Terpinen-4-ol and alpha-terpineol (tea tree oil components) inhibit the production of IL-1ß, IL-6 and IL-10 on human macrophages.

OBJECTIVE: Tea tree oil (TTO) is an essential oil with anti-inflammatory properties, steam distilled from the plant Melaleuca alternifolia. We investigated the immunomodulatory properties of TTO and its components (terpinen-4-ol and alpha-terpineol) using lipopolysaccharide (LPS)-stimulated macrophages. METHODS: The ability of TTO, terpinen-4-ol and alpha-terpineol to modulate the macrophage response to bacterial LPS stimulation was assessed by ELISA for tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6 and IL-10 cytokine production and by western blotting for the activation of nuclear factor kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) signaling, which are associated with the expression of pro-inflammatory cytokines. We used a human monocytic cell line (U937) differentiated into macrophages. RESULTS: LPS induced the production of all cytokines, and TTO and its components significantly reduced the production of IL-1ß, IL-6 and IL-10. The production of TNF-α was not affected by either TTO or its major components. The modulation of cytokine production was not mediated by changes in NF-κB or p38 MAPK activation. CONCLUSION: TTO, terpinen-4-ol and alpha-terpineol can suppress the production of inflammatory mediators in LPS-stimulated human macrophages; this inhibition was mediated by interfering with the NF-kB, p38 or ERK MAPK pathways.

Green tea extract and its major constituent, epigallocatechin-3-gallate, induce epithelial beta-defensin secretion and prevent beta-defensin degradation by Porphyromonas gingivalis.

BACKGROUND AND OBJECTIVE: Antimicrobial peptides, such as beta-defensins, secreted by gingival epithelial cells, are thought to play a major role in preventing periodontal diseases. In the present study, we investigated the ability of green tea polyphenols to induce human beta-defensin (hBD) secretion in gingival epithelial cells and to protect hBDs from proteolytic degradation by Porphyromonas gingivalis. MATERIAL AND METHODS: Gingival epithelial cells were treated with various amounts (25-200 µg/mL) of green tea extract or epigallocatechin-3-gallate (EGCG). The secretion of hBD1 and hBD2 was measured using ELISAs, and gene expression was quantified by real-time PCR. The treatments were also carried out in the presence of specific kinase inhibitors to identify the signaling pathways involved in hBD secretion. The ability of green tea extract and EGCG to prevent hBD degradation by proteases of P. gingivalis present in a bacterial culture supernatant was evaluated by ELISA. RESULTS: The secretion of hBD1 and hBD2 was up-regulated, in a dose-dependent manner, following the stimulation of gingival epithelial cells with a green tea extract or EGCG. Expression of the hBD gene in gingival epithelial cells treated with green tea polyphenols was also increased. EGCG-induced secretion of hBD1 and hBD2 appeared to involve extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase. Lastly, green tea extract and EGCG prevented the degradation of recombinant hBD1 and hBD2 by a culture supernatant of P. gingivalis. CONCLUSION: Green tea extract and EGCG, through their ability to induce hBD secretion by epithelial cells and to protect hBDs from proteolytic degradation by P. gingivalis, have the potential to strengthen the epithelial antimicrobial barrier. Future clinical studies will indicate whether these polyphenols represent a valuable therapeutic agent for treating/preventing periodontal diseases.

Evaluation of two alternative methods for disinfection of toothbrushes and tongue scrapers.

OBJECTIVE: The aim of this study was to investigate the effectiveness of two alternatives methods for the disinfection of oral cleaning devices. METHODS: One type of toothbrush and two types of tongue scrapers (steel and plastic) were tested in this study. Sixteen specimens of each group were cut with standardized dimensions, contaminated separately with Candida albicans, Streptococcus mutans and Staphylococcus aureus and incubated for 24 h. After this, oral cleaning devices were washed in saline solution to remove non-adhered cells and divided into two groups (n = 8), one irradiated in microwave and other immersed in 3.78% sodium perborate solution, and evaluated for microbial recovery. The values of cfu of each group of microorganism after disinfection were compared by Kruskal-Wallis and Dunn non-parametric test, considering 95% of confidence. RESULTS: The toothbrush harboured a significant larger number of viable organisms than the tongue scrapers. The steel tongue scraper was less susceptible to adhesion of the three oral microorganisms. The time required to inactivate all contaminating microorganisms using microwave oven was 1 min and, for the immersion in 3.78% sodium perborate solution, was 2 and 3 h, respectively, for C. albicans and S. mutans/S. aureus. CONCLUSION: Microwave irradiation proved to be an effective alternative method to the disinfection of tongue cleaners and toothbrushes.

Emprego do óleo de Melaleuca alternifolia Cheel (Myrtaceae) na odontologia: perspectivas quanto à utilização como antimicrobiano alternativo às doenças infecciosas de origem bucal / Use of Melaleuca alternifolia Cheel (Myrtaceae) oil in dentistry: perspectives on its use as alternative antimicrobial to infectious diseases of oral origin

O interesse por medicamentos alternativos, principalmente daqueles provenientes de extratos naturais, tem aumentado nas últimas décadas. A Melaleuca alternifolia é um arbusto pertencente ao gênero Melaleuca, popularmente conhecida como "árvore de chá", cujo principal produto é o óleo essencial (TTO - tea tree oil), de grande importância medicinal por possuir comprovada ação bactericida e antifúngica contra diversos patógenos humanos. Em virtude da atividade terapêutica em diversas especialidades médicas, o TTO passou a ser empregado na área odontológica. Esta revisão de literatura foi realizada com o objetivo de discutir os ensaios já realizados com o TTO contra microrganismos relacionados à doença cárie, doença periodontal e problemas pulpares. O óleo de Melaleuca tem demonstrado boa ação antibacteriana in vitro contra microrganismos bucais, porém, pesquisas envolvendo o estudo do mecanismo de ação sobre as células microbianas ou estudos in vivo ainda são escassos e precisam ser realizados, já que esse produto pode ser útil na odontologia, seja na manutenção química da higiene ou prevenção de doenças bucais.

The interest in alternative medicines, especially those from natural extracts, has increased in recent decades. Melaleuca alternifolia is a shrub belonging to the genus Melaleuca, popularly known as "tea tree", the main product of which is its essential oil (TTO - tea tree oil), of great medicinal importance for its proven bactericidal and antifungal activity against several human pathogens. By virtue of its therapeutic activity in various medical specialties, TTO is now used in dentistry. This literature review was conducted in order to discuss the tests already carried out with TTO against microorganisms related to dental caries, periodontal disease and pulpal problems. Melaleuca oil has shown good in vitro antibacterial activity against oral microorganisms; however, research involving the study of its mechanism of action on the microbial cells or in vivo studies are still scarce and need to be done since this product may be useful in dentistry, either in the chemical maintenance of hygiene or in the prevention of oral diseases.

Short-term induction of thrombocytopenia delays periodontal healing in rats with periodontal disease: participation of endostatin and vascular endothelial growth factor.

BACKGROUND AND OBJECTIVE: Platelets contain factors, including VEGF and endostatin, that can modulate the healing process. We evaluated the effects of severe thrombocytopenia on periodontal healing in rats and determined the contribution of VEGF and endostatin to the healing process. MATERIAL AND METHODS: Rats were distributed into three test groups and two control groups. Cotton ligatures were placed at the gingival margin level of the lower first molar in the test groups. Sham-operated rats and rats in one of the periodontitis groups were killed 15 days later. Rats in the remaining two periodontitis groups had the ligatures removed in order to study the spontaneous recovery from the periodontal disease 15 days later, and these rats were treated with rabbit antiplatelet serum, in order to induce thrombocytopenia, or normal rabbit serum. An additional group without ligatures received antiplatet serum in the same period. RESULTS: After ligature removal, rats treated with normal rabbit serum showed reduced myeloperoxidase activity, decreased alveolar bone loss and increased numbers of blood vessels. Thrombocytopenia caused a delay in alveolar bone regeneration, a decrease in the number of vessels and a modest decrease in myeloperoxidase activity. In the rats with periodontitis, serum endostatin concentrations were slightly decreased and serum VEGF remained unchanged compared with sham-operated animals. After ligature removal, a significant VEGF increase and endostatin decrease were observed in the rats treated with normal rabbit serum. Thrombocytopenia led to a dramatic fall in both VEGF and endostatin concentrations. CONCLUSION: Thrombocytopenia leads to a delay of periodontal healing in the situation of experimental periodontitis, which might be mediated in part by a decrease in the serum concentration of VEGF and endostatin derived from the platelets. However, other factors derived from the platelets may also have contributed to a delay of periodontal healing in the rats with thrombocytopenia.

Susceptibility of Staphylococcus aureus to porphyrin-mediated photodynamic antimicrobial chemotherapy: an in vitro study.

The ability of Staphylococcus aureus to develop multidrug resistance is well documented, and the antibiotic resistance showed by an increasing number of bacteria has shown the need for alternative therapies to treat infections, photodynamic therapy (PDT) being a potential candidate. The aim of this study was to determine the effect of photodynamic therapy as a light-based bactericidal modality to eliminate Staphylococcus aureus. The study investigated a technique based on a combination of light and a photosensitizer that is capable of producing oxidative species to induce a cytotoxic effect. A Staphylococcus aureus suspension was exposed to a light emitting diode (LED) emitting at 628 nm, 14.6 mW/cm(2), and energy density of 20 J/cm(2), 40 J/cm(2), or 60 J/cm(2) in the presence of different porphyrin concentrations (Photogem). Three drug concentrations were employed: 12 microl/ml, 25 microl/ml, and 50 microl/ml. The treatment response was evaluated by the number of bacterial colony forming units (CFU) after light exposure. The results indicated that exposure to 60 J/cm(2) eliminated 100% (10 log(10) scales) of bacteria, on average. The best PDT response rate to eliminate Staphylococcus aureus was achieved with exposure to LED light in combination with the photosensitizer at concentrations ranging from 25 microl/ml to 50 microl/ml. These data suggest that PDT has the potential to eliminate Staphylococcus aureus in suspension and indicates the necessary drug concentration and light fluency.

Distribution and hydrolytic enzyme characteristics of Candida albicans strains isolated from diabetic patients and their non-diabetic consorts.

INTRODUCTION: The aim of this study was to investigate the oral colonization profile of Candida albicans strains isolated from diabetic patients and their non-diabetic consorts. In addition hydrolytic enzyme activity of these isolates was analysed. METHODS: The genetic diversity of C. albicans oral isolates from 52 couples was established using isoenzyme marker and cluster analysis. Hydrolytic enzyme characteristics, namely secreted aspartyl proteinases (SAPs) and phospholipases (PLs) were also analysed. RESULTS: Simultaneous colonization by C. albicans was observed in the consorts of 12 couples (23.1%). Patterns of monoclonal and polyclonal oral colonization by C. albicans strains were identified and the coexistence of identical or highly related strains was observed in both members of eight couples. The genetic diversity observed in the total yeast population revealed four large, genetically distinct groups (A to D) and the coexistence of strains in couples or consorts conjugally unrelated. SAP and PL activity was observed in the majority of C. albicans isolates without any association to particular strain, strain clusters (highly related isolates), or clinical characteristics of the consorts (diabetic, non-diabetic, and gender). CONCLUSION: Possible sources of transmission and oral propagation of groups (clusters) of strains of C. albicans can occur between diabetic and non-diabetic consorts. A conjugal genotypic identity exists in most C. albicans-positive couples, that is, both consorts share identical or highly related strains; however, this identity is not couple-specific as seen by the coexistence of clusters in couples and unrelated consorts.

Simvastatin therapy in cyclosporine A-induced alveolar bone loss in rats.

BACKGROUND AND OBJECTIVE: Cyclosporine A treatment is important in the therapy of a number of medical conditions; however, alveolar bone loss is an important negative side-effect of this drug. As such, we evaluated whether concomitant administration of simvastatin would minimize cyclosporine A-associated alveolar bone loss in rats subjected, or not, to experimental periodontal disease. MATERIAL AND METHODS: Groups of 10 rats each were treated with cyclosporine A (10 mg/kg/day), simvastatin (20 mg/kg/day), cyclosporine A and simvastatin concurrently (cyclosporine A/simvastatin) or vehicle for 30 days. Four other groups of 10 rats each received a cotton ligature around the lower first molar and were treated similarly with cyclosporine A, simvastatin, cyclosporine A/simvastatin or vehicle. Calcium (Ca(2+)), phosphorus and alkaline phosphatase levels were evaluated in serum. Expression levels of interleukin-1beta, prostaglandin E(2) and inducible nitric oxide synthase were evaluated in the gingivomucosal tissues. Bone volume and numbers of osteoblasts and osteoclasts were also analyzed. RESULTS: Treatment with cyclosporine A in rats, with or without ligature, was associated with bone loss, represented by a lower bone volume and an increase in the number of osteoclasts. Treatment with cyclosporine A was associated with bone resorption, whereas simvastatin treatment improved cyclosporine A-associated alveolar bone loss in all parameters studied. In addition, simvastatin, in the presence of inflammation, can act as an anti-inflammatory agent. CONCLUSION: This study shows that simvastatin therapy leads to a reversal of the cyclosporine A-induced bone loss, which may be mediated by downregulation of interleukin-1beta and prostaglandin E(2) production.

Efeito do celecoxib sobre a resposta inflamatória em doença periodontal experimental: estudo histológico em ratos / Effect of celecoxib on the inflammatory response during experimental periodontal disease: a histological study in rats

Os metabólitos do ácido araquidônico exercem um reconhecido papel na patogênese da doença periodontal. O objetivo deste trabalho foi avaliar o efeito do celecoxib, um inibidor seletivo da enzima cicloxigenase-2 (COX-2), sobre o processo inflamatório durante o desenvolvimento de doença periodontal induzida por ligadura em ratos. Após a colocação de ligadura de algodão ao redor dos primeiros molares inferiores direitos, 108 ratos Wistar foram aleatoriamente subdivididos em três grupos experimentais com 36 animais cada. Nos grupos teste (Ce1 e Ce2), os animais receberam diariamente uma dose oral de celecoxib 10 mg ou 20 mg/ kg de peso corporal, respectivamente. No grupo controle, os animais receberam diariamente dose oral de 1ml/kg de peso corporal de cloreto de sódio (NaCl) a 0,9%. Aos 5, 18 e 30 dias após o início do experimento, 12 animais de cada grupo experimental foram sacrificados. As mandíbulas foram retiradas e submetidas à análise histológica. Observou-se através de análise estatística como teste não-paramétrico de Kruskal-Wallis, que o tratamento com celecoxib, em ambas as concentrações, diminuiu a magnitude do processo inflamatório agudo e, reduziu significativamente (p<0,05) a intensidade do infiltrado inflamatório crônico. Estes resultados demonstraram que, independentemente da dosagem utilizada, a inibição seletivada COX-2 através do celecoxib pode levar a um decréscimo da reação inflamatória do tecido periodontal em decorrência da presença de ligadura em ratos.

Arachidonic acid metabolites have a recognized role in the pathogenesis of periodontal disease. The purpose of this study was to evaluate the effect of a selective cyclooxygenase-2 (COX-2) inhibitor, celecoxib, on the progression of periodontal disease in a ligature-induced periodontitis model in rats. After ligature placement in the mandibular right first molars, 108, 6-week-old Wistar rats were ramdomly assigned to one of the following groups of treatment that consisted in a daily oral dose of 10mg/kg body weight of celecoxib (Ce1), 20mg/kg body weight of celecoxib (Ce2) or 10ml/kg of 0,9%NaCl (Control). At 5, 18 and 30 days later, 12 animals of each group were sacrificed and the specimens routinely processed. Treatment with celecoxib significantly (p < 0,05) decreased the acute and the chronic process, histologically observed. These results show that selective cyclooxygenase-2 (COX-2) inhibition with celecoxib, can decrease the periodontal inflammation due to ligature placement in rats.

Effectiveness of microwave disinfection of complete dentures on the treatment of Candida-related denture stomatitis.

UNLABELLED: The effectiveness of microwave disinfection of maxillary complete dentures on the treatment of Candida-related denture stomatitis was evaluated. Patients (n = 60) were randomly assigned to one of four treatment groups of 15 subjects each; CONTROL GROUP: patients performed the routine denture care; Mw group: patients had their upper denture microwaved (650 W per 6 min) three times per week for 30 days; group MwMz: patients received the treatment of Mw group in conjunction with topical application of miconazole three times per day for 30 days; group Mz: patients received the antifungal therapy of group MwMz. Cytological smears and mycological cultures were taken from the dentures and the palates of all patients before treatment at day 15 and 30 of treatment and at follow-up (days 60 and 90). The effectiveness of the treatments was evaluated by Kruskal-Wallis and Mann-Whitney tests. Microbial and clinical analysis of the control group demonstrated no significant decrease in the candidal infection over the clinical trial. Smears and cultures of palates and dentures of the groups Mw and MwMz exhibited absence of Candida at day 15 and 30 of treatment. On day 60 and 90, few mycelial forms were observed on 11 denture smears (36.6%) from groups Mw and MwMz, but not on the palatal smears. Miconazole (group Mz) neither caused significant reduction of palatal inflammation nor eradicated Candida from the dentures and palates. Microwaving dentures was effective for the treatment of denture stomatitis. The recurrence of Candida on microwaved dentures at follow-up was dramatically reduced.

Alendronate therapy in cyclosporine-induced alveolar bone loss in rats.

BACKGROUND AND OBJECTIVE: Cyclosporine A is an immunosuppressive drug that is widely used in organ transplant patients as well as to treat a number of autoimmune conditions. Bone loss is reported as a significant side-effect of cyclosporine A use because this can result in serious morbidity of the patients. As we have shown that cyclosporine A-associated bone loss can also affect the alveolar bone, the purpose of this study was to evaluate the effect of the concomitant administration of alendronate on alveolar bone loss in a rat model. MATERIAL AND METHODS: Forty Wistar rats (10 per group) were given cyclosporine A (10 mg/kg, daily), alendronate (0.3 mg/kg, weekly), or both cyclosporine A and alendronate, for 60 d. The control group received daily injections of sterile saline. The expression of proteins associated with bone turnover, including osteocalcin, alkaline phosphatase and tartrate-resistant acid phosphatase (TRAP), and also the calcium levels, were evaluated in the serum. Analysis of the bone volume, alveolar bone surface, the number of osteoblasts per bone surface and the number of osteoclasts per bone surface around the lower first molars was also performed. RESULTS: The results indicate that cyclosporine A treatment was associated with bone resorption, represented by a decrease in the bone volume, alveolar bone surface and the number of osteoblasts per bone surface and by an increase in the number of osteoclasts per bone surface and TRAP-5b. These effects were effectively counteracted by concomitant alendronate administration. CONCLUSION: It is concluded that concomitant administration of alendronate can prevent cyclosporine A-associated alveolar bone loss.

Protective effects of Tacrolimus, a calcineurin inhibitor, in experimental periodontitis in rats.

OBJECTIVE: Periodontitis is a well-appreciated example of leukocyte-mediated bone loss and inflammation with pathogenic features similar to those observed in other inflammatory diseases, such as arthritis. Since Tacrolimus, is an immunomodulatory drug used for the treatment of some cases of arthritis, we hypothesized that it may modulate periodontal disease. DESIGN: Using a murine model of ligature-induced periodontal disease, we assessed the effects of daily administrations of Tacrolimus (1mg/kg body weight) on bone loss, enzymatic (myeloperoxidase) analysis, differential white blood cells counts, airpouch exudate and cytokine expression for 5-30 days. RESULTS: Radiographic, enzymatic (myeloperoxidase) and histological analysis revealed that Tacrolimus reduced the severity of periodontitis. More specifically, Tacrolimus suppressed the expression of serum interleukin (IL-1beta), tumour necrosis factor (TNF-alpha), IL-6, airpouch exudate PGE(2) and leukocytosis usually observed after the induction of periodontitis. Tacrolimus treatment in periodontitis-induced rats conferred protection against the inflammation-induced tissue and bone loss associated with periodontitis, through a mechanism involving IL-1beta, TNF-alpha and IL-6. CONCLUSIONS: The effects of Tacrolimus on periodontal disease pathogenesis may provide clues to a novel approach to host modulation therapy in destructive periodontal disease.

The effectiveness of alumina powder on carious dentin removal.

This study determined the size of aluminum oxide particles used in an air abrasion system that is able to remove carious dentin tissue with maximum preservation of sound structure. Thirty extracted and carious-free third molars were used in this study. The dentin sample was obtained by sectioning the middle of the crown longitudinal to the long axis of the tooth in a mesio-distal direction. One half of the crown corresponded to the sound dentin group (SD), while the other half was used to develop artificial caries, constituting the carious dentin group (CD). The specimens were air abraded for 15 seconds. The SD and CD groups were each randomly divided into three subgroups (N=10) according to the particle diameter employed (27, 50 and 125 microm). The prepared cavity was perpendicularly cut in half, and the profiles of all hemi-fragments were observed using SEM microscopy. The cavity measurements were made using a modified cephalometric analysis. The 27, 50 and 125 microm aluminum oxide particles did not present selectivity in the removal of carious dentin. However, when using the air abrasive technique for carious dentin treatment, the use of 27 and 50 microm aluminum oxide particles is recommended, due to their capacity to remove less sound tissue than the 125 microm particles.

Molecular fingerprinting methods for the discrimination between C. albicans and C. dubliniensis.

Opportunistic fungal pathogens are becoming increasingly important causes of both community-acquired and nosocomial infections. The most important fungal pathogens are yeast species belonging to the genus Candida. These species show differences in levels of resistance to antifungal agents and mortality. Consequently, it is important to correctly identify the causative organism to the species level. Identification of Candida dubliniensis in particular remains problematic because of the high degree of phenotypic similarity between this species and Candida albicans. However, as the differences between both are most pronounced at the genetic level, several studies have been conducted in order to provide a specific and rapid identification fingerprinting molecular test. In most candidal infectious, no single DNA fingerprinting technique has evolved as a dominant method, and each method has its advantages, disadvantages and limitations. Moreover, the current challenge of these techniques is to compile standardized patterns in a database for interlaboratory use and future reference. This review provides an overview of most common molecular fingerprinting techniques currently available for discrimination of C. albicans and C. dubliniensis.

Oral health in renal transplant recipients administered cyclosporin A or tacrolimus.

OBJECTIVE: The aim of this study was to determine the oral status of renal transplant recipients receiving cyclosporin A (CsA) or tacrolimus (FK-506) as immunosuppressant. SUBJECTS AND METHODS: A total of 88 renal transplant recipients receiving CsA (63 men and 25 women, mean age 51.4 years) and 67 receiving FK-506 (57 men and 10 women, mean age 33.5 years) were included in the study. Donor type, histocompatibility, cold ischemia time and prior delayed graft function were similar between the two groups. Demographics and pharmacological data were recorded for all subjects. RESULTS: The results demonstrated that CsA caused a greater number of oral diseases. A greater number of gingival overgrowth was present in patients treated with CsA. However, the combined use with calcium channel blockers increased the gingival overgrowth number. The occurrence of candida in saliva was observed in 80 renal recipients treated with CsA and 20 treated with FK-506. The presence of squamous oral carcinoma (n = 3) and herpes simplex (n = 10) was observed in patients treated with CsA. These alterations were not observed in renal recipients treated with FK-506. CONCLUSIONS: Renal recipients constitute a high-risk group for oral diseases, as they are immunocompromised. However, the FK-506 regime appears to ameliorate this effect, compared with CsA. Adequate pre- and post-transplant oral health care is recommended for these subjects, irrespective of the time interval for which the drug is administered.

Phenotypic methods and commercial systems for the discrimination between C. albicans and C. dubliniensis.

Candida dubliniensis is a recently described Candida species associated with oral candidosis that exhibits a high degree of phenotypic similarity to Candida albicans. However, these species show differences in levels of resistance to antimycotic agents and ability to cause infections. Therefore, accurate clinical identification of C. dubliniensis and C. albicans species is important in order to treat oral candidal infections. Phenotypic identification methods are easy-to-use procedures for routine discrimination of oral isolates in the clinical microbiology laboratory. However, C. dubliniensis may be so far underreported in clinical samples because most currently used identification methods fail to recognize this yeast. Phenotypic methods depend on growth temperature, carbon source assimilation, chlamydospore and hyphal growth production, positive or negative growth on special media and intracellular enzyme production, among others. In this review, some phenotypic methods are presented with a special emphasis on the discrimination of C. dubliniensis and C. albicans.

Effects of long-term cyclosporin therapy on the periodontium of rats.

BACKGROUND: The treatment of cyclosporin A triggers an early bone loss and gingival overgrowth. There is a lack of studies exploring the effects of long-term cyclosporin A therapy on alveolar bone homeostasis and gingival tissue. OBJECTIVE: The purpose of this study was to evaluate the effects of long-term therapy with cyclosporin A on the gingival tissue and on the alveolar bone metabolism in rats. MATERIALS AND METHODS: Rats were treated for 60, 120, 180 and 240 days with a daily subcutaneous injection of 10 mg/kg body weight of cyclosporin A. At the end of experimental periods, animals were killed and the serum calcium (Ca(2+)) and alkaline phosphatase levels were measured in all groups. After histological processing, the oral epithelium and the connective tissue, as well as volume densities of alveolar bone (V(b)) and multinucleated osteoclasts (V(o)), were assessed at the region of the lower first molars. RESULTS: Significant increases in the serum alkaline phosphatase were observed in those groups that received cyclosporin A therapy. After 60 and 120 days of the treatment with cyclosporin A, evident gingival overgrowth associated with a significant increase of epithelium and connective tissue was observed, as well as a decrease of the densities of bone and an increase of densities of osteoclasts. After 180 and 240 days of the treatment, there was a reduction of the gingival overgrowth associated with significant decreases of epithelium and connective tissue, as well as an increase of bone densities and a decrease of osteoclasts. CONCLUSION: Within the limits of this experimental study, it can be concluded that the deleterious periodontal effects of cyclosporin A administration may be time-related side-effects.

Influence of age on combined effects of cyclosporin and nifedipine on rat alveolar bone.

BACKGROUND: There is some evidence showing that cyclosporin A (CsA) and nifedipine (NIF) affect bone metabolism. The purpose of this work was to study the effects of CsA and NIF, given alone or concurrently, on alveolar bone of rats of different ages. METHODS: Rats 15, 30, 60, and 90 days old were treated daily with 10 mg/kg body weight of CsA subcutaneously injected and/or 50 mg/kg body weight of NIF/day given orally for 60 days. Alveolar bone of the first lower molars was morphologically and stereologically evaluated in serial 5 microm bucco-lingual paraffin sections, stained with hematoxylin and eosin. Serum calcium and alkaline phosphatase levels were measured in all animals at the end of the experimental period. RESULTS: Rats treated with CsA or NIF alone or CsA and NIF concurrently showed decreased alveolar bone density. CsA was more effective than NIF. A significant decrease in serum calcium was found only in animals treated with CsA or CsA/NIF. The results were similar regardless of age. CONCLUSIONS: These results indicate that the decrease in the alveolar bone volume in rats caused by CsA and NIF alone or concurrently is not age dependent. Furthermore, NIF (50 mg/kg) did not further increase the loss of alveolar bone volume induced by CsA (10 mg/kg).

Combined effects of cyclosporin and nifedipine on gingival overgrowth in rats is not age dependent.

BACKGROUND: Cyclosporin A and nifedipine cause gingival overgrowth in rat, and the combined use of these drugs increases the overgrowth severity. OBJECTIVE: The purpose of this study was to compare gingival overgrowth of rats of differents ages treated with cyclosporin A and nifedipine alone or given concurrently. MATERIALS AND METHODS: Rats 15, 30, 60 and 90 d old were treated with 10 mg/kg body weight of cyclosporin A and/or 50 mg/kg body weight of nifedipine in the chow. RESULTS: Young rats showed evident gingival overgrowth with nifedipine, cyclosporin A, and cyclosporin A and nifedipine given concurrently. Adult rats did not show significant gingival alterations when treated with cyclosporin A and nifedipine alone. Nevertheless evident gingival overgrowth with alterations of the epithelium and connective tissue were observed when treated simultaneously with cyclosporin A and nifedipine. CONCLUSION: These results suggest that the combined effects of cyclosporin A and nifedipine on gingival overgrowth in rat is not age dependent.

Evaluation of argyrophilic nucleolar organizer regions in oral tumor progression.

The aim of this study was to compare the presence of nucleolar organizer regions (NORs) in normal oral mucosa, dysplasia and microinvasive carcinoma. All histological specimens were reviewed according to the modified classification and staging system for oral leukoplakia described by van-der-Waal et al. [Oral Oncol. 36 (2000) 264]. NOR quantification was performed with an image analyzer after staining by the argyrophilic nucleolar region technique. The morphometric results were statistically different for normal mucosa, dysplasia and microinvasive carcinoma. It was concluded that an increase of NOR activity follows the disease progression and may reflect the degree of cellular proliferation and malignancy.