Pulp preservation in immature permanent teeth

New treatment strategies for direct pulp capping and pulpotomy have shown promising potentials for improved outcomes in immature teeth with extensive caries, traumatic pulp exposures, or anatomical anomalies. Preservation and protection of the dental pulp in developing teeth promote root maturation and extend tooth survivability by postponing or even preventing more complex endodontic and restorative care. Early intervention using hydraulic calcium silicate cements such as mineral trioxide aggregate (MTA) stimulates pulpal cell recruitment and differentiation, up‐regulates transformation factors (gene expression), and promotes dentinogenesis. Calcium hydroxide, resin‐modified glass ionomer cements, hydrophilic resins, and formocresol have been shown to be less effective as bioactive agents when used in vital pulp therapy. Improved treatment procedures for pulp preservation include the use of caries detector dye to preserve the remineralizable inner carious layer and the use of sodium hypochlorite as a hemostatic and diagnostic agent to differentiate reversible from irreversible pulpitis. Although stepwise excavation and the use of calcium hydroxide is still being advocated, pulp capping and pulpotomy procedures using calcium silicate‐based cements are becoming widely accepted as more effective procedures. MTA and new hydraulic calcium silicate cements provide biocompatible environments that predictably promote reparative dentin bridge formation when placed under properly bonded and sealed composite restorations. Hydraulic calcium silicate cements appear to provide a promising future for the preservation of pulpal integrity in immature teeth when used with modified and conservative treatment protocols.     

Multifaceted use of ProRoot MTA root canal repair material

Mineral Trioxide Aggregate (MTA) is a new material recently approved by the FDA for use in pulpal therapy. MTA has been reported to have superior biocompatibility and sealing ability and is less cytotoxic than other materials currently used in pulpal therapy. This report is a review of MTA's physical and biological properties and the clinical techniques of direct pulp capping, apexification, and repair of failed calcium hydroxide therapy.     

Mineral trioxide aggregate pulpotomies: a case series outcomes assessment

BACKGROUND: The greatest threats to developing teeth are dental caries and traumatic injury. A primary goal of all restorative treatment is to maintain pulp vitality so that normal root development or apexogenesis can occur. If pulpal exposure occurs, then a pulpotomy procedure aims to preserve pulp vitality to allow for normal root development. Historically, calcium hydroxide has been the material of choice for pulpotomy procedures. Recently, an alternative material called mineral trioxide aggregate (MTA) has demonstrated the ability to induce hard-tissue formation in pulpal tissue. The authors describe the clinical and radiographic outcome of a series of cases involving the use of MTA in pulpotomy procedures. METHODS: Twenty-three cases in 18 patients were treated with MTA pulpotomy procedures in an endodontic private practice. All of the patients had been referred to the practice for diagnosis and treatment of a symptomatic tooth. All of the authors provided treatment. Pulpal exposures were either due to caries or complicated enamel dentin fractures. RESULTS: Nineteen teeth in 14 patients were available for recall. The mean time of recall was 19.7 months. Of the 19 cases, 15 involved healed teeth, and three involved teeth that were healing. One of 19 cases involved a tooth with persistent disease. CONCLUSIONS: MTA may be useful as a substitute for calcium hydroxide in pulpotomy procedures. Further research, however, is required to clarify this conclusion. CLINICAL IMPLICATIONS: MTA conceivably could replace calcium hydroxide as the material of choice for pulpotomy procedures, if future research continues to show promising results.     

MTA直接盖髓的动物实验研究

目的 比较MTA（mineraltrioxideaggregate）及氢氧化钙犬牙直接盖髓后牙髓的反应。方法 将三只健康雄性杂种犬共72颗牙齿机械开髓，然后用MTA和氩氧化钙分别盖髓。窝洞用玻璃离子水门汀充填。在5，7，9个月后。对实验牙齿进行组织切片制备，借助计算机图文处理系统对所形成的修复性牙本质宽度进行测量，对成牙本质细胞、牙髓细胞及毛细血管进行计数、分析。结果 5个月后，MTA及氢氧化钙盖髓效果相似。在7，9个月后。MTA组牙髓较氢氧化钙组可见更明显的修复性牙本质形成，更多的成牙本质细胞和牙髓细胞。结论 MTA具有临床活髓保存治疗应用价值。     

Management of traumatically injured pulps in immature teeth using MTA

Maintaining pulpal health during tooth development is an important goal in managing traumatic injuries in the immature dentition. The introduction of mineral trioxide aggregate has offered an improved method for pulp protection in such cases. This article describes a technique using MTA for vital pulp therapy on teeth with crown fractures that have resulted in pulp exposure.     

Will mineral trioxide aggregate replace calcium hydroxide in treating pulpal and periodontal healing complications subsequent to dental trauma? A review

Mineral trioxide aggregate (MTA) has over the last two decades begun to take the place of calcium hydroxide (CH) in the treatment of a variety of pulpal and periodontal healing complications following dental trauma. These conditions include teeth with: (i) exposed pulps, (ii) immature roots and pulp necrosis, (iii) root fractures and pulp necrosis located in the coronal part of the pulps, and (iv) external infection-related (inflammatory) root resorption. The main reasons for replacing CH with MTA in these situations have generally been the delayed effect when using CH to induce hard tissues, the quality of such induced hard tissues, and finally the dentin weakening effect of CH, which in some instances lead to cervical root fractures in immature teeth. MTA appears, from a relatively few clinical studies, to overcome these shortcomings of CH. The lack of long-term clinical studies, however, may warrant a certain reservation in an unrestricted replacement of CH with MTA. A definite need for randomized clinical studies comparing CH and MTA in trauma healing situations is urgently needed.     

MTA复合纤维粘连蛋白盖髓的临床疗效评价

目的 :观察MTA复合纤维粘连蛋白作为活髓保存剂的临床疗效。方法 :选择 10 9名患者 ,分别用MTA、MTA复合纤维粘连蛋白和氢氧化钙盖髓 ,评价盖髓后 4周与 12周时的盖髓成功率。结果 :盖髓 4周时 ,MTA、MTA复合纤维粘连蛋白和氢氧化钙组的盖髓成功率的差别无统计意义 (P >0 .0 5 )。盖髓 12周时 ,3组材料的盖髓成功率的差别有统计意义 (P <0 .0 5 )。结论 :MTA复合纤维粘连蛋白的临床盖髓效果显著 ,优于氢氧化钙组     

Histological, ultrastructural and quantitative investigations on the response of healthy human pulps to experimental capping with mineral trioxide aggregate: a randomized controlled trial

AIM: To investigate the pulpal response to direct pulp capping in healthy human teeth with mineral trioxide aggregate (MTA) as against calcium hydroxide cement (Dycal) as control. METHODOLOGY: Twenty healthy human third molars had iatrogenic pulpotomy and direct pulp capping with MTA. Another 13 teeth were capped with Dycal as controls. The teeth were restored, with IRM, clinically reviewed and extracted after a number of pre-determined intervals (1 week, 1 month and 3 months). The specimens were fixed, decalcified, subdivided axially into two halves in the oro-buccal (lingual-buccal) plane, embedded in plastic, serial sectioned and evaluated qualitatively and quantitatively by correlative light and transmission electron microscopy with appropriate statistical evaluation of the quantitative data. RESULTS: Iatrogenic pulpal wounds treated with MTA were mostly free from inflammation after 1 week and became covered with a compact, hard tissue barrier of steadily increasing length and thickness within 3 months following capping. Control teeth treated with Dycal revealed distinctly less consistent formation of a hard tissue barrier that had numerous tunnel defects. The presence of pulpal inflammation up to the longest observation period (3 months) after capping, was a common feature in Dycal specimens. CONCLUSIONS: The MTA was clinically easier to use as a direct pulp-capping agent and resulted in less pulpal inflammation and more predictable hard tissue barrier formation than Dycal. Therefore, MTA or equivalent products should be the material of choice for direct pulp capping procedures instead of hard setting calcium hydroxide cements.     

MTA用于犬牙直接盖髓术的组织学观察

目的 通过组织学观察，比较MTA（Mineral Trioxide Aggregate)和氢氧化钙制剂(Dycal)在直接盖髓时对牙髓的影响。方法 3条健康杂种犬尖牙12颗，随机分为2组：MTA，Dycal。用裂钻在尖牙唇侧颈部穿髓后以MTA和Dycal盖髓，GIC修复牙体缺损。4个月后将犬处死取下尖牙，常规制作组织切片，观察牙髓炎症反应和牙本质桥形成情况。结果 MTA盖髓的实验组中，5／6无炎症或仅有轻度炎症反应，该组所有标本均有牙本质桥形成。Dycal盖髓的对照组牙髓均有轻度或中度的炎症反应，只有2例出现了牙本质桥。结论 MTA具有良好的生物相容性，适用于直接盖髓术，有望替代现有的盖髓材料。     

The use of mineral trioxide aggregate to achieve root end closure: three case reports

Abstract – The use of mineral trioxide aggregate (MTA) to achieve root end closure has many advantages over the traditional calcium hydroxide (Ca(OH)₂) technique including the reduced number of visits and the reduced mechanical damage to dentine. Limited studies have reported the outcome of using MTA as an apexification material and a one‐stage obturation technique in non‐vital immature teeth. This article illustrates three successful clinical cases where MTA was used as an apexification material. In case study one: Type 1 Dens Invaginatus tooth with incomplete root formation, case study two: an immature tooth that suffered pulp necrosis following an enamel and dentine fracture trauma and case study three: a non‐vital tooth following an apical root fracture.     

Clinical assessment of mineral trioxide aggregate (MTA) as direct pulp capping in young permanent teeth

Carious pulp exposure in permanent molars of children is a common incident. Mineral trioxide aggregate is a new material that possesses numerous exciting possibilities for pulp therapy. AIM: The purpose of this study was to evaluate the efficiency of MTA as a direct pulp capping agent in young permanent teeth. METHODS: Thirty asymptomatic permanent molars with pulp exposures were treated by pulp capping using MTA. At each recall (6 12, 18 and 24 months), the teeth were assessed clinically, through pulpal sensitivity tests, as well as radiographically to evaluate periapical healing. RESULTS: None of the cases reported spontaneous pain at the six months follow up and the pulp showed signs of vitality and absence of periapical radiolucency. At 24 months, the clinical and radiographic success rate was 93% with evidence of continued root growth. CONCLUSION: Pulp capping with MTA is recommended for teeth with carious pulp exposures specially immature teeth with high potential for healing.     

Apexification with mineral trioxide aggregate: an overview of the material and technique

Mineral Trioxide Aggregate (MTA) was introduced as an alternative to traditional materials for the repair of root perforations, pulp-capping and as a retrograde root filling due to its superior biocompatibilty and ability to seal the root canal system. Traditionally, calcium hydroxide has been the material of choice for the apexification of immature permanent teeth but MTA holds significant promise as an alternative to multiple treatments with calcium hydroxide. The paper discusses the use of calcium hydroxide as a traditional apexification material and provides an overview of the composition, properties and applications of Mineral Trioxide Aggregate with emphasis on its use in apexification of immature permanent teeth. A case report is presented to highlight its use.     

Vital pulp therapy in cariously exposed permanent teeth and its limitations

Vital pulp therapy for cariously exposed permanent teeth remains one of the most controversial areas in dentistry. Because a vital, functioning pulp is capable of initiating several defence mechanisms to protect the body from bacterial invasion, it is beneficial to preserve the vitality and health of an exposed pulp rather than replace it with a root filling material following pulp exposure. There is no consensus on the survival rate of formerly cariously exposed pulps. Observation time, judgement criteria, pulpotomy/pulp capping technique and, most importantly, pulpal status at the time of treatment, vary to a great extent amongst studies. In mature teeth, a pulp exposed by caries is usually removed and the root canals are cleaned, shaped and filled. Amongst the methods for preservation of a cariously exposed pulp, partial pulpotomy has yielded a markedly high success rate in young teeth. Major limitations in the success of vital pulp therapy in cariously exposed permanent teeth exist. The lack of predictability and long-term success greatly influence decision-making. The decision-making itself is unreliable primarily due to the difficulty of accurately diagnosing the ability of the pulp to repair. While there are indications for vital pulp therapy in young permanent molars, it must be remembered that ultimately, none of these procedures enjoy the long-term success of complete root canal therapy.     

Human pulpal response to mineral trioxide aggregate (MTA): a histologic study

The purpose of this study was to study the histologic changes in the dental pulp following pulpotomy with Mineral Trioxide Aggregate (MTA) and Calcium hydroxide. Pulpotomies were performed on premolar teeth that were to be extracted for orthodontic reasons. The radicular pulp was capped with either MTA or Calcium hydroxide and restored with IRM. The teeth were extracted at 4 and 8 week intervals, fixed in 10% formalin and then kept in 5% nitric acid for 28 days for demineralization. Longitudinal sections were then prepared and viewed under light microscope. The pulps capped with MTA (at the end of 4 weeks and 8 weeks) showed dentin bridge formation which was more homogenous and continuous with the original dentin when compared to the pulps capped with calcium hydroxide. The pulpal inflammation was also less in the MTA group as compared to the calcium hydroxide group at the end of 4 and 8 weeks.     

三氧化物多聚体应用于活髓切断术的临床疗效研究

目的评价三氧化物多聚体(MTA)用于活髓切断术的临床效果。方法选取外伤冠折露髓的年轻恒前牙48颗,随机分为2组,每组24颗。氢氧化钙组用氢氧化钙盖髓,MTA组用MTA盖髓,追踪观察3年并进行临床评价。结果MTA组成功22颗,失败2颗,氢氧化钙组成功20颗,失败4颗,2组差异无统计学意义。结论MTA是一种较理想的直接盖髓剂。     

Clinical and radiographic evaluation of vital pulp therapy in open apex teeth with MTA and ZOE

The purpose of this study was to report the success rate of using mineral trioxide aggregate (MTA) and zinc oxide eugenol (ZOE) as vital pulp therapy agents in immature permanent teeth with carious or traumatic pulp exposure. Subjects were children with permanent teeth requiring pulpotomy (apexogenesis) and without systemic diseases. Both ZOE and MTA treatments as pulpotomy agents showed clinical and radiographic success in immature permanent teeth. Although MTA was more successful, it is more expensive, and dentin bridges may develop over canal orifices, complicating future root canal therapy.     

The effect of mineral trioxide aggregate on the contractility of the rat thoracic aorta

Mineral trioxide aggregate (MTA) is being advocated for vital pulp therapy. In the case of direct pulp capping, hemorrhage control is an important step on success, but little is known about the effect of MTA on pulpal bleeding. In addition, there has been a lack of information on the effect of MTA on smooth muscle contraction, such as can occur in the blood vessels of dental pulp. The present study assessed the vascular effects of MTA, using the rat aortic ring preparations as a tissue model. MTA (100-500 mg) induced dose-dependent contraction in rat thoracic aorta. The contractile effect of MTA was blocked by calcium channel blocker nifedipine (1 muM). These data suggest that the vasoconstrictor property of MTA is related to calcium influx and it may allow proper control of hemorrhage which is critical for the success of any pulp-capping treatment.     

Comparative in vitro study of the sealing efficiency of white vs grey ProRoot mineral trioxide aggregate formulas as apical barriers

Abstract –  Mineral trioxide aggregate (MTA) has been proposed as one of the materials which can be used in a one-visit apexification technique. Recently conventional grey MTA has been replaced by a new white MTA formula. The aim of this study was to compare the root canal adaptation of white MTA to that of grey MTA when used as an apical barrier in teeth with open apices. We also examined whether a previous calcium hydroxide intracanal medication affects MTA's sealing ability and investigated the ability to remove calcium hydroxide from the root canal walls. Forty-nine teeth were prepared in a manner to simulate a divergent open apex of immature teeth. Four teeth were used in a preliminary experiment to demonstrate the inefficacy of calcium hydroxide removal from the canal walls in teeth with open apices. Four groups of 10 teeth each were created: groups A and B were treated with calcium hydroxide intracanal medication and then received an apical plug of grey and white MTA respectively. Groups C and D received an apical plug of grey and white MTA respectively without previous intracanal medication. Four teeth served as negative and one as a positive control. The marginal adaptation and sealing ability of the apical barrier were tested by means of a dye tracer (basic fuchsine) after longitudinal sectioning. It was found that MTA apical barrier resisted displacement during gutta-percha condensation. Calcium hydroxide pretreatment, adversely affected white MTA sealing ability ( P  < 0.05).     

Evaluation of mineral trioxide aggregate and calcium hydroxide cement as pulp-capping agents in human teeth

This study evaluated the histomorphologic response of human dental pulps capped with mineral trioxide aggregate (MTA) and Ca(OH)2 cement (CH). Pulp exposures were performed on the occlusal floor of 40 human permanent premolars. After that, the pulp was capped either with CH or MTA and restored with composite resin. After 30 and 60 days, teeth were extracted and processed for histologic exam and categorized in a histologic score system. The data were subjected to Kruskal-Wallis and Conover tests (alpha = .05). All groups performed well in terms of hard tissue bridge formation, inflammatory response, and other pulpal findings. However, a lower response of CH30 was observed for the dentin bridge formation, when compared with MTA30 and MTA60 groups. Although the pulp healing with calcium hydroxide was slower than that of MTA, both materials were successful for pulp capping in human teeth.     

The sealing ability and retention characteristics of mineral trioxide aggregate in a model of apexification

Treatment of the immature pulpless tooth presents both an endodontic and restorative challenge. A more favorable long-term prognosis may be achieved with a mineral trioxide aggregate (MTA) apexification procedure followed by an internal bonding technique. We investigated the efficacy of this treatment option by testing the sealing ability and retention characteristics of MTA when placed as an apical barrier in a standardized in vitro open apex model. MTA was placed as an apical barrier at a thickness of 1 mm or 4 mm, with and without prior calcium hydroxide medication. The barriers were challenged with bacteria exposure within a leakage model and displacement forces on an Instron machine. In the leakage study, 100% of the MTA apical barriers showed bacterial penetration by day 70, compared with 20% of MTA root-end fillings used as controls. The displacement study demonstrated a statistically significant greater resistance to force with a 4-mm thickness of MTA, regardless of calcium hydroxide use. We concluded that it was the intracanal delivery technique and not the MTA that contributed to the leakage observed. MTA shows promise in our proposed treatment option of immature pulpless teeth if the sealing ability can be enhanced by improving the delivery technique.