Metabolism of phenytoin by the gingiva of normal humans: the possible role of reactive metabolites of phenytoin in the initiation of gingival hyperplasia

Gingival hyperplasia is a well-known complication of therapy with cyclosporine, calcium channel blockers, and phenytoin. It is characterized by the presence of inflammation and a marked fibrotic response. The mechanism of this adverse reaction is unknown. We propose that it may be initiated by the metabolic activation of these drugs to form reactive metabolites. These then cause cellular injury and lead to the gingival hyperplasia. To evaluate this hypothesis we examined phenytoin metabolism and the cytochrome P450 contents of gingival tissues from 10 patients undergoing surgery for various periodontal conditions. We found that microsomes obtained from the gingiva show significant phenytoin hydroxylase activity as determined by the production of 5-(4'-hydroxyphenyl)-5-phenylhydantoin (HPPH) (range, 12.8 pmol HPPH/min.mg microsomal protein to 276.9 pmol HPPH/min.mg microsomal protein; rat control, 133.7 +/- 11.5 pmol HPPH/min.mg microsomal protein). We also found that CYP1A1, CYP1A2, CYP2C9, CYP2E1, and CYP3A4 were present in these microsomes. We detected no CYP2B6 or CYP2D6. We believe that these data support our hypothesis that the proliferative inflammation observed with drugs such as phenytoin, nifedipine, and cyclosporine may be initiated by the formation of reactive metabolites and that the formation of these metabolites may be catalyzed by one or more CYPs found in the gingiva. These metabolites may then cause cellular injury and induce a reactive inflammatory response, followed by fibroblastic proliferation. This proliferation leads to the excess collagen deposition observed with gingival hyperplasia.

Effect of gingival fluid collection on subgingival plaque sampling

The purpose of this study was to determine whether gingival crevicular fluid (GCF) sampling by paper strip removes sufficient bacteria to affect subsequent subgingival plaque sampling using a curette. In 25 subjects, one healthy, gingivitis and periodontitis site was sampled for GCF using a strip followed by subgingival plaque sampling with a curette. Bacterial assays indicated that GCF strips removed significant numbers of bacteria when placed intracrevicularly for 5 s. A greater proportion of total bacteria was removed with strip sampling at healthy rather than gingivitis or periodontitis sites. Qualitative assessment of presence or absence of spirochaetes and dark-pigmented species indicated potential for significant interference of curette sampling by the strip at gingivitis and healthy sites. We concluded that paper strip GCF sampling may significantly affect curette sampling at the same sites. The magnitude of this impact depended on the clinical classification of specific sites and the assay performed.

Natural distribution of 5 bacteria associated with periodontal disease

The purpose of this study was to determine the prevalence and distribution of 5 bacterial pathogens in subgingival plaque, their relationship with each other and probing depth. Plaque was collected from 6905 sites in 938 subjects. A bacterial concentration fluorescence immunoassay and bacterial specific monoclonal antibodies were used to determine the presence and level of P. gingivalis (Pg), A. actinomycetemcomitans (Aa), P. intermedia (Pi), E. corrodens (Ec) and F. nucleatum (Fn) in each plaque sample. The prevalence in subjects was lowest for Pg (32%) and highest for Ec (49%). The site-based frequency distribution of these bacterial species ranged from 10.3% for Pg to 18.7% for Ec. Pi and Ec were the bacterial combination most often found together in a subject (27.2%). While 64.0% of the sites were without any of the 5 bacterial species evaluated, 20.2% had only 1 of the 5 bacterial species evaluated. The remaining 15.8% of sites had at least 2 bacteria species present. There was a general linear association of the detection level of bacterial species and probing depth. The odds ratios were 3.9 (Pg), 3.0 (Aa), 4.0 (Pi), 2.7 (Ec) and 2.8 (Fn) of finding high levels of these bacterial pathogens at > 5 mm probing depth (p < or = 0.01). Mean probing depth at molar sites without a specific bacteria was greater (p < or = 0.01) in subjects with a specific bacterium compared to molar sites in subjects without the bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Issues in the evaluation of clinical trials of periodontitis: a clinical perspective

The goals of clinical trials designed to establish claims for equivalency or superiority of treatment for periodontitis must be clearly stated and defined in terms of measurable and meaningful response variables. It is suggested that these clinical trials use designs that compare new treatment methods to basic periodontal therapy which consists of thorough scaling and root planing, oral hygiene instruction, and regular maintenance care. The primary response variable should be clinical attachment level. It is important to document changes in probing depth since this is a meaningful measure to many clinicians. Gingival inflammation and bleeding should be used as secondary response variables because these are not necessarily indicative of progressive periodontal destruction. Radiographic measures of disease may be useful as primary response variables if safe, reproducible and valid methods of measuring change are utilized. Microbiological monitoring should be a secondary response variable because of numerous questions concerning sampling methodology, quantitative expression of data, and meaningful interpretation in terms of relevance to disease activity. The length of periodontitis trials should be set at a minimum of 9 months if claims of superiority or equivalency are made compared to basic periodontal therapy. Calibration trials should be included and measurement error should be expressed in terms that are meaningful to the clinician while retaining statistical validity. Statistical methods for determining change should take into account site and subject heterogeneity, bursts of change and gradual change over time. It is important that statistical techniques be used that detect change as early as possible and that appropriate consideration be given to the clinical implications of the type, magnitude and duration of change in outcome variables.

Comparison of measurement variability using a standard and constant force periodontal probe

This study compared the intra- and inter-examiner reliability of the Florida Probe, Florida Disk Probe, and conventional periodontal probe. Using these instruments, each of three examiners made repeated measurements of probing depth (using the Florida Probe and conventional probe), relative attachment level (using the Florida Disk Probe), and clinical attachment level (using a conventional probe) at posterior, proximal sites in 10 subjects with early periodontitis. The mean intra-examiner standard deviation of differences in repeated probing depth measurements ranged from 0.46 to 0.77 mm demonstrating similar levels of reproducibility between the Florida Probe and conventional probe. The mean intra-examiner standard deviation of differences in repeated relative attachment level measurements using the Florida Disk Probe ranged from 0.44 to 0.57 mm using double passes and from 0.98 to 1.41 mm using single passes of measurements. For clinical attachment level measurements obtained using single passes of measurements with a conventional probe, the mean intra-examiner standard deviation of differences ranged from 0.78 to 0.95 mm. Inter-examiner variability was generally greater than intra-examiner variability for all instruments. It was concluded that double passes with the Florida Disk Probe offers significant advantages for measuring relative attachment level in longitudinal studies of early periodontitis when decisions for change must be made as soon as possible.

Oropharyngeal mucositis complicating bone marrow transplantation: prognostic factors and the effect of chlorhexidine mouth rinse

Oral mucosal ulceration complicating bone marrow transplantation interferes with patients' comfort, nutrition and may lead to systemic infection derived from the mouth. The mucosal injury results from epithelial damage due to the cytotoxic effects of chemotherapy and radiation conditioning as well as from superficial oropharyngeal infection. Because chlorhexidine gluconate is a broad spectrum topical antimicrobial which has been demonstrably effective in preventing oral infection and gingivitis, we performed a randomized, placebo controlled, double-blind trial of chlorhexidine as a mouth rinse in BMT recipients to study the severity of oral mucositis and both oral and systemic infectious complications. One hundred patients were randomly assigned to receive either chlorhexidine gluconate 0.12% mouth rinse or placebo three times daily from the initiation (day -8) of chemoradiotherapy conditioning until day +35 post-BMT. Chlorhexidine use resulted in a trend toward improved oral hygiene index (reduced dental plaque) (p = 0.06) but did not modify the oral mucositis. Patients using chlorhexidine developed a maximum ulceration of 18 +/- 22% of their oral mucosa, while placebo patients ulcerated 25 +/- 31% of the mouth. Ulcerative mucositis was significantly worse in adults compared with children, in individuals who received methotrexate for graft-versus-host disease prophylaxis, and was most prominent on non-keratinized epithelium. Overall, there was no clinically demonstrable additional therapeutic advantage to the use of chlorhexidine in either reducing the mucositis, controlling oral pain, facilitating oral nutrition, shortening hospital stay, or reducing oral infection with herpes simplex virus. There was a trend toward diminished oral candidiasis in chlorhexidine users (p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects on the periodontium of vertical bone cutting for segmental osteotomy

The periodontal response to vertical osteotomy was evaluated in seven males and ten females, aged 14-45 years (mean 26.8), who were scheduled for maxillary and/or mandibular segmental osteotomies. Plaque and gingival indices, pocket depth, clinical attachment level, width of attached gingiva, and osseous support were recorded from teeth adjacent to each osteotomy site prior to and from six months to three years after surgery. In each patient teeth numbers 3, 9, 13, 19, 25, and 29 were used as controls. There was no significant (P less than or equal to 0.05) difference between experimental and control teeth with respect to plaque, gingivitis, pocket depth, or clinical attachment level. Slightly decreased osseous support and width of attached gingiva were found adjacent to osteotomy sites. However, although these decreases were statistically significant (P = 0.005), they were not clinically very large. It was concluded that segmental osteotomies, in general, may be performed without producing significant changes in the periodontal structures.

Histopathology and electron and immunofluorescence microscopy of gingivitis granulomatosa associated with glossitis and cheilitis in a case of Anderson-Fabry disease

A 17-year-old white boy with signs, symptoms, and family history of angiokeratoma corporis diffusum universale, Anderson-Fabry disease (AFD), developed recurrent and then persistent swelling of both lips, erythematous hyperplastic gingivae, and a pebbled tongue. Positive blood findings were raised serum IgE, decreased T-cell level, and increased B-cell level. Histopathology of the gingiva showed noncaseating granulomas with multinucleate giant cells containing Schaumann bodies and large plasma-cell infiltrates in which immunofluorescence demonstrated immune globulins of several classes. Electron microscopy and histochemistry demonstrated ceramide in the vasculature. No glycolipid was found in the macrophages or giant cells of the granulomas which, in contrast, resembled sarcoid reactions. Plasma cells with Russell bodies and immune reaction-induced degranulation of mast cells were also identified. The pathogenesis of the oral findings possibly relates to altered immune reactivity associated with damage to the microvasculature analogous to that in Melkersson-Rosenthal syndrome.