Hydration of Biodentine,Theracal LC,and a Prototype Tricalcium Silicate–based Dentin Replacement Material after Pulp Capping in Entire Tooth Cultures

Introduction

The calcium-releasing ability of pulp-capping materials induces pulp tissue regeneration. Tricalcium silicate–based materials produce calcium hydroxide as a by-product of hydration. Assessment of hydration and calcium ion leaching is usually performed on samples that have been aged in physiological solution for a predetermined period of time. The hydration and activity of the materials in vivo may not be similar to those displayed in vitro because of insufficient fluid available in contact with dentin. The aim of this research was the assessment of hydration of Biodentine, Theracal LC, and a prototype radiopacified tricalcium silicate–based material after pulp capping and to compare it with direct hydration in an aqueous solution.

Methods

The extent of hydration of Biodentine, Theracal LC, and a prototype radiopacified tricalcium silicate–based material with a similar composition to Biodentine but not incorporating the additives was assessed by scanning electron microscopy and energy dispersive spectroscopy of polished specimens after being allowed to hydrate in Hank's balanced salt solution for 14 days. The extent of hydration was compared with material hydration when used as direct pulp capping materials by using a tooth culture model. Material activity was also assessed by x-ray diffraction analysis to investigate the deposition of calcium hydroxide by the materials, and calcium ion leaching in Hank's balanced salt solution was assessed by ion chromatography.

Results

Biodentine and the prototype tricalcium silicate cement hydrated and reaction by-products were deposited in the cement matrix both after pulp capping and when incubated in an aqueous solution. Calcium hydroxide was formed, and calcium ions were leached in solution. Theracal LC hydration was incomplete because of the limited moisture diffusion within the material. Thus, no calcium hydroxide was produced, and a lower calcium ion leaching was recorded.

Conclusions

Theracal LC had a heterogeneous structure with large unhydrated particles because not enough moisture was present to allow hydration to proceed. Biodentine composition was shown to be optimized, and the environmental conditions did not affect material microstructure. Biodentine exhibited formation of calcium hydroxide and calcium ion leaching, which are beneficial to the dental pulp.     

Application of High-frequency Radio Waves to Direct Pulp Capping

Introduction

In vital pulp therapy such as direct pulp capping, clinical success rates depend on achieving hemostasis in exposed pulp tissue. For hemostasis of exposed pulp tissue, gentle pressure by cotton pellets moistened with sodium hypochlorite is most commonly used. However, more rapid and reliable methods are necessary. Therefore, we focused on high-frequency radio waves (HRW).

Methods

To evaluate reparative dentin induction by HRW, we used a rat direct pulp capping model and performed hemostasis by using HRW of several strengths, covering the pulp with calcium hydroxide as a direct capping agent. After 14 or 28 days, rats were killed, and reparative dentin and pulp inflammation were investigated histologically.

Results

Radio wave–induced hemostasis required less time when compared with the control group. Reparative dentin with regularly arranged dentinal tubules was observed in the HRW group.

Conclusions

HRW induce hemostasis and produce high-quality reparative dentin and reduced pulpal inflammation.     

Comparison of Pulpal Responses to Pulpotomy and Pulp Capping with Biodentine and Mineral Trioxide Aggregate in Dogs

Introduction

This study evaluated the pulpal and periapical responses of dogs' teeth after pulpotomy and pulp capping with a new tricalcium silicate–based cement (Biodentine) when compared with mineral trioxide aggregate (MTA) by radiographic, histopathologic, and histomicrobiological analyses.

Methods

Sixty roots (30 teeth) of dogs were divided into 2 groups, Biodentine (n = 36 roots) and ProRoot MTA (control, n = 24 roots). Animals were killed after 120 days, and the teeth were subjected to histotechnical processing (hematoxylin-eosin and Brown and Brenn staining). Qualitative and quantitative histopathologic data were analyzed by Fisher exact and Mann-Whitney tests (α = 0.05).

Results

Radiographically, mineralized tissue bridge formation was observed in more specimens treated with Biodentine (96.8%) than with MTA (72.2%) (P = .02). Integrity of the lamina dura and absence of periapical bone rarefaction and root resorption (external and internal) were observed in all specimens. Histopathologic and histomicrobiological analyses revealed mineralized tissue bridge formation, pulpal vitality, odontoblast layer integrity, preserved periodontal ligament, and absence of bone or root resorption and microorganisms in both groups. Although the bridges formed at the amputation site had similar morphology, they were significantly thicker in the Biodentine group (P < .0001). Comparison between the radiographic and histopathologic results showed that radiographic visualization of more bridges in the Biodentine group was related to bridge thickness because radiographic diagnosis was flawed for bridges with thickness less than 0.5 mm. Fluorescence microscopy improved the visualization of bridge structure.

Conclusions

Biodentine presented tissue compatibility and allowed for mineralized tissue bridge formation after pulpotomy in all specimens with similar morphology and integrity to those formed with use of MTA. Periapical radiographs failed in detecting mineralized tissue bridges with thickness less than 0.5 mm.     

Efficacy of polyphasic calcium phosphates as a direct pulp capping material

Objectives

Polyphasic calcium phosphates (Poly-CaP), a complex of hydroxyapatite (HAp) and soluble calcium phosphates including α-tricalcium phosphate and tetracalcium phosphate, demonstrate promoting effects on hard tissue formation by osteoblasts. We hypothesized that a Poly-CaP block with a soluble calcium phosphates phase on one side and an insoluble HAp phase on the other side is useful for vital pulp therapy as it may promote dentin regeneration and provide the surface effective to achieve sealing. The purpose of this study was to investigate the efficacy of Poly-CaP as a direct pulp capping material by examining the Ca-release profile, the in vivo ability to induce reparative dentinogenesis, and the bonding of HAp surface with adhesive systems.

Methods

Poly-CaP prepared by annealing crude HAp disc was immersed in buffer solution at pH 7.4 or 4.0, and the concentration of Ca released was measured until 15 days. The pulp of 9-week-old Wister rat molar was exposed and capped with Poly-CaP or HAp block, and dentin bridge formation and pulpal inflammation was evaluated histopathologically after 2 or 4 weeks. Etch & rinse or self-etching adhesive was bonded to HAp surface, and the interface was observed using SEM.

Results

Poly-CaP exhibited continuous release of Ca with significantly greater amount than HAp at both pH conditions (P < 0.05, Student's t-test). Animal tests demonstrated formation of complete dentin bridge at higher rate for Poly-CaP compared with HAp after 4 weeks (P < 0.05, Steel–Dwass test). Impregnation of resin into etched HAp surface, with production of intimate contact at the bonding interface, was seen for all adhesives.

Conclusions

Poly-CaP is a potentially useful material for direct pulp capping with the advantages to promote dentin bridge formation and to provide tight sealing by adhesives.     

Treatment Outcome Following Direct Pulp Capping Using Bioceramic Materials in Mature Permanent Teeth with Carious Exposure: A Pilot Retrospective Study

Introduction

The aim of this study was to investigate the sequelae of direct pulp capping (DPC) using mineral trioxide aggregate (MTA) and Biodentine in mature permanent teeth with carious exposure.

Outcomes of Vital Pulp Therapy Using Mineral Trioxide Aggregate or Biodentine: A Prospective Randomized Clinical Trial

Introduction

Mineral trioxide aggregate (MTA) has been used in pulp capping of cariously exposed mature permanent teeth with promising results. The search for alternative materials that seal better and set faster than MTA and do not stain is ongoing. Biodentine (Septodont, St Maur-des-Fossés, France) exhibits these advantages but has not been tested yet for a prolonged duration in mature teeth. This study aimed to evaluate the clinical performance of Biodentine and white MTA (Angelus, Londrina, Brazil) in cariously exposed mature permanent teeth.

Is hard tissue formation in the dental pulp after the death of the primary odontoblasts a regenerative or a reparative process?

Objectives

Conceptually, two types of tertiary dentine may be produced in response to caries and environmental irritations: “reactionary dentine” that is secreted by existing primary odontoblasts and “reparative dentine”, formed after the death of the odontoblasts by proliferation and differentiation of progenitor cells into odontoblast-like cells. Because histologic evidence for tubular dentine generated by newly differentiated odontoblast-like cells is lacking in human teeth, the present study examined pulpal cellular changes associated with caries/restorations, in the presence or absence of pulpal exposures.

Methods

Ninety-six extracted human teeth were histologically processed and serial sectioned for light microscopy: 65 contained untreated enamel/dentine caries; 20 were heavily restored and 11 had carious exposures managed by direct pulp-capping.

Results

Sparsely distributed, irregularly arranged dentinal tubules were identified from the tertiary dentine formed in teeth with unexposed medium/deep caries and in restored teeth; those tubules were continuous with the tubules of secondary dentine; in some cases, tubules were absent. The palisade odontoblast layer was reduced to a single layer of flattened cells. In direct pulp-capping of pulp exposures, the defects were repaired by the deposition of an amorphous dystrophic calcified tissue that resembled pulp stones more than dentine, sometimes entrapping pulpal remnants. This atubular hard tissue was lined by fibroblasts and collagen fibrils.

Conclusions

Histological evidence from the present study indicates that reparative dentinogenesis cannot be considered as a regenerative process since the so-formed hard tissue lacks tubular features characteristic of genuine dentine. Rather, this process represents a repair response that produces calcified scar tissues by pulpal fibroblasts.

Clinical significance

Formation of hard tissue in the dental pulp after the death of the primary odontoblasts has often been regarded by clinicians as regeneration of dentine. If the objective of the clinical procedures involved is to induce healing, reduce dentine hypersensitivity, or minimise future bacteria exposure, such procedures may be regarded as clinical success. However, current clinical treatment procedures are not adept at regenerating physiological dentne because the tissues formed in the dental pulp are more likely the result of repair responses via the formation of calcified scar tissues.     

Outcomes of Direct Pulp Capping by Using Either ProRoot Mineral Trioxide Aggregate or Biodentine in Permanent Teeth with Carious Pulp Exposure in 6- to 18-Year-Old Patients: A Randomized Controlled Trial

Introduction

This study aimed to compare the success rates of direct pulp capping (DPC) by using either ProRoot Mineral Trioxide Aggregate (MTA) or Biodentine in the cariously exposed permanent teeth of 6- to 18-year-old patients. Gray discoloration was also evaluated.

Treatment Outcome of Mineral Trioxide Aggregate or Calcium Hydroxide Direct Pulp Capping: Long-term Results

Introduction

This controlled, historic cohort study project continues a previously reported trial aiming to assess treatment outcome of direct pulp capping with mineral trioxide aggregate (MTA) versus calcium hydroxide (CH). Potential prognostic factors were re-evaluated on the basis of a larger sample size and longer follow-up periods.

Methods

Clinical and radiographic outcomes of 229 teeth treated with direct pulp capping between 2001 and 2011 were investigated 24 up to 123 months post-treatment (median = 42 months). Pre-, intra-, and postoperative information was evaluated and statistically analyzed using a logistic regression model as well as generalized estimating equation logit models.

Results

Two hundred five patients (229 teeth) were available for follow-up (74% recall rate). The overall success rates were 80.5% (95% confidence interval [CI], 74.5–86.5) of teeth in the MTA group (137/170) and 59% (95% CI, 46.5–71.5) of teeth in the CH group (35/59). Multivariate analyses (generalized estimating equation logit model) indicated a significantly increased risk of failure for teeth that were directly pulp capped with CH compared with MTA (odds ratio = 2.67; 95% CI, 1.36–5.25; P = .001). Teeth that were permanently restored ≥2 days after direct pulp capping had a significantly worse prognosis irrespective of the pulp capping material chosen (odds ratio = 3.18; 95% CI, 1.61–6.3; P = .004).

Conclusions

The results of this study indicate that MTA provides better long-term results after direct pulp capping compared with CH. Placing a permanent restoration immediately after direct pulp capping is recommended.     

Direct Pulp Capping with Calcium Hydroxide,Mineral Trioxide Aggregate,and Biodentine in Permanent Young Teeth with Caries: A Randomized Clinical Trial

Introduction

Direct pulp capping treatment is intended to preserve pulp vitality, to avoid or retard root canal treatment, and, in cases with an open apex, to allow continued root development. Historically, calcium hydroxide (CH) was the gold standard material, but nowadays calcium silicate materials (CSMs) are displacing CH because of their high bioactivity, biocompatibility, sealing ability, and mechanical properties. However, more randomized clinical trials are needed to confirm the appropriateness of CSMs as replacement materials for CH in direct pulp capping procedures.

光敏黏接剂盖髓后牙髓的组织病理反应

目的观察应用3种光敏黏接剂直接盖髓后,兔牙髓的反应。方法兔前臼齿及臼齿72颗,分为4组,制备Ⅰ类洞机械穿髓,实验组3组(Excite,Prime & Bond NT,XenoⅢ),Dycal为对照,光敏树脂(SureFil)充填。于第7、14、21天每组拔除6颗牙齿,常规脱钙切片,镜下观察充血反应、炎细胞浸润、纤维化程度、牙本质桥形成、修复性牙本质形成、细菌污染等情况。结果所有实验牙齿都有牙本质桥形成,修复性牙本质封闭穿髓孔。同一时期内,兔牙髓对不同盖髓剂的反应无显著性差异。除对照组外,同种黏接剂在不同时期内对牙髓的影响无显著性差异。结论此3种黏接剂对兔牙髓具有良好的生物相容性,并能促进修复性牙本质生成。     

The Relationship of Surface Characteristics and Antimicrobial Performance of Pulp Capping Materials

Introduction

Pulp capping materials need to be able to protect the pulp but also bond to the overlying restorative materials. Light-curable pulp capping materials bond better to restorative materials and are easier to place than most water-based cements. The aim of this study was to characterize new light-curable tricalcium silicate–based pulp capping materials and compare their surface and antimicrobial properties with clinically available Theracal (Bisco, Schaumburg, IL) and Biodentine (Septodont, Saint-Maur-des-Fossés, France).

Odontogenic Effect of a Fast-setting Pozzolan-based Pulp Capping Material

Introduction

Mineral trioxide aggregate (MTA) is widely used as a pulp capping material. Recently, a MTA-derived fast-setting pozzolan cement (Endocem; Maruchi, Wonju, Korea) was introduced in the endodontic field. Our aim in this study was to investigate the odontogenic effects of this cement in vitro and in vivo.

Methods

Human dental pulp cells (hDPCs) were cultured, and the effects of Endocem and a previously marketed MTA (ProRoot; Dentsply, Tulsa, OK) on biocompatibility were evaluated by assessing cell morphology and performing a cell viability test. Chemical composition of each material was analyzed by energy-dispersive X-ray spectroscopic analysis. Odontoblastic differentiation was analyzed by alkaline phosphatase activity and alizarin red S staining. The expression of odontogenic-related markers, namely dentin sialophosphoprotein, dentin matrix protein 1, and osteonectin, was evaluated by real-time polymerase chain reaction, Western blotting, and immunofluorescence analysis. Pinpoint pulp exposures were made on rat teeth and then capped with ProRoot or Endocem. After 4 weeks, reparative tertiary dentin formation and inflammatory responses were investigated histologically.

Results

The biocompatibility of Endocem was similar to that of ProRoot. Energy-dispersive X-ray spectroscopic analysis showed that ProRoot and Endocem contained similar elemental constituents such as calcium, oxygen, and silicon. Alkaline phosphatase activity and mineralized nodule formation increased in ProRoot- and Endocem-treated cells compared with medium only–treated cells in the control group (P < .05). The expression of odontogenic-related markers was significantly higher in the ProRoot- and Endocem-treated groups than the control group (P < .05), but there was no significant difference in the expression of these markers between the 2 experimental groups (P > .05). Four weeks after the pulp capping procedure, continuous tertiary dentin had formed directly underneath the capping materials and the pulp exposure area in all samples in the 2 treated groups. Furthermore, most specimens either had no inflammation or minor pulpal inflammation.

Conclusions

Our results indicate that ProRoot and Endocem have similar biocompatibility and odontogenic effects. Therefore, Endocem is as effective a pulp capping material as ProRoot.     

Effect of Acid Etching Procedures on the Compressive Strength of 4 Calcium Silicate–based Endodontic Cements

Introduction

The purpose of this study was to evaluate the effect of acid etching on the compressive strength of 4 calcium silicate–based cements.

Methods

One gram of each corresponding powder of ProRoot MTA (Dentsply Tulsa Dental, Johnson City, TN), MTA Angelus (Angelus, Londrina, PR, Brazil), and CEM cement (BioniqueDent, Tehran, Iran) and a 0.33-g aliquot of liquid were placed in a plastic mixing capsule that was then mechanically mixed for 30 seconds at 4500 rpm in an amalgamator. For the preparation of Biodentine (Septodont, Saint Maur-des-Fossés, France), the liquid provided was added to the powder within the plastic capsule supplied by the manufacturer and then mechanically mixed for 30 seconds at 4500 rpm using the amalgamator. The resulting slurries were then placed incrementally into 40 cylindrical molds to give a total of 160 specimens that were incubated at 37°C for a week. Twenty specimens of each material were then subjected to the acid etch procedure. The compressive strength of the samples was then calculated in megapascals using a universal testing machine. The results were then subjected to 2-way analysis of variance analysis of variance followed by the Tukey post hoc test.

Results

The application of acid etch significantly reduced (P < .0001) the compressive strength of Angelus MTA and CEM cement; however, it did not reduce the compressive strength of ProRoot MTA or Biodentine. Regardless of the acid etch application, Biodentine showed significantly higher compressive strength values than the other materials (P < .0001), whereas CEM cement had the lowest compressive strength values. There was no significant difference between CEM cement and MTA Angelus. The compressive strength of ProRoot MTA was significantly lower (P < .0001) than Biodentine but significantly higher (P < .0001) than MTA Angelus and CEM cement in both the test and control groups.

Conclusions

When the application of acid etchants is required, Biodentine and ProRoot MTA seem to be better options than MTA Angelus or CEM cement.     

Evaluation of Pulp Response to Novel Bioactive Glass Pulp Capping Materials

Introduction

This study aimed to investigate dental pulp responses to novel bioactive glass (BG) pulp capping materials after direct pulp capping in vivo.

羟基磷灰石复合盖髓剂的动物实验研究

目的 :本研究从组织学角度评价羟基磷灰石复合盖髓剂 (HMEO)的盖髓效果。方法 :通过人工机械性暴露犬牙髓后行即刻盖髓和延迟 2 4小时盖髓。结果 :HMEO可诱导骨样牙本质和管样牙本质形成且不伴发坏死层 ,即刻盖髓和延迟盖髓的成功率相似。结论 :HMEO是一种颇有前途的活髓保存材料     

Pulp tissue reaction to a self-adhesive,resin-based direct pulp capping material containing surface pre-reacted glass-ionomer filler

ObjectiveThis study aimed to evaluate the effect of direct pulp capping using an experimental self-adhesive resin for direct pulp capping (SRD) containing silica and surface pre-reacted glass-ionomer (S-PRG) filler on pulpal healing and to monitor the dentin bridge formation in rat pulp 2–4 weeks after operation.MethodsFive types of SRDs (SRD-0: S-PRG fillers 0 wt%; SRD-1: S-PRG fillers 9.1 wt%; SRD-2: S-PRG fillers 18.4 wt%; SRD-3: S-PRG fillers 27.8 wt%; and SRD-6: S-PRG fillers 57.4 wt%) were prepared, and mineral trioxide aggregate (MTA) was used as control (n = 8). Direct pulp capping was performed on rats that were sacrificed for further evaluation 2 or 4 weeks after the operation. The pulp tissue disorganization (PTD), inflammatory cell infiltration (ICI), and reparative dentin formation were histopathologically evaluated; the data were statistically analyzed using the Kruskal–Wallis and the Mann–Whitney U tests.ResultsThe histopathological evaluation of SRD-1-treated test animals 2 weeks post-operation revealed inferior PTD and ICI when compared with that of MTA. Even 4 weeks after the operation in SRD-1- and SRD-2-treated rats, the PTD and ICI were inferior when compared with those of MTA. The dental specimens of SRD-0 and MTA showed orthodentin formation, whereas SRD-treated test animals showed osteodentin formation at a position slightly deeper than the site of the pulpal exposure.SignificanceThe reparative dentin formed by SRD-0 and MTA was genuine, whereas that formed by SRD-3 and SRD-6 was ossified and ectopic. SRD may have the potential to be utilized clinically as a direct pulp capping material.     

蚯蚓提取物用于小型猪牙盖髓的实验研究

目的 观察蚯蚓提取物对小型猪牙修复性牙本质形成的作用.方法 用蚯蚓提取物对30颗小型猪牙进行直接盖髓,对照组30颗牙采用氢氧化钙盖髓;分别于术后2、4、12周运用组织病理学方法观察其促进修复性牙本质形成的效果.结果 蚯蚓提取物盖髓后2周,骨样修复性牙本质团块形成,未见到创面周围牙髓变性坏死.盖髓后4周,穿髓孔下有修复性牙本质形成,大部分牙已将穿髓孔封闭.盖髓后12周,穿髓处可见完整的牙本质桥形成,结构致密,髓腔及根管内牙髓组织基本正常.氢氧化钙盖髓组:术后2周界面可见牙髓变性坏死区,有薄层牙本质团块形成,4～12周逐渐形成完整的牙本质桥,形成速度与蚯蚓提取物组相似.结论 本实验提示蚯蚓提取物能促进小型猪牙髓组织损伤的修复,形成修复性牙本质.