Análise comparativa da presença de mediadores inflamatórios no sulco gengival resultante das técnicas de moldagem em prótese fixa / Comparative analysis of inflammatory response in gingival fluid resulting from differents impression techniques for fixed prosthodontics

A qualidade de uma reconstrução protética depende, primordialmente, de sua integração biológica e da sua adaptação. O afastamento gengival serve para se obter espaço para o material de moldagem e também para a visualização e acesso aos limites gengivais dos preparos, que são essenciais para a confecção de próteses com uma justeza de adaptação clínica. No entanto, a inserção de um material (fio retrator ou casquete) pode romper o sistema de fibras gengivais que conectam a margem gengival à superfície do cemento causando recessão gengival. Ocasionalmente, ocorre significativa inflamação ou perda de inserção. O objetivo deste trabalho foi quantificar a resposta inflamatória decorrente das diferentes técnicas de moldagem para prótese fixa, em termos da quantidade de IL-2, IL-4, IL-5, IL-10, TNF-α, IFN-γ, presentes no fluido gengival dos dentes com necessidade protética. A amostra foi composta por 10 dentes moldados pela técnica de afastamento gengival com fio retrator e um grupo de 10 dentes moldados pela técnica do casquete. Os pacientes foram selecionados considerando-se a necessidade de prótese parcial fixa, higiene bucal satisfatória e não possuírem sinais clínicos de doença periodontal. Previamente à moldagem, uma tira de periopaper foi inserida no sulco gengival do paciente e foi mantida por 30 segundos. A coleta foi repetida 4 vezes para as faces mesiovestibular, distovestibular, mesiolingual e distolingual. Terminado o procedimento da moldagem, após 2 horas, 4 horas e 24 horas, respectivamente, foi repetido o procedimento de inserção do periopaper nos 4 sítios dos dentes. A amostra foi preparada para a citometria de fluxo (CBA - cytometric beads array). Os resultados foram analisados pelo teste de Tukey. Na análise de variância a 3 critérios, por meio da comparação entre técnica de moldagem, paciente e tempo para os valores de TNF-α, a relação tempo e paciente versus tempo...

he quality of a prosthetic reconstruction depends mostly on its integration and its biological adaptation. The gingival retraction serves to provide space for the impression material and also for visualize and give access to the gingival limit of tooth preparations, which are essential for making prostheses with a reliable clinical precision fit. However, the inclusion of a material (retractor cord or acrilic resin coping) can break the system of gingival fibers that connect the gingival margin to cementum´s surface, causing gingival recession. Occasionally, inflammation or significant insertion loss occurs. The aim of this study was to quantify the inflammatory response resulting from differents impression techniques for fixed prosthodontics in terms of the quantity of IL-2, IL-4, IL-5, IL-10, TNF-α, IFN-γ, found in gingival fluid of tooths needing prosthetic restorations. The sample consisted of 10 teeth impressed by gingival retraction cord technique and a group of 10 teeth using acrilic resin coping technique. Patients were selected considering the need for fixed partial denture, good oral hygiene and absence of periodontal disease´s clinical signs. Prior taking impressions, a Periopaper strip was inserted into the gingival sulcus of patients and was maintained for 30 seconds. The collect was repeated 4 times to the mesiobuccal, distovestibular, mesiolingual and distolingual sides: After the impression procedure, collecting was repeated after 2 hours, 4 hours and 24 hours respectively. the Periopaper strip was inserted on the teeth´s four sites. The sample was prepared for flow cytometry examination (CBA - cytometric beads array). The results were evalueted by Tukey test. The 3-way analysis of variance criteria,comparing impression technique, patient and time to values of TNF-α, the relationship between time and patient versus time was statistically significant (p < 0.05). Comparing the acrilic resin coping and retraction cord impression techniques...

Comparison of results following modified Widman flap surgery with and without surgical dressing.

The clinical effects of a periodontal dressing after modified Widman flap surgery were studied. A total of thirty surgical sites in 13 patients were included in the study. Half of the sites were not covered by a periodontal dressing while the other half were. To effect a blind evaluation, the dressings were placed and removed by someone other than the examiner. Gingival crevicular fluid flow and gingival inflammation were measured prior to surgery, 2 weeks, 1 month and 2 months after surgery. Clinical attachment level and pocket depth were measured prior to surgery, 1 month and 2 months after surgery. All patients were instructed in oral hygiene procedures and received rubber cup prophylaxes and flossing at 1 week, 2 weeks, 1 month and 2 months postoperatively. At the conclusion of the study, a questionnaire was administered to each patient. No significant differences were found between dressed and undressed segments regarding changes in clinical attachment levels, pocket depth, or gingival inflammation. The omission of a dressing did not result in a greater incidence of discomfort. More patients stated preference for no dressing.

Identification of a cathepsin b-like protease in the crevicular fluid of gingivitis patients.

Crevicular fluid from gingivitis patients contains significant levels of a cysteine protease which was characterized as the lysosomal protease cathepsin B, as judged by substrate specificity, thiol dependence, pH optimum, kinetic parameters, pH stability, and inhibitor sensitivities. A highly-sensitive fluorometric assay procedure was used to establish the mean level of cathepsin B activity for 25 gingivitis patients.

Lysozyme and lactoferrin quantitation in the crevicular fluid.

This study was designed to determine if quantitation of lysosomal products in crevicular fluid may be useful as a diagnostic test to evaluate clinical status in periodontal disease. Levels of lysozyme and lactoferrin were quantitated in crevicular fluid from patients with gingivitis, generalized adult periodontitis, localized juvenile periodontitis and normals. Crevicular fluid (CF) was collected from each patient by standardized filter paper strips and evaluated for lysozyme and lactoferrin by rocket immunoelectrophoresis. Levels of lysozyme (micrograms of protein per microliter of CF) were significantly higher in localized juvenile periodontitis patients as compared to gingivitis and adult periodontitis. On the other hand, levels of lactoferrin (micrograms of protein per microliter of CF) did not show significant differences between gingivitis, adult periodontitis and localized juvenile periodontitis. These results indicate that a lysozyme to lactoferrin ratio could be of value as a diagnostic test for localized juvenile periodontitis patients.

Increased thymocyte-activating factor in human gingival fluid during gingival inflammation.

In this study, human gingival fluid from normal subjects was shown to contain a low-molecular-weight factor (molecular weight, 10,000 to 25,000) which augmented murine thymocyte proliferation, enhanced the production of interleukin 2 by T lymphocytes, and augmented the proliferation of fibroblasts. These biochemical and biological properties are characteristic of both macrophage-derived interleukin 1 and epidermal cell-derived thymocyte-activating factor. In addition, we have established that epidermal thymocyte-activating factor or interleukin 1 or both are present to a greater extent in gingival fluid obtained from sites manifesting gingival inflammation. In fact, thymocyte-activating activities were found to be greater in gingival fluid from inflamed than from noninflamed gingival sites from the same subjects. These findings suggest that human gingival fluid contains epidermal thymocyte-activating factor or interleukin 1 or both, which may amplify the inflammatory response in periodontal tissues.

Capillary agar diffusion assay for measuring metronidazole in human gingival crevice fluid.

An agar diffusion assay in capillaries, with Fusobacterium nucleatum M2 as the indicator strain, has been developed to measure metronidazole concentrations in gingival crevice fluid. The assay allows the measurement of 1.9 micrograms of metronidazole per ml in sample amounts of 0.6 microliters.

Alpha 2-macroglobulin in sulci from healthy and inflamed human gingivae.

The concentration of alpha 2-macroglobulin (alpha 2-M) in human gingival sulci has been investigated in two studies: first, in gingival washings during a 21-day period of experimental gingivitis in eight human volunteers and, second, in crevicular fluid collected with filter paper strips before and after initial periodontal therapy in 11 patients. The concentration of total alpha 2-M was found to increase in the washings of the volunteers throughout the period of experimental gingivitis. In the group of patients receiving periodontal therapy, the absolute amount of alpha 2-M in the fluid showed a significant decrease after therapy. The gingival index of inflammation and the crevicular fluid flow also decreased significantly. The specific content of the inhibitor (micrograms of alpha 2-M per mg of fluid per min), however, was found to increase in the fluid with decreasing inflammation. As detected by crossed immunoelectrophoresis, the fluid collected in these patients before therapy, in the presence of severe inflammation, invariably showed peaks of both free and complexed alpha 2-M. In contrast, the fluid collected from the same sites after healing of the inflammation contained no detectable free alpha 2-M.

Clinical significance of gingival fluid measurement by "Periotron".

The accuracy of gingival fluid measurement with an electric device was compared with such clinical parameters as Gingival Index scores and pocket depths, and the treatment effect was evaluated by changes in the gingival fluid amount. After the initial examination 10 patients received oral hygiene instruction, scaling, root planing and soft tissue curettage. The operated areas were protected by a periodontal dressing for 1 week and all patients used a 0.2% chlorhexidine mouthrinse twice daily during that period and for the next week. Four weeks later the patients were reexamined for the same factors that were evaluated at the initial examination. The amount of gingival fluid correlated with the Gingival Index (r = 0.65), the pocket depth (r = 0.74) and the total amount of acid phosphatase in the gingival fluid (r = 0.92). Following treatment, a significant improvement in periodontal status was demonstrated by all of the parameters utilized.

Tetracycline: levels achievable in gingival crevice fluid and in vitro effect on subgingival organisms. Part I. Concentrations in crevicular fluid after repeated doses.

The concentration of tetracycline in gingival crevice fluid and blood was determined using a sensitive bioassay after oral administration of repeated doses of tetracycline. Crevicular fluid was sampled by an intracrevicular technique from four gingival sites in each individual and blood was obtained by finger puncture. Four volunteers received doses of 250 mg of tetracycline-HCl either every 6 hours or every 12 hours and were sampled at hours 0 to 15, 21 to 36, 48 to 60 and 96 to 102. Volunteers given 250 mg every 6 hours had average crevicular fluid concentrations between 4 to 8 micrograms/ml and blood concentrations between 2 to 2.5 micrograms/ml after 48 hours. The levels in crevicular fluid and blood of volunteers who received 250 mg every 12 hours were 2 to 4 micrograms/ml and 0.3 to 1.4 micrograms/ml respectively after 48 hours. The results demonstrated that after repeated doses of tetracycline the crevicular fluid levels were typically 2 to 4 times the blood levels.

Tetracycline: levels of achievable in gingival crevice fluid and in vitro effect on subgingival organisms. Part II. Susceptibilities of periodontal bacteria.

The sensitivity to tetracycline of 345 bacterial isolates from periodontal lesions was determined. Most species of bacteria, including those thought to be involved in the initiation and progress of destructive periodontal disease, were inhibited in vitro by tetracycline concentrations of 4 to 8 micrograms/ml. This concentration is equivalent to crevicular fluid levels of tetracycline at dosages of 1 gm/day. These data indicate that tetracycline is inhibitory at levels achieved in crevicular fluid for bacteria currently implicated in destructive periodontal disease.