Direct Pulp Capping Material Research Articles

Subcutaneous tissue reaction to castor oil bean and calcium hydroxide in rats

Castor oil bean cement (COB) is a new material that has been used as an endodontic sealer, and is a candidate material for direct pulp capping.ObjectiveThe purpose of this study was to evaluate the biocompatibility of a new formulation of COB compared to calcium hydroxide cement (CH) and a control group without any material, in the subcutaneous tissue of rats.Material and methodsThe materials were prepared, packed into polyethylene tubes, and implanted in the rat dorsal subcutaneous tissue. Animals were sacrificed at the 7th and 50th days after implantation. A quantitative analysis of inflammatory cells was performed and data were subjected to ANOVA and Tukey's tests at 5% significance level.ResultsComparing the mean number of inflammatory cells between the two experimental groups (COB and CH) and the control group, statistically significant difference (p=0.0001) was observed at 7 and 50 days. There were no significant differences (p=0.111) between tissue reaction to CH (382 inflammatory cells) and COB (330 inflammatory cells) after 7 days. After 50 days, significantly more inflammatory cells (p=0.02) were observed in the CH group (404 inflammatory cells) than in the COB group (177 inflammatory cells).ConclusionsThese results demonstrate that the COB cement induces less inflammatory response within long periods.

Visible light-induced crosslinkable gelatin

A novel visible light-crosslinkable porcine gelatin was prepared for gelation and micropatterning. The preparation employed a photo-oxidation-induced crosslinking mechanism. First, furfuryl groups were incorporated into the gelatin. Second, the modified gelatin was mixed in water with Rose Bengal, which is a visible light sensitizer. Irradiation by visible light solidified the aqueous solution. In addition, when the solution was cast on a plate, dried and photo-irradiated in the presence of a photomask a micropattern was formed that matched the micropattern on the photomask. The gelatin-immobilized regions enhanced cell adhesion. It was also confirmed that the gelatin incorporating furfuryl and Rose Bengal have no significant toxicity. The photo-crosslinkable gelatin was employed as a direct pulp capping material in the dental field. Considering these results, this system could be useful as a new type of visible light-induced crosslinkable biosealant.

Pulp response of beagle dog to direct pulp capping materials: Histological study

The purpose of this study was to evaluate the pulp tissue reaction to direct pulp capping of mechanically exposed beagle dogs' pulp with several capping materials. A total of 36 teeth of 2 healthy beagle dongs were used. The mechanically exposed pulps were capped with one of the followings: (1) Mineral Trioxide Aggregate (MTA: MTA. Dentsply, Tulsa, USA), (2) Clearfil SE Bond (Dentin adhesive system: Kuraray, Osaka, Japan), (3) Ultra-Blend (Photo-polymerized Calcium hydroxide: Ultradent, South Jordan, USA), (4) Dycal (Quick setting Calcium hydroxide: LD Caulk Co., Milford, USA) at 7, 30, and 90 days before sacrificing. The cavities were restored with Z350 flowable composite resin (3M ESPE, St. Paul. MN, USA). After the beagle dogs were sacrificed, the extracted teeth were fixed, decalcified, prepared for histological examination and stained with HE stain. The pulpal tissue responses to direct pulp capping materials were assessed. In MTA calcium hydroxide, and photo-polymerized calcium hydroxide groups, initial mild inflammatory cell infiltration, newly formed odontoblast-like cell layer and hard tissue bridge formation were observed. Compared with dentin adhesive system, these materials were biocompatible and good for pulp tissue regeneration. In dentin adhesive system group, severe inflammatory cell infiltration, pulp tissue degeneration and pulp tissue necrosis were observed. It seemed evident that application of dentin adhesive system in direct pulp capping of beagle dog teeth cannot lead to acceptable repair of the pulp tissue with dentine bridge formation.

Cytotoxicity and biocompatibility of direct and indirect pulp capping materials

There are several studies about the cytotoxic effects of dental materials in contact with the pulp tissue, such as calcium hydroxide (CH), adhesive systems, resin composite and glass ionomer cements. The aim of this review article was to summarize and discuss the cytotoxicity and biocompatibility of materials used for protection of the dentin-pulp complex, some components of resin composites and adhesive systems when placed in direct or indirect contact with the pulp tissue. A large number of dental materials present cytotoxic effects when applied close or directly to the pulp, and the only material that seems to stimulate early pulp repair and dentin hard tissue barrier formation is CH.

Efficacy of EMD versus calcium hydroxide in direct pulp capping of primary molars: a randomized controlled clinical trial

The aim was to compare the clinical and radiographic efficacy of enamel matrix derivative and self-hardening calcium hydroxide as direct pulp capping materials on decayed primary molars, with observation periods of 1, 6, and 12 months. A clinical, randomized, controlled trial was performed, following the "split-mouth" design. A total of 90 primary molars were treated. Assignation of materials and operative initial side were selected in a randomized manner. Five outcome variables were considered: internal dentin resorption, pain, gingival sinus tract, root external resorption, and pathologic mobility. The appearance of any of these signs or symptoms was considered to be a failure of treatment. Significant statistical or clinical differences were not found between the study groups. Two treatments were judged as failures, 1 per study group; both occurred during the first postoperative month. The technique used for direct pulp capping on primary molars in this study is recommended on the basis of the obtained clinical and radiographic results.

Clinical long‐term evaluation of MTA as a direct pulp capping material in primary teeth

To evaluate the effectiveness of mineral trioxide aggregate (MTA) when used as a pulp capping material in primary teeth. Clinical follow-up was performed on 25 symmetrical pairs of primary molars with deep occlusal caries, in 25 patients between the ages of 5 and 8 years. Pulps exposed during cavity preparation were treated by direct pulp capping with MTA or calcium hydroxide, based with resin-bonded zinc oxide eugenol cement and restored with amalgam. Clinical and radiographic examinations were carried out at 1, 3, 6, 9, 12, 18 and 24 months. Twenty-four-month clinical and radiographic follow-ups were carried out on 22 patients. One patient failed to return for evaluation after 1 month, one after 9 months and another after 12 months. During follow-up, none of the MTA and calcium hydroxide groups exhibited clinical or radiographic failure. Mineral trioxide aggregate was found to be as successful as calcium hydroxide when used for direct pulp capping in primary teeth. Further histological investigations are needed to support these findings.

Human tooth culture: A study model for reparative dentinogenesis and direct pulp capping materials biocompatibility

In a previous work, based on an in vitro entire tooth culture model of human immature third molars, we demonstrated that perivascular progenitor cells can proliferate and migrate to the injury site after pulp exposure. In this work, we investigated the differentiation of cells after direct capping with biomaterials classically used in restorative dentistry. Histological staining after direct pulp capping with Calcium Hydroxide XR(R) or MTA revealed early and progressive mineralized foci formation containing BrdU-labeled sequestered cells. The molecular characterization of the matrix and the sequestered cells by immunohistochemistry (Collagene type I, Dentin sialoprotein, and Nestin) clearly demonstrates that these areas share common characteristics of the mineralized matrix of reparative dentin formed by odontoblast-like cells. This reproduces some features of the pulp responses after applying these materials in vivo and demonstrates that the entire tooth culture model reproduces a part of the early steps of dentin regeneration in vivo. Its future development may be useful in studying the effects of biomaterials on this process.

SEM evaluation of pulp reaction to different pulp capping materials in dog's teeth.

This investigation evaluates the effects of mineral trioxide aggregate (MTA), calcium hydroxide (CH) and calcium enriched mixture (CEM) as pulp capping materials on dental pulp tissues. The experimental procedures were performed on eighteen intact dog canine teeth. The pulps were exposed. Cavities were randomly filled with CEM, MTA, or CH followed by glass ionomer filling. After 2 months, animals were sacrificed, each tooth was sectioned into halves, and the interface between each capping material and pulp tissue was evaluated by scanning electron microscope (SEM) in profile view of the specimens. Dentinal bridge formation as the most characteristic reaction was resulted from SEM observation in all examined groups. Odontoblast-like cells were formed and create dens collagen network, which was calcified gradually by deposition of calcosphirit structures to form newly dentinal bridge. Based on the results of this in vivo study, it was concluded that these test materials are able to produce calcified tissue in underlying pulp in the case of being used as a pulp capping agent. Additionally, it appears that CEM has the potential to be used as a direct pulp capping material during vital pulp therapy.

Maturogenesis of a cariously exposed immature permanent tooth using MTA for direct pulp capping: a case report

Successful direct pulp capping of cariously exposed permanent teeth with reversible pulpitis and incomplete apex formation can prevent the need for root canal treatment. A case report is presented which demonstrates the use of mineral trioxide aggregate (MTA) as a direct pulp capping material for the purpose of continued maturogenesis of the root. Clinical and radiographic follow-up demonstrated a vital pulp and physiologic root development in comparison with the contralateral tooth. MTA can be considered as an effective material for vital pulp therapy, with the goal of maturogenesis.

SEM evaluation of neodentinal bridging after direct pulp protection with mineral trioxide aggregate

The purpose of this study was to observe the basic morphology and determine the chemical composition of neodentinal bridges adjacent white mineral trioxide aggregate (WMTA) when used as a direct pulp capping material. The experimental procedures were performed on six intact dogs' teeth. The pulps were exposed and cavities were filled with WMTA. After 2 weeks, neodentinal bridge formation was evaluated by scanning electron microscope (SEM) of cross-sections of the specimens and electron probe microanalysis (EPMA) of the pulpal surfaces. Results of SEM observation showed that the most characteristic reaction of pulp cells was the intimate connection of cell processes and secreted extracellular fibres with the crystals of the pulp capping material. Results of EPMA indicated that the mineralisation of neodentinal bridge formation occurred progressively from the periphery to the central area. Based on these results, it appears that WMTA has the potential to be used as a direct pulp capping material during vital pulp therapy.

Pulpal reactions to two experimental bonding systems for pulp capping procedures.

This study evaluated the pulpal responses induced by application of two types of bonding system to the exposed dental pulp. One consisted of the following steps: etching with neutralized EDTA, application of an experimental water-based photocuring bonding agent, and restoration with a commercially available photocuring resin composite (EDTA etching system). The other was treatment with an experimental water-based self-etching primer, application of a commercially available bonding agent, and restoration with a commercially available photocuring resin composite (self-etching system). These two systems of treatment were applied to the exposed pulp. Calcium hydroxide was used as a control for the direct pulp-capping material. The pulps in class V cavities in the anterior teeth of beagles were mechanically exposed and then filled using the etching, the self-etching, or the Ca(OH)2 system. The beagles were sacrificed on the 7th, 30th or 90th postoperative day, and pulpal responses were investigated histopathologically using light microscopy. The EDTA etching system induced severe pulp reactions at 7 days after the operation. These reactions did not completely diminish after 90 days. Reparative dentin formation was observed at day 90. The self-etching system showed moderate pulp reactions, which gradually decreased over the experimental period. Reparative dentin bridge formation was observed at day 90. No necrosis of the pulp was observed at any time. Calcium hydroxide induced both moderate and severe initial pulp reactions, with reparative dentin formation evident at day 30. Necrosis was observed in the superficial pulp. It is suggested that the EDTA etching agent caused not only pulpal damage but also re-bleeding because of rinsing and drying. The self-etching system is a promising system for direct pulp capping.

Newly developed resinous direct pulp capping agent containing calcium hydroxide (MTYA1-Ca).

The aim of this study was to evaluate a newly developed resin (MTYA1-Ca) for direct pulp capping. The powder of MTY1-Ca is composed of 89.0% microfiller, 10.0% calcium hydroxide and 1.0% benzoyl peroxide and was mixed with liquid (67.5% triethyleneglycol dimethacrylate, 30.0% glyceryl methacrylate, 1.0% o-methacryloyl tyrosine amide, 1.0% dimethylaminoethylmethacrylate, and 0.5% camphorquinone). The shear bond, diametral tensile, bending and compressive strengths were measured. The alkaline activity of the elute dissolved from MTYA1-Ca was calculated. Cell viability by MTT assay and alkaline phosphatase (ALPase) activity were evaluated from dental pulp fibroblast reaction to the eluate dissolved from MTYA1-Ca. Histopathological studies of the response to exposed dental pulp of beagle dogs were completed with Dycal as a control. The physical properties of MTYA1-Ca were significantly superior to those of Dycal. It was impossible to measure these properties with Dycal because of poor physical properties. Both MTYA1-Ca and Dycal maintained high levels of alkaline activity (pH 10.96-12.20) over the 168-h duration of the study. Cell viability by MTT assay in the intact eluate of MTYA1-Ca was significantly higher than that of Dycal, whilst ALPase showed no difference between MTYA1-Ca and Dycal. A dentine bridge formed more slowly under MTYA1-Ca than under Dycal, but similar amounts had formed at 90 days. MTYA1-Ca has the potential to be used as a direct pulp capping material.

Response of pulpotomy wounds in normal human teeth to successively applied Ledermix and Calxyl

Ledermix was dressed on the pulps after pulpotomy of 20 premolars for periods of 24–96 hr, then rinsed and Calxyl used as a direct pulp-capping material for about 4 weeks. Histological examination revealed almost identical appearances in all, consisting of a necrotic area and a fibrous zone and below it an area of pale pulp followed by a dentine bridge, through which capillaries communicated between the supra and infra-bridge pulp. The infra-bridge pulp was normal but somewhat congested in the 24-hr treatment group but, in those groups treated for more than 24 hr, chronic inflammation and sporadically focal necrosis were seen. The most striking finding was early closure of the apical foramina by a diaphragm of newly formed dentine.

A Report on Dental Caries in Ten Thousand Four Hundred Forty-Five University Students (1928–1930)

Calcium hydroxide-based materials were the gold standard in vital pulp therapies for decades’ despite of several shortcomings. However, calcium silicates have been discussed as an alternative to overcome these drawbacks. It was aimed to investigate the in-vivo effectiveness of different calcium silicates based materials in pulp capping in this study.A parallel-design, randomized controlled trial with 213 patients who has deep dentin caries, vital pulps and without spontaneous pain or history of swelling was designed. 525 M teeth were randomized, blinded and allocated to one of the five groups for pulp capping treatment (n = 105). All teeth were followed up clinically and radiographically (after 1st, 6th, 12th and 36th months) by blinded investigators. The clinical and radiographic success, and the effect of the pulp exposure to the success rate analyzed with Wald chi-square and Z tests.Clinical and radiographic success of MTA+ (86.3%, 85.4%) and Biodentine (79.4%, 80.1%) were found the highest. Although results of Theracal LC group (72.1%, 73.6%) were better than Dycal group (69.4%, 70.2%), the difference was nonsignificant (p > 0.05). Only in light-cured groups, (TheraCal LC & LC Calcihyd) pulpal exposure size effected the success of the materials (p < 0.05). MTA+ and Biodentine resulted better scores, when compared with TheraCal LC in large pulpal exposures (p < 0.05).After 36-month follow-up, both MTA+ and Biodentine were found to be the appropriate material for direct pulp capping in permanent teeth. The filler ingredient of the Theracal-LC eases the usage of calcium silicates but decreases the success rate.