Abstract This in vitro study evaluated the impact of TiO2 nanotubes (n-TiO2) incorporated into glass ionomer cement (GIC) on Streptococcus mutans (S. mutans) characteristics at cellular and molecular levels. n-TiO2, synthesized by the alkaline method (20 nm in size), was added to Ketac Molar EasyMix® at 0%, 3%, 5%, and 7% by weight. S. mutans strains were cultured on GIC disks with addition or not of n-TiO2 for 1, 3, and 7 days and the following parameters were assessed: inhibition halo (mm) (n=3/group); cell viability (live/dead) (n=5/group); cell morphology (SEM) (n=3/group); and gene expression by real-time PCR (vicR, covR, gtfB, gtfC, and gtfD) (n=6/group). The data were analyzed by the Kruskal-Wallis test, repeated-measures ANOVA or two-way ANOVA, and Tukey’s and Dunn’s post-hoc tests (α=0.05). The agar diffusion test showed a higher antibacterial property for 5% n-TiO2 compared with 3% and 7% (p<0.05) with no effect of time (1, 3, and 7 days). The cell number was significantly affected by all n-TiO2 groups, while viability was mostly affected by 3% and 5% n-TiO2, which also affected cell morphology and organization. Real-time PCR demonstrated that n-TiO2 reduced the expression of covR when compared with GIC with no n-TiO2 (p<0.05), with no effect of time, except for 3% n-TiO2 on vicR expression. Within-group and between-group analyses revealed n-TiO2 did not affect mRNA levels of gtfB, gtfC, and gtfD (p>0.05). Incorporation of n-TiO2 at 3% and 5% potentially affected S. mutans viability and the expression of key genes for bacterial survival and growth, improving the anticariogenic properties of GIC.

Abstract Heterogeneous cell populations of osteo/cementoblastic (O/C) or fibroblastic phenotypes constitute the periodontal dental ligament (PDL). A better understanding of these PDL cell subpopulations is essential to propose regenerative approaches based on a sound biological rationale. Objective Our study aimed to clarify the differential transcriptome profile of PDL cells poised to differentiate into the O/C cell lineage. Methodology To characterize periodontal-derived cells with distinct differentiation capacities, single-cell-derived clones were isolated from adult human PDL progenitor cells and their potential to differentiate into osteo/cementoblastic (O/C) phenotype (C-O clones) or fibroblastic phenotype (C-F clones) was assessed in vitro. The transcriptome profile of the clonal cell lines in standard medium cultivation was evaluated using next-generation sequencing technology (RNA-seq). Over 230 differentially expressed genes (DEG) were identified, in which C-O clones showed a higher number of upregulated genes (193) and 42 downregulated genes. Results The upregulated genes were associated with the Cadherin and Wnt signaling pathways as well as annotated biological processes, including “anatomical structure development” and “cell adhesion.” Both transcriptome and RT-qPCR showed up-regulation of WNT2, WNT16, and WIF1 in C-O clones. Conclusions This comprehensive transcriptomic assessment of human PDL progenitor cells revealed that expression of transcripts related to the biological process “anatomical structure development,” Cadherin signaling, and Wnt signaling can identify PDL cells with a higher potential to commit to the O/C phenotype. A better understanding of these pathways and their function in O/C differentiation will help to improve protocols for periodontal regenerative therapies.

Abstract Cementum is the mineralized tissue covering the tooth root that functions in tooth attachment and post-eruptive adjustment of tooth position. It has been reported to be highly similar to bone in several respects but remains poorly understood in terms of development and regeneration. Here, we investigate whether cementocytes, the residing cells in cellular cementum, have the potential to be protagonist in cementum homeostasis, responding to endocrine signals and directing local cementum metabolism. Cells from healthy erupted human teeth were isolated using sequential collagenase/EDTA digestions, and maintained in standard cell culture conditions. A cementocyte-like cell line was cloned (HCY-23, for human cementocyte clone 23), which presented a cementocyte compatible gene expression signature, including the expression of dentin matrix protein 1 ( DMP1 ), sclerostin ( SOST ), and E11/gp38/podoplanin ( E11 ). In contrast, these cells did not express the odontoblast/dentin marker dentin sialoprotein ( DSPP ). HCY-23 cells produced mineral-like nodules in vitro under differentiation conditions, and were highly responsive to inorganic phosphate (Pi). Within the limits of the present study, it can be concluded that cementocytes are phosphate-responsive cells, and have the potential do play a key role in periodontal homeostasis and regeneration.

RESUMO A engenharia de tecidos é um campo contemporâneo da ciência, que visa criar condições baseadas em princípios de biologia celular e molecular, bioengenharia e biomateriais para regenerar tecidos. As células tronco mesenquimais apresentam altas taxas de proliferação e são capazes de se diferenciar, sob certas condições, em multi-linhagens, sugerindo que elas têm grande potencial para atuar no campo da regeneração. As células tronco derivadas de tecidos dentais são uma fonte alternativa adequada de células mesenquimais uma vez que são de fácil acesso e têm baixa morbidade para o doador. Estudos demonstraram que elas já foram isoladas e caracterizadas a partir de diversos tecidos tais como polpa dentária, dentes decíduos esfoliados, ligamento periodontal, gengiva, folículo dental e papila apical. Entretanto, os estudos demonstram que há heterogeneidade entre essas populações e não existe um método padrão para selecionar as células-tronco dentais mais apropriadas para procedimentos regenerativos. O objetivo desta revisão é apresentar o conhecimento atual dos vários tipos de células-tronco derivadas de dentes e discutir as novas perspectivas para seu uso na engenharia de tecidos periodontais.

ABSTRACT Tissue engineering is a contemporary field of science, which aims to create conditions based on principles of cell and molecular biology, bioengineering and biomaterials to regenerate tissues. Mesenchymal stem cells present high proliferation rates and are able to differentiate into multilineages under certain conditions, suggesting that they have great potential to act in regeneration field. Tooth derived stem cells are a suitable alternative source of mesenchymal cells once they are easily accessible and have poor morbidity to the donor. Studies showed that they have been isolated and characterized from diverse tissues such as dental pulp, exfoliated deciduous teeth, periodontal ligament, gingiva, dental follicle and apical papilla. However studies show that there is heterogeneity among these populations and there is no standard method to select the most appropriate tooth derived stem cells for regenerative procedures. The aim of this review is to present the current perspective of the multiple types of tooth-derived stem cells and to discuss the basis for their use in periodontal tissue engineering.

Abstract Periodontitis develops as a result of a continuous interaction between host cells and subgingival pathogenic bacteria. The periodontium has a limited capacity for regeneration, probably due to changes in periodontal ligament stem cells (PDLSCs) phenotype. The aim of this study was to evaluate the effects of lipopolysaccharides from Porphyromonas gingivalis (PgLPS) on mesenchymal phenotype and osteoblast/cementoblast (O/C) potential of PDLSCs. PDLSCs were assessed for Toll-like receptor 2 (TLR2) expression by immunostaining technique. After, cells were exposed to PgLPS, and the following assays were carried out: (i) cell metabolic activity using MTS; (ii) gene expression for IL-1β, TNF-α and OCT-4 by real-time polymerase chain reaction (RT-qPCR); (iii) flow cytometry for STRO-1 and CD105, and (iv) osteogenic differentiation. PDLSCs were positive for TLR2. PgLPS promoted cell proliferation, produced IL-1β and TNF-α, and did not affect the expression of stem cell markers, STRO-1, CD105 and OCT-4. Under osteogenic condition, PDLSCs exposed to PgLPS showed a similar potential to differentiate toward osteoblast/cementoblast phenotype compared to control group as revealed by mineralized matrix deposition and levels of transcripts for RUNX2, ALP and OCN. These results provide evidence that PgLPS induces pro-inflammatory cytokines, but does not change the mesenchymal phenotype and osteoblast/cementoblast differentiation potential of PDLSCs.

OBJECTIVE: This study was designed to evaluate the potential adjunctive benefits of platelet-rich plasma (PRP) when used with guided-tissue regeneration (GTR) and bioactive glass (BG) in the treatment of Class II furcation lesions. MATERIAL AND METHODS: Bilateral Class II furcation lesions were surgically created and allowed to become chronic in the mandibular third premolars of 9 dogs. The defects were randomly assigned to: A) GTR+BG and B) GTR+BG+PRP. Similar defects were created in the maxillary third premolars and received the same treatments after 45 days. Dogs were sacrificed 90 days after the first treatment. The histometric parameters evaluated were: connective tissue adaptation, new cementum, new bone, mineralized bone area, non-mineralized bone area, and residual BG particle area. RESULTS: Data analysis showed a superior length of new cementum and a greater mineralized bone area for group B in both periods (p<0.05). The non-mineralized bone area was greater in the control group (p<0.05) in both periods. CONCLUSION: Within the limits of this study, it can be concluded that the use of PRP in the treatment of Class II furcation defects may enhance the amount of new cementum and provide a more mineralized bone in a shorter period of time.

O objetivo do estudo foi avaliar a influência da inalação da fumaça de cigarros (IFC) sobre os períodos iniciais de reparo ósseo alveolar. Quarenta ratos Wistar foram aleatoriamente divididos em teste: animais expostos à IFC, que se iniciou 3 dias antes das extrações mantendo-se até o sacrifício (n=20)e controle (animais que não foram expostos à IFC; n=20). Os animais tiveram seus segundos molares inferiores extraídos bilateralmente (n=5/grupo/período) e foram sacrificados nos dias 3, 7, 10 e 14 dias após a cirurgia. Imagens digitalizadas foram analisadas de acordo com os seguintes parâmetros histométricos: tecido osteóide (OT), área remanescente (RA), tecido mineralizado (MT) e tecido não mineralizado (NMT) em cada alvéolo. Análise intergrupo mostrou que não houve diferença estatisticamente significante aos 3 dias (p>0,05) para todos os parâmetros. Aos 7 dias, a IFC influenciou negativamente (p?0,05) o preenchimento ósseo mostrando diferença estatisticamente significante para os parâmetros tecido não mineralizado e defeito remanescente (MT: 36%, NMT: 53%, RA: 12%; and MT: 39%, NMT: 29%, RA: 32%, para controle e teste, respectivamente). No entanto, não houve diferença estatisticamente significante (p>0,05) aos 10 e 14 dias. Conclui-se que a IFC pode afetar o reparo ósseo alveolar inicial, o que pode ser crítico para a quantidade e qualidade da nova formação óssea em fumantes.

The aim of this study was to evaluate, histometrically, the bone healing of the molar extraction socket just after cigarette smoke inhalation (CSI). Forty male Wistar rats were randomly assigned to a test group (animals exposed to CSI, starting 3 days before teeth extraction and maintained until sacrifice; n=20) and a control group (animals never exposed to CSI; n=20). Second mandibular molars were bilaterally extracted and the animals (n=5/group/period) were sacrificed at 3, 7, 10 and 14 days after surgery. Digital images were analyzed according to the following histometric parameters: osteoid tissue (OT), remaining area (RA), mineralized tissue (MT) and non-mineralized tissue (NMT) in the molar socket. Intergroup analysis showed no significant differences at day 3 (p>0.05) for all parameters. On the 7th day, CSI affected negatively (p<0.05) bone formation with respect to NMT and RA (MT: 36%, NMT: 53%, RA: 12%; and MT: 39%, NMT: 29%, RA: 32%, for the control and test groups, respectively). In contrast, no statistically significant differences (p>0.05) were found at days 10 and 14. It may be concluded that CSI may affect socket healing from the early events involved in the healing process, which may be critical for the amount and quality of new-bone formation in smokers.

OBJECTIVE: The aim of this controlled clinical trial was to evaluate the effect of topically applied povidone-iodine (PVP-I) used as an adjunct to non-surgical treatment of interproximal class II furcation involvements. MATERIAL AND METHODS: Thirty-two patients presenting at least one interproximal class II furcation involvement that bled on probing with probing pocket depth (PPD) >5 mm were recruited. Patients were randomly chosen to receive either subgingival instrumentation with an ultrasonic device using PVP-I (10%) as the cooling liquid (test group) or identical treatment using distilled water as the cooling liquid (control group). The following clinical outcomes were evaluated: visible plaque index, bleeding on probing (BOP), position of the gingival margin, relative attachment level (RAL), PPD and relative horizontal attachment level (RHAL). BAPNA (N-benzoyl-L-arginine-p-nitroanilide) testing was used to analyze trypsin-like activity in dental biofilm. All parameters were evaluated at baseline and 1, 3 and 6 months after non-surgical subgingival instrumentation. RESULTS: Six months after treatment, both groups had similar means of PPD reduction, RAL and RHAL gain (p>0.05). These variables were, respectively, 2.20±1.10 mm, 1.27±1.02 mm and 1.33±0.85 mm in the control group and 2.67±1.21 mm, 1.50±1.09 mm and 1.56±0.93 mm in the test group. No difference was observed between groups at none of the posttreatment periods, regarding the number of sites showing clinical attachment gain >2 mm. However, at 6 months posttreatment, the test group presented fewer sites with PPD >5 mm than the control group. Also at 6 months the test group had lower BAPNA values than control group. CONCLUSION: The use of PVP-I as an adjunct in the non-surgical treatment of interproximal class II furcation involvements provided limited additional clinical benefits.

O objetivo deste estudo foi avaliar os resultados clínicos e centrados no paciente após abordagem cirúrgica minimamente invasiva (CMI) associada à aplicação das proteínas derivadas da matriz do esmalte (PDE) no tratamento de defeitos infra-ósseos. Doze pacientes apresentando um sítio com profundidade de sondagem >5 mm e sangramento à sondagem , associado à evidência radiográfica de defeito infra-ósseo, foram tratados com CMI e aplicação das PDE. Os parâmetros clínicos foram avaliados imediatamente antes do procedimento e após 3 e 6 meses. A percepção de dor e desconforto do paciente durante o período trans-cirúrgico e ao longo da primeira semana de pós-operatório, bem como a satisfação estética 6 meses após o tratamento, foram avaliadas por meio de questionários. Os resultados mostraram que o uso da CMI associada à aplicação de PDE promoveu melhoras estatisticamente significantes nos parâmetros clínicos, mínima dor e desconforto e máxima satisfação estética aos pacientes. Dentro dos limites do estudo, foi demonstrado que a associação de CMI e PDE, no tratamento de defeitos infra-ósseos, é capaz de promover satisfatórios resultados clínicos e centrados no paciente.

This case series evaluated the clinical performance and patient-centered outcomes after a minimally invasive surgical technique (MIST) associated with enamel matrix protein derivative (EMD), for the treatment of intra-bony defects. Twelve patients presenting teeth with probing depth >5 mm and bleeding on probing associated with radiographic evidence of intra-bony defect were treated by MIST associated with EMD. Clinical parameters were measured at baseline, 3 and 6 months. Patient perception during the intraoperative period and during the first postoperative week was evaluated. The use of MIST with EDM promoted significant improvements in clinical parameters, minimal pain/discomfort and maximum esthetics satisfaction. Within of limits of the present study, it could be shown that MIST combined with EMD for the treatment of intra-bony defects promotes satisfactory clinical and patient-centered outcomes.

OBJETIVO: O objetivo do presente estudo foi avaliar a rugosidade radicular obtida após instrumentação por aparelho sônico com pontas diamantadas, curetas e ultrassom. MATERIAL E MÉTODOS: Quarenta superfícies radiculares, devidamente polidas e incluídas em resina acrílica, foram dividas em 4 grupos de tratamento: grupo controle (sem instrumentação) e instrumentação com cureta Gracey 5/6, ultrassom ou aparelho sônico com ponta diamantada. Em cada amostra foram realizados 15 movimentos de raspagem. Antes e após esta instrumentação foi utilizado um rugosímetro para a medição da rugosidade radicular. Além disso, a topografia da superfície radicular foi avaliada após o tratamento com microscopia eletrônica de varredura. RESULTADOS: Diferenças estatisticamente significantes (p<0.05) foram observadas ao se comparar o grupo controle (0.48±0.07mm) aos grupos tratados (cureta - 1.246±0.279mm, ultrassom - 1.468±0.177mm e aparelho sônico com ponta diamantada - 1.576±0.20mm). As maiores rugosidades foram produzidas pela ponta sônica diamantada e ponta universal de ultrassom (p>0.05). CONCLUSÃO: A instrumentação sônica com pontas diamantadas promove uma rugosidade radicular equivalente à instrumentação com ultrassom, sendo essa rugosidade superior àquela apresentada pela instrumentação manual.

OBJECTIVE: The purpose of this study was to evaluate the root surface roughness after instrumentation with hand curette and diamond-coated sonic and universal ultrasonic tips. MATERIALS AND METHODS: Forty root surfaces of human teeth were randomly assigned to four treatment groups: control group (without instrumentation), curette instrumentation, ultrasonic instrumentation with universal tip and sonic instrumentation with diamond-coated tip. Each sample was instrumented with fifteen strokes. Before and after instrumentation, surface roughness was measured. In addition, the root surface topography was examined after treatment under the scanning electron microscope. RESULTS: Significant statistical differences (p <0.05) were observed when comparing the control group (0.48±0.07mm) to the treated groups (hand - 1.246±0.279mm, ultrasonic - 1.468±0.177mm and sonic instrumentation - 1.576±0.20mm). The highest roughness was produced by diamond-coated sonic tip and by ultrasonic universal tip (p >0.05). CONCLUSION: The diamond-coated tip with sonic scaler instrumentation and ultrasonic instrumentation produce similar root surface roughness, higher than curette instrumentation.

Agentes antiinflamatórios têm sido descritos como reguladores do reparo ósseo. O objetivo deste estudo foi investigar o efeito de um inibidor seletivo da cicloxigenase-2 (meloxicam) no reparo ósseo em defeitos de calvárias de ratos. Trinta e seis ratos machos Wistar foram incluídos no estudo. Após anestesia, incisão linear e rebatimento de retalho de espessura total, um defeito de 4 mm de diâmetro foi criado na calvária dos animais com broca trefina. Os mesmos foram aleatoriamente distribuídos em um dos 4 grupos de tratamento (9 animais por grupo), recebendo injeções subcutâneas diárias de: A: soro fisiológico por 15 dias; B: soro fisiológico por 45 dias; C: 3 mg/kg de meloxicam por 15 dias; D: 3 mg/kg de meloxicam por 45 dias. Os animais foram sacrificados e os espécimes rotineiramente processados. Medidas do preenchimento ósseo foram histometricamente realizadas e analisadas estatisticamente. Comparações intergrupos demonstraram que os grupos com meloxicam apresentaram uma redução significativa no reparo ósseo quando comparados com os respectivos grupos-controle (grupo A, 44,5 ± 5,75%, contra grupo C, 57,5 ± 7,25%, p < 0,05; grupo B, 40,25 ± 13,75%, contra grupo D, 52,25 ± 17,25%). Dentro dos limites do presente estudo, pode ser concluído que os inibidores seletivos da cicloxigenase-2 podem reduzir o reparo ósseo em defeitos em calvárias de ratos após sua administração contínua.

Anti-inflammatory agents have been reported to regulate bone healing. The aim of this study was to investigate the effect of a selective cyclooxygenase-2 inhibitor (meloxicam) on bone healing in calvarial defects in rats. Thirty-six adult male Wistar rats were included. After anesthesia, a linear incision was made through the skin of the scalp, a full-thickness flap was reflected and a 4 mm round defect was made with a trephine drill. The animals were randomly assigned to one of the following 4 treatment groups (9 animals each), including daily subcutaneous injections: A: saline solution for 15 days; B: saline solution for 45 days; C: 3 mg/kg of meloxicam for 15 days and D: 3 mg/kg of meloxicam for 45 days. The animals were sacrificed and the specimens, routinely processed. The bone filling was histometrically measured and statistical analysis, performed. Intergroup comparisons demonstrated that the meloxicam groups presented a significant reduction in bone healing when compared to their respective controls (group A, 44.5 ± 5.75%, against group C, 57.5 ± 7.25%, p < 0.05; group B, 40.25 ± 13.75%, against group D, 52.25 ± 17.25%). Within the limits of the present study, it can be concluded that selective cyclooxygenase-2 inhibitors may reduce bone healing in calvarial defects in rats after continuous administration.

O objetivo deste estudo foi avaliar a influência da inalação da fumaça de cigarro (IFC) e o efeito de sua interrupção na qualidade óssea da tíbia. Quarenta e um ratos Wistar machos foram aleatoriamente designados a um dos seguintes grupos: Grupo 1 - controle (n = 14), Grupo 2 - 3 meses de IFC e 2 meses sem exposição à fumaça (n = 12) e Grupo 3 - 5 meses de IFC (n = 15). Ao final do período experimental, os animais foram sacrificados, as tíbias removidas e imediatamente radiografadas para a análise fotodensitométrica. Os resultados mostraram que a exposição contínua à fumaça de cigarro promoveu uma significante redução na densidade óssea (p < 0,05) (3,22 mm Al eq ± 0,58, 2,93 mm Al eq ± 0,45, 1,86 mm Al eq ± 0,35, para os grupos 1, 2 e 3, respectivamente). Níveis semelhantes de densidade óssea foram observados nos grupos controle e interrupção (grupos 1 e 2 - p > 0,05). Portanto, dentro dos limites do presente estudo, pode-se concluir que a IFC pode influenciar a qualidade óssea da tíbia e que a interrupção da inalação parece reverter esse efeito negativo resultando numa densidade óssea semelhante à do grupo controle.

The aim of this study was to evaluate the influence of cigarette smoke inhalation (CSI) and its cessation on tibiae bone quality. Forty-one male Wistar rats were randomly assigned to one of the following groups: Group 1 - control (n = 14), Group 2 - 3 months of CSI and 2 months without exposure to CSI (n = 12), and Group 3 - 5 months of CSI (n = 15). At the end of the experimental period, the animals were sacrificed, the tibiae removed and immediately radiographed for photodensitometric analysis. The results showed that continuous exposure to cigarette smoke promoted a significantly reduced bone density (p < 0.05) (3.22 mm Al eq ± 0.58; 2.93 mm Al eq ± 0.45; 1.86 mm Al eq ± 0.35; for groups 1, 2 and 3, respectively). Similar levels of bone density were observed for the control and cessation groups (groups 1 and 2 - p > 0.05). Thus, within the limits of the present study, it can be concluded that CSI may affect tibiae bone quality, and CSI cessation results in a return towards the level of the control group.

O objetivo do presente estudo foi avaliar histometricamente a influência da nicotina sobre a regeneração óssea de defeitos criados cirurgicamente em rebordos alveolares edêntulos de cães. Defeitos ósseos foram criados cirurgicamente em um dos lados da mandíbula de dezesseis cães e foram deixados para que curassem espontanea-mente. Os animais foram aleatoriamente designados para um dos seguintes grupos: Grupo 1 - controle (n = 8) e Grupo 2 - administração subcutânea de nicotina (2 mg/kg) duas vezes ao dia durante 4 meses (n = 8). Os animais foram sacrificados, e secções semi-seriadas descalcificadas, obtidas. Os parâmetros histométricos avaliados foram altura, largura, área e densidade do tecido ósseo neoformado. A análise intergrupos (Mann-Whitney "rank sum test") demonstrou que a administração de nicotina não influenciou altura, largura e área de tecido ósseo neoformado (p > 0,05). Entretanto, a administração de nicotina influenciou significativamente a densidade do tecido ósseo neoformado (p < 0,001). Dentro dos limites do presente estudo, pode-se concluir que a nicotina pode afetar, mas não impedir a regeneração de defeitos ósseos criados cirurgicamente em mandíbulas edêntulas de cães.

The objective of this study was to investigate the histometric impact of nicotine on bone regeneration of surgically created alveolar ridge defects in dogs. Sixteen mongrel dogs were used. One defect was surgically created unilaterally in the mandible, and left to heal spontaneously. The animals were randomly assigned to one of the following groups: Group 1 - control (n = 8) and Group 2 - subcutaneous nicotine administration (2 mg/kg) twice a day (n = 8). After 4 months, the animals were sacrificed and the specimens routinely processed for semi-serial decalcified sections. Bone height (BH), bone width (BW), bone density (BD), and bone area (BA) of the newly-formed bone were evaluated. Intergroup analysis (Mann-Whitney rank sum test) showed that regardless of the presence of nicotine, no significant differences were observed regarding bone width (BW), bone area (BA) and bone height (BH) (p > 0.05). On the other hand, it was demonstrated that nicotine administration significantly influenced the proportion of mineralized tissue within the limits of the newly-formed bone (BD) (p < 0.001). Within the limits of the present study, it can be concluded that nicotine might affect but not prevent bone healing in defects left to heal spontaneously.

O objetivo deste trabalho foi avaliar a influência da administração de ciclosporina A (CsA)/nifedipina e sua interrupção na densidade óssea em uma região lateral à superfície de implantes de titânio inseridos em coelhos. Dois implantes de titânio comercialmente puros foram inseridos bilateralmente em vinte e oito coelhos. Os animais foram aleatoriamente divididos em um dos seguintes grupos experimentais, recebendo injeções diárias subcutâneas por 14 dias: Grupos A e C: veículo (dimetil sulfóxido); Grupos B e D: CsA (10 mg/kg) e nifedipina (50 mg/kg). Os animais pertencentes aos Grupos A/B e C/D foram sacrificados 14 e 42 dias após a colocação dos implantes, respectivamente. Após o sacrifício, as tíbias foram removidas para a obtenção de secções não-descalcificadas. A densidade óssea foi obtida em uma zona de 500 mm lateral à superfície do implante através de análise histométrica. A análise intergrupo não revelou diferenças para os grupos teste e controle em 14 e 42 dias (p > 0,05). Dentro dos limites deste estudo podemos concluir que a associação CsA/nifedipina, administrada em um curto prazo, não apresenta uma influência negativa na densidade do osso preexistente ao redor de implantes de titânio inseridos em coelhos.

The aim of this study was to evaluate the influence of the administration and withdrawal of cyclosporin A/nifedipine on the bone density in a lateral area adjacent to implants placed in rabbits. Two screw-type titanium implants were placed bilaterally in twenty-eight New Zealand rabbits. The animals were assigned to one of the following groups and received daily subcutaneous injections for 14 days: Groups A and C: vehicle (dimethyl sulfoxide); Groups B and D: CsA (10 mg/kg) plus nifedipine (50 mg/kg). The animals in Groups A and B were sacrificed 14 days postoperatively and, in Groups C and D, 42 days postoperatively. After sacrifice, the tibiae were removed and undecalcified sections were obtained. Bone density was obtained in a 500 mm-wide zone lateral to the implant surface. Intergroup analysis showed no significant difference (p > 0.05) in the degree of bone density between control and test groups either on day 14 or on day 42. Thus, it appears that a short-term immunosuppressive therapy may not present a negative influence on the density of the pre-existing bone around titanium implants placed in rabbits.

O uso de agentes imunossupressores tem sido reconhecido como um fator que afeta os tecidos moles do periodonto. Entretanto, pouco se sabe sobre o seu efeito na progressão da periodontite. O objetivo do presente estudo foi investigar a influência da ciclosporina (CsA), associada ou não à nifedipina, na perda óssea resultante da periodontite induzida por ligaduras em ratos. Vinte e quatro ratos Wistar machos, adultos, foram incluídos no estudo. Após anestesia, foram colocadas ligaduras de fio de algodão ao redor do primeiro molar inferior direito ou esquerdo, aleatoriamente escolhido. O dente contralateral foi deixado sem ligadura. Os animais foram aleatoriamente escolhidos para receber um dos seguintes tratamentos: Grupo A - solução salina; Grupo B - CsA (10 mg/kg); Grupo C - nifedipina (50 mg/kg); Grupo D - CsA (10 mg/kg) e nifedipina (50 mg/kg). Após 45 dias, os animais foram sacrificados para a análise histométrica. A análise intergrupos não revelou diferenças significativas quanto ao volume da perda óssea entre os diferentes tratamentos (0,46 ± 0,11; 0,63 ± 0,32; 0,53 ± 0,14; 0,50 ± 0,18, para os grupos A, B, C e D respectivamente - p > 0,05). Entretanto, a análise intragrupo mostrou um maior volume de perda óssea nos dentes com ligadura, quando comparados aos dentes sem ligadura (p < 0,05). Dentro dos limites deste estudo, conclui-se que a administração de CsA, associada ou não à nifedipina, não influenciou a perda óssea alveolar na periodontite induzida por ligaduras em ratos.

Immunosuppressive agents have been recognized as a factor affecting the soft tissues of the periodontium. However, little is known about their effect on periodontitis progression. The aim of the present study was to investigate the influence of cyclosporin A (CsA) administration, associated or not with nifedipine, on the bone loss resulting from a ligature-induced periodontitis in rats. Twenty-four adult male Wistar rats were used. After anesthesia, the mandibular first molar was randomly assigned to receive the cotton ligature in the sulcular area while the contralateral tooth was left unligated. The animals were randomly assigned to one of the following treatments: Group A - saline solution; Group B - CsA (10 mg/kg); Group C - nifedipine (50 mg/kg); Group D - CsA (10 mg/kg) plus nifedipine (50 mg/kg). Forty-five days later, the animals were sacrificed and the specimens routinely processed for serial decalcified sections. Intergroup analysis did not reveal significant differences regarding the bone loss volume in the ligated teeth between the experimental treatments (0.46 ± 0.11, 0.63 ± 0.32, 0.53 ± 0.14, 0.50 ± 0.18, for groups A, B, C and D, respectively - p > 0.05). However, intragroup analysis showed a greater bone loss volume in the ligated teeth than in the unligated ones (p < 0.05). Within the limits of the present study, the conclusion was that the administration of CsA, associated or not with nifedipine, may not influence bone loss in ligature-induced periodontitis in rats.