Interleukin-6, tumor necrosis factor-α, and CD5 immunolabeling of new experimental endodontic sealer and repair material.

The aim of this study was to evaluate the biocompatibility and immunoinflammatory response of the Sealepox and Sealepox-RP, based on interleukin (IL)-6, tumor necrosis factor (TNF)-α, and CD5 immunolabelling. The ProRoot MTA (PRMTA) was used for comparison. Polyethylene tubes (1.0-mm internal, 1.6-mm external diameter, and 10.0-mm length; ISO 10993) with or without (control) materials were randomly implanted in the dorsum of 35 rats (4 per rat). After 7, 15, 30, 60, and 90 days (n = 7), the tubes were removed for histological and immunohistochemical analysis. The Kruskal-Wallis and Dunn's test for non-parametric data and, ANOVA and Tukey test for parametric data were used (P < 0.05). Hematoxylin and eosin staining revealed that the concentration of inflammatory cells decreased over time with no differences between groups in all periods (P > 0.05). Regarding IL-6 immunostaining, there was no difference at 7 days (P > 0.05); all groups decreased over time, being faster for the PRMTA group and also, with no differences between groups in the last period (P > 0.05). For TNF-α, at 7 days there was no difference between groups (P > 0.05); there was an increase at 15 days for PRMTA and, at 30 and 60 days, for PRMTA and Sealepox compared to the control (P < 0.05). At 90 days, Sealepox RP showed the lowest immunostaining being similar to the control (P > 0.05). Regarding CD5 cells, at 7 days, there was high immunostaining for PRMTA compared to the control (P < 0.05); and significant reduction over time with difference for all groups at 30 and 60 days. (P < 0.05); Sealepox was similar to the control in all periods (P > 0.05). Sealepox RP showed the highest immunostaining at 15 days, being different from the control and PRMTA (P < 0.05); in the other periods it was similar to the control (P > 0.05). It can be concluded that Sealepox and Sealepox-RP were biocompatible and demonstrated similar immunoinflammatory response regarding IL-6, TNF-α, and CD5 compared to PRMTA.

Otosporin reduz reação pulpar inflamatória após clareação dentária de molares de ratos / Otosporin reduces pulp inflammatory reactions after dental bleaching of rat molars

Pacientes submetidos à clareação dentária relatam sensibilidade pós-operatória relacionada ao peróxido de hidrogênio (H2 O2 ) que penetra no tecido pulpar. Objetivo: Avaliar o efeito anti-inflamatório do ibuprofeno, Otosporin® e gel de curcumina na polpa dentária de ratos após procedimento clareador. Métodos: Cinquenta ratos foram divididos em GC ­ controle (gel placebo); CLA ­ clareação (H2 O2 35%, 30 minutos); CLA-I ­ clareação e administração oral de ibuprofeno (duas vezes a cada 12 horas, 2 dias sucessivos); CLA-O ­ clareação seguida da aplicação de Otosporin® nas superfícies dos molares (10 minutos); e CLA-C ­ sessão clareadora seguida do gel de curcumina (10 minutos). Após dois dias, os ratos foram mortos para análise histológica e testes estatísticos foram realizados(p<0,05). Resultados: CLA, CLA-I e CLA-C apresentaram inflamação severa ou necrose no terço oclusal da polpa coronária (p>0,05); CLA-O apresentou inflamação leve e foi semelhante ao GC (p>0,05) e dife- rente dos outros grupos (p<0,05). No terço médio, o grupo CLA-O apresentou menor infiltrado inflamatório e permaneceu diferente do grupo CLA (p<0,05); CLA, CLA-I e CLA-C foram semelhantes (p>0,05). No terço cervical, CLA, CLA-I e CLA-C tiveram redução da inflamação, sem diferença entre os grupos clareados (p>0,05). Conclusões: O Otosporin® pode reduzir a inflamação na polpa após clareação dentária; esse resultado não foi observado utilizando ibuprofeno ou gel de curcumina. Portanto, esse estudo mostra uma nova possibilidade de pós-tratamento em dentes clareados por meio do uso de Otosporin®, que minimiza a inflamação gerada ao tecido pulpar pelo gel clareador. Consequentemente, poderá haver redução da sensibilidade pós-operatória (AU).

Introduction: Patients undergoing dental bleaching relate to postoperative sensitivity, that is linked to hydrogen peroxide (H2 O2 ) penetrating on the dental pulp. This study evaluated the anti-inflammatory effect of ibuprofen, Otosporin®, and curcumin gel on the pulp of the rats' teeth after bleaching. Methods: Fifty rats were divided into CG: controlplacebo gel; BLE: bleached (35% H2O2, 30 minutes); BLE-I: bleached and ibuprofen oral administration (twice every 12 hours in 2 successive days); BLE-O: bleached followed by Otosporin® application in the molar surfaces (10 minutes); and BLE-C: bleaching session followed curcumin gel (10 minutes). After two days, the rats were killed for histological analysis. Statistical tests were performed (P<.05). Results: BLE, BLE-I, and BLE-C had severe inflammation or necrosis in the occlusal third of coronal pulp (P>.05); BLE-O had mild inflammation and was similar from CG (P>.05) and different from other groups (P<.05). In the middle third, BLE-O group had lower inflammatory infiltration and remained different from BLE group (P<.05); BLE, BLE-I, and BLE-C were similar (P>.05). In the cervical third, BLE, BLE-I, and BLE-C had a reduction of inflammation, without difference between bleached groups (P>.05). Conclusions: Otosporin® can reduce the inflammation in the pulp after dental bleaching; this result was not observed using ibuprofen or curcumin gel. Therefore, this study shows a new teeth bleaching posttreatment possibility using Otosporin®, which minimizes the inflammation generated to the pulp tissue by the bleaching gel. This could consequently minimize the postoperative sensitivity (AU).

In Vivo Study of the Action of a Topical Anti-Inflammatory Drug In Rat Teeth Submitted To Dental Bleaching.

Bleaching gel containing hydrogen peroxide (H2O2) cause damages in pulp tissue. This study investigated the action of a topical anti-inflammatory, the Otosporin®, in rats' bleached teeth with the null hypothesis of which the Otosporin® is no able to minimize the pulp inflammation that bleaching gel generates. The rat's molars were divided into groups: BLE: bleached (35% H2O2 concentration /single application of 30 min); BLE-O: bleached followed by Otosporin® (10 min); and control: placebo gel. In the second day after dental bleaching, the rats were killed, and the jaws were processed for hematoxylin-eosin and immunohistochemistry analysis for tumor necrosis factor alpha (TNF-α), interleukin (IL)-6 and IL-17. The data collected were subjected to Kruskal-Wallis and Dunn statistical tests with at a 5% level of significance (p<0.05). The BLE group had moderate to strong inflammation in the occlusal third of the coronary pulp, with necrotic areas; and BLE-O, mild inflammation (p<0.05). There was a significant difference in the occlusal and middle thirds of the coronary pulp between the BLE with BLE-O and control groups (p<0.05). There was no difference in the cervical third (p>0.05). The BLE group had a high immunoexpression of TNF-α than BLE-O and control groups (p<0.05), with moderate and mild immunoexpression, respectively. Regarding IL-6 and IL-17, the BLE group had higher immunoexpression than control (p<0.05); the BLE-O was similar to the control (p>0.05). The topical anti-inflammatory Otosporin® can reduce pulp inflammation after dental bleaching in the rat teeth.

In vivo study of the action of a topical anti-inflammatory drug in rat teeth submitted to dental bleaching

Abstract Bleaching gel containing hydrogen peroxide (H2O2) cause damages in pulp tissue. This study investigated the action of a topical anti-inflammatory, the Otosporin®, in rats' bleached teeth with the null hypothesis of which the Otosporin® is no able to minimize the pulp inflammation that bleaching gel generates. The rat's molars were divided into groups: BLE: bleached (35% H2O2 concentration /single application of 30 min); BLE-O: bleached followed by Otosporin® (10 min); and control: placebo gel. In the second day after dental bleaching, the rats were killed, and the jaws were processed for hematoxylin-eosin and immunohistochemistry analysis for tumor necrosis factor alpha (TNF-α), interleukin (IL)-6 and IL-17. The data collected were subjected to Kruskal-Wallis and Dunn statistical tests with at a 5% level of significance (p<0.05). The BLE group had moderate to strong inflammation in the occlusal third of the coronary pulp, with necrotic areas; and BLE-O, mild inflammation (p<0.05). There was a significant difference in the occlusal and middle thirds of the coronary pulp between the BLE with BLE-O and control groups (p<0.05). There was no difference in the cervical third (p>0.05). The BLE group had a high immunoexpression of TNF-α than BLE-O and control groups (p<0.05), with moderate and mild immunoexpression, respectively. Regarding IL-6 and IL-17, the BLE group had higher immunoexpression than control (p<0.05); the BLE-O was similar to the control (p>0.05). The topical anti-inflammatory Otosporin® can reduce pulp inflammation after dental bleaching in the rat teeth.

Resumo O gel clareador à base de peróxido de hidrogênio (H2O2) causa danos ao tecido pulpar. Este estudo investigou a ação de um anti-inflamatório tópico, o Otosporin®, nos dentes de ratos clareados com a hipótese nula de que o Otosporin® não é capaz de minimizar a inflamação da polpa gerada pelo gel clareador. Os molares dos ratos foram divididos em grupos: ClA: clareado (H2O2 a 35% / aplicação única de 30 min); CLA-O: clareado seguido do Otosporin® (10 min); e controle: gel placebo. No segundo dia após a clareação dentária, os ratos foram mortos e suas maxilas foram processadas para análise de hematoxilina-eosina e imunohistoquímica para o fator de necrose tumoral alfa (TNF-a), interleucina (IL)-6 e IL-17. Os dados coletados foram submetidos aos testes estatísticos de Kruskal-Wallis e Dunn com um nível de significância de 5% (p<0,05). O grupo CLA apresentou inflamação moderada à severa no terço oclusal da polpa coronária, com áreas necróticas; e CLA-O, inflamação leve (p<0,05). Houve diferença significativa nos terços oclusal e médio da polpa coronária entre o grupo CLA com os grupos CLA-O e controle (p<0,05). Não houve diferença no terço cervical (p>0,05). O grupo CLA apresentou maior imunoexpressão para TNF-a comparado aos grupos CLA-O e controle (p<0,05), com imunoexpressão moderada e leve, respectivamente. Em relação a IL-6 e IL-17, o grupo CLA apresentou maior imunoexpressão comparado ao controle (p<0,05); o CLA-O foi semelhante ao controle (p>0,05). O anti-inflamatório tópico Otosporin® pode reduzir a inflamação pulpar após clareação em dentes de ratos.

Diabetic Rats Present High Mean Platelet Count in the Presence of Oral Infections.

Platelet count is associated with inflammatory diseases like diabetes mellitus (DM), which in turn, is related in a bidirectional manner with apical periodontitis and periodontal disease. The aim of this study was to evaluate the effects of apical periodontitis and/or periodontal disease on mean platelet count in a rat model of diabetes mellitus. Eighty Wistar rats were randomly divided into 8 groups (n=10): control (C), apical periodontitis (AP), periodontal disease (PD), apical periodontitis with periodontal disease (AP-PD), diabetes mellitus (DM), diabetes mellitus with apical periodontitis (DM-AP), diabetes mellitus with periodontal disease (DM-PD) and diabetes mellitus with apical periodontitis and periodontal disease (DM-AP-PD). Rats were anesthetized and DM was induced with a single dose of streptozotocin diluted in citrate buffer solution. After 6 days, the DM was confirmed. The animals were sedated and apical periodontitis was induced by dental exposure and periodontal disease was induced by periodontal ligature. After 30 days, animals were anesthetized and the blood was collected by cardiac puncture. Samples were processed and the mean platelet count was obtained. Data were tabulated and subjected to statistical analysis (p<0.05). Diabetic rats had higher mean glycemic levels compared with nondiabetic rats at 6 and 36 days after DM induction (p<0.05). The DM-PD and DM-PD-AP groups showed increased mean platelet count compared to control and AP groups (p<0.05). The periodontal disease alone or associated with apical periodontitis influence mean platelet count in a rat model of diabetes mellitus.

Evaluation of the Cytotoxicity and Biocompatibility of New Resin Epoxy-based Endodontic Sealer Containing Calcium Hydroxide.

INTRODUCTION: Many endodontic sealers are available, but the search for the ideal sealer continues. This study evaluated the cytotoxicity and biocompatibility of Sealer Plus, a new resin epoxy-based endodontic sealer containing calcium hydroxide. AH Plus, Endofill, and SimpliSeal endodontics sealers were used for comparison. METHODS: L929 fibroblasts were cultured, and an MTT assay was used to determine the cytotoxicity of the sealer extracts at 6, 24, 48, and 72 hours. Tubes containing materials or empty tubes for control were inserted into the subcutaneous tissues of 20 rats. After 7 and 30 days, the rats were killed, and the tubes were removed with the surrounding tissues for histologic analysis. The data were submitted to statistical tests (P < .05). RESULTS: Undiluted Sealer Plus exhibited less cytotoxicity compared with other undiluted extracts at 6 hours (P < .05), and cell viability was higher for all Sealer Plus extracts after 24 hours (P < .05). At 48 hours, the undiluted and ½ Sealer Plus dilution were the extracts with less cytotoxicity (P < .05). At 72 hours, cell viability was higher for the undiluted and ½ Sealer Plus dilution compared with the other sealers (P < .05). At 7 days, Endofill and SimpliSeal had higher inflammation compared with the control and Sealer Plus (P < .05); AH Plus had moderate inflammation (P > .05). At 30 days, control, Sealer Plus, and AH Plus had less inflammation (P < .05). The fibrous capsule was thick at 7 days and thin at 30 days, except for SimpliSeal. CONCLUSIONS: In general, Sealer Plus promoted greater cell viability and was more biocompatible compared with the other sealers.

Participation of endotoxin in root canal infections: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to evaluate the relationship between endotoxin levels and presence of clinical signs/symptoms and radiographic features in patients with endodontic infection. Electronic searches were performed on Medline/PubMed, Embase, Cochrane Library, Scielo, Science Direct, Web of Knowledge and Scopus databases for identification of relevant studies published up to December 2016. Grey literature was searched in Google Scholar. The selected literature was reviewed independently by two authors. Clinical studies evaluating the levels of endotoxin and the presence of clinical and radiographic features were included in this review. In order to determine the relationship between endotoxin levels and presence of clinical signs/symptoms and radiographic features meta-analyses were performed. Among the 385 articles identified in the initial search, 30 were included for full-text appraisal and only eight studies met the inclusion criteria for this systematic review. Meta-analysis revealed that individuals having teeth with tenderness to percussion (TTP) (P = 0.04; I2 57%) and previous episode of pain (PEP) (P = 0.001; I2 81%) had higher levels of endotoxin than their counterparts. Size of radiographic lesion >2 mm (P = 0.02; I2 68%) and presence of root canal exudation (EX) (P = 0.0007; I2 0%) were associated with higher levels of endotoxin. This systematic review and meta-analyses provided a strong evidence that endotoxin are related with the presence of clinical signs/symptoms and radiographic features in patients with endodontic infection.

Diabetic Rats Present High Mean Platelet Count in the Presence of Oral Infections

Abstract Platelet count is associated with inflammatory diseases like diabetes mellitus (DM), which in turn, is related in a bidirectional manner with apical periodontitis and periodontal disease. The aim of this study was to evaluate the effects of apical periodontitis and/or periodontal disease on mean platelet count in a rat model of diabetes mellitus. Eighty Wistar rats were randomly divided into 8 groups (n=10): control (C), apical periodontitis (AP), periodontal disease (PD), apical periodontitis with periodontal disease (AP-PD), diabetes mellitus (DM), diabetes mellitus with apical periodontitis (DM-AP), diabetes mellitus with periodontal disease (DM-PD) and diabetes mellitus with apical periodontitis and periodontal disease (DM-AP-PD). Rats were anesthetized and DM was induced with a single dose of streptozotocin diluted in citrate buffer solution. After 6 days, the DM was confirmed. The animals were sedated and apical periodontitis was induced by dental exposure and periodontal disease was induced by periodontal ligature. After 30 days, animals were anesthetized and the blood was collected by cardiac puncture. Samples were processed and the mean platelet count was obtained. Data were tabulated and subjected to statistical analysis (p<0.05). Diabetic rats had higher mean glycemic levels compared with nondiabetic rats at 6 and 36 days after DM induction (p<0.05). The DM-PD and DM-PD-AP groups showed increased mean platelet count compared to control and AP groups (p<0.05). The periodontal disease alone or associated with apical periodontitis influence mean platelet count in a rat model of diabetes mellitus.

Resumo A contagem de plaquetas está associada a doenças inflamatórias como a diabetes mellitus (DM), que, por sua vez, está relacionada de forma bidirecional com periodontite apical e com a doença periodontal. O objetivo deste estudo foi avaliar os efeitos da periodontite apical e/ou da doença periodontal na contagem de plaquetas utilizando o modelo de rato para DM. Oitenta ratos Wistar foram divididos aleatoriamente em 8 grupos (n=10): controle (C), periodontite apical (AP), doença periodontal (PD), periodontite apical com doença periodontal (AP-PD), diabetes mellitus (DM), diabetes mellitus com periodontite apical (DM-AP), diabetes mellitus com doença periodontal (DM-PD) e diabetes mellitus com periodontite apical e doença periodontal (DM-AP-PD). Os ratos foram anestesiados e a DM foi induzida com uma dose única de estreptozotocina diluída na solução tampão citrato. Após 6 dias, o DM foi confirmada. Os animais foram sedados e a periodontite apical foi induzida pela exposição dentária e a doença periodontal foi induzida por ligadura periodontal. Após 30 dias, os animais foram anestesiados e o sangue foi coletado por punção cardíaca. As amostras foram processadas e a contagem média de plaquetas foi obtida. Os dados foram tabulados e submetidos a análise estatística (p <0,05). Os ratos diabéticos apresentaram níveis glicêmicos médios mais elevados em comparação com ratos não diabéticos aos 6 e 36 dias após a indução da DM (p <0,05). Os grupos DM-PD e DM-PD-AP mostraram aumento da contagem média de plaquetas em comparação com os grupos controle e AP (p <0,05). A doença periodontal isolada ou associada à periodontite apical influencia na contagem de plaquetas em modelo de rato para diabetes mellitus.

Hydrogen peroxide induces cell proliferation and apoptosis in pulp of rats after dental bleaching in vivo: Effects of the dental bleaching in pulp.

OBJECTIVE: This study provides an in vivo evaluation of the inflammatory response, levels of cell proliferation and apoptosis, and the presence of necrosis after dental bleaching with two concentrations of hydrogen peroxide (H2O2). DESIGN: Wistar rats were divided into Control (placebo gel), BLUE (20% H2O2, 1×50min), and MAXX (35% H2O2, 3×15min) groups. At 2 and 30days, the rats were killed (n=10). The jaws were processed for histology analysis and PCNA and Caspase-3-cleaved immunohistochemistry, and data were submitted to the Mann-Whitney or ANOVA test (P<0.05). RESULTS: At 2days, the MAXX group showed necrosis and the BLUE group revealed moderate inflammation on the occlusal third of the crown (P<0.05). At 30days, tertiary dentin had formed and there was an absence of inflammation. The level of cell proliferation was higher in the middle third of the BLUE group (P<0.05), and cervical of MAXX at 2days (P<0.05), decreasing at 30days. The apoptosis was present at 2days, particularly in the cervical third of the crown in the bleached groups (P<0.05), with a decrease only at 30days in the BLUE group (P<0.05). CONCLUSIONS: The concentration of H2O2 influences effects on the pulp tissue, where a higher concentration of H2O2 can cause necrosis in the pulp and a prolonged effect within the apoptotic process; lower concentrations of H2O2 provide moderate inflammation, cell proliferation and apoptosis with a reduction of these processes over time.

Penetration Capacity, Color Alteration and Biological Response of Two In-office Bleaching Protocols.

Hydrogen peroxide (H2O2) penetrates into the dental hard tissues causing color alteration but also alterations in pulpal tissues. Hard-tissue penetration, color alteration and the pulp response alterations were evaluated for two in-office bleaching protocols with H2O2. For trans-enamel/dentin penetration and color alteration, discs of bovine teeth were attached to an artificial pulp chamber and bleached according to the groups: BLU (20% H2O2 - 1x50 min, Whiteness HP Blue); MAX (35% H2O2 - 3x15 min, Whiteness HP Maxx); Control (1x50 min, placebo). Trans-enamel/dentin penetration was quantified based on the reaction of H2O2 with leucocrystal violet and the color analyzed by CIELab System. Twenty Wistar rats were divided into two groups (BLU and MAX) and their maxillary right molars were treated according to the same protocols of the in vitro study; the maxillary left molars were used as controls. After 2 days, the animals were killed and their maxillae were examined by light microscopy. The inflammation of pulp tissue was scored according to the inflammatory infiltrate (1, absent; 2, mild; 3, moderate; 4, severe/necrosis). Data were analyzed by statistical tests (α=0.05). MAX showed higher trans-enamel/dentinal penetration of H2O2 (p<0.05). The color alteration was similar for both groups (p>0.05), and different when compared to Control group (p<0.05). MAX showed severe inflammation in the upper thirds of the coronal pulp, and BLU showed moderate inflammation (p<0.05). In-office bleaching protocols using lower concentrations of hydrogen peroxide should be preferred due to their reduced trans-enamel/dentinal penetration since they cause less pulp damage and provide same bleaching efficiency.

Evaluation of an experimental rat model for comparative studies of bleaching agents.

Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats' vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents.

Penetration Capacity, Color Alteration and Biological Response of Two In-office Bleaching Protocols

Abstract Hydrogen peroxide (H2O2) penetrates into the dental hard tissues causing color alteration but also alterations in pulpal tissues. Hard-tissue penetration, color alteration and the pulp response alterations were evaluated for two in-office bleaching protocols with H2O2. For trans-enamel/dentin penetration and color alteration, discs of bovine teeth were attached to an artificial pulp chamber and bleached according to the groups: BLU (20% H2O2 - 1x50 min, Whiteness HP Blue); MAX (35% H2O2 - 3x15 min, Whiteness HP Maxx); Control (1x50 min, placebo). Trans-enamel/dentin penetration was quantified based on the reaction of H2O2 with leucocrystal violet and the color analyzed by CIELab System. Twenty Wistar rats were divided into two groups (BLU and MAX) and their maxillary right molars were treated according to the same protocols of the in vitro study; the maxillary left molars were used as controls. After 2 days, the animals were killed and their maxillae were examined by light microscopy. The inflammation of pulp tissue was scored according to the inflammatory infiltrate (1, absent; 2, mild; 3, moderate; 4, severe/necrosis). Data were analyzed by statistical tests (α=0.05). MAX showed higher trans-enamel/dentinal penetration of H2O2 (p<0.05). The color alteration was similar for both groups (p>0.05), and different when compared to Control group (p<0.05). MAX showed severe inflammation in the upper thirds of the coronal pulp, and BLU showed moderate inflammation (p<0.05). In-office bleaching protocols using lower concentrations of hydrogen peroxide should be preferred due to their reduced trans-enamel/dentinal penetration since they cause less pulp damage and provide same bleaching efficiency.

Resumo O peróxido de hidrogênio (H2O2) é capaz de penetrar pelos tecidos dentários, alterando a coloração destes, e causar danos a polpa. Este estudo avaliou a penetração por esmalte e dentina, a alteração de cor e a reposta tecidual pulpar, provocadas pelo uso de duas concentrações de H2O2 em protocolos de clareação dentária de consultório. Discos de dentes bovinos em câmaras pulpares artificiais receberam géis clareadores para avaliação da penetração por esmalte e dentina e da alteração de cor, formando os grupos: BLU (H2O2 20% - 1x50 min, Whiteness HP Blue); MAX (H2O2 35% - 3x15 min, Whiteness HP Maxx); e Controle (gel placebo - 1x50 min). A penetração por esmalte e dentina foi quantificada baseada na reação do H2O2 com o corante violeta leucocristal, e a alteração de cor foi analisada pelo sistema CIELab. Vinte ratos Wistar foram divididos em dois grupos (BLU e MAX), e tiveram os molares direito superiores tratados com os mesmos protocolos do estudo in vitro; os molares superiores do lado esquerdo serviram de controle. Após 2 dias, os animais foram eutanasiados e as maxilas examinadas por microscopia de luz. Foram atribuídos escores ao infiltrado inflamatório (1, ausente; 2, leve; 3, moderado; 4 severo ou necrose). Os dados foram submetidos a testes estatísticos (=0,05). O grupo MAX apresentou maior penetração de H2O2 por esmalte e dentina (p<0,05). A alteração de cor foi semelhante nos grupos clareados (p>0,05), mas diferente quando comparados grupos clareados com controle (p<0,05). MAX apresentou inflamação severa nos terços superiores da polpa coronária, e BLU apresentou inflamação moderada (p<0,05). Assim, protocolo para procedimento clareador de consultório utilizando baixas concentrações de H2O2 deve ser de escolha na clínica, por reduzir a penetração por esmalte e dentina, causando menos danos à polpa, e proporcionar mesma eficiência clareadora.

Evaluation of an experimental rat model for comparative studies of bleaching agents

ABSTRACT Dental materials in general are tested in different animal models prior to the clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents, by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and Methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents.

Influência da clareação dentária sobre o tecido pulpar de ratos diabéticos: aspectos histológicos e imunológicos / Influence of dental bleaching on the pulp tissue of diabetic rats: histological and immunohistochemical aspects

Objetivo: Avaliar a influência da clareação dentária sobre o tecido pulpar de ratos diabéticos por meio da observação dos aspectos histológicos e imunológicos. Material e Método: Vinte e oito ratos Wistar foram divididos em quatro grupos: (N) normoglicêmicos; (NCla) normoglicêmicos-clareados; (D) diabéticos; (DCla) diabéticos-clareados. Quatorze animais receberam uma dose de 150mg/kg de aloxano para indução da diabetes, via IM. Após 3 dias, todos os animais foram anestesiados e realizado o procedimento clareador com gel de peróxido de hidrogênio (H2O2) a 35% (Whiteness HP Maxx) aplicado uma vez nos molares superiores direitos por 30 minutos. Os molares superiores esquerdos foram usados como controle. Após 2 e 30 dias os animais foram eutanaziados e as maxilas processadas para análise histológica e histoquímica. Foram realizadas análises qualitativas para a reação inflamatória e imunomarcação, e quantitativas para a redução da área da camara pulpar e fibras colágenas. Os resultados foram submetidos à análise estatística com nível de significância de 5% (p<0.05). Resultados: Aos 2 dias observou-se infiltrado inflamatório leve no grupo NCla e severo no grupo DCla (p<0.05). Quanto ao grau de maturação das fibras colágenas, aos 2 dias observou-se maior quantidade de fibras imaturas no grupo N, com diferença estatística para os demais grupos (p<0.05), e, menor quantidade de fibras maduras no grupo N com diferença significante para os demais grupos (p<0.05). Aos 30 dias não foi observado concentração de células inflamatórias e não houve diferença estatística entre os grupos para ambas as fibras colágenas (p>0.05). Entretanto, houve diferença significante quando comparados os grupos NCla e DCla em relação à redução da área da câmara pulpar devido a deposição de dentina reacionária (p<0.05). Quanto a análise imunoistoquímica, observou-se aos 2 dias aumento da imunomarcação para IL-6 nos grupos submetidos à clareação dentária (NCla e DCla) (p<0.05) e, aos 30 dias houve...

Objective: To evaluate the influence of dental bleaching on the pulp tissue of diabetic rats over the histological aspects and proinflammatory cytokines regulation. Methods: Twenty-eight Wistar rats were divided into four groups: (N) normoglycemic; (NBle) normoglycemic-bleached, (D) diabetic, (DBle) diabeticbleached. Fourteen animals reveiced a 150mg/kg dose of alloxan for diabetes induction, via IM. After 3 days, all animals were anesthetized and the dental bleaching performed using 35% hydrogen peroxide (H2O2) gel (Whiteness HP Maxx) in the right maxillary molars for 30 minutes. Left upper molars were used as control. Two and 30 days after the animals were euthanized, and the hemi-maxillae processed for histological and histochemistry analysis. Qualitative analyses were performed for inflammatory reaction and immunolabelling, and quantitative for pulp chamber area reduction and collagen fibers. The results were submitted to statistical analysis (p<0.05). Results: At two days a mild inflammation was observed in NBle group and severe for DCla (p<0.05). For the maturation of collagen fibers, at two days was observed an increase amount of immature fibers in the N group, with statistical difference to the other groups (p<0.05), and a reduced amount of mature fibers in the N group with significant diference to the other groups (p<0.05). At 30 days no inflammatory cells were observed and there was no statistical difference between the groups for both fibers type (p>0.05). However, there was a significant difference when NBle and DBle groups were compared with regards to reduction of the pulp chamber area due the presence of reactionary dentin deposition (p<0.05). With regards to immunoistochemistry, was observed for IL-6 at 2 days an increased immunolabelling in the bleached groups (NBle and DBle) (p<0.05) and, at 30 days, there was a significant difference only between N and DBle groups (p<0.05). For TNF-α, was observed an increase in the immunolabelling of...

Influência da clareação dentária sobre o tecido pulpar de ratos diabéticos: aspectos histológicos e imunológicos / Influence of dental bleaching on the pulp tissue of diabetic rats: histological and immunohistochemical aspects

Objetivo: Avaliar a influência da clareação dentária sobre o tecido pulpar de ratos diabéticos por meio da observação dos aspectos histológicos e imunológicos. Material e Método: Vinte e oito ratos Wistar foram divididos em quatro grupos: (N) normoglicêmicos; (NCla) normoglicêmicos-clareados; (D) diabéticos; (DCla) diabéticos-clareados. Quatorze animais receberam uma dose de 150mg/kg de aloxano para indução da diabetes, via IM. Após 3 dias, todos os animais foram anestesiados e realizado o procedimento clareador com gel de peróxido de hidrogênio (H2O2) a 35% (Whiteness HP Maxx) aplicado uma vez nos molares superiores direitos por 30 minutos. Os molares superiores esquerdos foram usados como controle. Após 2 e 30 dias os animais foram eutanaziados e as maxilas processadas para análise histológica e histoquímica. Foram realizadas análises qualitativas para a reação inflamatória e imunomarcação, e quantitativas para a redução da área da camara pulpar e fibras colágenas. Os resultados foram submetidos à análise estatística com nível de significância de 5% (p<0.05). Resultados: Aos 2 dias observou-se infiltrado inflamatório leve no grupo NCla e severo no grupo DCla (p<0.05). Quanto ao grau de maturação das fibras colágenas, aos 2 dias observou-se maior quantidade de fibras imaturas no grupo N, com diferença estatística para os demais grupos (p<0.05), e, menor quantidade de fibras maduras no grupo N com diferença significante para os demais grupos (p<0.05). Aos 30 dias não foi observado concentração de células inflamatórias e não houve diferença estatística entre os grupos para ambas as fibras colágenas (p>0.05). Entretanto, houve diferença significante quando comparados os grupos NCla e DCla em relação à redução da área da câmara pulpar devido a deposição de dentina reacionária (p<0.05). Quanto a análise imunoistoquímica, observou-se aos 2 dias aumento da imunomarcação para IL-6 nos grupos submetidos à clareação dentária (NCla e DCla) (p<0.05) e, aos 30 dias houve...

Objective: To evaluate the influence of dental bleaching on the pulp tissue of diabetic rats over the histological aspects and proinflammatory cytokines regulation. Methods: Twenty-eight Wistar rats were divided into four groups: (N) normoglycemic; (NBle) normoglycemic-bleached, (D) diabetic, (DBle) diabeticbleached. Fourteen animals reveiced a 150mg/kg dose of alloxan for diabetes induction, via IM. After 3 days, all animals were anesthetized and the dental bleaching performed using 35% hydrogen peroxide (H2O2) gel (Whiteness HP Maxx) in the right maxillary molars for 30 minutes. Left upper molars were used as control. Two and 30 days after the animals were euthanized, and the hemi-maxillae processed for histological and histochemistry analysis. Qualitative analyses were performed for inflammatory reaction and immunolabelling, and quantitative for pulp chamber area reduction and collagen fibers. The results were submitted to statistical analysis (p<0.05). Results: At two days a mild inflammation was observed in NBle group and severe for DCla (p<0.05). For the maturation of collagen fibers, at two days was observed an increase amount of immature fibers in the N group, with statistical difference to the other groups (p<0.05), and a reduced amount of mature fibers in the N group with significant diference to the other groups (p<0.05). At 30 days no inflammatory cells were observed and there was no statistical difference between the groups for both fibers type (p>0.05). However, there was a significant difference when NBle and DBle groups were compared with regards to reduction of the pulp chamber area due the presence of reactionary dentin deposition (p<0.05). With regards to immunoistochemistry, was observed for IL-6 at 2 days an increased immunolabelling in the bleached groups (NBle and DBle) (p<0.05) and, at 30 days, there was a significant difference only between N and DBle groups (p<0.05). For TNF-α, was observed an increase in the immunolabelling of...

The number of bleaching sessions influences pulp tissue damage in rat teeth.

INTRODUCTION: Hydrogen peroxide tooth bleaching is claimed to cause alterations in dental tissue structures. This study investigated the influence of the number of bleaching sessions on pulp tissue in rats. METHODS: Male Wistar rats were studied in 5 groups (groups 1S-5S) of 10 each, which differed by the number (1-5) of bleaching sessions. In each session, the animals were anesthetized, and 35% hydrogen peroxide gel was applied to 3 upper right molars. Two days after the experimental period, the animals were killed, and their jaws were processed for light microscope evaluation. Pulp tissue reactions were scored as follows: 1, no or few inflammatory cells and no reaction; 2, <25 cells and a mild reaction; 3, between 25 and 125 cells and a moderate reaction; and 4, 125 or more cells and a severe reaction. Results from each experimental group were compared between groups and within groups to the corresponding unbleached upper left molars and analyzed for significant differences using the Kruskal-Wallis test (P < .05). RESULTS: All tissue sections showed significant bleaching-induced changes in the dental pulp. After 1 bleaching session, necrotic tissue in the pulp horns and underlying inflammatory changes were observed. The extent and intensity of these changes increased with the number of bleaching sessions. After 5 sessions, the changes included necrotic areas in the pulp tissue involving the second third of the radicular pulp and intense inflammation in the apical third. CONCLUSIONS: The number of bleaching sessions directly influenced the extent of pulp damage.

Root reconstructed with mineral trioxide aggregate and guided tissue regeneration in apical surgery: a 5-year follow-up.

Apical surgery should be considered as the last treatment option and employed when conventional endodontic treatment does not provide the expected result. In teeth undergoing apical surgery, the type of retrograde filling material is one of the factors interfering with the repair of periapical tissues. The material in intimate contact with the periapical tissues plays a fundamental role in the repair process. Several materials have been studied and indicated for use in apical surgery procedures, but the mineral trioxide aggregate (MTA) is still the most frequently used one. Guided tissue regeneration (GTR) techniques have been proposed as an adjunct to apical surgery to enhance bone healing. Here is reported a clinical case in which apical surgery was performed in conjunction with MTA-based root reconstruction of the maxillary right second incisor. After the apical surgery, a root-end cavity was prepared at the vestibular face of the involved tooth and filled with MTA. A bovine bone graft and a cortical collagen membrane were placed on the bone defect. After 5 years, clinical and radiographic assessments showed that the treatment was successful. It may be concluded that MTA presents favorable characteristics in adverse conditions and can be used in conjunction with GTR in cases involving root reconstruction.

Root Reconstructed with Mineral Trioxide Aggregate and Guided Tissue Regeneration in Apical Surgery: A 5-year Follow-up

Apical surgery should be considered as the last treatment option and employed when conventional endodontic treatment does not provide the expected result. In teeth undergoing apical surgery, the type of retrograde filling material is one of the factors interfering with the repair of periapical tissues. The material in intimate contact with the periapical tissues plays a fundamental role in the repair process. Several materials have been studied and indicated for use in apical surgery procedures, but the mineral trioxide aggregate (MTA) is still the most frequently used one. Guided tissue regeneration (GTR) techniques have been proposed as an adjunct to apical surgery to enhance bone healing. Here is reported a clinical case in which apical surgery was performed in conjunction with MTA-based root reconstruction of the maxillary right second incisor. After the apical surgery, a root-end cavity was prepared at the vestibular face of the involved tooth and filled with MTA. A bovine bone graft and a cortical collagen membrane were placed on the bone defect. After 5 years, clinical and radiographic assessments showed that the treatment was successful. It may be concluded that MTA presents favorable characteristics in adverse conditions and can be used in conjunction with GTR in cases involving root reconstruction.

A cirurgia apical deve ser considerada como a última opção de tratamento, e realizada quando o tratamento endodôntico convencional não proporciona o resultado esperado. Em dentes submetidos à cirurgia apical, o tipo de material retro-obturador é um dos fatores que interferem no reparo dos tecidos periapicais. O material em íntimo contato com os tecidos periapicais desempenha um papel fundamental no processo de reparo. Vários materiais têm sido estudados e indicados para o uso em procedimentos de cirurgias apicais, entretanto o agregado de trióxido mineral (MTA) ainda é o mais frequentemente utilizado. A regeneração tecidual guiada (GTR) tem sido proposta como um auxiliar na cirurgia apical para melhorar a formação óssea. Aqui é relatado um caso clínico em que a cirurgia apical foi realizada em conjunto com a reconstrução radicular do incisivo lateral superior esquerdo com MTA. Após a cirurgia apical, foi preparada uma retro-cavidade na parede vestibular e o dente envolvido foi obturado com MTA. Um enxerto de osso bovino e uma membrana de colágeno cortical foram colocados no defeito ósseo. Após 5 anos, avaliações clínica e radiográfica mostram que o tratamento foi bem sucedido. Pode-se concluir que o MTA apresenta características favoráveis em condições adversas e que pode ser usado em conjunto com GTR em casos envolvendo reconstrução radicular.

Lack of pulp sensitivity in maxillary canines submitted to orthodontic traction: a retrospective clinical study

Introduction : Orthodontic movement may cause a great number of tissue alterations in the dental pulp. However, these changes may not be entirely recognized owing to the difficulty in simulating clinical situations. Objective : The aim of this study was to clinically assess the incidence of negative pulp sensitivity to cold among maxillary canines in infraocclusion submitted to orthodontic traction. Material and methods: Two study groups were selected: an experimental group, comprising 32 canine teeth with complete root formation that had been submitted to orthodontic traction, and a control group, comprising 32 canine teeth with complete root formation that had never been submitted to any orthodontic movement. Results: Fourteen teeth from the experimental group showed lack of pulp sensitivity, whereas only one tooth from the control group showed negative pulp sensitivity. Fischer's exact test revealed a significant difference between the groups (p < 0.05). Conclusion: In conclusion, the teeth that had been submitted to orthodontic traction were more likely to lack sensitivity than those that had not been submitted to the same procedure.