Assessment of the diagnostic accuracy of strip and furcal perforations in different sizes by cone beam computed tomography.

OBJECTIVE: Root perforation is an adverse event that may accidentally occur during root canal treatment and can adversely affect the treatment plan and tooth prognosis. This study aimed to assess the accuracy of cone beam computed tomography (CBCT) for detecting the strip and furcal perforations with different sizes. METHODS: The mesiolingual canals of 155 extracted human mandibular first molars were instrumented and randomly divided into four experimental groups and one control group (n = 31). Furcal (in the pulp chamber floor) and strip perforations with 0.5, 1, 1.5, and 2 mm in diameter were manually created. The teeth were randomly mounted in bovine ribs and scanned using CBCT. Two radiologists unaware of the study groups observed the images and reported the greatest perforation diameter. The inter-observer agreements were calculated. The diagnostic accuracy was compared for furcal and strip perforations with different sizes. RESULTS: The inter-observer agreement for detecting furcal and strip perforations with different sizes were good. The diagnostic accuracy was 100% for the absence of perforation in each group. CONCLUSIONS: CBCT can detect the absence of perforation with high accuracy. The diagnostic accuracy of CBCT in the presence of strip and furcal perforation with different sizes was not significant.

The Pushout Bond Strength of Three Calcium Silicate-based Materials in Furcal Perforation Repair and the Effect of a Novel Irrigation Solution: A Comparative In Vitro Study.

AIM: To evaluate the pushout bond strength of three calcium silicate-based materials used as furcal perforation repair materials and the effect of root canal irrigants on the pushout strength of the tested repair materials. MATERIALS AND METHODS: Furcal perforations measuring 1.3 mm in diameter were made in the center of the furcation area of 90 extracted human mandibular molars. The teeth were then randomly divided into three groups (n = 30) according to the repair material: Biodentine (Septodont, St-Maur-des-Fossés, France), PD-MTA White (Produits Dentaires, Vevey, Switzerland), and K-Biocer (REKITA, Lebanon). The specimens were stored at 100% humidity at 37°C for 72 hours. They were later divided into three subgroups (n = 10) based on the irrigation protocol: 2.5% sodium hypochlorite, BioAKT (Metabolic substrate, New Tech Solutions s.r.l., Brescia, Italy), and a control group. After incubation for 48 hours, the dislodgement resistance of the samples was measured using a universal testing machine. RESULTS: The mean bond strength was significantly different between repair materials in the irrigation control group (p-value <0.001). With PD-MTA White and K-Biocer, the mean bond strength was not significantly different between irrigation groups (p-value = 0.681). The mean bond strength of Biodentine was significantly different between irrigation groups (p-value = 0.002); it was the highest with BioAKT. CONCLUSION: Biodentine showed a high performance as a perforation repair material and its resistance to dislocation increased after being exposed to BioAKT. K-Biocer had the lowest pushout bond strength. PD-MTA White showed intermediate bond strength and was not affected by the tested irrigants. CLINICAL SIGNIFICANCE: The bond strength of endodontic materials to root dentin is an important factor to consider for long-term clinical success since the teeth are constantly subjected to masticatory forces.

Volumetric Evaluation of Voids and Gaps of Different Calcium-Silicate Based Materials Used in Furcal Perforations: A Micro-CT Study.

This study aimed at evaluating volumetrically gaps and voids of calcium-silicate based materials of different generations and handling properties (BC­Endosequence BC RRM-Fast Set Condensable Putty, MTA­ProRoot MTA, and BIO­Biodentine) in simulated furcal perforations in an ex vivo setup by microcomputed tomography (Micro-CT) analysis. Thirty-six extracted human mandibular molars with sound furcation areas were selected. Standardized perforations were created in the furcation area of the pulp chamber using #4 diamond burs. The specimens were randomly assigned to three groups (BC, MTA and BIO; n = 12). Samples were then scanned (SkyScan 1172; Bruker-microCT, Kontich, Belgium), and three-dimensional (3D) images reconstructed. The relative volume of gaps (VG%) and voids (VV%) present on each material was calculated. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey's HSD test (p < 0.05). Mean VG% for BC, MTA, and BIO groups were, respectively, 0.513%, 1.128%, 1.460%, with BC presenting statistically (p < 0.05) fewer gaps formation than the other groups. Mean VV% were, respectively, 0.018%, 0.037%, and 0.065%. The was no statistical difference regarding VV%. There were no gap-free and void-free samples. BC group had the lowest VG% among the groups with a significant statistical difference (p < 0.05).

In Vitro Assessment of Sealing Ability of Various Materials Used for Repair of Furcal Perforation: A SEM Study.

AIM: The aim of the current in vitro research was to evaluate the sealing capacity of three different agents employed for the repair of perforations at the furcation area. MATERIALS AND METHODS: Recently 60 extracted human mandibular permanent molars having well apart plus fully formed roots, and intact furcation were chosen. The 60 samples were allocated at random to three groups of 20 samples: Group I: Furcation perforation repair by means of mineral trioxide aggregate (MTA)-Angelus, Group II: Furcal perforation repair using Biodentine, Group III: Furcal perforation repair by EndoSequence. The specimens were subjected to sectioning with a hard tissue microtome and the sectioned parts of the samples were then examined. The specimens were subjected to gold sputtering and visualizing beneath scanning electron microscope (SEM) at 2000× magnification for assessing the sealing capacity of the agents. RESULTS: The highest sealing capacity was noted with the use of Biodentine at 0.96 ± 0.10, in pursuit by EndoSequence use at 1.18 ± 0.14 and MTA-Angelus use at 1.74 ± 0.08. The disparity amid the three groups was statistically significant with p < 0.001. CONCLUSION: In conclusion, it may be inferred that Biodentine exhibited the finest sealing capacity than EndoSequence and MTA- Angelus. It may thus be given consideration as a substance of preference for the repair of furcal perforation. CLINICAL SIGNIFICANCE: Using biologically compatible substances may be suggested to amend perforations thereby decreasing the occurrence of inflammatory response in the neighboring tissues. The sealing capacity is a significant feature in supporting the result of a root canal treatment of a tooth.

Outcomes of furcal perforation management using Mineral Trioxide Aggregate and Biodentine: a systematic review

Abstract Furcal perforation is an iatrogenic or pathologic communication between the pulp chamber floor and the alveolar bone. The outcome of perforation sealing depends greatly on the tissue compatibility and bioactivity and sealing properties of the repair materials. Mineral trioxide aggregate (MTA) and Biodentine are currently the most used materials to treat this condition. The present systematic review aimed to report the treatment outcome of repaired furcal perforation using MTA and Biodentine and identify which material would yield a better outcome. Methodology: A comprehensive search was conducted using the PubMed database to identify experimental studies and case reports that describe treatment of furcal perforation. Studies and case reports that evaluated the outcome of repaired furcal perforations using MTA and Biodentine, published in English from 2018 to April 2022, were identified. Unavailable full texts were excluded. Results: Initial screening of 724 articles (670 studies and 54 case reports). After discarding the duplicated studies, we reviewed 50 studies, selecting 13 for abstract analysis. We retrieved and evaluated full texts of eight studies and five case reports. Both materials had an equivalent success rate in the first three months but by 12 months Biodentine performed better than MTA clinically and radiographically. Conclusions: Repair of furcal perforation with Biodentine yields a better outcome compared to MTA.

Does MTA provide a more favourable histological response than other materials in the repair of furcal perforations? A systematic review.

BACKGROUND: There is no consensus on which furcal perforation repair material induces a more favourable histological response. This systematic review of laboratory studies provides an overview of the studies comparing repair materials in animal models. OBJECTIVES: To evaluate whether mineral trioxide aggregate (MTA) yields a more favourable histological response than other materials when used to repair furcal perforations in animal experimental models. METHODS: This review followed the PRISMA checklist. The studies included various materials used to repair furcal perforations and compared the histological responses with MTA. An electronic search was conducted in EMBASE, PubMed, Scopus and Web of Science up to 2 September 2020, with no language or publication date restrictions. Studies whose full text was unavailable were excluded. The ARRIVE and SYRCLE tools were used to assess the methodological quality and risk of bias (RoB) of the studies. RESULTS: The studies included in the qualitative synthesis were conducted in rat (n = 3) and dog (n = 17) models. They were classified as having a low quality, high methodological heterogeneity and high RoB. MTA and Biodentine, the materials most often compared, reduced the inflammatory reaction to mild over time. In addition, a mineralized tissue was formed in all studies. The response yielded by MTA was better than or equivalent to that of the other tested materials. DISCUSSION: This review confirmed that MTA is the reference standard material for furcal perforation repair. However, research using animal models has inherent limitations, and the substantial methodological heterogeneity across the studies included should be considered. Therefore, the knowledge generated by this systematic review should be translated into clinical practice cautiously. CONCLUSIONS: Features described in the report and quality assessment guidelines, such as PRIASE, ARRIVE and SYRCLE, should guide researchers. Despite the high RoB and the low methodological quality of the studies included, findings indicated that MTA yields a more favourable histological response than other materials in the repair of furcal perforations. REGISTRATION: PROSPERO (CRD42020181297).

Biocompatibility of NeoMTA Plus® versus MTA Angelus as delayed furcation perforation repair materials in a dog model.

BACKGROUND: The biocompatibility of NeoMTA Plus® (Avlon BioMed Inc., Bradenton, Fl) as a furcal perforation repair material is not fully understood. This study compares the biocompatibility of Mineral Trioxide Aggregate (MTA Angelus) and NeoMTA Plus® as delayed furcation perforation repair materials. METHODS: Pulpotomy and root canal obturation were performed in 72 premolars in six mongrel dogs and then a standardized furcal perforation was performed. The coronal access was left open for three weeks. After curetting, cleaning and drying of the perforations, these teeth were divided into three equal groups (N = 24 teeth/ 2 dogs each) according to the material used for perforation repair; group I: NeoMTA Plus®, group II: MTA Angelus and group III: no material (positive control). The coronal access cavities were sealed with a filling material. The inflammatory cell count and qualitative pathology (presence of calcific bridge, configuration of fibrous tissue formed, examination of tissue surrounding the furcation area, histology of intraradicular bone and the inflammatory nature of tissues) were carried out after one week (subgroup A, N = 8 teeth), one month (subgroup B, N = 8 teeth) and three months (subgroup C, N = 8 teeth). The inflammatory cell count was expressed as mean ± SD and statistically analyzed. P-value < 0.05 was considered significant. RESULTS: In all subgroups, the control group exhibited the highest number of inflammatory cell count, followed by MTA Angelus group and the least inflammatory cell count was shown by NeoMTA Plus® group. There was a significant difference in the inflammatory cell count between the NeoMTA Plus® and MTA Angelus after one week (P < 0.05) while no significant differences were recorded between them after one month and three months (P > 0.05). In contrast to group II, there was no significant differences in inflammatory cell count between the subgroups in groups I and III (P > 0.05). NeoMTA Plus® exhibited better qualitative pathological features than MTA Angelus after one week and nearly similar features after one month and three months of repair. CONCLUSION: NeoMTA Plus® has a better early biocompatibility than MTA Angelus after one week of delayed furcation perforation repair and a similar late biocompatibility after one month and three months.

Marginal adaptation, solubility and biocompatibility of TheraCal LC compared with MTA-angelus and biodentine as a furcation perforation repair material.

BACKGROUND: This study evaluated the marginal adaptation, solubility and biocompatibility of TheraCal LC compared with mineral trioxide aggregate (MTA-Angelus) and Biodentine when used as a furcation perforation repair material. METHODS: The marginal adaptation was assessed by scanning electronic microscope and presence of any gap between the dentin surface and filling material in each quadrant of the sample was analyzed at 1000 X magnification. The solubility was measured after one week by the ISO standard method. Biocompatibility was evaluated by the inflammatory response and radiography after one month and three months of repair of experimental furcation perforations in dog's teeth. RESULTS: There were significant differences in the marginal adaptation, solubility and biocompatibility of the tested materials (P < 0.05). TheraCal LC showed the highest frequency distribution of gap presence that was followed by the MTA-Angelus then Biodentine. The least soluble material after one week was TheraCal LC that was followed by the MTA-Angelus and Biodentine. After one month and three months, TheraCal LC showed the highest inflammatory response and highest frequency distribution of radiolucency that was followed by the Biodentine then MTA-Angelus. CONCLUSION: Unlike Biodentine, TheraCal LC is incapable of alternating the MTA in furcation perforation repair due to its poor biocompatibility and poor marginal adaptation.

Comparative evaluation of effect of chloroquick irrigating solution on push-out bond strength of endoseal mineral trioxide aggregate and endosequence root repair material when used as furcal perforation repair material: An in vitro study.

AIM: The purpose of this study was to comparatively evaluate the effect of Chloroquick irrigating solution on push-out bond strength of Endoseal mineral trioxide aggregate (MTA) and endosequence root repair material (ERRM) when used as furcal perforation repair materials. MATERIALS AND METHODS: Forty human extracted mandibular molars were collected. A standardized endodontic access cavity was prepared in 40 samples, and intentional perforation of 1.32 mm in diameter was created on the pulpal floor. Teeth were randomly divided into four groups: Group A: EndoSeal MTA with irrigation, Group B: ERRM with irrigation, Group C: EndoSeal MTA without irrigation (Control group), and Group D: ERRM without irrigation (Control group). The samples were subjected to universal testing machine then examined under a stereomicroscope at × 40 to determine the nature of the bond failures. RESULTS: EndoSeal MTA with Chloroquick irrigating solution irrigation showed the highest push-out bond strength (MPa) with a statistically significant difference among all the groups (P = 0.003). The majority of the samples exhibited cohesive and mixed types of failures. CONCLUSION: Chloroquick irrigating solution irrigation has no adverse effect on the push-out dentin bond strength of Endoseal MTA and ERRM.

Effect of perforation size and furcal lesion on stress distribution in mandibular molars: a finite element analysis.

AIM: To compare the effect of furcal perforations of various sizes on the biomechanical response of mandibular first molars with or without periodontal bone loss at the furcal region via three-dimensional (3D) finite element analysis (FEA). METHODOLOGY: The 3D geometric basic model was reconstructed from the micro-computed tomographic images of an extracted mandibular first molar. Five different models were constructed from this molar in group 1 as follows: intact molar model, root filled (RCF) model and three models with furcal perforations (1, 2 and 3 mm in diameter) repaired with a calcium silicate-based cement (CSC). In group 2, a lesion simulating bone resorption at the furcal region was modelled on the models in group 1. A force of 200 N was applied to simulate normal occlusal loads. Static linear FEA was performed using the Abaqus software (Abaqus 6.14; ABAQUS Inc., Providence, RI, USA). The maximum principal stresses (Pmax ) and maximum displacement magnitude were evaluated. RESULTS: The range of Pmax values of the models in group 1, from high to low, was as follows: RCF + 3 mm perforation > RCF + 2 mm perforation > RCF + 1 mm perforation > RCF > intact model, and the range of Pmax values of the models in group 2 was as follows: RCF + 3 mm perforation + furcal lesion > RCF + 2 mm perforation + furcal lesion > RCF + 1 mm perforation + furcal lesion > RCF + furcal lesion > intact model + furcal lesion. All of the models in group 2 exhibited lower Pmax values and higher maximum displacement magnitude than their counterparts without lesions in group 1. CONCLUSIONS: The size of the furcal perforation affected the accumulation and distribution of stress within the models. Mandibular molar teeth with large furcal perforations treated with a calcium silicate-based cement may be associated with an increased risk of fracture whether or not accompanied by bone resorption.

[Current situation and strategy on perforation repair].

Perforations are common complications of root canal therapy. In clinic, perforations that were improperly and untimely repaired can seriously affect the prognosis of teeth after root canal treatment. At present, the status of perforation repair in our country is worrisome. This paper focused on the progress of perforation repair in the country by discussing the current situation of repair methods and materials. This review aims to improve knowledge and aid clinical doctors in the sophistication of perforation repair in order to improve the retention rate of root-canal-treated teeth.

Immediate and Delayed Repair of 2 Sizes of Furcal Perforations in Dogs' Teeth Using Mineral Trioxide Aggregate Cement.

INTRODUCTION: This histologic study aimed to measure the morphometric and morphologic changes in periodontal tissue after immediate and delayed mineral trioxide aggregate (MTA) repair of 2 sizes of furcal perforations. METHODS: There were 72 premolars from 12 beagle dogs that were divided equally into 4 experimental and 2 control groups (n = 12). Experimental groups included immediate small (0.6 mm in diameter), immediate large (1.8 mm in diameter), delayed (30 days) small, and delayed large furcal perforation MTA repair. The control groups included negative (no furcal perforation) and positive (nonrepaired small and large furcal perforations) controls. After 3 months, tissue blocks were harvested and processed for histologic assessment. Morphometric analysis measured the thickness of periodontal ligaments (average, maximum, and minimum) in millimeters, the area of interest in square millimeters, and the area of healing tissue at the perforation site in square millimeters. Morphologic assessment consisted of 7 parameters for tissue inflammation, resorption, and repair. Histologic assessment was completed by 2 calibrated examiners who were blinded to the study group. RESULTS: Morphometric and morphologic measurements showed no significant difference between immediate and delayed MTA repair of small perforations and the negative control. The average thickness of the periodontal ligaments in delayed large perforations was 0.467 mm, which was significantly different from 0.294 mm in the delayed small perforations repair. The area of healing tissue in the positive control was 0.473 mm2, which was significantly different from 0.311 mm2 in delayed large perforation repair. CONCLUSIONS: Within the study limitations, periodontal tissue responded more favorably to MTA repair of furcal perforation when it was placed in smaller perforations. The time of treatment became more critical as the perforation size increased.

Management of Furcal Perforation with Advanced Furcation Defect by a Minimally Invasive Tunnel Technique.

A perforation in the furcation area is a potential risk factor for extension of pulpal inflammation into the periodontium and formation of advanced furcation defect with severe loss of clinical attachment and interradicular bone. Furthermore, the management of such furcal perforation is difficult due to poor accessibility, visibility, and regenerative potential. The development of such advanced furcation defects further compromises the prognosis of the treatment as they preclude effective plaque control and maintenance by the patient. Therefore, the management of advanced furcation defects remains an enigmatic and challenging task for the clinician. This case report describes a minimally invasive approach for the treatment of a furcal perforation by a conservative tunnel preparation. The present case report aims to highlight the importance of surgical tunnel preparation as an alternative to conventional flap procedure to repair furcal perforation with advanced furcation defects.

Current situation and strategy on perforation repair / 华西口腔医学杂志

Perforations are common complications of root canal therapy. In clinic, perforations that were improperly and untimely repaired can seriously affect the prognosis of teeth after root canal treatment. At present, the status of perforation repair in our country is worrisome. This paper focused on the progress of perforation repair in the country by discussing the current situation of repair methods and materials. This review aims to improve knowledge and aid clinical doctors in the sophistication of perforation repair in order to improve the retention rate of root-canal-treated teeth.

Sealing Ability of Four Calcium Containing Cements used for Repairing Furcal Perforations in Primary Molars: An in vitro study.

AIM: The aim of this study was to compare the sealing ability of mineral trioxide aggregate (MTA), Portland cement (PC), Biodentine(TM) and Tech biosealer in repairing furcal perforations in primary molars using the fluid-filtration technique. MATERIALS AND METHODS: Fifty freshly extracted maxillary second primary molars were sectioned horizontally at the furcation region to create dentin disks of 1.5 mm (+ 0.1 mm) thickness. Five disks were not perforated and served as negative controls. In the remaining 45 disks, furcation perforations were prepared. Five disks did not receive furcation repair and served as positive controls. The remaining 40 disks were then randomly divided into four equal groups (10 disks in each group). Perforations were repaired with: MTA, PC, Biodentine(TM) or Tech Biosealer. The sealing ability of the tested materials was evaluated by measuring microleakage for each disk after four different storage periods: 24-hour, 1-month, 6-month and 1-year storage using fluid-filtration. Comparisons between the four materials and the four time periods were done using the two-way analysis of variance and the Scheffe multiple comparisons test. RESULTS: There was no significant difference between the mean microleakage values obtained in the four tested materials after 24 hours, 1, 6 month and 1 year. However, microleakage values for each individual material were significantly higher at 24 hours than at the other time intervals. CONCLUSION: Mineral trioxide aggregate, PC, Biodentine(TM) and Tech biosealer showed similar capabilities in sealing the furcal perforations of the primary molars, where the sealing ability improved over time for each individual material.

Experimental Furcal Perforation Treated with MTA: Analysis of the Cytokine Expression

The aim of this study was to evaluate mineral trioxide aggregate (MTA)-induced cytokine expression in mice after experimental furcal perforation. BALB/c mice (n=5) were subjected to induced furcal drilling of the maxillary first molar followed by MTA sealing in the left side (experimental group) and paraffin sealing in the right side (control group). Animals were euthanized at 7, 14 and 21 days after sealing the perforations. The expression levels of the IFN-γ, TNF-α, IL-10, IL-4, TGF-β and RANKL genes were investigated by real time polymerase chain reaction (PCR) in the teeth and surrounding tissues. In the experimental groups, after the 7th day, there was a down-regulation of the mRNA levels of TNF-α and IL-4 compared to the 14th day (p<0.05). In these groups, the mRNA levels of RANKL, IFN-γ and TNF-α were statistically higher after 14 days compared to 21 days post-MTA sealing (p<0.05). The level of IL-10 mRNA was increased at the 21st day (p<0.05). The mRNA expression of TGF-β did not exhibit any statistically relevant results. There was a statistical down-regulation of IL-4 gene expressions when control and experimental groups were compared at days 7 and 21. In conclusion, MTA sealing favored the expression of pro-inflammatory cytokines in the intermediate phase of the immuno-inflammatory response (14th day). The reduction of these cytokines in later phase of the response was probably due to immunoregulation by IL-10.

O objetivo desse artigo foi avaliar a expressão das citocinas induzidas por MTA após a perfuração experimental de furca, em camundongos. Camundongos Balb/c (n=5) foram submetidos à perfuração induzida da furca do primeiro molar superior, seguido pelo selamento da mesma com MTA no lado esquerdo (grupo experimental) e com parafina no lado direito (grupo controle). Os animais foram sacrificados 7, 14 e 21 dias após o tratamento da perfuração. A expressão gênica dos níveis de IFN-γ, TNF- α, IL-10, IL-4, TGF- β e RANKL foram investigadas por PCR em tempo real nos dentes e tecidos adjacentes. No grupo experimental, após 7 dias, houve uma diminuição da expressão dos níveis de TNF- α e IL-4 comparados ao 14° dia (p<0,05). Nesses mesmos grupos, os níveis de mRNA de RANKL, IFN- γ e TNF- α foram estatisticamente maiores após 14 dias comparados a 21 dias após o tratamento com MTA (p<0,05). Os níveis de IL-10 estavam aumentados no 21^o dia (p<0,05). A expressão de mRNA do TGF- β não apresentou alteração estatisticamente relevante. Houve uma redução estatística da expressão gênica da IL-4 quando os grupos controle e experimental foram comparados nos dias 7 e 21. Em conclusão, o selamento com MTA favoreceu a expressão de citocinas pró-inflamatórias na fase intermediária da resposta imuno-inflamatória (14^o dia). A redução dessas citocinas, na fase tardia da resposta, ocorreu provavelmente devido à imunoregulação da expressão de IL-10.

An ex vivo comparison of diagnostic accuracy of cone-beam computed tomography and periapical radiography in the detection of furcal perforations.

INTRODUCTION: The purpose of this study was to assess cone-beam computed tomographic (CBCT) imaging with different voxel sizes and an intraoral sensor in the detection of furcation perforations. METHODS: In 40 teeth, furcation perforations were created, and 40 intact teeth served as the control. Five image sets were obtained: (1) CBCT, 0.1 mm(3) voxel size; (2) CBCT, 0.15 mm(3) voxel size; (3) CBCT, 0.2 mm(3) voxel size; (4) CBCT, 0.4 mm(3) voxel size; and (5) digital periapical images. Images were evaluated twice by 3 observers. Perforation widths were measured by CBCT software. Receiver operating characteristic analysis was used to assess the observers' ability to detect perforation, and area under the curve values were compared by using t tests, with a significance level of α = 0.05. RESULTS: No differences (P > .05) were found between any of the median area under the curve and true positive rate values obtained with different CBCT voxel sizes. Actual perforation width correlated highly with CBCT width measurements. CONCLUSIONS: Low-resolution CBCT imaging can be preferred for furcation perforation diagnosis because of its low dose and reliable diagnostic outcome.

Perfurações experimentais de furca tratadas com MTA acrescido de selênio: análise da resposta imune / Experimental furcal perforation treated with mineral trioxide aggregate plus selenium: immune response

A perfuração de furca é uma comunicação mecânica ou patológica entre o sistema de canais radiculares e a superfície externa do dente, permitindo contaminação bacteriana do tecido periodontal e consequente inflamação e perda do tecido de suporte. Atualmente, o MTA (Agregado de trióxido mineral) é o material mais indicado no tratamento dessas perfurações, por ser biocompatível e apresentar bom selamento. A literatura atual relata a capacidade do selênio em inibir crescimento bacteriano, alterar o metabolismo ósseo e estimular o sistema imunitário. O objetivo deste estudo foi avaliar a resposta imunológica do MTA acrescido de selênio. Neste estudo, induziram-se perfurações experimentais de furca em molares de camundongos isentos de germes. O primeiro molar superior esquerdo teve a furca perfurada e tratada com MTA + Selênio (grupo experimental) e no lado direito a furca foi perfurada e tratada com MTA (grupo controle). Os animais foram sacrificados com 07, 14 e 21 dias após a intervenção sendo 5 animais para cada grupo, (n=5). Os tecidos perirradiculares adjacentes à lesão foram extraídos e macerados, fazendo-se, a seguir, a extração do RNA. As expressões das citocinas TGF-ß, TNF-α, IFN-γ, IL-10, IL.4, RANK, RANKL, IL-1α, IL-17A e HPRT foram investigados por PCR em tempo real. No grupo experimental, após o 21 dias, houve um aumento da expressão de TNF-α e IL-10 em comparação com o grupo controle (p <0,05). A avaliação revelou expressão basal de IL-1α, IFN-γ, RANK, RANKL, IL-17A, IL-4 e TGF-ß nos níveis de mRNA, em ambos os grupos experimental e controle, , em todos os tempos experimentais (p > 0,05). O selamento com MTA + Se favoreceu a expressão da citocinas pró-inflamatórias TNFα na fase tardia de resposta (21o dia) paralelo ao aumento da citocina regulatória IL10 no mesmo período. Concluiu-se que, o aumento destas citocinas no grupo tratado com selênio na fase tardia da resposta, provavelmente, se deveu aos seus efeitos imunoregulatórios.

Furcal perforation is a mechanical or pathological communication between the root canal system and outer surface of the tooth. It may allow bacterial contamination and subsequent periodontal tissue inflammation and loss of supportive tissue. Currently, the MTA (mineral trioxide aggregate) is the most suitable material in the treatment of these perforations to be biocompatible and provide good sealing. The literature reports the selenium's ability to inhibit bacterial growth, alter bone metabolism and stimulate the immune system. The objective of this study was to evaluate the immune response of MTA associated with selenium. In this study, experimental furcal perforations were induced in molar of germ-free mice. The first maxillary left molar had the furcal perforated and treated with MTA / Selenium (experimental group) and the right molar, furcal was perforated and treated with MTA (control group). The animals were killed in 07, 14 and 21 days after the intervention (n = 5). mRNA was extracted from periradicular tissues and the eexpressions of TGF-ß, TNF-α, IFN γ, IL10, IL-4, RANK, RANKL, IL-1α, IL-17A e HPRT were investigated by real time PCR. In the experimental groups, on 21 days post MTA+Se sealing it was observed an upregulation of the mRNA levels of TNF-α and IL-10 compared with the control group (p<0.05). Assessment revealed basal expression of IL-1α, IFN-γ, RANK, RANKL, IL17A,IL-4 and TGF-ß gene expression all long of the experimental times, in both groups treated with MTA or MTA+Se (p>0.05). The MTA+Se sealing favored the expression of TNF-α and IL-10 in the later phase of response (21th day). The increase of these cytokines was probably due to immunoregulation of Se levels.

An In vitro Comparison of Furcal Perforation Repaired with Pro-root MTA and New Endodontic Cement in Primary Molar Teeth- A Microleakage Study.

STATEMENT OF PROBLEM: One of the most challenging procedural accidents during pulpotomy of primary molars is furcal perforation. To prevent bacterial invasion, the perforation site should be sealed as soon as possible. PURPOSE: The aim of the current study is to investigate the ability of the pro-root MTA and new endodontic cement (NEC) in repairing the furcation perforations of primary molar teeth. MATERIALS AND METHOD: In this in vitro study, 42 extracted primary molars were selected. Their roots were sectioned horizontally and standard access cavity was prepared. The orifices and the root apices were sealed with two layers of resin composite.The samples were randomly assigned into 2 groups. 6 teeth were considered as the positive and the negative controls. In the experimental groups; perforation was made. In group 1 and 2, perforation site received pro-root MTA and NEC respectively. The teeth were covered by two layers of nail polish except for the external surface of the perforation site. The negative control group received no repairing material. All teeth were mounted and sterilized for 24 hours. Lower chambers were filled with sterilized Muller Hinton broth. Bacterial suspension of Enterococcus faecalis in 0.5 McFarland was prepared. The repaired site was then exposed to the bacterial suspension of Enterococcus faecalis every 3 days. All samples were inserted in an incubator at 37(o)C and 100% humidity. The turbidity of the samples was detected for a period of 30 days. Data were analyzed by Chi- square test. RESULTS: 44% of samples in Pro- root group, 50% of the samples in the NEC group showed contaminations during 30 days. There was no significant difference between these two groups (p= 0.799). CONCLUSION: With limitations of this study, Pro- root MTA and NEC showed similar capability in sealing the furcal perforations of the primary molars.