentation, and 3, 6, and 9 months postoperatively. Eight grafted sites were successful and showed significant augmentation of the keratinized gingival width, with a mean increase of 5.8 +/- 0.7 mm, while 6 grafts failed and showed a slight decrease in the mean width of -0.4 +/- 0.5 from the preoperative to postoperative examination. All sites showed significant recession during the experimental period. Successful sites showed no statistically significant or clinically major difference in the rate or amount of recession than contralateral control sites. By 9 months, the average increase in recession from the baseline examination was 2.8 +/- 1.5 mm for successfully grafted sites and 2.6 +/- 1.3 mm for contralateral controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontal disease associated with HIV infection

Patients with severe immunosuppression as a consequence of infection by human immunodeficiency virus (HIV) are at risk for a number of severe periodontal diseases. HIV-associated gingivitis and HIV-associated periodontitis (HIV-P) are seen exclusively in HIV-infected persons. In some cases HIV-P may extend into adjacent soft tissue and bone, resulting in necrotizing stomatitis of periodontal origin. In addition, acute necrotizing ulcerative gingivitis has also been reported to have an increased prevalence in HIV-infected patients. The clinical and microbiologic features of HIV-associated gingivitis and HIV-P suggest that these diseases are early and later stages of the same lesion, that results in severe gingival erythema, extensive soft tissue necrosis, and destruction of alveolar bone. Although acute necrotizing gingivitis and the initial stages of HIV-P share a number of clinical signs current evidence indicates that they are distinct pathologic processes. Treatment of these lesions requires debridement, local antimicrobial therapy, immediate follow-up care, and long-term maintenance. In addition, patients with systemic involvement or extensive and rapidly progressing lesions may require systemic antibiotics appropriate to the organisms that dominate the lesion.

Effects of ascorbic acid depletion and supplementation on periodontal health and subgingival microflora in humans

This study describes the relationship between varying ascorbate intake, periodontal status, and subgingival microflora as part of a multidisciplinary investigation of ascorbic acid (AA) metabolism in young men housed for 13 weeks in a nutrition suite that provided controlled periods of ascorbic acid depletion and repletion. Twelve medically healthy non-smoking men, aged 25 to 43 years, ate a rotating four-day diet adequate in all nutrients except ascorbic acid. Following an initial baseline period during which the subjects received 250 mg AA/day, the subjects received 5 mg AA/day for a 32-day depletion period. Eight of the 12 subjects participated in a subsequent 56-day repletion period designed to replace the reduced body AA pool slowly. Plasma and leukocyte ascorbate levels, Plaque Index, Gingival Index, probing depths, and attachment level were monitored at the beginning and end of the depletion and repletion periods. Subgingival plaque samples were obtained and examined for selected organisms by indirect immunofluorescence microscopy. A uniform oral hygiene program was reinforced after each examination. Ascorbate concentrations in plasma and leukocytes responded rapidly to changes in vitamin C intake. There were no significant changes in plaque accumulation, probing pocket depth, or attachment level during the study. In contrast, gingival bleeding increased significantly after the period of AA depletion and returned to baseline values after the period of AA repletion. However, no relationship could be demonstrated between either the presence or proportion of target periodontal micro-organisms and measures of bleeding or ascorbate levels.

The association of simple anterior dental crossbite to gingival margin discrepancy

The purpose of this study was to determine the severity of gingival margin discrepancy affecting the mandibular incisors in children with a single-tooth anterior crossbite. The response of the position of the gingival margin to correction of the crossbite also was investigated. Twenty-two subjects with a single central crossbite and 16 subjects with a single lateral crossbite were identified from two orthodontic practices. Seventeen of the 22 central incisor patients had immediate posttreatment records available; six patients had long-term follow-up records. An insufficient number of posttreatment records were available for the patients with lateral crossbites. The mean clinical crown length of crossbite mandibular incisors, measured on the study models, was compared with mean crown length of contralateral control incisors and the difference in clinical crown length was determined. A gingival margin discrepancy was identified when the gingival margin of the crossbite incisor was at least 1.0 mm apical to the gingival margin of the control incisor. The proportion of subjects with gingival margin discrepancy was significantly higher in subjects with central incisor crossbite (12/22 = 54%) than in those with lateral incisor crossbite (4/16 = 25%), P less than 0.05. While a gingival margin discrepancy persisted for eight of the 17 central incisor crossbites after discontinuing the appliance, 8.9 +/- 4.7 months, the severity of the discrepancy showed a significant reduction from 2.2 +/- 0.5 mm to 1.3 +/- 0.8 mm, P less than 0.05. True recession with exposure of cementum was not observed in any subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Periodontal effects associated with the use of smokeless tobacco

This report describes periodontal findings from a comprehensive study of smokeless tobacco use in professional baseball players. Subjects consisted of 1,094 players, coaches, and training staff of seven major league and their associated minor league teams. Before being examined, subjects completed questionnaires on patterns of smokeless tobacco use (validated by blood chemistry studies), rinsed their mouths under supervision, and were cautioned not to discuss their use of tobacco with the dental examiners. They then received a complete oral examination that included recording of all mucosal abnormalities, missing teeth, caries, extrinsic stain, attrition, Plaque Index, Gingival Index, pocket depth, attachment loss, and gingival recession. More than 50% of team members reported using smokeless tobacco, and 39% reported use during the current week. Among current week users, 46% had oral mucosal lesions, located primarily in the mandible at sites where the smokeless tobacco quid was placed. The use of smokeless tobacco was not necessarily associated with severe forms of periodontal disease, and the presence of poor oral hygiene and gingivitis in these users was not related to the development of oral lesions. However, sites adjacent to mucosal lesions in smokeless tobacco users showed significantly greater recession and attachment loss than in sites not adjacent to lesions in users or comparable sites in non-users.

Oral mucosal lesions found in smokeless tobacco users

The risk for oral mucosal lesions associated with use of smokeless tobacco among 1,109 professional baseball players during spring training in 1988 was investigated. Leukoplakia was very strongly associated with use of smokeless tobacco in this population of healthy young men. Of the 423 current smokeless tobacco users, 196 had leukoplakia compared to seven of the 493 nonusers (OR = 60.0, 95% CI = 40.5-88.8). The amount of smokeless tobacco used (in hours per day that smokeless tobacco was held in the mouth), recency of smokeless tobacco use (hours since last use), type (snuff versus chewing tobacco), and brand of snuff used were significantly associated with risk for leukoplakic lesions among smokeless tobacco users. Ninety-eight leukoplakic areas in 92 subjects were biopsied and examined microscopically. All lesions were benign, but one specimen had mild epithelial dysplasia. The long-term significance of leukoplakia in smokeless tobacco users and their relation to oral cancer is not clear.

Effect of rotary electric toothbrush versus manual toothbrush on periodontal status during orthodontic treatment

Adolescents with fixed orthodontic appliances frequently have increased levels of plaque accumulation and gingivitis. The purpose of this study was to determine whether a rotary electric toothbrush would be more effective than conventional toothbrushing in maintaining periodontal health in these patients. Forty adolescent patients were divided into equal groups matched for sex and age. Before and during placement of orthodontic appliances, one group was instructed in use of the rotary electric toothbrush and the other in the use of a conventional toothbrush; these instructions were reinforced at monthly visits thereafter. Baseline clinical assessments of Plaque Index, Gingival Index, and bleeding tendency were made on six standard teeth before appliances were placed. assessments were repeated at 1, 3, 6, 9, 12, and 18 months after appliances were placed. Intragroup and intergroup differences were tested by a two-way analysis of variance. At baseline there were no significant differences between the two groups for any study variable. During the 18-month study period, however, plaque accumulation and gingivitis increased significantly over baseline levels in the control group (p less than 0.01) but remained stable in the group using the rotary electric toothbrush. In addition, the control group showed significantly greater plaque (p less than 0.01), gingival inflammation (p less than 0.001), and gingival bleeding on probing (p less than 0.001) than did the treatment group from the 1- to 18-month examinations. These data suggest that the rotary electric toothbrush is more effective than conventional toothbrushes for removing plaque and controlling gingivitis in adolescents during orthodontic treatment with fixed appliances.

Comparison of manual and power toothbrushing, with and without adjunctive oral irrigation, for controlling plaque and gingivitis

We compared the effects of four oral hygiene methods (manual tooth-brushing, power toothbrushing, manual toothbrushing plus irrigation, and power toothbrushing plus irrigation) on plaque and periodontal disease. These methods were tested both when used alone and when used in conjunction with professional mechanical oral hygiene. 108 subjects were clinically assessed for plaque, stain, gingival inflammation, bleeding to probing, probing depth and attachment loss, and randomly assigned to one of the 4 oral hygiene groups. Subjects were carefully instructed in the use of their assigned method and asked to discontinue all other forms of oral hygiene. After 3-months, subjects returned for re-examination and full-month professional mechanical oral hygiene care. 3 months later, subjects returned for a final oral examination. All subjects kept a diary of use of their assigned method and were called every 2 weeks to monitor discomfort, provide reinforcement and answer questions. Results showed that all the oral hygiene methods were equally effective in reducing plaque and stain accumulation, gingival bleeding, bleeding to probing ratio and the % of pockets 4 mm or deeper. None of the oral hygiene methods was associated with injury to soft or hard tissues.

Effect of periodontal status of rotary electric toothbrushes vs. manual toothbrushes during periodontal maintenance. II. Microbiological results

We compared the use of a rotary electric toothbrush with conventional toothbrushing for their effectiveness in modulating the subgingival microbiota. Forty subjects who had received periodontal treatment for moderate to advanced periodontitis and were on 3-month periodontal maintenance were divided into two equal groups matched for age and sex. One group used only the rotary tooth cleaner and the other group used conventional toothbrushing, dental floss, and toothpicks for 12 months. Subgingival plaque samples (two sites per patient) were taken from 10 subjects per group at baseline, 6 months, and 12 months and analyzed for percentage of obligate anaerobes and colony-forming units of black-pigmented Bacteroides, Fusobacterium, Actinomyces, Streptococcus, and Veillonella spp. The percentage of spirochetes and motile rods was determined by darkfield microscopy. Results showed that levels of obligate anaerobes, Fusobacterium, and Actinomyces and percentage of spirochetes and motile rods decreased significantly (P less than 0.05), while levels of Streptococcus spp. increased (P less than 0.05) for both groups. However, there was no significant difference between the two groups, indicating that the rotary tooth cleaner and conventional toothbrushing are equally effective in controlling gingivitis and fostering a less pathogenic microflora.

Effect on periodontal status of rotary electric toothbrushes vs. manual toothbrushes during periodontal maintenance. I. Clinical results

The purpose of this study was to compare the Rotadent rotary electric toothbrush with conventional toothbrushing for its effectiveness in controlling supragingival plaque and gingival inflammation in periodontal maintenance patients. Forty subjects who had received periodontal treatment, including periodontal surgery, for moderate to advanced periodontitis and were on a 3-month periodontal maintenance were divided into two equal groups matched for age and sex. One group used conventional toothbrushing, dental floss, and toothpicks and the other used only the rotary electric toothbrush for a 12-month study period. Single-blind clinical assessments (Plaque Index, Gingival Index, bleeding tendency, pocket depth, and loss of attachment) were made at baseline and at 3, 6, 9, and 12 months after baseline. Subgingival debridement was performed 1 week after the baseline assessment and the 6- and 12-month examinations. Plaque removal was reinforced at 3-month intervals. Both groups had significantly improved scores (P less than 0.01) for Gingival Index and bleeding tendency during the 12-month period, but no differences were found between the groups at any examination. These results indicate that the rotary electric toothbrush is as effective for plaque removal and control of gingival inflammation as a combination of conventional toothbrushing, flossing, and toothpicks for patients in periodontal maintenance.

Hazards of occupational transmission and strategies for prevention of infectious disease in dental education

The emergence of AIDS has alerted the nation's health care community to the dangers of occupational transmission of infectious disease. This article assesses the risk of occupational transmission in the health care setting and examines two prevention strategies: vaccination programs and infection control protocols. The implementation of these strategies by the School of Dentistry, University of California at San Francisco, is recounted to illustrate an institutional response to the issue of infection control in the dental setting.

Effects on gingivitis of two different 0.4% SnF2 gels

For nine months we monitored the periodontal health of 81 adolescents undergoing orthodontic treatment with fixed appliances, to determine whether daily use of a brush-on 0.4% SnF2 gel would be better than toothbrushing alone in maintaining periodontal health in these patients, and whether a gel supplying a high percentage of available Sn2+ ion would be more beneficial than a gel supplying a low percentage of available Sn2+ ion. The subjects were matched for age and sex and placed into a control group, which used toothbrushing alone, and two treatment groups, which used toothbrushing supplemented with daily use of a SnF2 gel. One treatment group used a gel with 98% available Sn2+ ion twice daily for the entire nine months. The other treatment group used a gel with less than 2% available Sn2+ once a day for six months, then twice a day for the remaining three months of the study. Clinical assessments (Plaque Index, Gingival Index, Bleeding Tendency, pocket depth, and coronal staining) were made before appliances were placed and at one, three, six, and nine months after appliances were placed. Results indicated that the group using the high-availability Sn2+ gel twice daily had significantly lower Gingival Index and Bleeding Tendency scores at the one-, three-, six-, and nine-month examinations than did the control group. The group using the low-availability Sn2+ gel showed no significant differences in these assessments from the control group. Neither treatment group showed significant differences from the control group in Plaque Index or pocket depth. In the group using the high-availability Sn2+ gel, one subject developed mild coronal staining, and two developed moderate staining.

Radiographic detection of dental calculus

To determine the sensitivity and specificity of the radiographic detection of calculus, 275 proximal tooth surfaces from 18 patients were evaluated. Standardized periapical radiographs obtained before extraction were coded, batch processed, and evaluated independently by two investigators under optimum viewing conditions. After extraction, the teeth were photographed and evaluated both microscopically and by planimetry on 40 X linear projections. Evaluation of calculus by conventional radiography showed low sensitivity: radiographic deposits were detected on only 44% of surfaces that demonstrated calculus microscopically. Specificity was high and the rate of false positives was only 7.5%. Detection of calculus was influenced by the thickness of calculus, the percentage of root surface occupied by calculus, and by tooth type; but not by attachment loss, probing depth, proximal surface, or arch location. These results show that present radiographic techniques are not appropriate for detecting calculus on root surfaces.

Fission-Track Dating of Haughton Astrobleme and Included Biota, Devon Island, Canada

Haughton Astrobleme is a major extraterrestrial impact structure located on Devon Island in the Canadian Arctic Archipelago, Northwest Territories. Apatite grains separated from shocked Precambrian gneiss contained in a polymict breccia from the center of the astrobleme yielded a fission-track date of 22.4 million +/- 1.4 million years before the present or early Miocene (Aquitanian). This provides a date for the impact event and an upper limit on the age of crater-filling lake sediments and a flora and vertebrate fauna occurring in them. A geologically precise date for these fossils provides an important biostratigraphic reference point for interpreting the biotic evolution of the Arctic.

Calculus removal by scaling/root planing with and without surgical access

We assessed the presence and extent of calculus on subgingival root surfaces of teeth that received scaling and root planing (S/RP) alone, S/RP with modified Widman flap, or no treatment. After extraction, each surface was examined to determine the pocket depth (PD), area of root surface exposed to the pocket (A), and amount of pocket area showing retained calculus (C). Calculus-positive teeth (CPT) and surfaces (CPS) and percentage of pocket area occupied by calculus (C/A) were derived for each group. In general, CPT and CPS were significantly lower after S/RP with flap (37% and 14%, respectively) than after S/RP alone (62% and 24%). The advantage of S/RP with flap was greatest for facial and lingual surfaces and for anterior and premolar teeth. In both treatment groups CPS were similar over a pocket depth range of 0 to 6 mm. But in deeper pockets, CPS in teeth treated by S/RP with flap remained constant at 17% while after S/RP alone CPS increased linearly to approximately 45% at greater than 8 mm. The mean C/A was essentially equal in both treatment groups (11%) and was not related to pocket depth.

The effect of controlled ascorbic acid depletion and supplementation on periodontal health

To determine if systemic levels of vitamin C influence periodontal health, changes in plaque accumulation, gingival health and periodontal probing depth were measured in healthy subjects housed for 3 months in a nutrition suite that provided controlled periods of ascorbic acid depletion and supplementation. Eleven healthy, nonsmoking men, aged 19 to 28 years, ate a rotating 7-day diet adequate in all nutrients except ascorbic acid. This basal diet, which contained less than 5 mg/day ascorbic acid, was supplemented with 60 mg/day ascorbic acid for 2 weeks, 0 mg/day ascorbic acid for 4 weeks, 600 mg/day ascorbic acid for 3 weeks and 0 mg/day ascorbic acid for 4 weeks. Plasma, urine and leukocyte ascorbate levels, Plaque Index, Gingival Index, Bleeding Index and probing depths were monitored throughout the study. A uniform oral hygiene program was maintained in which oral hygiene instructions were reinforced bi-weekly. Ascorbate concentrations in body fluids and leukocytes responded rapidly to changes in ascorbic acid intake. No mucosal pathoses or changes in plaque accumulation or probing depths were noted during any of the periods of depletion or supplementation. However, measures of gingival inflammation were directly related to the ascorbic acid status. The results suggest that ascorbic acid may influence early stages of gingivitis, particularly crevicular bleeding.

Clinical and microbiologic effects of single-dose metronidazole or scaling and root planing in treatment of adult periodontitis

Sites affected with adult periodontitis were observed for 3 months to compare their clinical and microbiologic responses to a single 2 g dose of metronidazole, scaling and root planing, or no treatment. 2 sites with probing depths greater than or equal to 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.

Response of lingual ascorbic acid test and salivary ascorbate levels to changes in ascorbic acid intake

This study sought to determine whether the lingual ascorbic acid test (LAAT) and measurement of salivary ascorbate reflect plasma and leukocyte ascorbate levels during controlled periods of ascorbic acid depletion and supplementation. Eleven healthy non-smoking men, aged 19-28 years, ate a diet that was repeated every seven days and was adequate in all nutrients except ascorbic acid (AA). This basal diet, which provided less than 5 mg of AA per day, was supplemented with 60 mg of AA per day for two weeks, 0 mg (placebo) per day for four weeks, 600 mg per day for three weeks, and 0 mg per day for four weeks. Oral examinations, the lingual ascorbic acid test, and measurement of salivary, plasma, and leukocyte ascorbate concentrations were conducted throughout the study. Ascorbic acid concentrations in plasma and leukocytes responded rapidly to changes in vitamin C intake. LAAT-derived ascorbate values were unrelated to ascorbic acid intake and plasma and leukocyte ascorbate concentrations. Salivary ascorbate levels approached the lower limits of detection of the assay and remained constant throughout the investigation. Oral hygiene was consistently excellent, and no severe mucosal or periodontal changes were observed. It was concluded that lingual ascorbic acid test values and salivary ascorbate levels are not related to changes in ascorbic acid intake and are not consistent with plasma or leukocyte ascorbate concentrations.

Clinical and microbiological evaluation of therapy for juvenile periodontitis

Eight patients (mean age 15.6 yrs) with severe molar-incisor bone loss and pocket formation characteristic of juvenile periodontitis were entered into a clinical protocol of three sequential stages: scaling and root planing (S/RP); S/RP concurrent with systemic tetracycline therapy (1 gm/day for 28 days); periodontal surgery concurrent with systemic tetracycline therapy. Clinical and microbiological examinations were scheduled at baseline, at 1 to 2 months after Stage I, at 1 to 2 months after completion of tetracycline therapy in Stages II and III, and during recall. A decision to progress to the next stage or to place the patient on a 3-month recall was based solely on clinical findings (suppuration, bleeding upon probing and pocket depth) at the deepest site in each patient. Paperpoint subgingival plaque samples from representative affected sites were analyzed for percentage of total cultivable microflora composed of black-pigmented Bacteroides species (BPB), surface translocating bacteria (STB) and Actinobacillus actinomycetemcomitans (Aa). At baseline, all sites bled to probing, seven of eight sites showed suppuration, and deepest pocket depths averaged 8.0 mm. STB were detected in one and BPB in four sites, respectively, and all sites demonstrated Aa, which constituted approximately 40% of the total cultivable flora. S/RP alone had essentially no effect on either clinical or microbiological findings, and all patients progressed to Stage II. Five went on to Stage III. S/RP with tetracycline was clinically and microbiologically more effective at sites in which Aa was predominant. Surgery was required in all sites containing high levels of both BPB and Aa. These results suggest that microbiological diagnosis may be useful in selecting and monitoring treatment for juvenile periodontitis.

Surgical periodontal therapy: indications, selection and limitations

The goal of all periodontal therapy is to restore health and function to the periodontium and preserve the teeth for life. A variety of periodontal surgical procedures have been described to meet this goal in patients with periodontitis. The differences among procedures are not always clear and in many instances represent technical variations of a previously established method. A review of longitudinal studies of periodontal surgery suggests that the particular method employed is less important than thorough debridement of the diseased area, frequent professional care and excellent oral hygiene practices by the patient. Under these conditions, periodontal disease can be controlled irrespective of the method of surgical therapy.

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.

Pulpal effects of electrosurgery involving based and unbased cervical amalgam restorations

The pulpal effects of electrosurgery involving unrestored enamel, cementum, calcium hydroxide-copal varnish-based restorations and unbased restorations were evaluated in extracted human teeth and posterior teeth of cynomolgus monkeys. Electrosurgery for all studies was performed with a fully rectified filtered unit under conditions of normal clinical usage. Studies in extracted human teeth measured the voltage potential generated between a reference probe in apical pulp tissue and an activated electrosurgery electrode placed on enamel, cementum, based restorations, and unbased restorations. Placement of a base reduced but did not prevent passage of electrosurgical current, and no measurable potential was associated with activated electrode contact on cementum or enamel. Studies in three cynomolgus monkeys included electrosurgery of based and unbased cervical silver amalgam restorations, electrosurgery of unrestored enamel, restored teeth not subjected to electrosurgery and teeth that were neither restored nor subjected to electrosurgery. Electrosurgery of restored teeth, regardless of the presence of a base, consistently resulted in pulpal damage characterized by an altered dentin matrix, necrosis adjacent to the cavity preparation, and a transition zone between necrotic and apparently vital pulp tissue. By 8 weeks following electrosurgery, the majority of specimens showed replacement of the odontoblastic layer and adjacent pulp tissue by dense connective tissue with areas of irregular calcification.