Abstract: The aim of the present study was to analyze the relationship of OM with possible risk factors such as oral health condition, immunological status and IL-1β profile in patients submitted to hematopoietic stem cell transplantation (HSCT). Fifty-four individuals submitted to HSCT were included. All patients received previous dental treatment and photobiomodulation (PBM) as the institutional OM preventive protocol. OM scores, immune status, and IL-1β levels were determined during the conditioning period and at D+3 and D+8 after HSC infusion. IL-1β gene polymorphism was also analyzed during conditioning. Possible associations of OM with risk factors were analyzed using conditional Fisher's exact test. OM was observed in 34 patients (62.9%) classified as Grade 1 (13 patients/24.1%), Grade 2 (14 patients/25.9%), Grade 3 (3 patients/5.5%), and Grade 4 (4 patients/7.4%). Allogeneic HSCT individuals exhibited a higher OM grade than autologous subjects. Moreover, an association was observed between severe OM and severe gingivitis (p = 0.01), neutropenia (p = 0.03), and leukopenia (p = 0.04). A significant association between OM and lower IL-1β levels was detected at three time points, i.e., conditioning (p = 0.048), D+3 (p = 0.01), and D+8 (p = 0.005). The results showed that IL-1β gene polymorphism was not associated with OM. Our study provided important insights into the scope of OM risk factors in the setting of HSCT. Patients submitted to HSCT with severe gingivitis prior to chemotherapy and with severe neutropenia and leukopenia exhibited a higher OM grade. Further investigation will be necessary to better understand the exact role of IL-1β in the context of OM pathobiology and to validate cytokine analysis in larger cohorts.

Abstract The aim of this review was to update the evidence of new approaches to non-surgical therapy (NSPT) in the treatment of periodontitis. Preclinical and clinical studies addressing the benefits of adjunctive antimicrobial photodynamic therapy, probiotics, prebiotics/synbiotics, statins, pro-resolving mediators, omega-6 and -3, ozone, and epigenetic therapy were scrutinized and discussed. Currently, the outcomes of these nine new approaches, when compared with subgingival debridement alone, did not demonstrate a significant added clinical benefit. However, some of these new alternative interventions may have the potential to improve the outcomes of NSPT alone. Future evidence based on randomized controlled clinical trials would help clinicians and patients in the selection of different adjunctive therapies.

Resumo O presente estudo objetivou verificar o efeito da heparina de baixo peso molecular (HBPM) sob a perda óssea alveolar (POA), contagem de células sanguíneas, megacariócitos e adipócitos em ratos Wistar machos. Quarenta ratos Wistar de 60 dias foram randomicamente divididos em quatro grupo: Controle (C), Doença Periodontal (DP), Heparina (Hp) e Heparina + Doença Periodontal (Hp+DP). HBPM foi aplicada durante 60 dias em doses de 1 mL/kg/dia. Coletas sanguíneas foram realizadas nos dias 0, 30 e 60. No dia 49, os grupos DP e Hp+DP receberam indução de doença periodontal por ligadura ao redor do segundo molar superior direito. No lado esquerdo, verificou-se perda óssea alveolar espontânea. A média de POA no lado com ligadura mostrou-se estatisticamente diferente entre os grupos C (0,35±0,07 mm) e Hp+PD (0,49±0,09 mm) (p<0,001), entre os grupos DP (0,55±0,11 mm) e Hp (0,32±0,06 mm) (p<0,001) e entre os grupos Hp e Hp+DP (p<0,001). Nenhuma diferente significativa foi observada entre os grupos no lado sem ligadura. Peso dos animais, consumo de ração e ingestão de água não mostraram diferenças significativas entre os grupos. Megacariócitos e adipócitos foram contados por microscopia óptica e nenhuma diferença significativa foi encontrada. Dentro dos grupos, houve um aumento e uma diminuição, respectivamente, na contagem de linfócitos (p=0,005 no grupo C e p=0,009 no grupo Hp+DP somente) e leucócitos (p=0,003 no grupo C, p=0.001 no grupo DP e p=0,002 no grupo Hp e Hp+DP). Não houve diminuição no número de plaquetas nos três períodos de coleta. HBPM não foi capaz de modificar a POA, porém modificou a contagem de células sanguíneas, especialmente aumentando o número de linfócitos.

Abstract This study aimed to assess the effects of low molecular weight heparin (LMWH) on alveolar bone loss (ABL), blood count, and counting of megakaryocytes and adipocytes in male Wistar rats. Forty male 60-day Wistar rats were randomly divided into four groups: Control (C), Periodontal Disease (PD), Heparin (Hp) and Heparin + Periodontal Disease (Hp+PD). LMWH was applied for 60 days at doses of 1 ml/kg/day. Blood samples were collected at baseline, 30 and 60. On day-49, PD and Hp+PD groups were subjected to ligature-induced periodontitis around second upper right molar. The left side was assessed as spontaneous alveolar bone loss. Mean ABL in the side with ligature showed significantly different between C (0.35±0.07 mm) and Hp+DP (0.49±0.09 mm) groups (p<0.001), between PD (0.55±0.11 mm) and Hp (0.32±0.06 mm) groups (p<0.001) and between Hp and Hp+DP groups (p<0.001). No significant differences were found among groups for ABL in the side without ligature. Animal weight, food intake, and water consumption showed no statistically significant difference among groups. Megakaryocytes and adipocytes were counted using optical microscopy and no statistically significant differences were found. Within-groups, there were an increase and a decrease, respectively, in the counting of lymphocytes (p=0.005 for C and p=0.009 for Hp+PD groups only) and leukocytes (p=0.003 for C, p=0.001 for PD, p=0.002 for Hp, and p<0.001 for Hp+PD groups). There was no decrease in the number of platelets in the three collection periods. LMWH was not able to affect ABL, but it may change the blood counting, especially increasing lymphocytes.

Abstract This study aimed to evaluate the anti-plaque and anti-gingivitis effects of two mouthwashes containing cetylpyridinium chloride (CPC), in comparison to negative control mouthwash. One hundred and twenty subjects were randomly assigned to study groups: test (0.075% CPC and 0.28% zinc lactate), positive control (0.07% CPC) and negative control mouthwash without CPC. All volunteers were examined by a calibrated examiner for the Quigley-Hein Plaque Index (Turesky modification) and Löe-Silness Gingival Index (GI). Gingival severity was also measured by the percentage of sites with positive gingival bleeding. During six weeks, oral hygiene consisted of brushing twice daily with a toothbrush and toothpaste and rising with their assigned mouthwash. Plaque and gingival parameters were assessed at baseline, after four and six weeks of product use. Statistical analyses were performed separately for plaque and gingival indices, by ANOVA, paired t-test and ANCOVA (α < 0.05). After 4 and 6 weeks, all mouthwashes groups presented statistically significant reductions in plaque and gingival parameters as compared to baseline. In comparison to the positive control, the test group presented additional reductions in dental plaque of 19.8% and 16.8%, after 4 and 6 weeks, respectively. For GI, the additional reductions in the test group were 9.7% and 14.3%, at 4 and 6 weeks, respectively. The test group showed additional reduction of 35.3% and 54.5% in the gingival severity, at week 4 and 6, respectively. It is concluded that the mouthwash containing CPC and zinc lactate presents significant anti-plaque and anti-gingivitis effects as compared to positive and negative control mouthwashes.

Resumo O objetivo do presente estudo foi avaliar o efeito da dependência de álcool a 15% sobre a perda óssea alveolar induzida e secreção de TNF-α em ratos Wistar. Trinta e três ratos wistar com idade entre 45 e 60 dias (peso médio=253 g) foram alocados aleatoriamente para o grupo teste ou controle. O grupo teste (n=18) recebeu álcool a 15% como ingestão líquida e o grupo controle (n=15) recebeu água durante o período experimental. TNF-α foi analisado por meio de ELISA em 11 animais por grupo. Após 14 dias de ingestão de álcool/água a dependência do álcool foi determinada e ligaduras de seda foram colocadas ao redor dos segundos molares superiores esquerdos. A presença das ligaduras e o peso corporal foram verificadas semanalmente. Depois de 40 dias os animais foram sacrificados e as maxilas foram preparadas para análise morfométrica em fotografias estandardizadas. Todos os animais do grupo teste apresentaram sinais de dependência de álcool no dia 14. Não foram observadas diferenças estatisticamente significativas no peso corporal final entre os grupos (334,83±21,38 vs. 322,48±30,65 gramas, p=0,20) Em relação a perda óssea alveolar, não foram observadas diferenças estatisticamente significativas entre os grupos teste e controle tanto para dentes com (0,76±0,06 vs. 0,74±0,10 mm, p=0,60) como para dentes sem ligadura (0,41±0,16 vs. 0,35±0,05 mm, p=0,22). A secreção de TNF-α também não demonstrou diferenças estatisticamente significativas entre os grupos teste e controle (10,78±1,84 vs. 12,13±2,11 pg/mL, p=0,12). Pode-se concluir que a dependência de álcool a 15% não foi capaz de alterar a perda óssea alveolar e a secreção de TNF-α em ratos Wistar.

Abstract The aim of the present study was to evaluate the effect of 15% alcohol dependence on ligature-induced alveolar bone loss and TNF- secretion in Wistar rats. Thirty-three male Wistar rats aged 45-60 days (mean weight=253 g) were randomly allocated test or control groups. Test group (n=18) received 15% alcohol as liquid intake and control group (n=15) received water during the experimental period. TNF-α was analyzed by ELISA assay in 11 animals per group. After 14 days of alcohol/water intake, alcohol dependency was assessed and silk ligatures were placed around the left second upper molars. Ligature presence and body weight were checked weekly. After 40 days, animals were sacrificed and the maxillae were defleshed for morphometric analysis using standardized images. All animals in the test group displayed signs of alcohol dependency at day 14. No statistically significant differences in final body weight (334.83±21.38 vs. 322.48±30.65 g, p=0.20) were observed between groups. In relation to alveolar bone loss, no statistically significant difference was observed among test and control groups both for ligated teeth (0.76±0.06 vs. 0.74±0.10 mm, p=0.60) and unligated teeth (0.41±0.16 vs. 0.35±0.05 mm, p=0.22). The TNF-α secretion also did not display statistically significant differences between test and control groups (10.78±1.84 vs. 12.13±2.11 pg/mL, p=0.12). It may be concluded that 15% alcohol dependency was not capable to alter alveolar bone loss and TNF-α secretion in Wistar rats.

Abstract The aim of this study was to compare the efficacy in supragingival plaque removal of two soft-bristle toothbrushes. Seventy volunteers were allocated randomly to the Colgate Slim Soft or Curaprox CS5460 toothbrush grourps. At baseline appointment, volunteers underwent plaque examination using the Rustogi Modification of the Navy Plaque Index. Under supervision, they then brushed their teeth for 1minute with their assigned toothbrushes and the plaque examination was repeated. Volunteers performed daily oral hygiene with their assigned toothbrush and a regular dentifrice provided by the researchers for 7 days. The baseline experimental procedures were then repeated. Separate analyses of variance were performed for the whole-mouth, interproximal, and gumline plaque scores (p < 0.05). No difference in baseline pre-brushing scores was found between groups. After a single toothbrushing, the mean plaque score was significantly reduced in both groups (p < 0.05), with greater reduction of whole-mouth and interproximal plaque scores observed in the SlimSoft group compared with the Curaprox group (p < 0.05). After 7 days, the SlimSoft group showed greater reduction of the whole-mouth and interproximal plaque scores compared with the Curaprox group (p < 0.05). In conclusion, the SlimSoft toothbrush presented greater efficacy in supragingival plaque removal than did the Curaprox CS5460 toothbrush, as reflected by whole-mouth and interproximal plaque scores.

O objetivo do presente estudo foi avaliar o efeito da exposição do álcool e/ou tabaco sobre a perda óssea alveolar (POA) espontânea em ratos Wistar. Vinte e quatro ratos, machos, com 60 dias de vida foram divididos em 4 grupos: Grupo 1 recebeu 10 mL/kg de solução de glicose (5%). Grupo 2 recebeu 2 g/kg de álcool (20%). Grupo 3 foi exposto a fumaça do tabaco (6 cigarros/60 min). Grupo 4 recebeu a mesma intervenção dos grupos 2 e 3. A solução de álcool foi dada por meio de gavagem e a exposição ao tabaco foi realizada por meio de câmara de ventilação forçada. Após 30 dias de experimento, os animais foram sacrificados e as maxilas removidas. Análise morfométrica da POA ao redor do segundo molar superior foi realizada de modo padronizada. A análise estatística dos dados foi realizada por meio de teste t pareado e ANOVA. Ocorrência de doença periodontal espontânea (POA ≥ 0,39 mm) foi realizada pelo teste exato de Fisher. Diferenças significativas no peso corporal médio foram observadas em todos os grupos. Grupo 2 apresentou maior peso corporal médio quando comparado aos outros 3 grupos ao fim do experimento (p≤0,05). A média de POA foi 0,31 mm (±0,08); 0,29 mm (±0,07); 0,33 mm (±0,10) e 0,33 mm (±0,08) para os grupos 1, 2, 3 e 4, respectivamente. Não houve diferenças significativas entre os grupos. Na análise de ocorrência de destruição periodontal, a exposição de álcool diminuiu sua ocorrência, enquanto que exposição ao tabaco aumentou a POA espontânea. A combinação de álcool e tabaco não diferiu do grupo controle

The aim of the present study was to evaluate the effect of alcohol and/or tobacco exposure on spontaneous alveolar bone loss in Wistar rats. Twenty-four, male, 60 day-old, Wistar rats were assigned to 4 groups: Group 1 received 10 mL/kg of glucose solution (5%). Group 2 received 2 g/kg alcohol (20%). Group 3 was exposed to tobacco smoke (6 cigarettes/60 min). Group 4 received both interventions of groups 2 and 3. Alcohol was given by gastric gavage and cigarette exposure was performed using a forced ventilation chamber. After 30 days, animals were sacrificed and the upper maxillae removed and defleshed. Morphometric analysis of alveolar bone loss (ABL) around the second molar was performed in standardized digital photographs. Statistical analysis was conducted using paired t-test, one-way ANOVA and occurrence of spontaneous periodontal disease (ABL ≥ 0.39 mm) was analyzed by Fisher's exact test. Significant differences in body weight were observed between all groups. Group 2 presented higher body weight as compared to the 3 other groups at 4 weeks (p≤0.05). Mean ABL values were 0.31 mm (±0.08), 0.29 mm (±0.07), 0.33 mm (±0.10), and 0.33 mm (±0.08) for groups 1, 2, 3, and 4, respectively. No significant differences were found among groups. In the analysis of occurrence of periodontal breakdown, alcohol exposure decreased the occurrence of ABL and cigarette exposure increased ABL. The combination of alcohol and cigarette exposure did not differ from the control group. Alcohol consumption decreased the occurrence of periodontal breakdown, while tobacco increased this rate.

The aim was to correlate alveolar bone loss in the buccal/palatal and the mesial/distal surfaces of upper molars in rats. Thirty-three, 60-day-old, male Wistar rats were divided in two groups, one treated with alcohol and the other not treated with alcohol. All rats received silk ligatures on the right upper second molars for 4 weeks. The rats were then euthanized and their maxillae were split and defleshed with sodium hypochlorite (9%). The cemento-enamel junction (CEJ) was stained with 1% methylene blue and the alveolar bone loss in the buccal/palatal surfaces was measured linearly in 5 points on standardized digital photographs. Measurement of the proximal sites was performed by sectioning the hemimaxillae, restaining the CEJ and measuring the alveolar bone loss linearly in 3 points. A calibrated and blinded examiner performed all the measurements. Intraclass Correlation Coefficient revealed values of 0.96 and 0.89 for buccal/lingual and proximal surfaces, respectively. The Pearson Correlation Coefficient (r) between measurements in buccal/palatal and proximal surfaces was 0.35 and 0.05 for the group treated with alcohol, with and without ligatures, respectively. The best correlations between buccal/palatal and proximal surfaces were observed in animals not treated with alcohol, in sites both with and without ligatures (r = 0.59 and 0.65, respectively). A positive correlation was found between alveolar bone loss in buccal/palatal and proximal surfaces. The correlation is stronger in animals that were not treated with alcohol, in sites without ligatures. Areas with and without ligature-induced periodontal destruction allow detection of alveolar bone loss in buccal/palatal and proximal surfaces.

Obesity has been linked to higher inflammatory status and periodontal breakdown. OBJECTIVE: The purpose of this study was to investigate the effect of obesity on alveolar bone loss in experimental periodontitis in rats. MATERIAL AND METHODS: Twenty-four female Wistar rats were randomly divided into two groups: obese (n=13), which were fed with "cafeteria diet" (CAF diet - high amounts of sucrose and fat) for 90 days in order to gain weight, and non-obese (n=11) regularly fed rats. Ligature-induced experimental periodontitis was created in all animals. Body weight differed statistically between obese and non-obese groups (277.59 and 223.35 g, respectively) at the moment of the ligature placement. Morphometric registration of alveolar bone loss was carried out after 30 days of ligature placement to determine the effect of obesity on the progression of experimental periodontitis. RESULTS: Intra-group comparisons showed significantly higher alveolar bone loss mean values in maxillary teeth with ligature (P<0.05). Alveolar bone loss [mean (SD), mm] was not statistically different between obese and non-obese groups [0.71 (0.09) and 0.65 (0.07) mm, respectively]. However, when palatal sides are analyzed separately, obese group presented significantly higher alveolar bone loss (P<0.05) as compared to non-obese [0.68 (0.12) and 0.53 (0.13) mm, respectively]. CONCLUSIONS: In spite of the weak differences, it is possible to conclude that the progression of alveolar bone loss in ligature-induced periodontitis can be potentially influenced by body weight in rats.

There are many studies that evaluate possible risk factors for periodontal diseases in animals. Most of them have focused only on the biological aspects of disease occurrence; therefore, it has been difficult to compare studies of the different methodological approaches. The aim of the present study was to compare different methods - linear and area - of the evaluation of morphometrical alveolar bone loss. Sixty hemimaxillae, defleshed and stained with 1% methylene blue to delineate the cementoenamel junction and alveolar bone crest, were obtained from a previous study that induced periodontal disease by means of ligatures in two groups of fifteen Wistar rats during 9 weeks. Ligatures were placed around the right upper second molars, and the contra-lateral teeth remained as intra-group controls. Digital photographs were taken from the specimens and submitted to a single, calibrated, blind examiner who performed the morphometrical evaluation of alveolar bone loss using both linear and area methods. Mean values of linear and area measurements were obtained from each side - buccal and palatal - of the specimens. The degree of association between the two methods was determined by Pearson's Correlation Coefficient. An almost perfect association (0.98) was determined between the linear and area evaluations. A mathematical formula was subsequently created to estimate the total area of alveolar bone loss, from linear mean measurements. Both methods were suitable for detecting bone level alterations. The results of the present study allow for the transformation of data and better compilation of results from different studies.

O objetivo deste estudo foi comparar procedimentos de medida da altura óssea histológica e morfométrica. O método mais freqüente de mensuração da altura óssea em estudos em animais são as medidas microscópicas. No entanto, tem limitada capacidade de identificar os níveis ósseos associados com os tecidos saudáveis e doença periodontal. Foram colocadas ligaduras no segundo molar superior esquerdo de 10 ratos machos Wistar com 60 dias de vida durante um período de 30 dias. Hemimaxilas direitas e esquerdas de 5 ratos foram processadas para a análise histológica (H), cortadas no sentido vestíbulo-lingual e coradas com HE. Hemimaxilas dos outros 5 ratos tiveram toda a matéria orgânica removida para análise morfométrica (M). Medidas histométricas da junção cemento-esmalte (JCE) à crista óssea alveolar foram realizadas. Fotografias padronizadas foram utilizadas na análise morfométrica. O teste t foi utilizado para amostras dependentes e independentes (alfa = 0,05%). As distâncias entre a JCE e a crista óssea na face palatina foram de 0,95 ± 0,25 e 1,07 ± 0,30 mm para H e M, respectivamente. As medidas vestibulares foram 0,92 ± 0,16 e 1,08 ± 0,35 mm para H e M. Os valores obtidos usando H e M para áreas sem ligadura foram 0,44 ± 0,15 e 0,47 ± 0,11 mm por lingual e 0,23 ± 0,08 e 0,41 ± 0,10 mm por vestibular, respectivamente. Não houve diferenças estatisticamente significativas entre os dois métodos na detecção da altura óssea associada à colocação de ligaduras em ratos.

The purpose of this study was to compare histologic and morphometric procedures of bone height measurement. Microscopic measurements are the most frequent methods in periodontal studies with animals, but have limited capacity to identify bone levels associated with both healthy tissues and periodontal disease. Ligatures were placed in the maxillary left second molars of 10 male 60-day-old Wistar rats for 30 days. Left and right maxillary sides of 5 rats were processed for histologic analysis (H), sectioned buccolingually, and stained with HE. The maxillae of the other 5 rats were defleshed and used for morphometric analysis (M). Histometric measurements from the cementoenamel junction to the bone crest were performed. Standardized photographs were used for morphometric analysis. The t test was used for dependent or independent samples (alpha = 0.05%). Distances from cementoenamel junction to bone crest were 0.95 ± 0.25 and 1.07 ± 0.30 mm for H and M, respectively. Buccal measurements were 0.92 ± 0.16 and 1.08 ± 0.35 mm for H and M. The values obtained using H and M for areas without ligatures were 0.44 ± 0.15 and 0.47 ± 0.11 mm for lingual measurements and 0.23 ± 0.08 and 0.41 ± 0.10 mm for buccal measurements. No significant differences were found between the two methods in the detection of bone height associated with the placement of ligatures in rats.

O modelo rato é extensamente usado na pesquisa periodontal, e a qualidade dos cortes histológicos é essencial. A proposta deste estudo foi avaliar as características histológicas dos tecidos periodontais nas maxilas de ratos Wistar, após diferentes períodos de fixação e descalcificação pelo ácido nítrico ou pelo ácido fórmico (Solução de Anna Morse). Quinze ratos foram usados. A fixação foi realizada nos períodos de 24, 48 e 72 horas. As maxilas foram divididas e parte foi descalcificada em ácido nítrico durante 7 dias e parte com solução de Anna Morse por 35 dias. Dois examinadores treinados e cegos executaram a avaliação. Quarenta e oito horas de fixação e descalcificação com solução de Anna Morse mostraram características mais evidentes da interface epitélio-conjuntivo, assim como das estruturas periodontais. As médias, por vestibular, entre a junção cemento-esmalte e a crista óssea nos diferentes tempos experimentais variaram entre 176,5 (± 60,45) e 210,94 (± 39,33) "pixels", e, na face palatina, entre 199,69 (± 38,33) e 298,55 (± 70,81) "pixels", sem nenhuma diferença estatisticamente significativa (ANOVA, p > 0,05). No mesmo período de fixação, a descalcificação com ácido nítrico ou solução de Anna Morse não mostrou diferenças estatisticamente significantes. Pode-se concluir que, para a análise histológica qualitativa, a fixação deve ser preferivelmente em 48 horas e a desmineralização por solução de Anna Morse. Para a análise histo-morfométrica, a solução descalcificadora não interferiu nos resultados.

The rat model is widely used in periodontal research and the quality of histological sections is essential. The purpose of this study was to evaluate the histological characteristics of periodontal tissues in Wistar rat maxillae, with different times of fixation and decalcified by nitric acid or formic acid (Anna Morse Solution). Fifteen rats were used. Fixation was performed for 24, 48 and 72 hours. The maxillae were hemi-sectioned and each part was decalcified either in nitric acid for 7 days or in Anna Morse solution for 35 days. Two trained and blinded examiners performed the evaluation. Fourty eight hours of fixation and decalcification with Anna Morse solution showed more clear characteristics of the epithelium-connective tissue interface and of the periodontal structures. Mean measurements between the cementum-enamel junction and the bone crest varied in the different experimental times from 176.5 (± 60.45) to 210.94 (± 39.33) pixels on the buccal aspect, and from 199.69 (± 38.33) to 298.55 (± 70.81) pixels on the palatal aspect, with no statistically significant differences (ANOVA, p > 0.05). In the same fixation period, decalcification with nitric acid or Anna Morse solution did not display any statistically significant differences. It may be concluded that for a qualitative histological analysis, fixation should preferably be for 48 hours and the demineralization should be made by Anna Morse solution. For a histomorphometric analysis, the decalcification solution does not interfere in the results.

O objetivo deste estudo foi avaliar o papel do uso sistêmico da dexametasona na patogênese da perda óssea alveolar induzida em ratos. Em 26 ratos Wistar fêmeas, foram colocadas ligaduras em torno do seu segundo molar superior, servindo o lado contralateral como controle intragrupo. Foram formados dois grupos. O grupo teste recebeu 0,5 mg/kg de dexametasona subcutaneamente a cada três dias durante um período de 30 dias. O grupo controle recebeu a mesma quantidade de solução salina. Após 30 dias, os animais foram sacrificados e suas maxilas removidas. Para o preparo das peças foi usado hipoclorito de sódio e, para corar a junção cemento-esmalte, foi usado azul de metileno. A análise morfométrica da perda óssea alveolar foi realizada por fotografias digitais padronizadas, e a distância entre a junção cemento-esmalte e a crista óssea alveolar foi medida pelo programa ImageTool 3.0. A calibração intra-examinador revelou um coeficiente de Pearson de 0,99. A análise estatística foi realizada pelo teste t pareado ou teste t para amostras independentes, conforme apropriado (alfa = 0,05). A dexametasona aumentou a média de perda óssea alveolar na periodontite induzida por ligadura em relação ao grupo controle (0,77 e 0,61 por vestibular e 0,65 e 0,56 por palatino, respectivamente). Não foram observadas diferenças significativas intergrupos nos dentes sem ligadura. No modelo animal usado neste estudo, a dexametasona aumentou a progressão de perda óssea alveolar induzida por ligadura.

The aim of this study was to evaluate, in rats, the role of the systemic use of dexamethasone in the pathogenesis of induced alveolar bone loss. In 26 female Wistar rats, ligatures were placed around the second upper molars, and the contralateral ones served as intra-group controls. Two groups were formed. The test group received 0.5 mg/kg of dexamethasone subcutaneously every third day during thirty days. The control group received the same amount of saline solution. After thirty days, the animals were sacrificed and their maxillae were removed. Sodium hypochlorite was used to prepare the specimens, and the cementum-enamel junction was stained with 1% methylene blue. Morphometric analysis of the alveolar bone loss was performed with standardized digital photographs, and the distance between the cementum-enamel junction and the alveolar bone crest was measured with the software ImageTool 3.0. Intra-examiner calibration revealed a Pearson correlation coefficient of 0.99. Statistical analysis was performed by paired or independent samplet tests, as appropriate (alpha = 0.05). Dexamethasone increased the mean alveolar bone loss in ligature-induced periodontitis in relation to the control group (0.77 and 0.61 buccally, and 0.65 and 0.56 palatally, respectively). No significant differences were observed intergroups in the teeth without ligatures. In the animal model used here, the use of dexamethasone increased the progression of ligature-induced alveolar bone loss.